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-rw-r--r--Documentation/ABI/testing/sysfs-devices-cache_disable18
-rw-r--r--Documentation/ABI/testing/sysfs-devices-system-cpu156
-rw-r--r--Documentation/RCU/trace.txt254
-rw-r--r--Documentation/RCU/whatisRCU.txt2
-rw-r--r--Documentation/cputopology.txt47
-rw-r--r--Documentation/dontdiff3
-rw-r--r--Documentation/fb/framebuffer.txt6
-rw-r--r--Documentation/filesystems/caching/fscache.txt110
-rw-r--r--Documentation/filesystems/caching/netfs-api.txt21
-rw-r--r--Documentation/filesystems/ext4.txt8
-rw-r--r--Documentation/filesystems/ocfs2.txt6
-rw-r--r--Documentation/hwmon/sysfs-interface57
-rw-r--r--Documentation/i2c/busses/i2c-piix42
-rw-r--r--Documentation/kernel-parameters.txt21
-rw-r--r--Documentation/pcmcia/driver-changes.txt12
-rw-r--r--Documentation/slow-work.txt160
-rw-r--r--Documentation/sound/alsa/ALSA-Configuration.txt2
-rw-r--r--Documentation/thermal/sysfs-api.txt389
-rw-r--r--Documentation/vm/hwpoison.txt136
-rw-r--r--Documentation/vm/page-types.c2
20 files changed, 952 insertions, 460 deletions
diff --git a/Documentation/ABI/testing/sysfs-devices-cache_disable b/Documentation/ABI/testing/sysfs-devices-cache_disable
deleted file mode 100644
index 175bb4f7051..00000000000
--- a/Documentation/ABI/testing/sysfs-devices-cache_disable
+++ /dev/null
@@ -1,18 +0,0 @@
-What: /sys/devices/system/cpu/cpu*/cache/index*/cache_disable_X
-Date: August 2008
-KernelVersion: 2.6.27
-Contact: mark.langsdorf@amd.com
-Description: These files exist in every cpu's cache index directories.
- There are currently 2 cache_disable_# files in each
- directory. Reading from these files on a supported
- processor will return that cache disable index value
- for that processor and node. Writing to one of these
- files will cause the specificed cache index to be disabled.
-
- Currently, only AMD Family 10h Processors support cache index
- disable, and only for their L3 caches. See the BIOS and
- Kernel Developer's Guide at
- http://www.amd.com/us-en/assets/content_type/white_papers_and_tech_docs/31116-Public-GH-BKDG_3.20_2-4-09.pdf
- for formatting information and other details on the
- cache index disable.
-Users: joachim.deguara@amd.com
diff --git a/Documentation/ABI/testing/sysfs-devices-system-cpu b/Documentation/ABI/testing/sysfs-devices-system-cpu
new file mode 100644
index 00000000000..a703b9e9aeb
--- /dev/null
+++ b/Documentation/ABI/testing/sysfs-devices-system-cpu
@@ -0,0 +1,156 @@
+What: /sys/devices/system/cpu/
+Date: pre-git history
+Contact: Linux kernel mailing list <linux-kernel@vger.kernel.org>
+Description:
+ A collection of both global and individual CPU attributes
+
+ Individual CPU attributes are contained in subdirectories
+ named by the kernel's logical CPU number, e.g.:
+
+ /sys/devices/system/cpu/cpu#/
+
+What: /sys/devices/system/cpu/sched_mc_power_savings
+ /sys/devices/system/cpu/sched_smt_power_savings
+Date: June 2006
+Contact: Linux kernel mailing list <linux-kernel@vger.kernel.org>
+Description: Discover and adjust the kernel's multi-core scheduler support.
+
+ Possible values are:
+
+ 0 - No power saving load balance (default value)
+ 1 - Fill one thread/core/package first for long running threads
+ 2 - Also bias task wakeups to semi-idle cpu package for power
+ savings
+
+ sched_mc_power_savings is dependent upon SCHED_MC, which is
+ itself architecture dependent.
+
+ sched_smt_power_savings is dependent upon SCHED_SMT, which
+ is itself architecture dependent.
+
+ The two files are independent of each other. It is possible
+ that one file may be present without the other.
+
+ Introduced by git commit 5c45bf27.
+
+
+What: /sys/devices/system/cpu/kernel_max
+ /sys/devices/system/cpu/offline
+ /sys/devices/system/cpu/online
+ /sys/devices/system/cpu/possible
+ /sys/devices/system/cpu/present
+Date: December 2008
+Contact: Linux kernel mailing list <linux-kernel@vger.kernel.org>
+Description: CPU topology files that describe kernel limits related to
+ hotplug. Briefly:
+
+ kernel_max: the maximum cpu index allowed by the kernel
+ configuration.
+
+ offline: cpus that are not online because they have been
+ HOTPLUGGED off or exceed the limit of cpus allowed by the
+ kernel configuration (kernel_max above).
+
+ online: cpus that are online and being scheduled.
+
+ possible: cpus that have been allocated resources and can be
+ brought online if they are present.
+
+ present: cpus that have been identified as being present in
+ the system.
+
+ See Documentation/cputopology.txt for more information.
+
+
+
+What: /sys/devices/system/cpu/cpu#/node
+Date: October 2009
+Contact: Linux memory management mailing list <linux-mm@kvack.org>
+Description: Discover NUMA node a CPU belongs to
+
+ When CONFIG_NUMA is enabled, a symbolic link that points
+ to the corresponding NUMA node directory.
+
+ For example, the following symlink is created for cpu42
+ in NUMA node 2:
+
+ /sys/devices/system/cpu/cpu42/node2 -> ../../node/node2
+
+
+What: /sys/devices/system/cpu/cpu#/topology/core_id
+ /sys/devices/system/cpu/cpu#/topology/core_siblings
+ /sys/devices/system/cpu/cpu#/topology/core_siblings_list
+ /sys/devices/system/cpu/cpu#/topology/physical_package_id
+ /sys/devices/system/cpu/cpu#/topology/thread_siblings
+ /sys/devices/system/cpu/cpu#/topology/thread_siblings_list
+Date: December 2008
+Contact: Linux kernel mailing list <linux-kernel@vger.kernel.org>
+Description: CPU topology files that describe a logical CPU's relationship
+ to other cores and threads in the same physical package.
+
+ One cpu# directory is created per logical CPU in the system,
+ e.g. /sys/devices/system/cpu/cpu42/.
+
+ Briefly, the files above are:
+
+ core_id: the CPU core ID of cpu#. Typically it is the
+ hardware platform's identifier (rather than the kernel's).
+ The actual value is architecture and platform dependent.
+
+ core_siblings: internal kernel map of cpu#'s hardware threads
+ within the same physical_package_id.
+
+ core_siblings_list: human-readable list of the logical CPU
+ numbers within the same physical_package_id as cpu#.
+
+ physical_package_id: physical package id of cpu#. Typically
+ corresponds to a physical socket number, but the actual value
+ is architecture and platform dependent.
+
+ thread_siblings: internel kernel map of cpu#'s hardware
+ threads within the same core as cpu#
+
+ thread_siblings_list: human-readable list of cpu#'s hardware
+ threads within the same core as cpu#
+
+ See Documentation/cputopology.txt for more information.
+
+
+What: /sys/devices/system/cpu/cpuidle/current_driver
+ /sys/devices/system/cpu/cpuidle/current_governer_ro
+Date: September 2007
+Contact: Linux kernel mailing list <linux-kernel@vger.kernel.org>
+Description: Discover cpuidle policy and mechanism
+
+ Various CPUs today support multiple idle levels that are
+ differentiated by varying exit latencies and power
+ consumption during idle.
+
+ Idle policy (governor) is differentiated from idle mechanism
+ (driver)
+
+ current_driver: displays current idle mechanism
+
+ current_governor_ro: displays current idle policy
+
+ See files in Documentation/cpuidle/ for more information.
+
+
+What: /sys/devices/system/cpu/cpu*/cache/index*/cache_disable_X
+Date: August 2008
+KernelVersion: 2.6.27
+Contact: mark.langsdorf@amd.com
+Description: These files exist in every cpu's cache index directories.
+ There are currently 2 cache_disable_# files in each
+ directory. Reading from these files on a supported
+ processor will return that cache disable index value
+ for that processor and node. Writing to one of these
+ files will cause the specificed cache index to be disabled.
+
+ Currently, only AMD Family 10h Processors support cache index
+ disable, and only for their L3 caches. See the BIOS and
+ Kernel Developer's Guide at
+ http://www.amd.com/us-en/assets/content_type/white_papers_and_tech_docs/31116-Public-GH-BKDG_3.20_2-4-09.pdf
+ for formatting information and other details on the
+ cache index disable.
+Users: joachim.deguara@amd.com
diff --git a/Documentation/RCU/trace.txt b/Documentation/RCU/trace.txt
index 187bbf10c92..8608fd85e92 100644
--- a/Documentation/RCU/trace.txt
+++ b/Documentation/RCU/trace.txt
@@ -1,185 +1,10 @@
CONFIG_RCU_TRACE debugfs Files and Formats
-The rcupreempt and rcutree implementations of RCU provide debugfs trace
-output that summarizes counters and state. This information is useful for
-debugging RCU itself, and can sometimes also help to debug abuses of RCU.
-Note that the rcuclassic implementation of RCU does not provide debugfs
-trace output.
-
-The following sections describe the debugfs files and formats for
-preemptable RCU (rcupreempt) and hierarchical RCU (rcutree).
-
-
-Preemptable RCU debugfs Files and Formats
-
-This implementation of RCU provides three debugfs files under the
-top-level directory RCU: rcu/rcuctrs (which displays the per-CPU
-counters used by preemptable RCU) rcu/rcugp (which displays grace-period
-counters), and rcu/rcustats (which internal counters for debugging RCU).
-
-The output of "cat rcu/rcuctrs" looks as follows:
-
-CPU last cur F M
- 0 5 -5 0 0
- 1 -1 0 0 0
- 2 0 1 0 0
- 3 0 1 0 0
- 4 0 1 0 0
- 5 0 1 0 0
- 6 0 2 0 0
- 7 0 -1 0 0
- 8 0 1 0 0
-ggp = 26226, state = waitzero
-
-The per-CPU fields are as follows:
-
-o "CPU" gives the CPU number. Offline CPUs are not displayed.
-
-o "last" gives the value of the counter that is being decremented
- for the current grace period phase. In the example above,
- the counters sum to 4, indicating that there are still four
- RCU read-side critical sections still running that started
- before the last counter flip.
