diff options
Diffstat (limited to 'Documentation')
| -rw-r--r-- | Documentation/ABI/testing/sysfs-fs-ext4 | 10 | ||||
| -rw-r--r-- | Documentation/ABI/testing/sysfs-pps | 73 | ||||
| -rw-r--r-- | Documentation/Changes | 7 | ||||
| -rw-r--r-- | Documentation/cgroups/memory.txt | 16 | ||||
| -rw-r--r-- | Documentation/connector/cn_test.c | 7 | ||||
| -rw-r--r-- | Documentation/feature-removal-schedule.txt | 14 | ||||
| -rw-r--r-- | Documentation/filesystems/ext2.txt | 2 | ||||
| -rw-r--r-- | Documentation/filesystems/ext4.txt | 4 | ||||
| -rw-r--r-- | Documentation/filesystems/isofs.txt | 9 | ||||
| -rw-r--r-- | Documentation/filesystems/proc.txt | 268 | ||||
| -rw-r--r-- | Documentation/gcov.txt | 246 | ||||
| -rw-r--r-- | Documentation/ioctl/ioctl-number.txt | 2 | ||||
| -rw-r--r-- | Documentation/kernel-parameters.txt | 7 | ||||
| -rw-r--r-- | Documentation/pps/pps.txt | 172 | ||||
| -rw-r--r-- | Documentation/rfkill.txt | 137 | ||||
| -rw-r--r-- | Documentation/robust-futex-ABI.txt | 4 | ||||
| -rw-r--r-- | Documentation/watchdog/hpwdt.txt | 84 |
17 files changed, 932 insertions, 130 deletions
diff --git a/Documentation/ABI/testing/sysfs-fs-ext4 b/Documentation/ABI/testing/sysfs-fs-ext4 index 4e79074de28..5fb709997d9 100644 --- a/Documentation/ABI/testing/sysfs-fs-ext4 +++ b/Documentation/ABI/testing/sysfs-fs-ext4 @@ -79,3 +79,13 @@ Description: This file is read-only and shows the number of kilobytes of data that have been written to this filesystem since it was mounted. + +What: /sys/fs/ext4/<disk>/inode_goal +Date: June 2008 +Contact: "Theodore Ts'o" <tytso@mit.edu> +Description: + Tuning parameter which (if non-zero) controls the goal + inode used by the inode allocator in p0reference to + all other allocation hueristics. This is intended for + debugging use only, and should be 0 on production + systems. diff --git a/Documentation/ABI/testing/sysfs-pps b/Documentation/ABI/testing/sysfs-pps new file mode 100644 index 00000000000..25028c7bc37 --- /dev/null +++ b/Documentation/ABI/testing/sysfs-pps @@ -0,0 +1,73 @@ +What: /sys/class/pps/ +Date: February 2008 +Contact: Rodolfo Giometti <giometti@linux.it> +Description: + The /sys/class/pps/ directory will contain files and + directories that will provide a unified interface to + the PPS sources. + +What: /sys/class/pps/ppsX/ +Date: February 2008 +Contact: Rodolfo Giometti <giometti@linux.it> +Description: + The /sys/class/pps/ppsX/ directory is related to X-th + PPS source into the system. Each directory will + contain files to manage and control its PPS source. + +What: /sys/class/pps/ppsX/assert +Date: February 2008 +Contact: Rodolfo Giometti <giometti@linux.it> +Description: + The /sys/class/pps/ppsX/assert file reports the assert events + and the assert sequence number of the X-th source in the form: + + <secs>.<nsec>#<sequence> + + If the source has no assert events the content of this file + is empty. + +What: /sys/class/pps/ppsX/clear +Date: February 2008 +Contact: Rodolfo Giometti <giometti@linux.it> +Description: + The /sys/class/pps/ppsX/clear file reports the clear events + and the clear sequence number of the X-th source in the form: + + <secs>.<nsec>#<sequence> + + If the source has no clear events the content of this file + is empty. + +What: /sys/class/pps/ppsX/mode +Date: February 2008 +Contact: Rodolfo Giometti <giometti@linux.it> +Description: + The /sys/class/pps/ppsX/mode file reports the functioning + mode of the X-th source in hexadecimal encoding. + + Please, refer to linux/include/linux/pps.h for further + info. + +What: /sys/class/pps/ppsX/echo +Date: February 2008 +Contact: Rodolfo Giometti <giometti@linux.it> +Description: + The /sys/class/pps/ppsX/echo file reports if the X-th does + or does not support an "echo" function. + +What: /sys/class/pps/ppsX/name +Date: February 2008 +Contact: Rodolfo Giometti <giometti@linux.it> +Description: + The /sys/class/pps/ppsX/name file reports the name of the + X-th source. + +What: /sys/class/pps/ppsX/path +Date: February 2008 +Contact: Rodolfo Giometti <giometti@linux.it> +Description: + The /sys/class/pps/ppsX/path file reports the path name of + the device connected with the X-th source. + + If the source is not connected with any device the content + of this file is empty. diff --git a/Documentation/Changes b/Documentation/Changes index 664392481c8..6d0f1efc5bf 100644 --- a/Documentation/Changes +++ b/Documentation/Changes @@ -72,6 +72,13 @@ assembling the 16-bit boot code, removing the need for as86 to compile your kernel. This change does, however, mean that you need a recent release of binutils. +Perl +---- + +You will need perl 5 and the following modules: Getopt::Long, Getopt::Std, +File::Basename, and File::Find to build the kernel. + + System utilities ================ diff --git a/Documentation/cgroups/memory.txt b/Documentation/cgroups/memory.txt index 1a608877b14..23d1262c077 100644 --- a/Documentation/cgroups/memory.txt +++ b/Documentation/cgroups/memory.txt @@ -152,14 +152,19 @@ When swap is accounted, following files are added. usage of mem+swap is limited by memsw.limit_in_bytes. -Note: why 'mem+swap' rather than swap. +* why 'mem+swap' rather than swap. The global LRU(kswapd) can swap out arbitrary pages. Swap-out means to move account from memory to swap...there is no change in usage of -mem+swap. +mem+swap. In other words, when we want to limit the usage of swap without +affecting global LRU, mem+swap limit is better than just limiting swap from +OS point of view. -In other words, when we want to limit the usage of swap without affecting -global LRU, mem+swap limit is better than just limiting swap from OS point -of view. +* What happens when a cgroup hits memory.memsw.limit_in_bytes +When a cgroup his memory.memsw.limit_in_bytes, it's useless to do swap-out +in this cgroup. Then, swap-out will not be done by cgroup routine and file +caches are dropped. But as mentioned above, global LRU can do swapout memory +from it for sanity of the system's memory management state. You can't forbid +it by cgroup. 