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2008-12-18"Tree RCU": scalable classic RCU implementationPaul E. McKenney
This patch fixes a long-standing performance bug in classic RCU that results in massive internal-to-RCU lock contention on systems with more than a few hundred CPUs. Although this patch creates a separate flavor of RCU for ease of review and patch maintenance, it is intended to replace classic RCU. This patch still handles stress better than does mainline, so I am still calling it ready for inclusion. This patch is against the -tip tree. Nevertheless, experience on an actual 1000+ CPU machine would still be most welcome. Most of the changes noted below were found while creating an rcutiny (which should permit ejecting the current rcuclassic) and while doing detailed line-by-line documentation. Updates from v9 (http://lkml.org/lkml/2008/12/2/334): o Fixes from remainder of line-by-line code walkthrough, including comment spelling, initialization, undesirable narrowing due to type conversion, removing redundant memory barriers, removing redundant local-variable initialization, and removing redundant local variables. I do not believe that any of these fixes address the CPU-hotplug issues that Andi Kleen was seeing, but please do give it a whirl in case the machine is smarter than I am. A writeup from the walkthrough may be found at the following URL, in case you are suffering from terminal insomnia or masochism: http://www.kernel.org/pub/linux/kernel/people/paulmck/tmp/rcutree-walkthrough.2008.12.16a.pdf o Made rcutree tracing use seq_file, as suggested some time ago by Lai Jiangshan. o Added a .csv variant of the rcudata debugfs trace file, to allow people having thousands of CPUs to drop the data into a spreadsheet. Tested with oocalc and gnumeric. Updated documentation to suit. Updates from v8 (http://lkml.org/lkml/2008/11/15/139): o Fix a theoretical race between grace-period initialization and force_quiescent_state() that could occur if more than three jiffies were required to carry out the grace-period initialization. Which it might, if you had enough CPUs. o Apply Ingo's printk-standardization patch. o Substitute local variables for repeated accesses to global variables. o Fix comment misspellings and redundant (but harmless) increments of ->n_rcu_pending (this latter after having explicitly added it). o Apply checkpatch fixes. Updates from v7 (http://lkml.org/lkml/2008/10/10/291): o Fixed a number of problems noted by Gautham Shenoy, including the cpu-stall-detection bug that he was having difficulty convincing me was real. ;-) o Changed cpu-stall detection to wait for ten seconds rather than three in order to reduce false positive, as suggested by Ingo Molnar. o Produced a design document (http://lwn.net/Articles/305782/). The act of writing this document uncovered a number of both theoretical and "here and now" bugs as noted below. o Fix dynticks_nesting accounting confusion, simplify WARN_ON() condition, fix kerneldoc comments, and add memory barriers in dynticks interface functions. o Add more data to tracing. o Remove unused "rcu_barrier" field from rcu_data structure. o Count calls to rcu_pending() from scheduling-clock interrupt to use as a surrogate timebase should jiffies stop counting. o Fix a theoretical race between force_quiescent_state() and grace-period initialization. Yes, initialization does have to go on for some jiffies for this race to occur, but given enough CPUs... Updates from v6 (http://lkml.org/lkml/2008/9/23/448): o Fix a number of checkpatch.pl complaints. o Apply review comments from Ingo Molnar and Lai Jiangshan on the stall-detection code. o Fix several bugs in !CONFIG_SMP builds. o Fix a misspelled config-parameter name so that RCU now announces at boot time if stall detection is configured. o Run tests on numerous combinations of configurations parameters, which after the fixes above, now build and run correctly. Updates from v5 (http://lkml.org/lkml/2008/9/15/92, bad subject line): o Fix a compiler error in the !CONFIG_FANOUT_EXACT case (blew a changeset some time ago, and finally got around to retesting this option). o Fix some tracing bugs in rcupreempt that caused incorrect totals to be printed. o I now test with a more brutal random-selection online/offline script (attached). Probably more brutal than it needs to be on the people reading it as well, but so it goes. o A number of optimizations and usability improvements: o Make rcu_pending() ignore the grace-period timeout when there is no grace period in progress. o Make force_quiescent_state() avoid going for a global lock in the case where there is no grace period in progress. o Rearrange struct fields to improve struct layout. o Make call_rcu() initiate a grace period if RCU was idle, rather than waiting for the next scheduling clock interrupt. o Invoke rcu_irq_enter() and rcu_irq_exit() only when idle, as suggested by Andi Kleen. I still don't completely trust this change, and might back it out. o Make CONFIG_RCU_TRACE be the single config variable manipulated for all forms of RCU, instead of the prior confusion. o Document tracing files and formats for both rcupreempt and rcutree. Updates from v4 for those missing v5 given its bad subject line: o Separated dynticks interface so that NMIs and irqs call separate functions, greatly simplifying it. In particular, this code no longer requires a proof of correctness. ;-) o Separated