-
-o "cur" gives the value of the counter that is currently being
- both incremented (by rcu_read_lock()) and decremented (by
- rcu_read_unlock()). In the example above, the counters sum to
- 1, indicating that there is only one RCU read-side critical section
- still running that started after the last counter flip.
-
-o "F" indicates whether RCU is waiting for this CPU to acknowledge
- a counter flip. In the above example, RCU is not waiting on any,
- which is consistent with the state being "waitzero" rather than
- "waitack".
-
-o "M" indicates whether RCU is waiting for this CPU to execute a
- memory barrier. In the above example, RCU is not waiting on any,
- which is consistent with the state being "waitzero" rather than
- "waitmb".
-
-o "ggp" is the global grace-period counter.
-
-o "state" is the RCU state, which can be one of the following:
-
- o "idle": there is no grace period in progress.
-
- o "waitack": RCU just incremented the global grace-period
- counter, which has the effect of reversing the roles of
- the "last" and "cur" counters above, and is waiting for
- all the CPUs to acknowledge the flip. Once the flip has
- been acknowledged, CPUs will no longer be incrementing
- what are now the "last" counters, so that their sum will
- decrease monotonically down to zero.
-
- o "waitzero": RCU is waiting for the sum of the "last" counters
- to decrease to zero.
-
- o "waitmb": RCU is waiting for each CPU to execute a memory
- barrier, which ensures that instructions from a given CPU's
- last RCU read-side critical section cannot be reordered
- with instructions following the memory-barrier instruction.
-
-The output of "cat rcu/rcugp" looks as follows:
-
-oldggp=48870 newggp=48873
-
-Note that reading from this file provokes a synchronize_rcu(). The
-"oldggp" value is that of "ggp" from rcu/rcuctrs above, taken before
-executing the synchronize_rcu(), and the "newggp" value is also the
-"ggp" value, but taken after the synchronize_rcu() command returns.
-
-
-The output of "cat rcu/rcugp" looks as follows:
-
-na=1337955 nl=40 wa=1337915 wl=44 da=1337871 dl=0 dr=1337871 di=1337871
-1=50989 e1=6138 i1=49722 ie1=82 g1=49640 a1=315203 ae1=265563 a2=49640
-z1=1401244 ze1=1351605 z2=49639 m1=5661253 me1=5611614 m2=49639
-
-These are counters tracking internal preemptable-RCU events, however,
-some of them may be useful for debugging algorithms using RCU. In
-particular, the "nl", "wl", and "dl" values track the number of RCU
-callbacks in various states. The fields are as follows:
-
-o "na" is the total number of RCU callbacks that have been enqueued
- since boot.
-
-o "nl" is the number of RCU callbacks waiting for the previous
- grace period to end so that they can start waiting on the next
- grace period.
-
-o "wa" is the total number of RCU callbacks that have started waiting
- for a grace period since boot. "na" should be roughly equal to
- "nl" plus "wa".
-
-o "wl" is the number of RCU callbacks currently waiting for their
- grace period to end.
-
-o "da" is the total number of RCU callbacks whose grace periods
- have completed since boot. "wa" should be roughly equal to
- "wl" plus "da".
-
-o "dr" is the total number of RCU callbacks that have been removed
- from the list of callbacks ready to invoke. "dr" should be roughly
- equal to "da".
-
-o "di" is the total number of RCU callbacks that have been invoked
- since boot. "di" should be roughly equal to "da", though some
- early versions of preemptable RCU had a bug so that only the
- last CPU's count of invocations was displayed, rather than the
- sum of all CPU's counts.
-
-o "1" is the number of calls to rcu_try_flip(). This should be
- roughly equal to the sum of "e1", "i1", "a1", "z1", and "m1"
- described below. In other words, the number of times that
- the state machine is visited should be equal to the sum of the
- number of times that each state is visited plus the number of
- times that the state-machine lock acquisition failed.
-
-o "e1" is the number of times that rcu_try_flip() was unable to
- acquire the fliplock.
-
-o "i1" is the number of calls to rcu_try_flip_idle().
-
-o "ie1" is the number of times rcu_try_flip_idle() exited early
- due to the calling CPU having no work for RCU.
-
-o "g1" is the number of times that rcu_try_flip_idle() decided
- to start a new grace period. "i1" should be roughly equal to
- "ie1" plus "g1".
-
-o "a1" is the number of calls to rcu_try_flip_waitack().
-
-o "ae1" is the number of times that rcu_try_flip_waitack() found
- that at least one CPU had not yet acknowledge the new grace period
- (AKA "counter flip").
-
-o "a2" is the number of time rcu_try_flip_waitack() found that
- all CPUs had acknowledged. "a1" should be roughly equal to
- "ae1" plus "a2". (This particular output was collected on
- a 128-CPU machine, hence the smaller-than-usual fraction of
- calls to rcu_try_flip_waitack() finding all CPUs having already
- acknowledged.)
-
-o "z1" is the number of calls to rcu_try_flip_waitzero().
-
-o "ze1" is the number of times that rcu_try_flip_waitzero() found
- that not all of the old RCU read-side critical sections had
- completed.
-
-o "z2" is the number of times that rcu_try_flip_waitzero() finds
- the sum of the counters equal to zero, in other words, that
- all of the old RCU read-side critical sections had completed.
- The value of "z1" should be roughly equal to "ze1" plus
- "z2".
-
-o "m1" is the number of calls to rcu_try_flip_waitmb().
-
-o "me1" is the number of times that rcu_try_flip_waitmb() finds
- that at least one CPU has not yet executed a memory barrier.
-
-o "m2" is the number of times that rcu_try_flip_waitmb() finds that
- all CPUs have executed a memory barrier.
+The rcutree implementation of RCU provides debugfs trace output that
+summarizes counters and state. This information is useful for debugging
+RCU itself, and can sometimes also help to debug abuses of RCU.
+The following sections describe the debugfs files and formats.
Hierarchical RCU debugfs Files and Formats
@@ -210,9 +35,10 @@ rcu_bh:
6 c=-275 g=-275 pq=1 pqc=-275 qp=0 dt=859/1 dn=0 df=15 of=0 ri=0 ql=0 b=10
7 c=-275 g=-275 pq=1 pqc=-275 qp=0 dt=3761/1 dn=0 df=15 of=0 ri=0 ql=0 b=10
-The first section lists the rcu_data structures for rcu, the second for
-rcu_bh. Each section has one line per CPU, or eight for this 8-CPU system.
-The fields are as follows:
+The first section lists the rcu_data structures for rcu_sched, the second
+for rcu_bh. Note that CONFIG_TREE_PREEMPT_RCU kernels will have an
+additional section for rcu_preempt. Each section has one line per CPU,
+or eight for this 8-CPU system. The fields are as follows:
o The number at the beginning of each line is the CPU number.
CPUs numbers followed by an exclamation mark are offline,
@@ -223,9 +49,9 @@ o The number at the beginning of each line is the CPU number.
o "c" is the count of grace periods that this CPU believes have
completed. CPUs in dynticks idle mode may lag quite a ways
- behind, for example, CPU 4 under "rcu" above, which has slept
- through the past 25 RCU grace periods. It is not unusual to
- see CPUs lagging by thousands of grace periods.
+ behind, for example, CPU 4 under "rcu_sched" above, which has
+ slept through the past 25 RCU grace periods. It is not unusual
+ to see CPUs lagging by thousands of grace periods.
o "g" is the count of grace periods that this CPU believes have
started. Again, CPUs in dynticks idle mode may lag behind.
@@ -308,8 +134,10 @@ The output of "cat rcu/rcugp" looks as follows:
rcu_sched: completed=33062 gpnum=33063
rcu_bh: completed=464 gpnum=464
-Again, this output is for both "rcu" and "rcu_bh". The fields are
-taken from the rcu_state structure, and are as follows:
+Again, this output is for both "rcu_sched" and "rcu_bh". Note that
+kernels built with CONFIG_TREE_PREEMPT_RCU will have an additional
+"rcu_preempt" line. The fields are taken from the rcu_state structure,
+and are as follows:
o "completed" is the number of grace periods that have completed.
It is comparable to the "c" field from rcu/rcudata in that a
@@ -324,23 +152,24 @@ o "gpnum" is the number of grace periods that have started. It is
If these two fields are equal (as they are for "rcu_bh" above),
then there is no grace period in progress, in other words, RCU
is idle. On the other hand, if the two fields differ (as they
- do for "rcu" above), then an RCU grace period is in progress.
+ do for "rcu_sched" above), then an RCU grace period is in progress.