2.5 Reclaim @@ -204,6 +209,7 @@ We can alter the memory limit: NOTE: We can use a suffix (k, K, m, M, g or G) to indicate values in kilo, mega or gigabytes. +NOTE: We can write "-1" to reset the *.limit_in_bytes(unlimited). # cat /cgroups/0/memory.limit_in_bytes 4194304 diff --git a/Documentation/connector/cn_test.c b/Documentation/connector/cn_test.c index 6977c178729..f688eba8770 100644 --- a/Documentation/connector/cn_test.c +++ b/Documentation/connector/cn_test.c @@ -41,6 +41,12 @@ void cn_test_callback(void *data) msg->seq, msg->ack, msg->len, (char *)msg->data); } +/* + * Do not remove this function even if no one is using it as + * this is an example of how to get notifications about new + * connector user registration + */ +#if 0 static int cn_test_want_notify(void) { struct cn_ctl_msg *ctl; @@ -117,6 +123,7 @@ nlmsg_failure: kfree_skb(skb); return -EINVAL; } +#endif static u32 cn_test_timer_counter; static void cn_test_timer_func(unsigned long __data) diff --git a/Documentation/feature-removal-schedule.txt b/Documentation/feature-removal-schedule.txt index 7129846a278..8d07ed31207 100644 --- a/Documentation/feature-removal-schedule.txt +++ b/Documentation/feature-removal-schedule.txt @@ -6,6 +6,20 @@ be removed from this file. --------------------------- +What: IRQF_SAMPLE_RANDOM +Check: IRQF_SAMPLE_RANDOM +When: July 2009 + +Why: Many of IRQF_SAMPLE_RANDOM users are technically bogus as entropy + sources in the kernel's current entropy model. To resolve this, every + input point to the kernel's entropy pool needs to better document the + type of entropy source it actually is. This will be replaced with + additional add_*_randomness functions in drivers/char/random.c + +Who: Robin Getz <rgetz@blackfin.uclinux.org> & Matt Mackall <mpm@selenic.com> + +--------------------------- + What: The ieee80211_regdom module parameter When: March 2010 / desktop catchup diff --git a/Documentation/filesystems/ext2.txt b/Documentation/filesystems/ext2.txt index e055acb6b2d..67639f905f1 100644 --- a/Documentation/filesystems/ext2.txt +++ b/Documentation/filesystems/ext2.txt @@ -322,7 +322,7 @@ an upper limit on the block size imposed by the page size of the kernel, so 8kB blocks are only allowed on Alpha systems (and other architectures which support larger pages). -There is an upper limit of 32768 subdirectories in a single directory. +There is an upper limit of 32000 subdirectories in a single directory. There is a "soft" upper limit of about 10-15k files in a single directory with the current linear linked-list directory implementation. This limit diff --git a/Documentation/filesystems/ext4.txt b/Documentation/filesystems/ext4.txt index 608fdba97b7..7be02ac5fa3 100644 --- a/Documentation/filesystems/ext4.txt +++ b/Documentation/filesystems/ext4.txt @@ -235,6 +235,10 @@ minixdf Make 'df' act like Minix. debug Extra debugging information is sent to syslog. +abort Simulate the effects of calling ext4_abort() for + debugging purposes. This is normally used while + remounting a filesystem which is already mounted. + errors=remount-ro Remount the filesystem read-only on an error. errors=continue Keep going on a filesystem error. errors=panic Panic and halt the machine if an error occurs. diff --git a/Documentation/filesystems/isofs.txt b/Documentation/filesystems/isofs.txt index 6973b980ca2..3c367c3b360 100644 --- a/Documentation/filesystems/isofs.txt +++ b/Documentation/filesystems/isofs.txt @@ -23,8 +23,13 @@ Mount options unique to the isofs filesystem. map=off Do not map non-Rock Ridge filenames to lower case map=normal Map non-Rock Ridge filenames to lower case map=acorn As map=normal but also apply Acorn extensions if present - mode=xxx Sets the permissions on files to xxx - dmode=xxx Sets the permissions on directories to xxx + mode=xxx Sets the permissions on files to xxx unless Rock Ridge + extensions set the permissions otherwise + dmode=xxx Sets the permissions on directories to xxx unless Rock Ridge + extensions set the permissions otherwise + overriderockperm Set permissions on files and directories according to + 'mode' and 'dmode' even though Rock Ridge extensions are + present. nojoliet Ignore Joliet extensions if they are present. norock Ignore Rock Ridge extensions if they are present. hide Completely strip hidden files from the file system. diff --git a/Documentation/filesystems/proc.txt b/Documentation/filesystems/proc.txt index ebff3c10a07..fad18f9456e 100644 --- a/Documentation/filesystems/proc.txt +++ b/Documentation/filesystems/proc.txt @@ -5,11 +5,12 @@ Bodo Bauer <bb@ricochet.net> 2.4.x update Jorge Nerin <comandante@zaralinux.com> November 14 2000 -move /proc/sys Shen Feng <shen@cn.fujitsu.com> April 1 2009 +move /proc/sys Shen Feng <shen@cn.fujitsu.com> April 1 2009 ------------------------------------------------------------------------------ Version 1.3 Kernel version 2.2.12 Kernel version 2.4.0-test11-pre4 ------------------------------------------------------------------------------ +fixes/update part 1.1 Stefani Seibold <stefani@seibold.net> June 9 2009 Table of Contents ----------------- @@ -116,7 +117,7 @@ The link self points to the process reading the file system. Each process subdirectory has the entries listed in Table 1-1. -Table 1-1: Process specific entries in /proc +Table 1-1: Process specific entries in /proc .............................................................................. File Content clear_refs Clears page referenced bits shown in smaps output @@ -134,46 +135,103 @@ Table 1-1: Process specific entries in /proc status Process status in human readable form wchan If CONFIG_KALLSYMS is set, a pre-decoded wchan stack Report full stack trace, enable via CONFIG_STACKTRACE - smaps Extension based on maps, the rss size for each mapped file + smaps a extension based on maps, showing the memory consumption of + each mapping .............................................................................. For example, to get the status information of a process, all you have to do is read the file /proc/PID/status: - >cat /proc/self/status - Name: cat - State: R (running) - Pid: 5452 - PPid: 743 + >cat /proc/self/status + Name: cat + State: R (running) + Tgid: 5452 + Pid: 5452 + PPid: 743 TracerPid: 0 (2.4) - Uid: 501 501 501 501 - Gid: 100 100 100 100 - Groups: 100 14 16 - VmSize: 1112 kB - VmLck: 0 kB - VmRSS: 348 kB - VmData: 24 kB - VmStk: 12 kB - VmExe: 8 kB - VmLib: 1044 kB - SigPnd: 0000000000000000 - SigBlk: 0000000000000000 - SigIgn: 0000000000000000 - SigCgt: 0000000000000000 - CapInh: 00000000fffffeff - CapPrm: 0000000000000000 - CapEff: 0000000000000000 - + Uid: 501 501 501 501 + Gid: 100 100 100 100 + FDSize: 256 + Groups: 100 14 16 + VmPeak: 5004 kB + VmSize: 5004 kB + VmLck: 0 kB + VmHWM: 476 kB + VmRSS: 476 kB + VmData: 156 kB + VmStk: 88 kB + VmExe: 68 kB + VmLib: 1412 kB + VmPTE: 20 kb + Threads: 1 + SigQ: 0/28578 + SigPnd: 0000000000000000 + ShdPnd: 0000000000000000 + SigBlk: 0000000000000000 + SigIgn: 0000000000000000 + SigCgt: 0000000000000000 + CapInh: 00000000fffffeff + CapPrm: 0000000000000000 + CapEff: 0000000000000000 + CapBnd: ffffffffffffffff + voluntary_ctxt_switches: 0 + nonvoluntary_ctxt_switches: 1 This shows you nearly the same information you would get if you viewed it with the ps command. In fact, ps uses the proc file system to obtain its -information. The statm file contains more detailed information about the -process memory usage. Its seven fields are explained in Table 1-2. The stat -file contains details information about the process