dynticks state out into its own per-CPU structure, avoiding the duplicated accounting. o The case where a dynticks-idle CPU runs an irq handler that invokes call_rcu() is now correctly handled, forcing that CPU out of dynticks-idle mode. o Review comments have been applied (thank you all!!!). For but one example, fixed the dynticks-ordering issue that Manfred pointed out, saving me much debugging. ;-) o Adjusted rcuclassic and rcupreempt to handle dynticks changes. Attached is an updated patch to Classic RCU that applies a hierarchy, greatly reducing the contention on the top-level lock for large machines. This passes 10-hour concurrent rcutorture and online-offline testing on 128-CPU ppc64 without dynticks enabled, and exposes some timekeeping bugs in presence of dynticks (exciting working on a system where "sleep 1" hangs until interrupted...), which were fixed in the 2.6.27 kernel. It is getting more reliable than mainline by some measures, so the next version will be against -tip for inclusion. See also Manfred Spraul's recent patches (or his earlier work from 2004 at http://marc.info/?l=linux-kernel&m=108546384711797&w=2). We will converge onto a common patch in the fullness of time, but are currently exploring different regions of the design space. That said, I have already gratefully stolen quite a few of Manfred's ideas. This patch provides CONFIG_RCU_FANOUT, which controls the bushiness of the RCU hierarchy. Defaults to 32 on 32-bit machines and 64 on 64-bit machines. If CONFIG_NR_CPUS is less than CONFIG_RCU_FANOUT, there is no hierarchy. By default, the RCU initialization code will adjust CONFIG_RCU_FANOUT to balance the hierarchy, so strongly NUMA architectures may choose to set CONFIG_RCU_FANOUT_EXACT to disable this balancing, allowing the hierarchy to be exactly aligned to the underlying hardware. Up to two levels of hierarchy are permitted (in addition to the root node), allowing up to 16,384 CPUs on 32-bit systems and up to 262,144 CPUs on 64-bit systems. I just know that I am going to regret saying this, but this seems more than sufficient for the foreseeable future. (Some architectures might wish to set CONFIG_RCU_FANOUT=4, which would limit such architectures to 64 CPUs. If this becomes a real problem, additional levels can be added, but I doubt that it will make a significant difference on real hardware.) In the common case, a given CPU will manipulate its private rcu_data structure and the rcu_node structure that it shares with its immediate neighbors. This can reduce both lock and memory contention by multiple orders of magnitude, which should eliminate the need for the strange manipulations that are reported to be required when running Linux on very large systems. Some shortcomings: o More bugs will probably surface as a result of an ongoing line-by-line code inspection. Patches will be provided as required. o There are probably hangs, rcutorture failures, &c. Seems quite stable on a 128-CPU machine, but that is kind of small compared to 4096 CPUs. However, seems to do better than mainline. Patches will be provided as required. o The memory footprint of this version is several KB larger than rcuclassic. A separate UP-only rcutiny patch will be provided, which will reduce the memory footprint significantly, even compared to the old rcuclassic. One such patch passes light testing, and has a memory footprint smaller even than rcuclassic. Initial reaction from various embedded guys was "it is not worth it", so am putting it aside. Credits: o Manfred Spraul for ideas, review comments, and bugs spotted, as well as some good friendly competition. ;-) o Josh Triplett, Ingo Molnar, Peter Zijlstra, Mathieu Desnoyers, Lai Jiangshan, Andi Kleen, Andy Whitcroft, and Andrew Morton for reviews and comments. o Thomas Gleixner for much-needed help with some timer issues (see patches below). o Jon M. Tollefson, Tim Pepper, Andrew Theurer, Jose R. Santos, Andy Whitcroft, Darrick Wong, Nishanth Aravamudan, Anton Blanchard, Dave Kleikamp, and Nathan Lynch for keeping machines alive despite my heavy abuse^Wtesting. Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-12-18Merge branch 'linus' into core/rcuIngo Molnar
2008-12-17USB: fix comment about endianness of descriptorsPhil Endecott
This patch fixes a comment and clarifies the documentation about the endianness of descriptors. The current policy is that descriptors will be little-endian at the API even on big-endian systems; however the /proc/bus/usb API predates this policy and presents descriptors with some multibyte fields byte-swapped. Signed-off-by: Phil Endecott <usb_endian_patch@chezphil.org> Signed-off-by: Alan Stern <stern@rowland.harvard.edu> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2008-12-15Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-2.6Linus Torvalds
* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-2.6: Phonet: keep TX queue disabled when the device is off SCHED: netem: Correct documentation comment in code. netfilter: update rwlock initialization for nat_table netlabel: Compiler warning and NULL pointer dereference fix e1000e: fix double release of mutex IA64: HP_SIMETH needs to depend upon NET netpoll: fix race on poll_list resulting in garbage entry ipv6: silence log messages for locally generated multicast sungem: improve ethtool output with internal pcs and serdes tcp: tcp_vegas cong avoid fix sungem: Make PCS PHY support partially work again.