The output of "cat rcu/rcuhier" looks as follows, with very long lines:
-c=6902 g=6903 s=2 jfq=3 j=72c7 nfqs=13142/nfqsng=0(13142) fqlh=6
-1/1 0:127 ^0
-3/3 0:35 ^0 0/0 36:71 ^1 0/0 72:107 ^2 0/0 108:127 ^3
-3/3f 0:5 ^0 2/3 6:11 ^1 0/0 12:17 ^2 0/0 18:23 ^3 0/0 24:29 ^4 0/0 30:35 ^5 0/0 36:41 ^0 0/0 42:47 ^1 0/0 48:53 ^2 0/0 54:59 ^3 0/0 60:65 ^4 0/0 66:71 ^5 0/0 72:77 ^0 0/0 78:83 ^1 0/0 84:89 ^2 0/0 90:95 ^3 0/0 96:101 ^4 0/0 102:107 ^5 0/0 108:113 ^0 0/0 114:119 ^1 0/0 120:125 ^2 0/0 126:127 ^3
+c=6902 g=6903 s=2 jfq=3 j=72c7 nfqs=13142/nfqsng=0(13142) fqlh=6 oqlen=0
+1/1 .>. 0:127 ^0
+3/3 .>. 0:35 ^0 0/0 .>. 36:71 ^1 0/0 .>. 72:107 ^2 0/0 .>. 108:127 ^3
+3/3f .>. 0:5 ^0 2/3 .>. 6:11 ^1 0/0 .>. 12:17 ^2 0/0 .>. 18:23 ^3 0/0 .>. 24:29 ^4 0/0 .>. 30:35 ^5 0/0 .>. 36:41 ^0 0/0 .>. 42:47 ^1 0/0 .>. 48:53 ^2 0/0 .>. 54:59 ^3 0/0 .>. 60:65 ^4 0/0 .>. 66:71 ^5 0/0 .>. 72:77 ^0 0/0 .>. 78:83 ^1 0/0 .>. 84:89 ^2 0/0 .>. 90:95 ^3 0/0 .>. 96:101 ^4 0/0 .>. 102:107 ^5 0/0 .>. 108:113 ^0 0/0 .>. 114:119 ^1 0/0 .>. 120:125 ^2 0/0 .>. 126:127 ^3
rcu_bh:
-c=-226 g=-226 s=1 jfq=-5701 j=72c7 nfqs=88/nfqsng=0(88) fqlh=0
-0/1 0:127 ^0
-0/3 0:35 ^0 0/0 36:71 ^1 0/0 72:107 ^2 0/0 108:127 ^3
-0/3f 0:5 ^0 0/3 6:11 ^1 0/0 12:17 ^2 0/0 18:23 ^3 0/0 24:29 ^4 0/0 30:35 ^5 0/0 36:41 ^0 0/0 42:47 ^1 0/0 48:53 ^2 0/0 54:59 ^3 0/0 60:65 ^4 0/0 66:71 ^5 0/0 72:77 ^0 0/0 78:83 ^1 0/0 84:89 ^2 0/0 90:95 ^3 0/0 96:101 ^4 0/0 102:107 ^5 0/0 108:113 ^0 0/0 114:119 ^1 0/0 120:125 ^2 0/0 126:127 ^3
+c=-226 g=-226 s=1 jfq=-5701 j=72c7 nfqs=88/nfqsng=0(88) fqlh=0 oqlen=0
+0/1 .>. 0:127 ^0
+0/3 .>. 0:35 ^0 0/0 .>. 36:71 ^1 0/0 .>. 72:107 ^2 0/0 .>. 108:127 ^3
+0/3f .>. 0:5 ^0 0/3 .>. 6:11 ^1 0/0 .>. 12:17 ^2 0/0 .>. 18:23 ^3 0/0 .>. 24:29 ^4 0/0 .>. 30:35 ^5 0/0 .>. 36:41 ^0 0/0 .>. 42:47 ^1 0/0 .>. 48:53 ^2 0/0 .>. 54:59 ^3 0/0 .>. 60:65 ^4 0/0 .>. 66:71 ^5 0/0 .>. 72:77 ^0 0/0 .>. 78:83 ^1 0/0 .>. 84:89 ^2 0/0 .>. 90:95 ^3 0/0 .>. 96:101 ^4 0/0 .>. 102:107 ^5 0/0 .>. 108:113 ^0 0/0 .>. 114:119 ^1 0/0 .>. 120:125 ^2 0/0 .>. 126:127 ^3
-This is once again split into "rcu" and "rcu_bh" portions. The fields are
-as follows:
+This is once again split into "rcu_sched" and "rcu_bh" portions,
+and CONFIG_TREE_PREEMPT_RCU kernels will again have an additional
+"rcu_preempt" section. The fields are as follows:
o "c" is exactly the same as "completed" under rcu/rcugp.
@@ -372,6 +201,11 @@ o "fqlh" is the number of calls to force_quiescent_state() that
exited immediately (without even being counted in nfqs above)
due to contention on ->fqslock.
+o "oqlen" is the number of callbacks on the "orphan" callback
+ list. RCU callbacks are placed on this list by CPUs going
+ offline, and are "adopted" either by the CPU helping the outgoing
+ CPU or by the next rcu_barrier*() call, whichever comes first.
+
o Each element of the form "1/1 0:127 ^0" represents one struct
rcu_node. Each line represents one level of the hierarchy, from
root to leaves. It is best to think of the rcu_data structures
@@ -379,7 +213,7 @@ o Each element of the form "1/1 0:127 ^0" represents one struct
might be either one, two, or three levels of rcu_node structures,
depending on the relationship between CONFIG_RCU_FANOUT and
CONFIG_NR_CPUS.
-
+
o The numbers separated by the "/" are the qsmask followed
by the qsmaskinit. The qsmask will have one bit
set for each entity in the next lower level that
@@ -389,10 +223,19 @@ o Each element of the form "1/1 0:127 ^0" represents one struct
The value of qsmaskinit is assigned to that of qsmask
at the beginning of each grace period.
- For example, for "rcu", the qsmask of the first entry
- of the lowest level is 0x14, meaning that we are still
- waiting for CPUs 2 and 4 to check in for the current
- grace period.
+ For example, for "rcu_sched", the qsmask of the first
+ entry of the lowest level is 0x14, meaning that we
+ are still waiting for CPUs 2 and 4 to check in for the
+ current grace period.
+
+ o The characters separated by the ">" indicate the state
+ of the blocked-tasks lists. A "T" preceding the ">"
+ indicates that at least one task blocked in an RCU
+ read-side critical section blocks the current grace
+ period, while a "." preceding the ">" indicates otherwise.
+ The character following the ">" indicates similarly for
+ the next grace period. A "T" should appear in this
+ field only for rcu-preempt.
o The numbers separated by the ":" are the range of CPUs
served by this struct rcu_node. This can be helpful
@@ -431,8 +274,9 @@ rcu_bh:
6 np=120834 qsp=9902 cbr=0 cng=0 gpc=6 gps=3 nf=2 nn=110921
7 np=144888 qsp=26336 cbr=0 cng=0 gpc=8 gps=2 nf=0 nn=118542
-As always, this is once again split into "rcu" and "rcu_bh" portions.
-The fields are as follows:
+As always, this is once again split into "rcu_sched" and "rcu_bh"
+portions, with CONFIG_TREE_PREEMPT_RCU kernels having an additional
+"rcu_preempt" section. The fields are as follows:
o "np" is the number of times that __rcu_pending() has been invoked
for the corresponding flavor of RCU.
diff --git a/Documentation/RCU/whatisRCU.txt b/Documentation/RCU/whatisRCU.txt
index e41a7fecf0d..d542ca243b8 100644
--- a/Documentation/RCU/whatisRCU.txt
+++ b/Documentation/RCU/whatisRCU.txt
@@ -830,7 +830,7 @@ sched: Critical sections Grace period Barrier
SRCU: Critical sections Grace period Barrier
srcu_read_lock synchronize_srcu N/A
- srcu_read_unlock
+ srcu_read_unlock synchronize_srcu_expedited
SRCU: Initialization/cleanup
init_srcu_struct
diff --git a/Documentation/cputopology.txt b/Documentation/cputopology.txt
index b41f3e58aef..f1c5c4bccd3 100644
--- a/Documentation/cputopology.txt
+++ b/Documentation/cputopology.txt
@@ -1,15 +1,28 @@
-Export cpu topology info via sysfs. Items (attributes) are similar
+Export CPU topology info via sysfs. Items (attributes) are similar
to /proc/cpuinfo.
1) /sys/devices/system/cpu/cpuX/topology/physical_package_id:
-represent the physical package id of cpu X;
+
+ physical package id of cpuX. Typically corresponds to a physical
+ socket number, but the actual value is architecture and platform
+ dependent.
+
2) /sys/devices/system/cpu/cpuX/topology/core_id:
-represent the cpu core id to cpu X;
+
+ the CPU core ID of cpuX. Typically it is the hardware platform's
+ identifier (rather than the kernel's). The actual value is
+ architecture and platform dependent.
+
3) /sys/devices/system/cpu/cpuX/topology/thread_siblings:
-represent the thread siblings to cpu X in the same core;
+
+ internel kernel map of cpuX's hardware threads within the same
+ core as cpuX
+
4) /sys/devices/system/cpu/cpuX/topology/core_siblings:
-represent the thread siblings to cpu X in the same physical package;
+
+ internal kernel map of cpuX's hardware threads within the same
+ physical_package_id.
To implement it in an architecture-neutral way, a new source file,
drivers/base/topology.c, is to export the 4 attributes.
@@ -32,32 +45,32 @@ not defined by include/asm-XXX/topology.h:
3) thread_siblings: just the given CPU
4) core_siblings: just the given CPU
-Additionally, cpu topology information is provided under
+Additionally, CPU topology information is provided under
/sys/devices/system/cpu and includes these files. The internal
source for the output is in brackets ("[]").
- kernel_max: the maximum cpu index allowed by the kernel configuration.
+ kernel_max: the maximum CPU index allowed by the kernel configuration.
[NR_CPUS-1]
- offline: cpus that are not online because they have been
+ offline: CPUs that are not online because they have been
HOTPLUGGED off (see cpu-hotplug.txt) or exceed the limit
- of cpus allowed by the kernel configuration (kernel_max
+ of CPUs allowed by the kernel configuration (kernel_max
above). [~cpu_online_mask + cpus >= NR_CPUS]
- online: cpus that are online and being scheduled [cpu_online_mask]
+ online: CPUs that are online and being scheduled [cpu_online_mask]
- possible: cpus that have been allocated resources and can be
+ possible: CPUs that have been allocated resources and can be
brought online if they are present. [cpu_possible_mask]
- present: cpus that have been identified as being present in the
+ present: CPUs that have been identified as being present in the
system. [cpu_present_mask]
The format for the above output is compatible with cpulist_parse()
[see <linux/cpumask.h>]. Some examples follow.
-In this example, there are 64 cpus in the system but cpus 32-63 exceed
+In this example, there are 64 CPUs in the system but cpus 32-63 exceed
the kernel max which is limited to 0..31 by the NR_CPUS config option
-being 32. Note also that cpus 2 and 4-31 are not online but could be
+being 32. Note also that CPUs 2 and 4-31 are not online but could be
brought online as they are both present and possible.
kernel_max: 31
@@ -67,8 +80,8 @@ brought online as they are both present and possible.
present: 0-31
In this example, the NR_CPUS config option is 128, but the kernel was
-started with possible_cpus=144. There are 4 cpus in the system and cpu2
-was manually taken offline (and is the only cpu that can be brought
+started with possible_cpus=144. There are 4 CPUs in the system and cpu2
+was manually taken offline (and is the only CPU that can be brought
online.)
kernel_max: 127
@@ -78,4 +91,4 @@ online.)
present: 0-3
See cpu-hotplug.txt for the possible_cpus=NUM kernel start parameter
-as well as more information on the various cpumask's.