itself. Its fields are -explained in Table 1-3. +information. But you get a more detailed view of the process by reading the +file /proc/PID/status. It fields are described in table 1-2. + +The statm file contains more detailed information about the process +memory usage. Its seven fields are explained in Table 1-3. The stat file +contains details information about the process itself. Its fields are +explained in Table 1-4. +Table 1-2: Contents of the statm files (as of 2.6.30-rc7) +.............................................................................. + Field Content + Name filename of the executable + State state (R is running, S is sleeping, D is sleeping + in an uninterruptible wait, Z is zombie, + T is traced or stopped) + Tgid thread group ID + Pid process id + PPid process id of the parent process + TracerPid PID of process tracing this process (0 if not) + Uid Real, effective, saved set, and file system UIDs + Gid Real, effective, saved set, and file system GIDs + FDSize number of file descriptor slots currently allocated + Groups supplementary group list + VmPeak peak virtual memory size + VmSize total program size + VmLck locked memory size + VmHWM peak resident set size ("high water mark") + VmRSS size of memory portions + VmData size of data, stack, and text segments + VmStk size of data, stack, and text segments + VmExe size of text segment + VmLib size of shared library code + VmPTE size of page table entries + Threads number of threads + SigQ number of signals queued/max. number for queue + SigPnd bitmap of pending signals for the thread + ShdPnd bitmap of shared pending signals for the process + SigBlk bitmap of blocked signals + SigIgn bitmap of ignored signals + SigCgt bitmap of catched signals + CapInh bitmap of inheritable capabilities + CapPrm bitmap of permitted capabilities + CapEff bitmap of effective capabilities + CapBnd bitmap of capabilities bounding set + Cpus_allowed mask of CPUs on which this process may run + Cpus_allowed_list Same as previous, but in "list format" + Mems_allowed mask of memory nodes allowed to this process + Mems_allowed_list Same as previous, but in "list format" + voluntary_ctxt_switches number of voluntary context switches + nonvoluntary_ctxt_switches number of non voluntary context switches +.............................................................................. -Table 1-2: Contents of the statm files (as of 2.6.8-rc3) +Table 1-3: Contents of the statm files (as of 2.6.8-rc3) .............................................................................. Field Content size total program size (pages) (same as VmSize in status) @@ -188,7 +246,7 @@ Table 1-2: Contents of the statm files (as of 2.6.8-rc3) .............................................................................. -Table 1-3: Contents of the stat files (as of 2.6.22-rc3) +Table 1-4: Contents of the stat files (as of 2.6.30-rc7) .............................................................................. Field Content pid process id @@ -222,10 +280,10 @@ Table 1-3: Contents of the stat files (as of 2.6.22-rc3) start_stack address of the start of the stack esp current value of ESP eip current value of EIP - pending bitmap of pending signals (obsolete) - blocked bitmap of blocked signals (obsolete) - sigign bitmap of ignored signals (obsolete) - sigcatch bitmap of catched signals (obsolete) + pending bitmap of pending signals + blocked bitmap of blocked signals + sigign bitmap of ignored signals + sigcatch bitmap of catched signals wchan address where process went to sleep 0 (place holder) 0 (place holder) @@ -234,19 +292,99 @@ Table 1-3: Contents of the stat files (as of 2.6.22-rc3) rt_priority realtime priority policy scheduling policy (man sched_setscheduler) blkio_ticks time spent waiting for block IO + gtime guest time of the task in jiffies + cgtime guest time of the task children in jiffies .............................................................................. +The /proc/PID/map file containing the currently mapped memory regions and +their access permissions. + +The format is: + +address perms offset dev inode pathname + +08048000-08049000 r-xp 00000000 03:00 8312 /opt/test +08049000-0804a000 rw-p 00001000 03:00 8312 /opt/test +0804a000-0806b000 rw-p 00000000 00:00 0 [heap] +a7cb1000-a7cb2000 ---p 00000000 00:00 0 +a7cb2000-a7eb2000 rw-p 00000000 00:00 0 +a7eb2000-a7eb3000 ---p 00000000 00:00 0 +a7eb3000-a7ed5000 rw-p 00000000 00:00 0 +a7ed5000-a8008000 r-xp 00000000 03:00 4222 /lib/libc.so.6 +a8008000-a800a000 r--p 00133000 03:00 4222 /lib/libc.so.6 +a800a000-a800b000 rw-p 00135000 03:00 4222 /lib/libc.so.6 +a800b000-a800e000 rw-p 00000000 00:00 0 +a800e000-a8022000 r-xp 00000000 03:00 14462 /lib/libpthread.so.0 +a8022000-a8023000 r--p 00013000 03:00 14462 /lib/libpthread.so.0 +a8023000-a8024000 rw-p 00014000 03:00 14462 /lib/libpthread.so.0 +a8024000-a8027000 rw-p 00000000 00:00 0 +a8027000-a8043000 r-xp 00000000 03:00 8317 /lib/ld-linux.so.2 +a8043000-a8044000 r--p 0001b000 03:00 8317 /lib/ld-linux.so.2 +a8044000-a8045000 rw-p 0001c000 03:00 8317 /lib/ld-linux.so.2 +aff35000-aff4a000 rw-p 00000000 00:00 0 [stack] +ffffe000-fffff000 r-xp 00000000 00:00 0 [vdso] + +where "address" is the address space in the process that it occupies, "perms" +is a set of permissions: + + r = read + w = write + x = execute + s = shared + p = private (copy on write) + +"offset" is the offset into the mapping, "dev" is the device (major:minor), and +"inode" is the inode on that device. 0 indicates that no inode is associated +with the memory region, as the case would be with BSS (uninitialized data). +The "pathname" shows the name associated file for this mapping. If the mapping +is not associated with a file: + + [heap] = the heap of the program + [stack] = the stack of the main process + [vdso] = the "virtual dynamic shared object", + the kernel system call handler + + or if empty, the mapping is anonymous. + + +The /proc/PID/smaps is an extension based on maps, showing the memory +consumption for each of the process's mappings. For each of mappings there +is a series of lines such as the following: + +08048000-080bc000 r-xp 00000000 03:02 13130 /bin/bash +Size: 1084 kB +Rss: 892 kB +Pss: 374 kB +Shared_Clean: 892 kB +Shared_Dirty: 0 kB +Private_Clean: 0 kB +Private_Dirty: 0 kB +Referenced: 892 kB +Swap: 0 kB +KernelPageSize: 4 kB +MMUPageSize: 4 kB + +The first of these lines shows the same information as is displayed for the +mapping in /proc/PID/maps. The remaining lines show the size of the mapping, +the amount of the mapping that is currently resident in RAM, the "proportional +set size” (divide each shared page by the number of processes sharing it), the +number of clean and dirty shared pages in the mapping, and the number of clean +and dirty private pages in the mapping. The "Referenced" indicates the amount +of memory currently marked as referenced or accessed. + +This file is only present if the CONFIG_MMU kernel configuration option is +enabled. 