2008-12-15Define smp_call_function_many for UPRusty Russell
Otherwise those using it in transition patches (eg. kvm) can't compile with CONFIG_SMP=n: arch/x86/kvm/../../../virt/kvm/kvm_main.c: In function 'make_all_cpus_request': arch/x86/kvm/../../../virt/kvm/kvm_main.c:380: error: implicit declaration of function 'smp_call_function_many' Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-12-10Revert "radeonfb: accelerate imageblit and other improvements"Linus Torvalds
This reverts commit b1ee26bab14886350ba12a5c10cbc0696ac679bf, along with the "fixes" for it that all just caused problems: - c4c6fa9891f3d1bcaae4f39fb751d5302965b566 "radeonfb: fix problem with color expansion & alignment" - f3179748a157c21d44d929fd3779421ebfbeaa93 "radeonfb: Disable new color expand acceleration unless explicitely enabled" because even when disabled, it breaks for people. See http://bugzilla.kernel.org/show_bug.cgi?id=12191 for the latest example. Acked-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Acked-by: David S. Miller <davem@davemloft.net> Cc: Krzysztof Halasa <khc@pm.waw.pl> Cc: James Cloos <cloos@jhcloos.com> Cc: "Rafael J. Wysocki" <rjw@sisk.pl> Cc: Krzysztof Helt <krzysztof.h1@poczta.fm> Cc: Jean-Luc Coulon <jean.luc.coulon@gmail.com> Cc: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-12-10MN10300: Fix __put_user_asm8()Akira Takeuchi
Fix __put_user_asm8() by jumping to the end label (3:) from the exception handler, rather than jumping back to retry the second store instruction (label 2:). Signed-off-by: Akira Takeuchi <takeuchi.akr@jp.panasonic.com> Signed-off-by: David Howells <dhowells@redhat.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-12-10KSYM_SYMBOL_LEN fixesHugh Dickins
Miles Lane tailing /sys files hit a BUG which Pekka Enberg has tracked to my 966c8c12dc9e77f931e2281ba25d2f0244b06949 sprint_symbol(): use less stack exposing a bug in slub's list_locations() - kallsyms_lookup() writes a 0 to namebuf[KSYM_NAME_LEN-1], but that was beyond the end of page provided. The 100 slop which list_locations() allows at end of page looks roughly enough for all the other stuff it might print after the symbol before it checks again: break out KSYM_SYMBOL_LEN earlier than before. Latencytop and ftrace and are using KSYM_NAME_LEN buffers where they need KSYM_SYMBOL_LEN buffers, and vmallocinfo a 2*KSYM_NAME_LEN buffer where it wants a KSYM_SYMBOL_LEN buffer: fix those before anyone copies them. [akpm@linux-foundation.org: ftrace.h needs module.h] Signed-off-by: Hugh Dickins <hugh@veritas.com> Cc: Christoph Lameter <cl@linux-foundation.org> Cc Miles Lane <miles.lane@gmail.com> Acked-by: Pekka Enberg <penberg@cs.helsinki.fi> Acked-by: Steven Rostedt <srostedt@redhat.com> Acked-by: Frederic Weisbecker <fweisbec@gmail.com> Cc: Rusty Russell <rusty@rustcorp.com.au> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-12-10atomic: fix a typo in atomic_long_xchg()Eric Dumazet
atomic_long_xchg() is not correctly defined for 32bit arches. Signed-off-by: Eric Dumazet <dada1@cosmosbay.com> Cc: Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-12-10revert "percpu_counter: new function percpu_counter_sum_and_set"Andrew Morton
Revert commit e8ced39d5e8911c662d4d69a342b9d053eaaac4e Author: Mingming Cao <cmm@us.ibm.com> Date: Fri Jul 11 19:27:31 2008 -0400 percpu_counter: new function percpu_counter_sum_and_set As described in revert "percpu counter: clean up percpu_counter_sum_and_set()" the new percpu_counter_sum_and_set() is racy against updates to the cpu-local accumulators on other CPUs. Revert that change. This means that ext4 will be slow again. But correct. Reported-by: Eric Dumazet <dada1@cosmosbay.com> Cc: "David S. Miller" <davem@davemloft.net> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Mingming Cao <cmm@us.ibm.com> Cc: <linux-ext4@vger.kernel.org> Cc: <stable@kernel.org> [2.6.27.x] Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-12-10revert "percpu counter: clean up percpu_counter_sum_and_set()"Andrew Morton