+as well as more information on the various cpumasks.
diff --git a/Documentation/dontdiff b/Documentation/dontdiff
index e1efc400bed..e151b2a3626 100644
--- a/Documentation/dontdiff
+++ b/Documentation/dontdiff
@@ -65,6 +65,7 @@ aicdb.h*
asm-offsets.h
asm_offsets.h
autoconf.h*
+av_permissions.h
bbootsect
bin2c
binkernel.spec
@@ -95,12 +96,14 @@ docproc
elf2ecoff
elfconfig.h*
fixdep
+flask.h
fore200e_mkfirm
fore200e_pca_fw.c*
gconf
gen-devlist
gen_crc32table
gen_init_cpio
+genheaders
genksyms
*_gray256.c
ihex2fw
diff --git a/Documentation/fb/framebuffer.txt b/Documentation/fb/framebuffer.txt
index b3e3a035683..fe79e3c8847 100644
--- a/Documentation/fb/framebuffer.txt
+++ b/Documentation/fb/framebuffer.txt
@@ -312,10 +312,8 @@ and to the following documentation:
8. Mailing list
---------------
-There are several frame buffer device related mailing lists at SourceForge:
- - linux-fbdev-announce@lists.sourceforge.net, for announcements,
- - linux-fbdev-user@lists.sourceforge.net, for generic user support,
- - linux-fbdev-devel@lists.sourceforge.net, for project developers.
+There is a frame buffer device related mailing list at kernel.org:
+linux-fbdev@vger.kernel.org.
Point your web browser to http://sourceforge.net/projects/linux-fbdev/ for
subscription information and archive browsing.
diff --git a/Documentation/filesystems/caching/fscache.txt b/Documentation/filesystems/caching/fscache.txt
index 9e94b9491d8..a91e2e2095b 100644
--- a/Documentation/filesystems/caching/fscache.txt
+++ b/Documentation/filesystems/caching/fscache.txt
@@ -235,6 +235,7 @@ proc files.
neg=N Number of negative lookups made
pos=N Number of positive lookups made
crt=N Number of objects created by lookup
+ tmo=N Number of lookups timed out and requeued
Updates n=N Number of update cookie requests seen
nul=N Number of upd reqs given a NULL parent
run=N Number of upd reqs granted CPU time
@@ -250,8 +251,10 @@ proc files.
ok=N Number of successful alloc reqs
wt=N Number of alloc reqs that waited on lookup completion
nbf=N Number of alloc reqs rejected -ENOBUFS
+ int=N Number of alloc reqs aborted -ERESTARTSYS
ops=N Number of alloc reqs submitted
owt=N Number of alloc reqs waited for CPU time
+ abt=N Number of alloc reqs aborted due to object death
Retrvls n=N Number of retrieval (read) requests seen
ok=N Number of successful retr reqs
wt=N Number of retr reqs that waited on lookup completion
@@ -261,6 +264,7 @@ proc files.
oom=N Number of retr reqs failed -ENOMEM
ops=N Number of retr reqs submitted
owt=N Number of retr reqs waited for CPU time
+ abt=N Number of retr reqs aborted due to object death
Stores n=N Number of storage (write) requests seen
ok=N Number of successful store reqs
agn=N Number of store reqs on a page already pending storage
@@ -268,12 +272,37 @@ proc files.
oom=N Number of store reqs failed -ENOMEM
ops=N Number of store reqs submitted
run=N Number of store reqs granted CPU time
+ pgs=N Number of pages given store req processing time
+ rxd=N Number of store reqs deleted from tracking tree
+ olm=N Number of store reqs over store limit
+ VmScan nos=N Number of release reqs against pages with no pending store
+ gon=N Number of release reqs against pages stored by time lock granted
+ bsy=N Number of release reqs ignored due to in-progress store
+ can=N Number of page stores cancelled due to release req
Ops pend=N Number of times async ops added to pending queues
run=N Number of times async ops given CPU time
enq=N Number of times async ops queued for processing
+ can=N Number of async ops cancelled
+ rej=N Number of async ops rejected due to object lookup/create failure
dfr=N Number of async ops queued for deferred release
rel=N Number of async ops released
gc=N Number of deferred-release async ops garbage collected
+ CacheOp alo=N Number of in-progress alloc_object() cache ops
+ luo=N Number of in-progress lookup_object() cache ops
+ luc=N Number of in-progress lookup_complete() cache ops
+ gro=N Number of in-progress grab_object() cache ops
+ upo=N Number of in-progress update_object() cache ops
+ dro=N Number of in-progress drop_object() cache ops
+ pto=N Number of in-progress put_object() cache ops
+ syn=N Number of in-progress sync_cache() cache ops
+ atc=N Number of in-progress attr_changed() cache ops
+ rap=N Number of in-progress read_or_alloc_page() cache ops
+ ras=N Number of in-progress read_or_alloc_pages() cache ops
+ alp=N Number of in-progress allocate_page() cache ops
+ als=N Number of in-progress allocate_pages() cache ops
+ wrp=N Number of in-progress write_page() cache ops
+ ucp=N Number of in-progress uncache_page() cache ops
+ dsp=N Number of in-progress dissociate_pages() cache ops
(*) /proc/fs/fscache/histogram
@@ -299,6 +328,87 @@ proc files.
jiffy range covered, and the SECS field the equivalent number of seconds.
+===========
+OBJECT LIST
+===========
+
+If CONFIG_FSCACHE_OBJECT_LIST is enabled, the FS-Cache facility will maintain a
+list of all the objects currently allocated and allow them to be viewed
+through:
+
+ /proc/fs/fscache/objects
+
+This will look something like:
+
+ [root@andromeda ~]# head /proc/fs/fscache/objects
+ OBJECT PARENT STAT CHLDN OPS OOP IPR EX READS EM EV F S | NETFS_COOKIE_DEF TY FL NETFS_DATA OBJECT_KEY, AUX_DATA
+ ======== ======== ==== ===== === === === == ===== == == = = | ================ == == ================ ================
+ 17e4b 2 ACTV 0 0 0 0 0 0 7b 4 0 8 | NFS.fh DT 0 ffff88001dd82820 010006017edcf8bbc93b43298fdfbe71e50b57b13a172c0117f38472, e567634700000000000000000000000063f2404a000000000000000000000000c9030000000000000000000063f2404a
+ 1693a 2 ACTV 0 0 0 0 0 0 7b 4 0 8 | NFS.fh DT 0 ffff88002db23380 010006017edcf8bbc93b43298fdfbe71e50b57b1e0162c01a2df0ea6, 420ebc4a000000000000000000000000420ebc4a0000000000000000000000000e1801000000000000000000420ebc4a
+
+where the first set of columns before the '|' describe the object:
+
+ COLUMN DESCRIPTION
+ ======= ===============================================================
+ OBJECT Object debugging ID (appears as OBJ%x in some debug messages)
+ PARENT Debugging ID of parent object
+ STAT Object state
+ CHLDN Number of child objects of this object
+ OPS Number of outstanding operations on this object
+ OOP Number of outstanding child object management operations
+ IPR
+ EX Number of outstanding exclusive operations
+ READS Number of outstanding read operations
+ EM Object's event mask
+ EV Events raised on this object
+ F Object flags
+ S Object slow-work work item flags
+
+and the second set of columns describe the object's cookie, if present:
+
+ COLUMN DESCRIPTION
+ =============== =======================================================
+ NETFS_COOKIE_DEF Name of netfs cookie definition
+ TY Cookie type (IX - index, DT - data, hex - special)
+ FL Cookie flags
+ NETFS_DATA Netfs private data stored in the cookie
+ OBJECT_KEY Object key } 1 column, with separating comma
+ AUX_DATA Object aux data } presence may be configured
+
+The data shown may be filtered by attaching the a key to an appropriate keyring
+before viewing the file. Something like:
+
+ keyctl add user fscache:objlist <restrictions> @s
+
+where <restrictions> are a selection of the following letters:
+
+ K Show hexdump of object key (don't show if not given)
+ A Show hexdump of object aux data (don't show if not given)
+
+and the following paired letters:
+
+ C Show objects that have a cookie
+ c Show objects that don't have a cookie
+ B Show objects that are busy
+ b Show objects that aren't busy
+ W Show objects that have pending writes
+ w Show objects that don't have pending writes
+ R Show objects that have outstanding reads
+ r Show objects that don't have outstanding reads
+ S Show objects that have slow work queued
+ s Show objects that don't have slow work queued
+
+If neither side of a letter pair is given, then both are implied. For example:
+
+ keyctl add user fscache:objlist KB @s
+
+shows objects that are busy, and lists their object keys, but does not dump
+their auxiliary data. It also implies "CcWwRrSs", but as 'B' is given, 'b' is
+not implied.
+
+By default all objects and all fields will be shown.
+
+
=========
DEBUGGING
=========
diff --git a/Documentation/filesystems/caching/netfs-api.txt b/Documentation/filesystems/caching/netfs-api.txt
index 2666b1ed5e9..1902c57b72e 100644
--- a/Documentation/filesystems/caching/netfs-api.txt
+++ b/Documentation/filesystems/caching/netfs-api.txt
@@ -641,7 +641,7 @@ data file must be retired (see the relinquish cookie function below).
Furthermore, note that this does not cancel the asynchronous read or write
operation started by the read/alloc and write functions, so the page
-invalidation and release functions must use:
+invalidation functions must use:
bool fscache_check_page_write(struct fscache_cookie *cookie,
struct page *page);
@@ -654,6 +654,25 @@ to see if a page is being written to the cache, and:
to wait for it to finish if it is.
+When releasepage() is being implemented, a special FS-Cache function exists to
+manage the heuristics of coping with vmscan trying to eject pages, which may
+conflict with the cache trying to write pages to the cache (which may itself
+need to allocate memory):
+
+ bool fscache_maybe_release_page(struct fscache_cookie *cookie,
+ struct page *page,
+ gfp_t gfp);
+
+This takes the netfs cookie, and the page and gfp arguments as supplied to
+releasepage(). It will return false if the page cannot be released yet for
+some reason and if it returns true, the page has been uncached and can now be
+released.
+
+To make a page available for release, this function may wait for an outstanding
+storage request to complete, or it may attempt to cancel the storage request -
+in which case the page will not be stored in the cache this time.
+
+
==========================
INDEX AND DATA FILE UPDATE
==========================
diff --git a/Documentation/filesystems/ext4.txt b/Documentation/filesystems/ext4.txt
index bf4f4b7e11b..6d94e0696f8 100644
--- a/Documentation/filesystems/ext4.txt
+++ b/Documentation/filesystems/ext4.txt
@@ -134,9 +134,15 @@ ro Mount filesystem read only. Note that ext4 will
mount options "ro,noload" can be used to prevent
writes to the filesystem.
+journal_checksum Enable checksumming of the journal transactions.