1.2 Kernel data --------------- Similar to the process entries, the kernel data files give information about the running kernel. The files used to obtain this information are contained in -/proc and are listed in Table 1-4. Not all of these will be present in your +/proc and are listed in Table 1-5. Not all of these will be present in your system. It depends on the kernel configuration and the loaded modules, which files are there, and which are missing. -Table 1-4: Kernel info in /proc +Table 1-5: Kernel info in /proc .............................................................................. File Content apm Advanced power management info @@ -283,6 +421,7 @@ Table 1-4: Kernel info in /proc rtc Real time clock scsi SCSI info (see text) slabinfo Slab pool info + softirqs softirq usage stat Overall statistics swaps Swap space utilization sys See chapter 2 @@ -597,6 +736,25 @@ on the kind of area : 0xffffffffa0017000-0xffffffffa0022000 45056 sys_init_module+0xc27/0x1d00 ... pages=10 vmalloc N0=10 +.............................................................................. + +softirqs: + +Provides counts of softirq handlers serviced since boot time, for each cpu. + +> cat /proc/softirqs + CPU0 CPU1 CPU2 CPU3 + HI: 0 0 0 0 + TIMER: 27166 27120 27097 27034 + NET_TX: 0 0 0 17 + NET_RX: 42 0 0 39 + BLOCK: 0 0 107 1121 + TASKLET: 0 0 0 290 + SCHED: 27035 26983 26971 26746 + HRTIMER: 0 0 0 0 + RCU: 1678 1769 2178 2250 + + 1.3 IDE devices in /proc/ide ---------------------------- @@ -614,10 +772,10 @@ IDE devices: More detailed information can be found in the controller specific subdirectories. These are named ide0, ide1 and so on. Each of these -directories contains the files shown in table 1-5. +directories contains the files shown in table 1-6. -Table 1-5: IDE controller info in /proc/ide/ide? +Table 1-6: IDE controller info in /proc/ide/ide? .............................................................................. File Content channel IDE channel (0 or 1) @@ -627,11 +785,11 @@ Table 1-5: IDE controller info in /proc/ide/ide? .............................................................................. Each device connected to a controller has a separate subdirectory in the -controllers directory. The files listed in table 1-6 are contained in these +controllers directory. The files listed in table 1-7 are contained in these directories. -Table 1-6: IDE device information +Table 1-7: IDE device information .............................................................................. File Content cache The cache @@ -673,12 +831,12 @@ the drive parameters: 1.4 Networking info in /proc/net -------------------------------- -The subdirectory /proc/net follows the usual pattern. Table 1-6 shows the +The subdirectory /proc/net follows the usual pattern. Table 1-8 shows the additional values you get for IP version 6 if you configure the kernel to -support this. Table 1-7 lists the files and their meaning. +support this. Table 1-9 lists the files and their meaning. -Table 1-6: IPv6 info in /proc/net +Table 1-8: IPv6 info in /proc/net .............................................................................. File Content udp6 UDP sockets (IPv6) @@ -693,7 +851,7 @@ Table 1-6: IPv6 info in /proc/net .............................................................................. -Table 1-7: Network info in /proc/net +Table 1-9: Network info in /proc/net .............................................................................. File Content arp Kernel ARP table @@ -817,10 +975,10 @@ The directory /proc/parport contains information about the parallel ports of your system. It has one subdirectory for each port, named after the port number (0,1,2,...). -These directories contain the four files shown in Table 1-8. +These directories contain the four files shown in Table 1-10. -Table 1-8: Files in /proc/parport +Table 1-10: Files in /proc/parport .............................................................................. File Content autoprobe Any IEEE-1284 device ID information that has been acquired. @@ -838,10 +996,10 @@ Table 1-8: Files in /proc/parport Information about the available and actually used tty's can be found in the directory /proc/tty.You'll find entries for drivers and line disciplines in -this directory, as shown in Table 1-9. +this directory, as shown in Table 1-11. -Table 1-9: Files in /proc/tty +Table 1-11: Files in /proc/tty .............................................................................. File Content drivers list of drivers and their usage @@ -883,6 +1041,7 @@ since the system first booted. For a quick look, simply cat the file: processes 2915 procs_running 1 procs_blocked 0 + softirq 183433 0 21755 12 39 1137 231 21459 2263 The very first "cpu" line aggregates the numbers in all of the other "cpuN" lines. These numbers identify the amount of time the CPU has spent performing @@ -918,6 +1077,11 @@ CPUs. The "procs_blocked" line gives the number of processes currently blocked, waiting for I/O to complete. +The "softirq" line gives counts of softirqs serviced since boot time, for each +of the possible system softirqs. The first column is the total of all +softirqs serviced; each subsequent column is the total for that particular +softirq. + 1.9 Ext4 file system parameters ------------------------------ @@ -926,9 +1090,9 @@ Information about mounted ext4 file systems can be found in /proc/fs/ext4. Each mounted filesystem will have a directory in /proc/fs/ext4 based on its device name (i.e., /proc/fs/ext4/hdc or /proc/fs/ext4/dm-0). The files in each per-device directory are shown -in Table 1-10, below. +in Table 1-12, below. -Table 1-10: Files in /proc/fs/ext4/<devname> +Table 1-12: Files in /proc/fs/ext4/<devname> .............................................................................. File Content mb_groups details of multiblock allocator buddy cache of free blocks diff --git a/Documentation/gcov.txt b/Documentation/gcov.txt new file mode 100644 index 00000000000..e716aadb3a3 --- /dev/null +++ b/Documentation/gcov.txt @@ -0,0 +1,246 @@ +Using gcov with the Linux kernel +================================ + +1. Introduction +2. Preparation +3. Customization +4. Files +5. Modules +6. Separated build and test machines +7. Troubleshooting +Appendix A: sample script: gather_on_build.sh +Appendix B: sample script: gather_on_test.sh + + +1. Introduction +=============== + +gcov profiling kernel support enables the use of GCC's coverage testing +tool gcov [1] with the Linux kernel. Coverage data of a running kernel +is exported