Revert commit 1f7c14c62ce63805f9574664a6c6de3633d4a354 Author: Mingming Cao <cmm@us.ibm.com> Date: Thu Oct 9 12:50:59 2008 -0400 percpu counter: clean up percpu_counter_sum_and_set() Before this patch we had the following: percpu_counter_sum(): return the percpu_counter's value percpu_counter_sum_and_set(): return the percpu_counter's value, copying that value into the central value and zeroing the per-cpu counters before returning. After this patch, percpu_counter_sum_and_set() has gone, and percpu_counter_sum() gets the old percpu_counter_sum_and_set() functionality. Problem is, as Eric points out, the old percpu_counter_sum_and_set() functionality was racy and wrong. It zeroes out counters on "other" cpus, without holding any locks which will prevent races agaist updates from those other CPUS. This patch reverts 1f7c14c62ce63805f9574664a6c6de3633d4a354. This means that percpu_counter_sum_and_set() still has the race, but percpu_counter_sum() does not. Note that this is not a simple revert - ext4 has since started using percpu_counter_sum() for its dirty_blocks counter as well. Note that this revert patch changes percpu_counter_sum() semantics. Before the patch, a call to percpu_counter_sum() will bring the counter's central counter mostly up-to-date, so a following percpu_counter_read() will return a close value. After this patch, a call to percpu_counter_sum() will leave the counter's central accumulator unaltered, so a subsequent call to percpu_counter_read() can now return a significantly inaccurate result. If there is any code in the tree which was introduced after e8ced39d5e8911c662d4d69a342b9d053eaaac4e was merged, and which depends upon the new percpu_counter_sum() semantics, that code will break. Reported-by: Eric Dumazet <dada1@cosmosbay.com> Cc: "David S. Miller" <davem@davemloft.net> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Mingming Cao <cmm@us.ibm.com> Cc: <linux-ext4@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-12-09netpoll: fix race on poll_list resulting in garbage entryNeil Horman
A few months back a race was discused between the netpoll napi service path, and the fast path through net_rx_action: http://kerneltrap.org/mailarchive/linux-netdev/2007/10/16/345470 A patch was submitted for that bug, but I think we missed a case. Consider the following scenario: INITIAL STATE CPU0 has one napi_struct A on its poll_list CPU1 is calling netpoll_send_skb and needs to call poll_napi on the same napi_struct A that CPU0 has on its list CPU0 CPU1 net_rx_action poll_napi !list_empty (returns true) locks poll_lock for A poll_one_napi napi->poll netif_rx_complete __napi_complete (removes A from poll_list) list_entry(list->next) In the above scenario, net_rx_action assumes that the per-cpu poll_list is exclusive to that cpu. netpoll of course violates that, and because the netpoll path can dequeue from the poll list, its possible for CPU0 to detect a non-empty list at the top of the while loop in net_rx_action, but have it become empty by the time it calls list_entry. Since the poll_list isn't surrounded by any other structure, the returned data from that list_entry call in this situation is garbage, and any number of crashes can result based on what exactly that garbage is. Given that its not fasible for performance reasons to place exclusive locks arround each cpus poll list to provide that mutal exclusion, I think the best solution is modify the netpoll path in such a way that we continue to guarantee that the poll_list for a cpu is in fact exclusive to that cpu. To do this I've implemented the patch below. It adds an additional bit to the state field in the napi_struct. When executing napi->poll from the netpoll_path, this bit will be set. When a driver calls netif_rx_complete, if that bit is set, it will not remove the napi_struct from the poll_list. That work will be saved for the next iteration of net_rx_action. I've tested this and it seems to work well. About the biggest drawback I can see to it is the fact that it might result in an extra loop through net_rx_action in the event that the device is actually contended for (i.e. the netpoll path actually preforms all the needed work no the device, and the call to net_rx_action winds up doing nothing, except removing the napi_struct from the poll_list. However I think this is probably a small price to pay, given that the alternative is a crash. Signed-off-by: Neil Horman <nhorman@tuxdriver.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2008-12-09Merge branch 'audit.b59' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/viro/audit-current * 'audit.b59' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/audit-current: [PATCH] fix broken timestamps in AVC generated by kernel threads [patch 1/1] audit: remove excess kernel-doc [PATCH] asm/generic: fix bug - kernel fails to build when enable some common audit code on Blackfin [PATCH] return records for fork() both to child and parent [PATCH] Audit: make audit=0 actually turn off audit