+ This will allow the recovery code in e2fsck and the
+ kernel to detect corruption in the kernel. It is a
+ compatible change and will be ignored by older kernels.
+
journal_async_commit Commit block can be written to disk without waiting
for descriptor blocks. If enabled older kernels cannot
- mount the device.
+ mount the device. This will enable 'journal_checksum'
+ internally.
journal=update Update the ext4 file system's journal to the current
format.
diff --git a/Documentation/filesystems/ocfs2.txt b/Documentation/filesystems/ocfs2.txt
index c2a0871280a..c58b9f5ba00 100644
--- a/Documentation/filesystems/ocfs2.txt
+++ b/Documentation/filesystems/ocfs2.txt
@@ -20,15 +20,16 @@ Lots of code taken from ext3 and other projects.
Authors in alphabetical order:
Joel Becker <joel.becker@oracle.com>
Zach Brown <zach.brown@oracle.com>
-Mark Fasheh <mark.fasheh@oracle.com>
+Mark Fasheh <mfasheh@suse.com>
Kurt Hackel <kurt.hackel@oracle.com>
+Tao Ma <tao.ma@oracle.com>
Sunil Mushran <sunil.mushran@oracle.com>
Manish Singh <manish.singh@oracle.com>
+Tiger Yang <tiger.yang@oracle.com>
Caveats
=======
Features which OCFS2 does not support yet:
- - quotas
- Directory change notification (F_NOTIFY)
- Distributed Caching (F_SETLEASE/F_GETLEASE/break_lease)
@@ -70,7 +71,6 @@ commit=nrsec (*) Ocfs2 can be told to sync all its data and metadata
performance.
localalloc=8(*) Allows custom localalloc size in MB. If the value is too
large, the fs will silently revert it to the default.
- Localalloc is not enabled for local mounts.
localflocks This disables cluster aware flock.
inode64 Indicates that Ocfs2 is allowed to create inodes at
any location in the filesystem, including those which
diff --git a/Documentation/hwmon/sysfs-interface b/Documentation/hwmon/sysfs-interface
index dcbd502c879..82def883361 100644
--- a/Documentation/hwmon/sysfs-interface
+++ b/Documentation/hwmon/sysfs-interface
@@ -353,10 +353,20 @@ power[1-*]_average Average power use
Unit: microWatt
RO
-power[1-*]_average_interval Power use averaging interval
+power[1-*]_average_interval Power use averaging interval. A poll
+ notification is sent to this file if the
+ hardware changes the averaging interval.
Unit: milliseconds
RW
+power[1-*]_average_interval_max Maximum power use averaging interval
+ Unit: milliseconds
+ RO
+
+power[1-*]_average_interval_min Minimum power use averaging interval
+ Unit: milliseconds
+ RO
+
power[1-*]_average_highest Historical average maximum power use
Unit: microWatt
RO
@@ -365,6 +375,18 @@ power[1-*]_average_lowest Historical average minimum power use
Unit: microWatt
RO
+power[1-*]_average_max A poll notification is sent to
+ power[1-*]_average when power use
+ rises above this value.
+ Unit: microWatt
+ RW
+
+power[1-*]_average_min A poll notification is sent to
+ power[1-*]_average when power use
+ sinks below this value.
+ Unit: microWatt
+ RW
+
power[1-*]_input Instantaneous power use
Unit: microWatt
RO
@@ -381,6 +403,39 @@ power[1-*]_reset_history Reset input_highest, input_lowest,
average_highest and average_lowest.
WO
+power[1-*]_accuracy Accuracy of the power meter.
+ Unit: Percent
+ RO
+
+power[1-*]_alarm 1 if the system is drawing more power than the
+ cap allows; 0 otherwise. A poll notification is
+ sent to this file when the power use exceeds the
+ cap. This file only appears if the cap is known
+ to be enforced by hardware.
+ RO
+
+power[1-*]_cap If power use rises above this limit, the
+ system should take action to reduce power use.
+ A poll notification is sent to this file if the
+ cap is changed by the hardware. The *_cap
+ files only appear if the cap is known to be
+ enforced by hardware.
+ Unit: microWatt
+ RW
+
+power[1-*]_cap_hyst Margin of hysteresis built around capping and
+ notification.
+ Unit: microWatt
+ RW
+
+power[1-*]_cap_max Maximum cap that can be set.
+ Unit: microWatt
+ RO
+
+power[1-*]_cap_min Minimum cap that can be set.
+ Unit: microWatt
+ RO
+
**********
* Energy *
**********
diff --git a/Documentation/i2c/busses/i2c-piix4 b/Documentation/i2c/busses/i2c-piix4
index c5b37c57055..ac540c71c7e 100644
--- a/Documentation/i2c/busses/i2c-piix4
+++ b/Documentation/i2c/busses/i2c-piix4
@@ -8,7 +8,7 @@ Supported adapters:
Datasheet: Only available via NDA from ServerWorks
* ATI IXP200, IXP300, IXP400, SB600, SB700 and SB800 southbridges
Datasheet: Not publicly available
- * AMD SB900
+ * AMD Hudson-2
Datasheet: Not publicly available
* Standard Microsystems (SMSC) SLC90E66 (Victory66) southbridge
Datasheet: Publicly available at the SMSC website http://www.smsc.com
diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt
index c8d1b2be28e..51138b3dc8c 100644
--- a/Documentation/kernel-parameters.txt
+++ b/Documentation/kernel-parameters.txt
@@ -85,7 +85,6 @@ parameter is applicable:
PPT Parallel port support is enabled.
PS2 Appropriate PS/2 support is enabled.
RAM RAM disk support is enabled.
- ROOTPLUG The example Root Plug LSM is enabled.
S390 S390 architecture is enabled.
SCSI Appropriate SCSI support is enabled.
A lot of drivers has their options described inside of
@@ -2039,8 +2038,15 @@ and is between 256 and 4096 characters. It is defined in the file
print-fatal-signals=
[KNL] debug: print fatal signals
- print-fatal-signals=1: print segfault info to
- the kernel console.
+
+ If enabled, warn about various signal handling
+ related application anomalies: too many signals,
+ too many POSIX.1 timers, fatal signals causing a
+ coredump - etc.
+
+ If you hit the warning due to signal overflow,
+ you might want to try "ulimit -i unlimited".
+
default: off.
printk.time= Show timing data prefixed to each printk message line
@@ -2171,15 +2177,6 @@ and is between 256 and 4096 characters. It is defined in the file
Useful for devices that are detected asynchronously
(e.g. USB and MMC devices).
- root_plug.vendor_id=
- [ROOTPLUG] Override the default vendor ID
-
- root_plug.product_id=
- [ROOTPLUG] Override the default product ID
-
- root_plug.debug=
- [ROOTPLUG] Enable debugging output
-
rw [KNL] Mount root device read-write on boot
S [KNL] Run init in single mode
diff --git a/Documentation/pcmcia/driver-changes.txt b/Documentation/pcmcia/driver-changes.txt
index 059934363ca..446f43b309d 100644
--- a/Documentation/pcmcia/driver-changes.txt
+++ b/Documentation/pcmcia/driver-changes.txt
@@ -1,5 +1,17 @@
This file details changes in 2.6 which affect PCMCIA card driver authors:
+* no cs_error / CS_CHECK / CONFIG_PCMCIA_DEBUG (as of 2.6.33)
+ Instead of the cs_error() callback or the CS_CHECK() macro, please use
+ Linux-style checking of return values, and -- if necessary -- debug
+ messages using "dev_dbg()" or "pr_debug()".
+
+* New CIS tuple access (as of 2.6.33)
+ Instead of pcmcia_get_{first,next}_tuple(), pcmcia_get_tuple_data() and
+ pcmcia_parse_tuple(), a driver shall use "pcmcia_get_tuple()" if it is
+ only interested in one (raw) tuple, or "pcmcia_loop_tuple()" if it is
+ interested in all tuples of one type. To decode the MAC from CISTPL_FUNCE,
+ a new helper "pcmcia_get_mac_from_cis()" was added.
+
* New configuration loop helper (as of 2.6.28)
By calling pcmcia_loop_config(), a driver can iterate over all available
configuration options. During a driver's probe() phase, one doesn't need
diff --git a/Documentation/slow-work.txt b/Documentation/slow-work.txt
index ebc50f808ea..9dbf4470c7e 100644
--- a/Documentation/slow-work.txt
+++ b/Documentation/slow-work.txt
@@ -41,6 +41,13 @@ expand files, provided the time taken to do so isn't too long.
Operations of both types may sleep during execution, thus tying up the thread
loaned to it.
+A further class of work item is available, based on the slow work item class:
+
+ (*) Delayed slow work items.
+
+These are slow work items that have a timer to defer queueing of the item for
+a while.
+
THREAD-TO-CLASS ALLOCATION
--------------------------
@@ -64,9 +71,11 @@ USING SLOW WORK ITEMS
Firstly, a module or subsystem wanting to make use of slow work items must
register its interest:
- int ret = slow_work_register_user();
+ int ret = slow_work_register_user(struct module *module);
-This will return 0 if successful, or a -ve error upon failure.
+This will return 0 if successful, or a -ve error upon failure. The module
+pointer should be the module interested in using this facility (almost
+certainly THIS_MODULE).
Slow work items may then be set up by:
@@ -93,6 +102,10 @@ Slow work items may then be set up by:
or:
+ delayed_slow_work_init(&myitem, &myitem_ops);
+
+ or:
+
vslow_work_init(&myitem, &myitem_ops);
depending on its class.
@@ -102,15 +115,92 @@ A suitably set up work item can then be enqueued for processing:
int ret = slow_work_enqueue(&myitem);
This will return a -ve error if the thread pool is unable to gain a reference
-on the item, 0 otherwise.
+on the item, 0 otherwise, or (for delayed work):
+
+ int ret = delayed_slow_work_enqueue(&myitem, my_jiffy_delay);
The items are reference counted, so there ought to be no need for a flush
-operation. When all a module's slow work items have been processed, and the
+operation. But as the reference counting is optional, means to cancel
+existing work items are also included:
+
+ cancel_slow_work(&myitem);
+ cancel_delayed_slow_work(&myitem);
+
+can be used to cancel pending work. The above cancel function waits for
+existing work to have been executed (or prevent execution of them, depending
+on timing).