in gcov-compatible format via the "gcov" debugfs directory. +To get coverage data for a specific file, change to the kernel build +directory and use gcov with the -o option as follows (requires root): + +# cd /tmp/linux-out +# gcov -o /sys/kernel/debug/gcov/tmp/linux-out/kernel spinlock.c + +This will create source code files annotated with execution counts +in the current directory. In addition, graphical gcov front-ends such +as lcov [2] can be used to automate the process of collecting data +for the entire kernel and provide coverage overviews in HTML format. + +Possible uses: + +* debugging (has this line been reached at all?) +* test improvement (how do I change my test to cover these lines?) +* minimizing kernel configurations (do I need this option if the + associated code is never run?) + +-- + +[1] http://gcc.gnu.org/onlinedocs/gcc/Gcov.html +[2] http://ltp.sourceforge.net/coverage/lcov.php + + +2. Preparation +============== + +Configure the kernel with: + + CONFIG_DEBUGFS=y + CONFIG_GCOV_KERNEL=y + +and to get coverage data for the entire kernel: + + CONFIG_GCOV_PROFILE_ALL=y + +Note that kernels compiled with profiling flags will be significantly +larger and run slower. Also CONFIG_GCOV_PROFILE_ALL may not be supported +on all architectures. + +Profiling data will only become accessible once debugfs has been +mounted: + + mount -t debugfs none /sys/kernel/debug + + +3. Customization +================ + +To enable profiling for specific files or directories, add a line +similar to the following to the respective kernel Makefile: + + For a single file (e.g. main.o): + GCOV_PROFILE_main.o := y + + For all files in one directory: + GCOV_PROFILE := y + +To exclude files from being profiled even when CONFIG_GCOV_PROFILE_ALL +is specified, use: + + GCOV_PROFILE_main.o := n + and: + GCOV_PROFILE := n + +Only files which are linked to the main kernel image or are compiled as +kernel modules are supported by this mechanism. + + +4. Files +======== + +The gcov kernel support creates the following files in debugfs: + + /sys/kernel/debug/gcov + Parent directory for all gcov-related files. + + /sys/kernel/debug/gcov/reset + Global reset file: resets all coverage data to zero when + written to. + + /sys/kernel/debug/gcov/path/to/compile/dir/file.gcda + The actual gcov data file as understood by the gcov + tool. Resets file coverage data to zero when written to. + + /sys/kernel/debug/gcov/path/to/compile/dir/file.gcno + Symbolic link to a static data file required by the gcov + tool. This file is generated by gcc when compiling with + option -ftest-coverage. + + +5. Modules +========== + +Kernel modules may contain cleanup code which is only run during +module unload time. The gcov mechanism provides a means to collect +coverage data for such code by keeping a copy of the data associated +with the unloaded module. This data remains available through debugfs. +Once the module is loaded again, the associated coverage counters are +initialized with the data from its previous instantiation. + +This behavior can be deactivated by specifying the gcov_persist kernel +parameter: + + gcov_persist=0 + +At run-time, a user can also choose to discard data for an unloaded +module by writing to its data file or the global reset file. + + +6. Separated build and test machines +==================================== + +The gcov kernel profiling infrastructure is designed to work out-of-the +box for setups where kernels are built and run on the same machine. In +cases where the kernel runs on a separate machine, special preparations +must be made, depending on where the gcov tool is used: + +a) gcov is run on the TEST machine + +The gcov tool version on the test machine must be compatible with the +gcc version used for kernel build. Also the following files need to be +copied from build to test machine: + +from the source tree: + - all C source files + headers + +from the build tree: + - all C source files + headers + - all .gcda and .gcno files + - all links to directories + +It is important to note that these files need to be placed into the +exact same file system location on the test machine as on the build +machine. If any of the path components is symbolic link, the actual +directory needs to be used instead (due to make's CURDIR handling). + +b) gcov is run on the BUILD machine + +The following files need to be copied after each test case from test +to build machine: + +from the gcov directory in sysfs: + - all .gcda files + - all links to .gcno files + +These files can be copied to any location on the build machine. gcov +must then be called with the -o option pointing to that directory. + +Example directory setup on the build machine: + + /tmp/linux: kernel source tree + /tmp/out: kernel build directory as specified by make O= + /tmp/coverage: location of the files copied from the test machine + + [user@build] cd /tmp/out + [user@build] gcov -o /tmp/coverage/tmp/out/init main.c + + +7. Troubleshooting +================== + +Problem: Compilation aborts during linker step. +Cause: Profiling flags are specified for source files which are not + linked to the main kernel or which are linked by a custom + linker procedure. +Solution: Exclude affected source files from profiling by specifying + GCOV_PROFILE := n or GCOV_PROFILE_basename.o := n in the + corresponding Makefile. + + +Appendix A: gather_on_build.sh +============================== + +Sample script to gather coverage meta files on the build machine +(see 6a): + +#!/bin/bash + +KSRC=$1 +KOBJ=$2 +DEST=$3 + +if [ -z "$KSRC" ] || [ -z "$KOBJ" ] || [ -z "$DEST" ]; then + echo "Usage: $0 <ksrc directory> <kobj directory> <output.tar.gz>" >&2 + exit 1 +fi + +KSRC=$(cd $KSRC; printf "all:\n\t@echo \${CURDIR}\n" | make -f -) +KOBJ=$(cd $KOBJ; printf "all:\n\t@echo \${CURDIR}\n" | make -f -) + +find $KSRC $KOBJ \( -name '*.gcno' -o -name '*.[ch]' -o -type l \) -a \ + -perm /u+r,g+r | tar cfz $DEST -P -T - + +if [ $? -eq 0 ] ; then + echo "$DEST successfully created, copy to test system and unpack with:" + echo " tar xfz $DEST -P" +else + echo "Could not create file $DEST" +fi + + +Appendix B: gather_on_test.sh +============================= + +Sample script to gather coverage data files on the test machine +(see 6b): + +#!