2008-12-09[PATCH] fix broken timestamps in AVC generated by kernel threadsAl Viro
Timestamp in audit_context is valid only if ->in_syscall is set. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2008-12-09[PATCH] asm/generic: fix bug - kernel fails to build when enable some common ↵Mike Frysinger
audit code on Blackfin If you enable some common audit code, the kernel fails to build. In file included from lib/audit.c:17: include/asm-generic/audit_write.h:3: error: '__NR_swapon' undeclared here (not in a function) make[1]: *** [lib/audit.o] Error 1 make: *** [lib] Error 2 So do not use __NR_swapon if it isnt defined for a port. Signed-off-by: Mike Frysinger <vapier.adi@gmail.com> Signed-off-by: Bryan Wu <cooloney@kernel.org> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2008-12-09[PATCH] return records for fork() both to child and parentAl Viro
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2008-12-08Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-2.6Linus Torvalds
* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-2.6: tproxy: fixe a possible read from an invalid location in the socket match zd1211rw: use unaligned safe memcmp() in-place of compare_ether_addr() mac80211: use unaligned safe memcmp() in-place of compare_ether_addr() ipw2200: fix netif_*_queue() removal regression iwlwifi: clean key table in iwl_clear_stations_table function tcp: tcp_vegas ssthresh bug fix can: omit received RTR frames for single ID filter lists ATM: CVE-2008-5079: duplicate listen() on socket corrupts the vcc table netx-eth: initialize per device spinlock tcp: make urg+gso work for real this time enc28j60: Fix sporadic packet loss (corrected again) hysdn: fix writing outside the field on 64 bits b1isa: fix b1isa_exit() to really remove registered capi controllers can: Fix CAN_(EFF|RTR)_FLAG handling in can_filter Phonet: do not dump addresses from other namespaces netlabel: Fix a potential NULL pointer dereference bnx2: Add workaround to handle missed MSI. xfrm: Fix kernel panic when flush and dump SPD entries
2008-12-05Enforce a minimum SG_IO timeoutLinus Torvalds
There's no point in having too short SG_IO timeouts, since if the command does end up timing out, we'll end up through the reset sequence that is several seconds long in order to abort the command that timed out. As a result, shorter timeouts than a few seconds simply do not make sense, as the recovery would be longer than the timeout itself. Add a BLK_MIN_SG_TIMEOUT to match the existign BLK_DEFAULT_SG_TIMEOUT. Suggested-by: Alan Cox <alan@lxorguk.ukuu.org.uk> Acked-by: Tejun Heo <tj@kernel.org> Acked-by: Jens Axboe <jens.axboe@oracle.com> Cc: Jeff Garzik <jeff@garzik.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-12-04[PATCH 2/2] documnt FMODE_ constantsChristoph Hellwig
Make sure all FMODE_ constants are documents, and ensure a coherent style for the already existing comments. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2008-12-04[PATCH 1/2] kill FMODE_NDELAY_NOWChristoph Hellwig
Update FMODE_NDELAY before each ioctl call so that we can kill the magic FMODE_NDELAY_NOW. It would be even better to do this directly in setfl(), but for that we'd need to have FMODE_NDELAY for all files, not just block special files. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2008-12-03can: Fix CAN_(EFF|RTR)_FLAG handling in can_filterOliver Hartkopp
Due to a wrong safety check in af_can.c it was not possible to filter for SFF frames with a specific CAN identifier without getting the same selected CAN identifier from a received EFF frame also. This fix has a minimum (but user visible) impact on the CAN filter API and therefore the CAN version is set to a new date. Indeed the 'old' API is still working as-is. But when now setting CAN_(EFF|RTR)_FLAG in can_filter.can_mask you might get less traffic than before - but still the stuff that you expected to get for your defined filter ... Thanks to Kurt Van Dijck for pointing at this issue and for the review. Signed-off-by: Oliver Hartkopp <oliver@hartkopp.net> Acked-by: Kurt Van Dijck <kurt.van.dijck@eia.be> Signed-off-by: David S. Miller <davem@davemloft.net>
2008-12-03block: fix setting of max_segment_size and seg_boundary maskMilan Broz