+
+
+When all a module's slow work items have been processed, and the
module has no further interest in the facility, it should unregister its
interest:
- slow_work_unregister_user();
+ slow_work_unregister_user(struct module *module);
+
+The module pointer is used to wait for all outstanding work items for that
+module before completing the unregistration. This prevents the put_ref() code
+from being taken away before it completes. module should almost certainly be
+THIS_MODULE.
+
+
+================
+HELPER FUNCTIONS
+================
+
+The slow-work facility provides a function by which it can be determined
+whether or not an item is queued for later execution:
+
+ bool queued = slow_work_is_queued(struct slow_work *work);
+
+If it returns false, then the item is not on the queue (it may be executing
+with a requeue pending). This can be used to work out whether an item on which
+another depends is on the queue, thus allowing a dependent item to be queued
+after it.
+
+If the above shows an item on which another depends not to be queued, then the
+owner of the dependent item might need to wait. However, to avoid locking up
+the threads unnecessarily be sleeping in them, it can make sense under some
+circumstances to return the work item to the queue, thus deferring it until
+some other items have had a chance to make use of the yielded thread.
+
+To yield a thread and defer an item, the work function should simply enqueue
+the work item again and return. However, this doesn't work if there's nothing
+actually on the queue, as the thread just vacated will jump straight back into
+the item's work function, thus busy waiting on a CPU.
+
+Instead, the item should use the thread to wait for the dependency to go away,
+but rather than using schedule() or schedule_timeout() to sleep, it should use
+the following function:
+
+ bool requeue = slow_work_sleep_till_thread_needed(
+ struct slow_work *work,
+ signed long *_timeout);
+
+This will add a second wait and then sleep, such that it will be woken up if
+either something appears on the queue that could usefully make use of the
+thread - and behind which this item can be queued, or if the event the caller
+set up to wait for happens. True will be returned if something else appeared
+on the queue and this work function should perhaps return, of false if
+something else woke it up. The timeout is as for schedule_timeout().
+
+For example:
+
+ wq = bit_waitqueue(&my_flags, MY_BIT);
+ init_wait(&wait);
+ requeue = false;
+ do {
+ prepare_to_wait(wq, &wait, TASK_UNINTERRUPTIBLE);
+ if (!test_bit(MY_BIT, &my_flags))
+ break;
+ requeue = slow_work_sleep_till_thread_needed(&my_work,
+ &timeout);
+ } while (timeout > 0 && !requeue);
+ finish_wait(wq, &wait);
+ if (!test_bit(MY_BIT, &my_flags)
+ goto do_my_thing;
+ if (requeue)
+ return; // to slow_work
===============
@@ -118,7 +208,8 @@ ITEM OPERATIONS
===============
Each work item requires a table of operations of type struct slow_work_ops.
-All members are required:
+Only ->execute() is required; the getting and putting of a reference and the
+describing of an item are all optional.
(*) Get a reference on an item:
@@ -148,6 +239,16 @@ All members are required:
This should perform the work required of the item. It may sleep, it may
perform disk I/O and it may wait for locks.
+ (*) View an item through /proc:
+
+ void (*desc)(struct slow_work *work, struct seq_file *m);
+
+ If supplied, this should print to 'm' a small string describing the work
+ the item is to do. This should be no more than about 40 characters, and
+ shouldn't include a newline character.
+
+ See the 'Viewing executing and queued items' section below.
+
==================
POOL CONFIGURATION
@@ -172,3 +273,50 @@ The slow-work thread pool has a number of configurables:
is bounded to between 1 and one fewer than the number of active threads.
This ensures there is always at least one thread that can process very
slow work items, and always at least one thread that won't.
+
+
+==================================
+VIEWING EXECUTING AND QUEUED ITEMS
+==================================
+
+If CONFIG_SLOW_WORK_DEBUG is enabled, a debugfs file is made available:
+
+ /sys/kernel/debug/slow_work/runqueue
+
+through which the list of work items being executed and the queues of items to
+be executed may be viewed. The owner of a work item is given the chance to
+add some information of its own.
+
+The contents look something like the following:
+
+ THR PID ITEM ADDR FL MARK DESC
+ === ===== ================ == ===== ==========
+ 0 3005 ffff880023f52348 a 952ms FSC: OBJ17d3: LOOK
+ 1 3006 ffff880024e33668 2 160ms FSC: OBJ17e5 OP60d3b: Write1/Store fl=2
+ 2 3165 ffff8800296dd180 a 424ms FSC: OBJ17e4: LOOK
+ 3 4089 ffff8800262c8d78 a 212ms FSC: OBJ17ea: CRTN
+ 4 4090 ffff88002792bed8 2 388ms FSC: OBJ17e8 OP60d36: Write1/Store fl=2
+ 5 4092 ffff88002a0ef308 2 388ms FSC: OBJ17e7 OP60d2e: Write1/Store fl=2
+ 6 4094 ffff88002abaf4b8 2 132ms FSC: OBJ17e2 OP60d4e: Write1/Store fl=2
+ 7 4095 ffff88002bb188e0 a 388ms FSC: OBJ17e9: CRTN
+ vsq - ffff880023d99668 1 308ms FSC: OBJ17e0 OP60f91: Write1/EnQ fl=2
+ vsq - ffff8800295d1740 1 212ms FSC: OBJ16be OP4d4b6: Write1/EnQ fl=2
+ vsq - ffff880025ba3308 1 160ms FSC: OBJ179a OP58dec: Write1/EnQ fl=2
+ vsq - ffff880024ec83e0 1 160ms FSC: OBJ17ae OP599f2: Write1/EnQ fl=2
+ vsq - ffff880026618e00 1 160ms FSC: OBJ17e6 OP60d33: Write1/EnQ fl=2
+ vsq - ffff880025a2a4b8 1 132ms FSC: OBJ16a2 OP4d583: Write1/EnQ fl=2
+ vsq - ffff880023cbe6d8 9 212ms FSC: OBJ17eb: LOOK
+ vsq - ffff880024d37590 9 212ms FSC: OBJ17ec: LOOK
+ vsq - ffff880027746cb0 9 212ms FSC: OBJ17ed: LOOK
+ vsq - ffff880024d37ae8 9 212ms FSC: OBJ17ee: LOOK
+ vsq - ffff880024d37cb0 9 212ms FSC: OBJ17ef: LOOK
+ vsq - ffff880025036550 9 212ms FSC: OBJ17f0: LOOK
+ vsq - ffff8800250368e0 9 212ms FSC: OBJ17f1: LOOK
+ vsq - ffff880025036aa8 9 212ms FSC: OBJ17f2: LOOK
+
+In the 'THR' column, executing items show the thread they're occupying and
+queued threads indicate which queue they're on. 'PID' shows the process ID of
+a slow-work thread that's executing something. 'FL' shows the work item flags.
+'MARK' indicates how long since an item was queued or began executing. Lastly,
+the 'DESC' column permits the owner of an item to give some information.
+
diff --git a/Documentation/sound/alsa/ALSA-Configuration.txt b/Documentation/sound/alsa/ALSA-Configuration.txt
index 1c8eb4518ce..fd9a2f67edf 100644
--- a/Documentation/sound/alsa/ALSA-Configuration.txt
+++ b/Documentation/sound/alsa/ALSA-Configuration.txt
@@ -522,7 +522,7 @@ Prior to version 0.9.0rc4 options had a 'snd_' prefix. This was removed.
pcm_devs - Number of PCM devices assigned to each card
(default = 1, up to 4)
pcm_substreams - Number of PCM substreams assigned to each PCM
- (default = 8, up to 16)
+ (default = 8, up to 128)
hrtimer - Use hrtimer (=1, default) or system timer (=0)
fake_buffer - Fake buffer allocations (default = 1)
diff --git a/Documentation/thermal/sysfs-api.txt b/Documentation/thermal/sysfs-api.txt
index 70d68ce8640..a87dc277a5c 100644
--- a/Documentation/thermal/sysfs-api.txt
+++ b/Documentation/thermal/sysfs-api.txt
@@ -1,5 +1,5 @@
Generic Thermal Sysfs driver How To
-=========================
+===================================
Written by Sujith Thomas <sujith.thomas@intel.com>, Zhang Rui <rui.zhang@intel.com>
@@ -10,20 +10,20 @@ Copyright (c) 2008 Intel Corporation
0. Introduction
-The generic thermal sysfs provides a set of interfaces for thermal zone devices (sensors)
-and thermal cooling devices (fan, processor...) to register with the thermal management
-solution and to be a part of it.
+The generic thermal sysfs provides a set of interfaces for thermal zone
+devices (sensors) and thermal cooling devices (fan, processor...) to register
+with the thermal management solution and to be a part of it.
-This how-to focuses on enabling new thermal zone and cooling devices to participate
-in thermal management.
-This solution is platform independent and any type of thermal zone devices and
-cooling devices should be able to make use of the infrastructure.
+This how-to focuses on enabling new thermal zone and cooling devices to
+participate in thermal management.
+This solution is platform independent and any type of thermal zone devices
+and cooling devices should be able to make use of the infrastructure.
-The main task of the thermal sysfs driver is to expose thermal zone attributes as well
-as cooling device attributes to the user space.
-An intelligent thermal management application can make decisions based on inputs
-from thermal zone attributes (the current temperature and trip point temperature)
-and throttle appropriate devices.
+The main task of the thermal sysfs driver is to expose thermal zone attributes
+as well as cooling device attributes to the user space.
+An intelligent thermal management application can make decisions based on
+inputs from thermal zone attributes (the current temperature and trip point
+temperature) and throttle appropriate devices.
[0-*] denotes any positive number starting from 0
[1-*] denotes any positive number starting from 1
@@ -31,77 +31,77 @@ and throttle appropriate devices.
1. thermal sysfs driver interface functions
1.1 thermal zone device interface
-1.1.1 struct thermal_zone_device *thermal_zone_device_register(char *name, int trips,
- void *devdata, struct thermal_zone_device_ops *ops)
-
- This interface function adds a new thermal zone device (sensor) to
- /sys/class/thermal folder as thermal_zone[0-*].
- It tries to bind all the thermal cooling devices registered at the same time.
-
- name: the thermal zone name.
- trips: the total number of trip points this thermal zone supports.
- devdata: device private data
- ops: thermal zone device call-backs.
- .bind: bind the thermal zone device with a thermal cooling device.
- .unbind: unbind the thermal zone device with a thermal cooling device.
- .get_temp: get the current temperature of the thermal zone.
- .get_mode: get the current mode (user/kernel) of the thermal zone.
- "kernel" means thermal management is done in kernel.