/bin/bash + +DEST=$1 +GCDA=/sys/kernel/debug/gcov + +if [ -z "$DEST" ] ; then + echo "Usage: $0 <output.tar.gz>" >&2 + exit 1 +fi + +find $GCDA -name '*.gcno' -o -name '*.gcda' | tar cfz $DEST -T - + +if [ $? -eq 0 ] ; then + echo "$DEST successfully created, copy to build system and unpack with:" + echo " tar xfz $DEST" +else + echo "Could not create file $DEST" +fi diff --git a/Documentation/ioctl/ioctl-number.txt b/Documentation/ioctl/ioctl-number.txt index 1f779a25c70..7bb0d934b6d 100644 --- a/Documentation/ioctl/ioctl-number.txt +++ b/Documentation/ioctl/ioctl-number.txt @@ -149,6 +149,8 @@ Code Seq# Include File Comments 'p' 40-7F linux/nvram.h 'p' 80-9F user-space parport <mailto:tim@cyberelk.net> +'p' a1-a4 linux/pps.h LinuxPPS + <mailto:giometti@linux.it> 'q' 00-1F linux/serio.h 'q' 80-FF Internet PhoneJACK, Internet LineJACK <http://www.quicknet.net> diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt index 5578248c18a..08def8deb5f 100644 --- a/Documentation/kernel-parameters.txt +++ b/Documentation/kernel-parameters.txt @@ -48,6 +48,7 @@ parameter is applicable: EFI EFI Partitioning (GPT) is enabled EIDE EIDE/ATAPI support is enabled. FB The frame buffer device is enabled. + GCOV GCOV profiling is enabled. HW Appropriate hardware is enabled. IA-64 IA-64 architecture is enabled. IMA Integrity measurement architecture is enabled. @@ -796,6 +797,12 @@ and is between 256 and 4096 characters. It is defined in the file Format: off | on default: on + gcov_persist= [GCOV] When non-zero (default), profiling data for + kernel modules is saved and remains accessible via + debugfs, even when the module is unloaded/reloaded. + When zero, profiling data is discarded and associated + debugfs files are removed at module unload time. + gdth= [HW,SCSI] See header of drivers/scsi/gdth.c. diff --git a/Documentation/pps/pps.txt b/Documentation/pps/pps.txt new file mode 100644 index 00000000000..125f4ab4899 --- /dev/null +++ b/Documentation/pps/pps.txt @@ -0,0 +1,172 @@ + + PPS - Pulse Per Second + ---------------------- + +(C) Copyright 2007 Rodolfo Giometti <giometti@enneenne.com> + +This program is free software; you can redistribute it and/or modify +it under the terms of the GNU General Public License as published by +the Free Software Foundation; either version 2 of the License, or +(at your option) any later version. + +This program is distributed in the hope that it will be useful, +but WITHOUT ANY WARRANTY; without even the implied warranty of +MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the +GNU General Public License for more details. + + + +Overview +-------- + +LinuxPPS provides a programming interface (API) to define in the +system several PPS sources. + +PPS means "pulse per second" and a PPS source is just a device which +provides a high precision signal each second so that an application +can use it to adjust system clock time. + +A PPS source can be connected to a serial port (usually to the Data +Carrier Detect pin) or to a parallel port (ACK-pin) or to a special +CPU's GPIOs (this is the common case in embedded systems) but in each +case when a new pulse arrives the system must apply to it a timestamp +and record it for userland. + +Common use is the combination of the NTPD as userland program, with a +GPS receiver as PPS source, to obtain a wallclock-time with +sub-millisecond synchronisation to UTC. + + +RFC considerations +------------------ + +While implementing a PPS API as RFC 2783 defines and using an embedded +CPU GPIO-Pin as physical link to the signal, I encountered a deeper +problem: + + At startup it needs a file descriptor as argument for the function + time_pps_create(). + +This implies that the source has a /dev/... entry. This assumption is +ok for the serial and parallel port, where you can do something +useful besides(!) the gathering of timestamps as it is the central +task for a PPS-API. But this assumption does not work for a single +purpose GPIO line. In this case even basic file-related functionality +(like read() and write()) makes no sense at all and should not be a +precondition for the use of a PPS-API. + +The problem can be simply solved if you consider that a PPS source is +not always connected with a GPS data source. + +So your programs should check if the GPS data source (the serial port +for instance) is a PPS source too, and if not they should provide the +possibility to open another device as PPS source. + +In LinuxPPS the PPS sources are simply char devices usually mapped +into files /dev/pps0, /dev/pps1, etc.. + + +Coding example +-------------- + +To register a PPS source into the kernel you should define a struct +pps_source_info_s as follows: + + static struct pps_source_info pps_ktimer_info = { + .name = "ktimer", + .path = "", + .mode = PPS_CAPTUREASSERT | PPS_OFFSETASSERT | \ + PPS_ECHOASSERT | \ + PPS_CANWAIT | PPS_TSFMT_TSPEC, + .echo = pps_ktimer_echo, + .owner = THIS_MODULE, + }; + +and then calling the function pps_register_source() in your +intialization routine as follows: + + source = pps_register_source(&pps_ktimer_info, + PPS_CAPTUREASSERT | PPS_OFFSETASSERT); + +The pps_register_source() prototype is: + + int pps_register_source(struct pps_source_info_s *info, int default_params) + +where "info" is a pointer to a structure that describes a particular +PPS source, "default_params" tells the system what the initial default +parameters for the device should be (it is obvious that these parameters +must be a subset of ones defined in the struct +pps_source_info_s which describe the capabilities of the driver). + +Once you have registered a new PPS source into the system you can +signal an assert event (for example in the interrupt handler routine) +just using: + + pps_event(source, &ts, PPS_CAPTUREASSERT, ptr) + +where "ts" is the event's timestamp. + +The same function may also run the defined echo function +(pps_ktimer_echo(), passing to it the "ptr" pointer) if the user +asked for that... etc.. + +Please see the file drivers/pps/clients/ktimer.c for example code. + + +SYSFS support +------------- + +If the SYSFS filesystem is enabled in the kernel it provides a new class: + + $ ls /sys/class/pps/ + pps0/ pps1/ pps2/ + +Every directory is the ID of a PPS sources defined in the system and +inside you find several files: + + $ ls /sys/class/pps/pps0/ + assert clear echo mode name path subsystem@ uevent + +Inside each "assert" and "clear" file you can find the timestamp and a +sequence number: + + $ cat /sys/class/pps/pps0/assert + 1170026870.983207967#8 + +Where before the "#" is the timestamp in seconds; after it is the +sequence number. Other files are: + +* echo: reports if the PPS source has an echo function or not; + +* mode: reports available PPS functioning modes; + +* name: reports the PPS source's name; + +* path: reports the PPS source's device path, that is the device the + PPS source is connected to (if it exists). + + +Testing the PPS support +----------------------- + +In order to test the PPS support even without specific hardware you can use +the ktimer driver (see the client subsection in the PPS configuration menu) +and the userland tools provided into Documentaion/pps/ directory. + +Once you have enabled the compilation of ktimer just modprobe it (if +not statically compiled): + + # modprobe ktimer + +and the run ppstest as follow: + + $ ./ppstest /dev/pps0 + trying PPS source "/dev/pps1" + found PPS source "/dev/pps1" + ok, found 1 source(s), now start fetching data... + source 0 - assert 1186592699.388832443, sequence: 364 - clear 0.000000000, sequence: 0 + source 0 - assert 1186592700.388931295, sequence: 365 - clear 0.000000000, sequence: 0 + source 0 - assert 1186592701.389032765, sequence: 366 - clear 0.000000000, sequence: 0 + +Please, note that to compile userland programs you need the file timepps.h +(see Documentation/pps/). diff --git a/Documentation/rfkill.txt b/Documentation/rfkill.txt index 1b74b5f30af..c8acd8659e9 100644 --- a/Documentation/rfkill.txt +++ b/Documentation/rfkill.txt @@ -3,9 +3,8 @@ rfkill - RF kill switch support 1. Introduction 2. Implementation details -3. Kernel driver guidelines -4. Kernel API -5. Userspace support +3. Kernel API +4. Userspace support 1. Introduction @@ -19,82 +18,62 @@ disable all transmitters of a certain type (or all). This is intended for situations where transmitters need to be turned off, for example on aircraft. +The rfkill subsystem has a concept of "hard" and "soft" block, which +differ little in their meaning (block == transmitters off) but rather in +whether they can be changed or not: + - hard block: read-only radio block that cannot be overriden by software + - soft block: writable radio block (need not be readable) that is set by + the system software. 2. Implementation details -The rfkill subsystem is composed of various components: the rfkill class, the -rfkill-input module (an input layer handler), and some specific input layer -events. - -The rfkill class is provided for kernel drivers to register their radio -transmitter with the kernel, provide methods for turning it on and off and, -optionally, letting the system know about hardware-disabled states that may -be implemented on the device. This code is enabled with the CONFIG_RFKILL -Kconfig option, which drivers can "select". - -The rfkill class code also notifies userspace of state changes, this is -achieved via uevents. It also provides some sysfs files for userspace to -check the status of radio transmitters. See the "Userspace support" section -below. +The rfkill subsystem is composed of three main components: + * the rfkill core, + * the deprecated rfkill-input module (an input layer handler, being + replaced by userspace policy code) and + * the rfkill drivers. +The rfkill core provides API for kernel drivers to register their radio +transmitter with the kernel, methods for turning it on and off and, letting +the system know about hardware-disabled states that may be implemented on +the device. -The rfkill-input code implements a basic response to rfkill buttons -- it -implements turning on/off all devices of a certain class (or all). +The rfkill core code also notifies userspace of state changes, and provides +ways for userspace to query the current states. See the "Userspace support" +section below. When the device is hard-blocked (either by a call to rfkill_set_hw_state() -or from query_hw_block) set_block() will be invoked but drivers can well -ignore the method call since they can use the return value of the function -rfkill_set_hw_state() to sync the software state instead of keeping track -of calls to set_block(). - - -The entire functionality is spread over more than one subsystem: - - * The kernel input layer generates KEY_WWAN, KEY_WLAN etc. and - SW_RFKILL_ALL -- when the user presses a button. Drivers for radio - transmitters generally do not register to the input layer, unless the - device really provides an input device (i.e. a button that has no - effect other than generating a button press event) - - * The rfkill-input code hooks up to these events and switches the soft-block - of the various radio transmitters, depending on the button type. - - * The rfkill drivers turn off/on their transmitters as requested. - - * The rfkill class will generate userspace notifications (uevents) to tell - userspace what the current state is. +or from query_hw_block) set_block() will be invoked for additional software +block, but drivers can ignore the method call since they can use the return +value of the function rfkill_set_hw_state() to sync the software state +instead of keeping track of calls to set_block(). In fact, drivers should +use the return value of rfkill_set_hw_state() unless the hardware actually +keeps track of soft and hard block separately. +3. Kernel API -3. Kernel driver guidelines - -Drivers for radio transmitters normally implement only the rfkill class. -These drivers may not unblock the transmitter based on own decisions, they -should act on information provided by the rfkill class only. +Drivers for radio transmitters normally implement an rfkill driver. Platform drivers might implement input devices if the rfkill button is just that, a button. If that button influences the hardware then you need to -implement an rfkill class instead. This also applies if the platform provides +implement an rfkill driver instead. This also applies if the platform provides a way to turn on/off the transmitter(s). -During suspend/hibernation, transmitters should only be left enabled when -wake-on wlan or similar functionality requires it and the device wasn't -blocked before suspend/hibernate. Note that it may be necessary to update -the rfkill subsystem's idea of what the current state is at resume time if -the state may have changed over suspend. - +For some platforms, it is possible that the hardware state changes during +suspend/hibernation, in which case it will be necessary to update the rfkill +core with the current state is at resume time. +To create an rfkill driver, driver's Kconfig needs to have -4. Kernel API + depends on RFKILL || !RFKILL -To build a driver with rfkill subsystem support, the driver should depend on -(or select) the Kconfig symbol RFKILL. - -The hardware the driver talks to may be write-only (where the current state -of the hardware is unknown), or read-write (where the hardware can be queried -about its current state). +to ensure the driver cannot be built-in when rfkill is modular. The !RFKILL +case allows the driver to be built when rfkill is not configured, which which +case all rfkill API can still be used but will be provided by static inlines +which compile to almost nothing. Calling rfkill_set_hw_state() when a state change happens is required from rfkill drivers that control devices that can be hard-blocked unless they also @@ -105,10 +84,33 @@ device). Don't do this unless you cannot get the event in any other way. 5. Userspace support -The following sysfs entries exist for every rfkill device: +The recommended userspace interface to use is /dev/rfkill, which is a misc +character device that