Fix setting of max_segment_size and seg_boundary mask for stacked md/dm devices. When stacking devices (LVM over MD over SCSI) some of the request queue parameters are not set up correctly in some cases by default, namely max_segment_size and and seg_boundary mask. If you create MD device over SCSI, these attributes are zeroed. Problem become when there is over this mapping next device-mapper mapping - queue attributes are set in DM this way: request_queue max_segment_size seg_boundary_mask SCSI 65536 0xffffffff MD RAID1 0 0 LVM 65536 -1 (64bit) Unfortunately bio_add_page (resp. bio_phys_segments) calculates number of physical segments according to these parameters. During the generic_make_request() is segment cout recalculated and can increase bio->bi_phys_segments count over the allowed limit. (After bio_clone() in stack operation.) Thi is specially problem in CCISS driver, where it produce OOPS here BUG_ON(creq->nr_phys_segments > MAXSGENTRIES); (MAXSEGENTRIES is 31 by default.) Sometimes even this command is enough to cause oops: dd iflag=direct if=/dev/<vg>/<lv> of=/dev/null bs=128000 count=10 This command generates bios with 250 sectors, allocated in 32 4k-pages (last page uses only 1024 bytes). For LVM layer, it allocates bio with 31 segments (still OK for CCISS), unfortunatelly on lower layer it is recalculated to 32 segments and this violates CCISS restriction and triggers BUG_ON(). The patch tries to fix it by: * initializing attributes above in queue request constructor blk_queue_make_request() * make sure that blk_queue_stack_limits() inherits setting (DM uses its own function to set the limits because it blk_queue_stack_limits() was introduced later. It should probably switch to use generic stack limit function too.) * sets the default seg_boundary value in one place (blkdev.h) * use this mask as default in DM (instead of -1, which differs in 64bit) Bugs related to this: https://bugzilla.redhat.com/show_bug.cgi?id=471639 http://bugzilla.kernel.org/show_bug.cgi?id=8672 Signed-off-by: Milan Broz <mbroz@redhat.com> Reviewed-by: Alasdair G Kergon <agk@redhat.com> Cc: Neil Brown <neilb@suse.de> Cc: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp> Cc: Tejun Heo <htejun@gmail.com> Cc: Mike Miller <mike.miller@hp.com> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2008-12-03block: internal dequeue shouldn't start timerTejun Heo
blkdev_dequeue_request() and elv_dequeue_request() are equivalent and both start the timeout timer. Barrier code dequeues the original barrier request but doesn't passes the request itself to lower level driver, only broken down proxy requests; however, as the original barrier code goes through the same dequeue path and timeout timer is started on it. If barrier sequence takes long enough, this timer expires but the low level driver has no idea about this request and oops follows. Timeout timer shouldn't have been started on the original barrier request as it never goes through actual IO. This patch unexports elv_dequeue_request(), which has no external user anyway, and makes it operate on elevator proper w/o adding the timer and make blkdev_dequeue_request() call elv_dequeue_request() and add timer. Internal users which don't pass the request to driver - barrier code and end_that_request_last() - are converted to use elv_dequeue_request(). Signed-off-by: Tejun Heo <tj@kernel.org> Cc: Mike Anderson <andmike@linux.vnet.ibm.com> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2008-12-02Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-2.6Linus Torvalds
* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-2.6: (30 commits) MAINTAINERS: add netdev to ATM ATM: horizon, fix hrz_probe fail path pppol2tp: Add missing sock_put() in pppol2tp_release() net: Fix soft lockups/OOM issues w/ unix garbage collector macvlan: don't broadcast PAUSE frames to macvlan devices Phonet: fix oops in phonet_address_del() on non-Phonet device netfilter: ctnetlink: fix GFP_KERNEL allocation under spinlock sungem: Fix PCS_MIICTRL register write in gem_init_phy(). net: make skb_truesize_bug() call WARN() net: hp-plus uses eip_poll net/wireless/reg.c: fix bad WARN_ON in if statement ath5k: disable beacon filter when station is not associated ath5k: fix Security issue in DebugFS part of ath5k ath9k: correct expected max RX buffer size ath9k: Fix SW-IOMMU bounce buffer starvation mac80211 : Fix setting ad-hoc mode and non-ibss channel iwlagn: fix DMA sync phylib: Add Vitesse VSC8221 SGMII PHY rose: zero length frame filtering in af_rose.c bridge: netfilter: fix update_pmtu crash with GRE ...