- "user" will prevent kernel thermal driver actions upon trip points
- so that user applications can take charge of thermal management.
- .set_mode: set the mode (user/kernel) of the thermal zone.
- .get_trip_type: get the type of certain trip point.
- .get_trip_temp: get the temperature above which the certain trip point
- will be fired.
+1.1.1 struct thermal_zone_device *thermal_zone_device_register(char *name,
+ int trips, void *devdata, struct thermal_zone_device_ops *ops)
+
+ This interface function adds a new thermal zone device (sensor) to
+ /sys/class/thermal folder as thermal_zone[0-*]. It tries to bind all the
+ thermal cooling devices registered at the same time.
+
+ name: the thermal zone name.
+ trips: the total number of trip points this thermal zone supports.
+ devdata: device private data
+ ops: thermal zone device call-backs.
+ .bind: bind the thermal zone device with a thermal cooling device.
+ .unbind: unbind the thermal zone device with a thermal cooling device.
+ .get_temp: get the current temperature of the thermal zone.
+ .get_mode: get the current mode (user/kernel) of the thermal zone.
+ - "kernel" means thermal management is done in kernel.
+ - "user" will prevent kernel thermal driver actions upon trip points
+ so that user applications can take charge of thermal management.
+ .set_mode: set the mode (user/kernel) of the thermal zone.
+ .get_trip_type: get the type of certain trip point.
+ .get_trip_temp: get the temperature above which the certain trip point
+ will be fired.
1.1.2 void thermal_zone_device_unregister(struct thermal_zone_device *tz)
- This interface function removes the thermal zone device.
- It deletes the corresponding entry form /sys/class/thermal folder and unbind all
- the thermal cooling devices it uses.
+ This interface function removes the thermal zone device.
+ It deletes the corresponding entry form /sys/class/thermal folder and
+ unbind all the thermal cooling devices it uses.
1.2 thermal cooling device interface
1.2.1 struct thermal_cooling_device *thermal_cooling_device_register(char *name,
- void *devdata, struct thermal_cooling_device_ops *)
-
- This interface function adds a new thermal cooling device (fan/processor/...) to
- /sys/class/thermal/ folder as cooling_device[0-*].
- It tries to bind itself to all the thermal zone devices register at the same time.
- name: the cooling device name.
- devdata: device private data.
- ops: thermal cooling devices call-backs.
- .get_max_state: get the Maximum throttle state of the cooling device.
- .get_cur_state: get the Current throttle state of the cooling device.
- .set_cur_state: set the Current throttle state of the cooling device.
+ void *devdata, struct thermal_cooling_device_ops *)
+
+ This interface function adds a new thermal cooling device (fan/processor/...)
+ to /sys/class/thermal/ folder as cooling_device[0-*]. It tries to bind itself
+ to all the thermal zone devices register at the same time.
+ name: the cooling device name.
+ devdata: device private data.
+ ops: thermal cooling devices call-backs.
+ .get_max_state: get the Maximum throttle state of the cooling device.
+ .get_cur_state: get the Current throttle state of the cooling device.
+ .set_cur_state: set the Current throttle state of the cooling device.
1.2.2 void thermal_cooling_device_unregister(struct thermal_cooling_device *cdev)
- This interface function remove the thermal cooling device.
- It deletes the corresponding entry form /sys/class/thermal folder and unbind
- itself from all the thermal zone devices using it.
+ This interface function remove the thermal cooling device.
+ It deletes the corresponding entry form /sys/class/thermal folder and
+ unbind itself from all the thermal zone devices using it.
1.3 interface for binding a thermal zone device with a thermal cooling device
1.3.1 int thermal_zone_bind_cooling_device(struct thermal_zone_device *tz,
- int trip, struct thermal_cooling_device *cdev);
+ int trip, struct thermal_cooling_device *cdev);
- This interface function bind a thermal cooling device to the certain trip point
- of a thermal zone device.
- This function is usually called in the thermal zone device .bind callback.
- tz: the thermal zone device
- cdev: thermal cooling device
- trip: indicates which trip point the cooling devices is associated with
- in this thermal zone.
+ This interface function bind a thermal cooling device to the certain trip
+ point of a thermal zone device.
+ This function is usually called in the thermal zone device .bind callback.
+ tz: the thermal zone device
+ cdev: thermal cooling device
+ trip: indicates which trip point the cooling devices is associated with
+ in this thermal zone.
1.3.2 int thermal_zone_unbind_cooling_device(struct thermal_zone_device *tz,
- int trip, struct thermal_cooling_device *cdev);
+ int trip, struct thermal_cooling_device *cdev);
- This interface function unbind a thermal cooling device from the certain trip point
- of a thermal zone device.
- This function is usually called in the thermal zone device .unbind callback.
- tz: the thermal zone device
- cdev: thermal cooling device
- trip: indicates which trip point the cooling devices is associated with
- in this thermal zone.
+ This interface function unbind a thermal cooling device from the certain
+ trip point of a thermal zone device. This function is usually called in
+ the thermal zone device .unbind callback.
+ tz: the thermal zone device
+ cdev: thermal cooling device
+ trip: indicates which trip point the cooling devices is associated with
+ in this thermal zone.
2. sysfs attributes structure
@@ -114,153 +114,166 @@ if hwmon is compiled in or built as a module.
Thermal zone device sys I/F, created once it's registered:
/sys/class/thermal/thermal_zone[0-*]:
- |-----type: Type of the thermal zone
- |-----temp: Current temperature
- |-----mode: Working mode of the thermal zone
- |-----trip_point_[0-*]_temp: Trip point temperature
- |-----trip_point_[0-*]_type: Trip point type
+ |---type: Type of the thermal zone
+ |---temp: Current temperature
+ |---mode: Working mode of the thermal zone
+ |---trip_point_[0-*]_temp: Trip point temperature
+ |---trip_point_[0-*]_type: Trip point type
Thermal cooling device sys I/F, created once it's registered:
/sys/class/thermal/cooling_device[0-*]:
- |-----type : Type of the cooling device(processor/fan/...)
- |-----max_state: Maximum cooling state of the cooling device
- |-----cur_state: Current cooling state of the cooling device
+ |---type: Type of the cooling device(processor/fan/...)
+ |---max_state: Maximum cooling state of the cooling device
+ |---cur_state: Current cooling state of the cooling device
-These two dynamic attributes are created/removed in pairs.
-They represent the relationship between a thermal zone and its associated cooling device.
-They are created/removed for each
-thermal_zone_bind_cooling_device/thermal_zone_unbind_cooling_device successful execution.
+Then next two dynamic attributes are created/removed in pairs. They represent
+the relationship between a thermal zone and its associated cooling device.
+They are created/removed for each successful execution of
+thermal_zone_bind_cooling_device/thermal_zone_unbind_cooling_device.
-/sys/class/thermal/thermal_zone[0-*]
- |-----cdev[0-*]: The [0-*]th cooling device in the current thermal zone
- |-----cdev[0-*]_trip_point: Trip point that cdev[0-*] is associated with
+/sys/class/thermal/thermal_zone[0-*]:
+ |---cdev[0-*]: [0-*]th cooling device in current thermal zone
+ |---cdev[0-*]_trip_point: Trip point that cdev[0-*] is associated with
Besides the thermal zone device sysfs I/F and cooling device sysfs I/F,
-the generic thermal driver also creates a hwmon sysfs I/F for each _type_ of
-thermal zone device. E.g. the generic thermal driver registers one hwmon class device
-and build the associated hwmon sysfs I/F for all the registered ACPI thermal zones.
+the generic thermal driver also creates a hwmon sysfs I/F for each _type_
+of thermal zone device. E.g. the generic thermal driver registers one hwmon
+class device and build the associated hwmon sysfs I/F for all the registered
+ACPI thermal zones.
+
/sys/class/hwmon/hwmon[0-*]:
- |-----name: The type of the thermal zone devices.
- |-----temp[1-*]_input: The current temperature of thermal zone [1-*].
- |-----temp[1-*]_critical: The critical trip point of thermal zone [1-*].
+ |---name: The type of the thermal zone devices
+ |---temp[1-*]_input: The current temperature of thermal zone [1-*]
+ |---temp[1-*]_critical: The critical trip point of thermal zone [1-*]
+
Please read Documentation/hwmon/sysfs-interface for additional information.
***************************
* Thermal zone attributes *
***************************
-type Strings which represent the thermal zone type.
- This is given by thermal zone driver as part of registration.
- Eg: "acpitz" indicates it's an ACPI thermal device.
- In order to keep it consistent with hwmon sys attribute,
- this should be a short, lowercase string,
- not containing spaces nor dashes.
- RO
- Required
-
-temp Current temperature as reported by thermal zone (sensor)
- Unit: millidegree Celsius
- RO
- Required
-
-mode One of the predefined values in [kernel, user]
- This file gives information about the algorithm
- that is currently managing the thermal zone.
- It can be either default kernel based algorithm
- or user space application.
- RW
- Optional
- kernel = Thermal management in kernel thermal zone driver.
- user = Preventing kernel thermal zone driver actions upon
- trip points so that user application can take full
- charge of the thermal management.
-
-trip_point_[0-*]_temp The temperature above which trip point will be fired
- Unit: millidegree Celsius
- RO
- Optional
-
-trip_point_[0-*]_type Strings which indicate the type of the trip point
- E.g. it can be one of critical, hot, passive,
- active[0-*] for ACPI thermal zone.
- RO
- Optional
-
-cdev[0-*] Sysfs link to the thermal cooling device node where the sys I/F
- for cooling device throttling control represents.
- RO
- Optional
-
-cdev[0-*]_trip_point The trip point with which cdev[0-*] is associated in this thermal zone
- -1 means the cooling device is not associated with any trip point.
- RO
- Optional
-
-******************************
-* Cooling device attributes *
-******************************
-
-type String which represents the type of device
- eg: For generic ACPI: this should be "Fan",
- "Processor" or "LCD"
- eg. For memory controller device on intel_menlow platform:
- this should be "Memory controller"
- RO
- Required
-
-max_state The maximum permissible cooling state of this cooling device.
- RO
- Required
-
-cur_state The current cooling state of this cooling device.
- the value can any integer numbers between 0 and max_state,
- cur_state == 0 means no cooling
- cur_state == max_state means the maximum cooling.
- RW
- Required
+type
+ Strings which represent the thermal zone type.
+ This is given by thermal zone driver as part of registration.
+ E.g: "acpitz" indicates it's an ACPI thermal device.