allows userspace to obtain and set the state of rfkill +devices and sets of devices. It also notifies userspace about device addition +and removal. The API is a simple read/write API that is defined in +linux/rfkill.h, with one ioctl that allows turning off the deprecated input +handler in the kernel for the transition period. + +Except for the one ioctl, communication with the kernel is done via read() +and write() of instances of 'struct rfkill_event'. In this structure, the +soft and hard block are properly separated (unlike sysfs, see below) and +userspace is able to get a consistent snapshot of all rfkill devices in the +system. Also, it is possible to switch all rfkill drivers (or all drivers of +a specified type) into a state which also updates the default state for +hotplugged devices. + +After an application opens /dev/rfkill, it can read the current state of +all devices, and afterwards can poll the descriptor for hotplug or state +change events. + +Applications must ignore operations (the "op" field) they do not handle, +this allows the API to be extended in the future. + +Additionally, each rfkill device is registered in sysfs and there has the +following attributes: name: Name assigned by driver to this key (interface or driver name). - type: Name of the key type ("wlan", "bluetooth", etc). + type: Driver type string ("wlan", "bluetooth", etc). state: Current state of the transmitter 0: RFKILL_STATE_SOFT_BLOCKED transmitter is turned off by software @@ -117,7 +119,12 @@ The following sysfs entries exist for every rfkill device: 2: RFKILL_STATE_HARD_BLOCKED transmitter is forced off by something outside of the driver's control. - claim: 0: Kernel handles events (currently always reads that value) + This file is deprecated because it can only properly show + three of the four possible states, soft-and-hard-blocked is + missing. + claim: 0: Kernel handles events + This file is deprecated because there no longer is a way to + claim just control over a single rfkill instance. rfkill devices also issue uevents (with an action of "change"), with the following environment variables set: @@ -128,9 +135,3 @@ RFKILL_TYPE The contents of these variables corresponds to the "name", "state" and "type" sysfs files explained above. - -An alternative userspace interface exists as a misc device /dev/rfkill, -which allows userspace to obtain and set the state of rfkill devices and -sets of devices. It also notifies userspace about device addition and -removal. The API is a simple read/write API that is defined in -linux/rfkill.h. diff --git a/Documentation/robust-futex-ABI.txt b/Documentation/robust-futex-ABI.txt index 535f69fab45..fd1cd8aae4e 100644 --- a/Documentation/robust-futex-ABI.txt +++ b/Documentation/robust-futex-ABI.txt @@ -135,7 +135,7 @@ manipulating this list), the user code must observe the following protocol on 'lock entry' insertion and removal: On insertion: - 1) set the 'list_op_pending' word to the address of the 'lock word' + 1) set the 'list_op_pending' word to the address of the 'lock entry' to be inserted, 2) acquire the futex lock, 3) add the lock entry, with its thread id (TID) in the bottom 29 bits @@ -143,7 +143,7 @@ On insertion: 4) clear the 'list_op_pending' word. On removal: - 1) set the 'list_op_pending' word to the address of the 'lock word' + 1) set the 'list_op_pending' word to the address of the 'lock entry' to be removed, 2) remove the lock entry for this lock from the 'head' list, 2) release the futex lock, and diff --git a/Documentation/watchdog/hpwdt.txt b/Documentation/watchdog/hpwdt.txt new file mode 100644 index 00000000000..127839e5304 --- /dev/null +++ b/Documentation/watchdog/hpwdt.txt @@ -0,0 +1,84 @@ +Last reviewed: 06/02/2009 + + HP iLO2 NMI Watchdog Driver + NMI sourcing for iLO2 based ProLiant Servers + Documentation and Driver by + Thomas Mingarelli <thomas.mingarelli@hp.com> + + The HP iLO2 NMI Watchdog driver is a kernel module that provides basic + watchdog functionality and the added benefit of NMI sourcing. Both the + watchdog functionality and the NMI sourcing capability need to be enabled + by the user. Remember that the two modes are not dependant on one another. + A user can have the NMI sourcing without the watchdog timer and vice-versa. + + Watchdog functionality is enabled like any other common watchdog driver. That + is, an application needs to be started that kicks off the watchdog timer. A + basic application exists in the Documentation/watchdog/src directory called + watchdog-test.c. Simply compile the C file and kick it off. If the system + gets into a bad state and hangs, the HP ProLiant iLO 2 timer register will + not be updated in a timely fashion and a hardware system reset (also known as + an Automatic Server Recovery (ASR)) event will occur. + + The hpwdt driver also has three (3) module parameters. They are the following: + + soft_margin - allows the user to set the watchdog timer value + allow_kdump - allows the user to save off a kernel dump image after an NMI + nowayout - basic watchdog parameter that does not allow the timer to + be restarted or an impending ASR to be escaped. + + NOTE: More information about watchdog drivers in general, including the ioctl + interface to /dev/watchdog can be found in + Documentation/watchdog/watchdog-api.txt and Documentation/IPMI.txt. + + The NMI sourcing capability is disabled when the driver discovers that the + nmi_watchdog is turned on (nmi_watchdog = 1). This is due to the inability to + distinguish between "NMI Watchdog Ticks" and "HW generated NMI events" in the + Linux kernel. What this means is that the hpwdt nmi handler code is called + each time the NMI signal fires off. This could amount to several thousands of + NMIs in a matter of seconds. If a user sees the Linux kernel's "dazed and + confused" message in the logs or if the system gets into a hung state, then + the user should reboot with nmi_watchdog=0. + + 1. If the kernel has not been booted with nmi_watchdog turned off then + edit /boot/grub/menu.lst and place the nmi_watchdog=0 at the end of the + currently booting kernel line. + 2. reboot the sever + + Now, the hpwdt can successfully receive and source the NMI and provide a log + message that details the reason for the NMI (as determined by the HP BIOS). + + Below is a list of NMIs the HP BIOS understands along with the associated + code (reason): + + No source found 00h + + Uncorrectable Memory Error 01h + + ASR NMI 1Bh + + PCI Parity Error 20h + + NMI Button Press 27h + + SB_BUS_NMI 28h + + ILO Doorbell NMI 29h + + ILO IOP NMI 2Ah + + ILO Watchdog NMI 2Bh + + Proc Throt NMI 2Ch + + Front Side Bus NMI 2Dh + + PCI Express Error 2Fh + + DMA controller NMI 30h + + Hypertransport/CSI Error 31h + + + + -- Tom Mingarelli + (thomas.mingarelli@hp.com) |