2008-12-02Merge git://git.kernel.org/pub/scm/linux/kernel/git/bart/ide-2.6Linus Torvalds
* git://git.kernel.org/pub/scm/linux/kernel/git/bart/ide-2.6: alim15x3: fix sparse warning ide: remove dead code from drive_is_ready() ide: fix build for DEBUG_PM ide: respect current DMA setting during resume ide: add SAMSUNG SP0822N with firmware WA100-10 to ivb_list[] amd74xx: workaround unreliable AltStatus register for nVidia controllers ide: fix the ide_release_lock imbalance
2008-12-02Merge git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi-rc-fixes-2.6Linus Torvalds
* git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi-rc-fixes-2.6: [SCSI] stex: switch to block timeout [SCSI] make scsi_eh_try_stu use block timeout [SCSI] megaraid_sas: switch to block timeout [SCSI] ibmvscsi: switch to block timeout [SCSI] aacraid: switch to block timeout [SCSI] zfcp: prevent double decrement on host_busy while being busy [SCSI] zfcp: fix deadlock between wq triggered port scan and ERP [SCSI] zfcp: eliminate race between validation and locking [SCSI] zfcp: verify for correct rport state before scanning for SCSI devs [SCSI] zfcp: returning an ERR_PTR where a NULL value is expected [SCSI] zfcp: Fix opening of wka ports [SCSI] zfcp: fix remote port status check [SCSI] fc_transport: fix old bug on bitflag definitions [SCSI] Fix hang in starved list processing
2008-12-02nfsd: fix vm overcommit crash fix #2Junjiro R. Okajima
The previous patch from Alan Cox ("nfsd: fix vm overcommit crash", commit 731572d39fcd3498702eda4600db4c43d51e0b26) fixed the problem where knfsd crashes on exported shmemfs objects and strict overcommit is set. But the patch forgot supporting the case when CONFIG_SECURITY is disabled. This patch copies a part of his fix which is mainly for detecting a bug earlier. Acked-by: James Morris <jmorris@namei.org> Signed-off-by: Alan Cox <alan@redhat.com> Signed-off-by: Junjiro R. Okajima <hooanon05@yahoo.co.jp> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-12-02amd74xx: workaround unreliable AltStatus register for nVidia controllersBartlomiej Zolnierkiewicz
It seems that on some nVidia controllers using AltStatus register can be unreliable so default to Status register if the PCI device is in Compatibility Mode. In order to achieve this: * Add ide_pci_is_in_compatibility_mode() inline helper to <linux/ide.h>. * Add IDE_HFLAG_BROKEN_ALTSTATUS host flag and set it in amd74xx host driver for nVidia controllers in Compatibility Mode. * Teach actual_try_to_identify() and drive_is_ready() about the new flag. This fixes the regression caused by removal of CONFIG_IDEPCI_SHARE_IRQ config option in 2.6.25 and using AltStatus register unconditionally when available (kernel.org bugs #11659 and #10216). [ Moreover for CONFIG_IDEPCI_SHARE_IRQ=y (which is what most people and distributions use) it never worked correctly. ] Thanks to Remy LABENE and Lars Winterfeld for help with debugging the problem. More info at: http://bugzilla.kernel.org/show_bug.cgi?id=11659 http://bugzilla.kernel.org/show_bug.cgi?id=10216 Reported-by: Remy LABENE <remy.labene@free.fr> Tested-by: Remy LABENE <remy.labene@free.fr> Tested-by: Lars Winterfeld <lars.winterfeld@tu-ilmenau.de> Acked-by: Borislav Petkov <petkovbb@gmail.com> Signed-off-by: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>
2008-12-01lib/idr.c: fix rcu related race with idr_findManfred Spraul
2nd part of the fixes needed for http://bugzilla.kernel.org/show_bug.cgi?id=11796. When the idr tree is either grown or shrunk, then the update to the number of layers and the top pointer were not atomic. This race caused crashes. The attached patch fixes that by replicating the layers counter in each layer, thus idr_find doesn't need idp->layers anymore. Signed-off-by: Manfred Spraul <manfred@colorfullife.com> Cc: Clement Calmels <cboulte@gmail.com> Cc: Nadia Derbey <Nadia.Derbey@bull.net> Cc: Pierre Peiffer <peifferp@gmail.com> Cc: <stable@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-12-01epoll: introduce resource usage limitsDavide Libenzi