+ In order to keep it consistent with hwmon sys attribute; this should
+ be a short, lowercase string, not containing spaces nor dashes.
+ RO, Required
+
+temp
+ Current temperature as reported by thermal zone (sensor).
+ Unit: millidegree Celsius
+ RO, Required
+
+mode
+ One of the predefined values in [kernel, user].
+ This file gives information about the algorithm that is currently
+ managing the thermal zone. It can be either default kernel based
+ algorithm or user space application.
+ kernel = Thermal management in kernel thermal zone driver.
+ user = Preventing kernel thermal zone driver actions upon
+ trip points so that user application can take full
+ charge of the thermal management.
+ RW, Optional
+
+trip_point_[0-*]_temp
+ The temperature above which trip point will be fired.
+ Unit: millidegree Celsius
+ RO, Optional
+
+trip_point_[0-*]_type
+ Strings which indicate the type of the trip point.
+ E.g. it can be one of critical, hot, passive, active[0-*] for ACPI
+ thermal zone.
+ RO, Optional
+
+cdev[0-*]
+ Sysfs link to the thermal cooling device node where the sys I/F
+ for cooling device throttling control represents.
+ RO, Optional
+
+cdev[0-*]_trip_point
+ The trip point with which cdev[0-*] is associated in this thermal
+ zone; -1 means the cooling device is not associated with any trip
+ point.
+ RO, Optional
+
+passive
+ Attribute is only present for zones in which the passive cooling
+ policy is not supported by native thermal driver. Default is zero
+ and can be set to a temperature (in millidegrees) to enable a
+ passive trip point for the zone. Activation is done by polling with
+ an interval of 1 second.
+ Unit: millidegrees Celsius
+ RW, Optional
+
+*****************************
+* Cooling device attributes *
+*****************************
+
+type
+ String which represents the type of device, e.g:
+ - for generic ACPI: should be "Fan", "Processor" or "LCD"
+ - for memory controller device on intel_menlow platform:
+ should be "Memory controller".
+ RO, Required
+
+max_state
+ The maximum permissible cooling state of this cooling device.
+ RO, Required
+
+cur_state
+ The current cooling state of this cooling device.
+ The value can any integer numbers between 0 and max_state:
+ - cur_state == 0 means no cooling
+ - cur_state == max_state means the maximum cooling.
+ RW, Required
3. A simple implementation
-ACPI thermal zone may support multiple trip points like critical/hot/passive/active.
-If an ACPI thermal zone supports critical, passive, active[0] and active[1] at the same time,
-it may register itself as a thermal_zone_device (thermal_zone1) with 4 trip points in all.
-It has one processor and one fan, which are both registered as thermal_cooling_device.
-If the processor is listed in _PSL method, and the fan is listed in _AL0 method,
-the sys I/F structure will be built like this:
+ACPI thermal zone may support multiple trip points like critical, hot,
+passive, active. If an ACPI thermal zone supports critical, passive,
+active[0] and active[1] at the same time, it may register itself as a
+thermal_zone_device (thermal_zone1) with 4 trip points in all.
+It has one processor and one fan, which are both registered as
+thermal_cooling_device.
+
+If the processor is listed in _PSL method, and the fan is listed in _AL0
+method, the sys I/F structure will be built like this:
/sys/class/thermal:
|thermal_zone1:
- |-----type: acpitz
- |-----temp: 37000
- |-----mode: kernel
- |-----trip_point_0_temp: 100000
- |-----trip_point_0_type: critical
- |-----trip_point_1_temp: 80000
- |-----trip_point_1_type: passive
- |-----trip_point_2_temp: 70000
- |-----trip_point_2_type: active0
- |-----trip_point_3_temp: 60000
- |-----trip_point_3_type: active1
- |-----cdev0: --->/sys/class/thermal/cooling_device0
- |-----cdev0_trip_point: 1 /* cdev0 can be used for passive */
- |-----cdev1: --->/sys/class/thermal/cooling_device3
- |-----cdev1_trip_point: 2 /* cdev1 can be used for active[0]*/
+ |---type: acpitz
+ |---temp: 37000
+ |---mode: kernel
+ |---trip_point_0_temp: 100000
+ |---trip_point_0_type: critical
+ |---trip_point_1_temp: 80000
+ |---trip_point_1_type: passive
+ |---trip_point_2_temp: 70000
+ |---trip_point_2_type: active0
+ |---trip_point_3_temp: 60000
+ |---trip_point_3_type: active1
+ |---cdev0: --->/sys/class/thermal/cooling_device0
+ |---cdev0_trip_point: 1 /* cdev0 can be used for passive */
+ |---cdev1: --->/sys/class/thermal/cooling_device3
+ |---cdev1_trip_point: 2 /* cdev1 can be used for active[0]*/
|cooling_device0:
- |-----type: Processor
- |-----max_state: 8
- |-----cur_state: 0
+ |---type: Processor
+ |---max_state: 8
+ |---cur_state: 0
|cooling_device3:
- |-----type: Fan
- |-----max_state: 2
- |-----cur_state: 0
+ |---type: Fan
+ |---max_state: 2
+ |---cur_state: 0
/sys/class/hwmon:
|hwmon0:
- |-----name: acpitz
- |-----temp1_input: 37000
- |-----temp1_crit: 100000
+ |---name: acpitz
+ |---temp1_input: 37000
+ |---temp1_crit: 100000
diff --git a/Documentation/vm/hwpoison.txt b/Documentation/vm/hwpoison.txt
new file mode 100644
index 00000000000..3ffadf8da61
--- /dev/null
+++ b/Documentation/vm/hwpoison.txt
@@ -0,0 +1,136 @@
+What is hwpoison?
+
+Upcoming Intel CPUs have support for recovering from some memory errors
+(``MCA recovery''). This requires the OS to declare a page "poisoned",
+kill the processes associated with it and avoid using it in the future.
+
+This patchkit implements the necessary infrastructure in the VM.
+
+To quote the overview comment:
+
+ * High level machine check handler. Handles pages reported by the
+ * hardware as being corrupted usually due to a 2bit ECC memory or cache
+ * failure.
+ *
+ * This focusses on pages detected as corrupted in the background.
+ * When the current CPU tries to consume corruption the currently
+ * running process can just be killed directly instead. This implies
+ * that if the error cannot be handled for some reason it's safe to
+ * just ignore it because no corruption has been consumed yet. Instead
+ * when that happens another machine check will happen.
+ *
+ * Handles page cache pages in various states. The tricky part
+ * here is that we can access any page asynchronous to other VM
+ * users, because memory failures could happen anytime and anywhere,
+ * possibly violating some of their assumptions. This is why this code
+ * has to be extremely careful. Generally it tries to use normal locking
+ * rules, as in get the standard locks, even if that means the
+ * error handling takes potentially a long time.
+ *
+ * Some of the operations here are somewhat inefficient and have non
+ * linear algorithmic complexity, because the data structures have not
+ * been optimized for this case. This is in particular the case
+ * for the mapping from a vma to a process. Since this case is expected
+ * to be rare we hope we can get away with this.
+
+The code consists of a the high level handler in mm/memory-failure.c,
+a new page poison bit and various checks in the VM to handle poisoned
+pages.
+
+The main target right now is KVM guests, but it works for all kinds
+of applications. KVM support requires a recent qemu-kvm release.
+
+For the KVM use there was need for a new signal type so that
+KVM can inject the machine check into the guest with the proper
+address. This in theory allows other applications to handle
+memory failures too. The expection is that near all applications
+won't do that, but some very specialized ones might.
+
+---
+
+There are two (actually three) modi memory failure recovery can be in:
+
+vm.memory_failure_recovery sysctl set to zero:
+ All memory failures cause a panic. Do not attempt recovery.
+ (on x86 this can be also affected by the tolerant level of the
+ MCE subsystem)
+
+early kill
+ (can be controlled globally and per process)
+ Send SIGBUS to the application as soon as the error is detected
+ This allows applications who can process memory errors in a gentle
+ way (e.g. drop affected object)
+ This is the mode used by KVM qemu.
+
+late kill
+ Send SIGBUS when the application runs into the corrupted page.
+ This is best for memory error unaware applications and default
+ Note some pages are always handled as late kill.
+
+---
+
+User control:
+
+vm.memory_failure_recovery
+ See sysctl.txt
+
+vm.memory_failure_early_kill
+ Enable early kill mode globally
+
+PR_MCE_KILL
+ Set early/late kill mode/revert to system default
+ arg1: PR_MCE_KILL_CLEAR: Revert to system default
+ arg1: PR_MCE_KILL_SET: arg2 defines thread specific mode
+ PR_MCE_KILL_EARLY: Early kill
+ PR_MCE_KILL_LATE: Late kill
+ PR_MCE_KILL_DEFAULT: Use system global default
+PR_MCE_KILL_GET
+ return current mode
+
+
+---
+
+Testing:
+
+madvise(MADV_POISON, ....)
+ (as root)
+ Poison a page in the process for testing
+
+
+hwpoison-inject module through debugfs
+ /sys/debug/hwpoison/corrupt-pfn
+
+Inject hwpoison fault at PFN echoed into this file
+
+
+Architecture specific MCE injector
+
+x86 has mce-inject, mce-test
+
+Some portable hwpoison test programs in mce-test, see blow.
+
+---
+
+References:
+
+http://halobates.de/mce-lc09-2.pdf
+ Overview presentation from LinuxCon 09
+
+git://git.kernel.org/pub/scm/utils/cpu/mce/mce-test.git
+ Test suite (hwpoison specific portable tests in tsrc)
+
+git://git.kernel.org/pub/scm/utils/cpu/mce/mce-inject.git
+ x86 specific injector
+
+
+---
+
+Limitations:
+
+- Not all page types are supported and never will. Most kernel internal
+objects cannot be recovered, only LRU pages for now.
+- Right now hugepage support is missing.
+
+---
+Andi Kleen, Oct 2009
+
diff --git a/Documentation/vm/page-types.c b/Documentation/vm/page-types.c
index 3ec4f2a2258..4793c6aac73 100644
--- a/Documentation/vm/page-types.c
+++ b/Documentation/vm/page-types.c
@@ -218,7 +218,7 @@ static void fatal(const char *x, ...)
exit(EXIT_FAILURE);
}
-int checked_open(const char *pathname, int flags)
+static int checked_open(const char *pathname, int flags)
{
int fd = open(pathname, flags);
generated by cgit v1.2.3-70-g09d2 (git 2.46.0) at 2024-12-18 09:02:26 +0000