It has been thought that the per-user file descriptors limit would also limit the resources that a normal user can request via the epoll interface. Vegard Nossum reported a very simple program (a modified version attached) that can make a normal user to request a pretty large amount of kernel memory, well within the its maximum number of fds. To solve such problem, default limits are now imposed, and /proc based configuration has been introduced. A new directory has been created, named /proc/sys/fs/epoll/ and inside there, there are two configuration points: max_user_instances = Maximum number of devices - per user max_user_watches = Maximum number of "watched" fds - per user The current default for "max_user_watches" limits the memory used by epoll to store "watches", to 1/32 of the amount of the low RAM. As example, a 256MB 32bit machine, will have "max_user_watches" set to roughly 90000. That should be enough to not break existing heavy epoll users. The default value for "max_user_instances" is set to 128, that should be enough too. This also changes the userspace, because a new error code can now come out from EPOLL_CTL_ADD (-ENOSPC). The EMFILE from epoll_create() was already listed, so that should be ok. [akpm@linux-foundation.org: use get_current_user()] Signed-off-by: Davide Libenzi <davidel@xmailserver.org> Cc: Michael Kerrisk <mtk.manpages@gmail.com> Cc: <stable@kernel.org> Cc: Cyrill Gorcunov <gorcunov@gmail.com> Reported-by: Vegard Nossum <vegardno@ifi.uio.no> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-12-01Merge branch 'upstream-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/jgarzik/libata-dev * 'upstream-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jgarzik/libata-dev: libata: blacklist Seagate drives which time out FLUSH_CACHE when used with NCQ [libata] pata_rb532_cf: fix signature of the xfer function [libata] pata_rb532_cf: fix and rename register definitions ata_piix: add borked Tecra M4 to broken suspend list
2008-12-01Merge branch 'for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/roland/infiniband * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/roland/infiniband: IB/mlx4: Fix MTT leakage in resize CQ IB/ehca: Fix problem with generated flush work completions IB/ehca: Change misleading error message on memory hotplug mlx4_core: Save/restore default port IB capability mask
2008-12-01libata: blacklist Seagate drives which time out FLUSH_CACHE when used with NCQTejun Heo
Some recent Seagate harddrives have firmware bug which causes FLUSH CACHE to timeout under certain circumstances if NCQ is being used. This can be worked around by disabling NCQ and fixed by updating the firmware. Implement ATA_HORKAGE_FIRMWARE_UPDATE and blacklist these devices. The wiki page has been updated to contain information on this issue. http://ata.wiki.kernel.org/index.php/Known_issues Signed-off-by: Tejun Heo <tj@kernel.org> Signed-off-by: Jeff Garzik <jgarzik@redhat.com>
2008-11-30Merge master.kernel.org:/home/rmk/linux-2.6-armLinus Torvalds
* master.kernel.org:/home/rmk/linux-2.6-arm: Allow architectures to override copy_user_highpage() [ARM] pxa/palmtx: misc fixes to use generic GPIO API ARM: OMAP: Fixes for suspend / resume GPIO wake-up handling [ARM] pxa/corgi: update default config to exclude tosa from being built [ARM] pxa/pcm990: use negative number for an invalid GPIO in camera data ARM: OMAP: Typo fix for clock_allow_idle ARM: OMAP: Remove broken LCD driver for SX1 [ARM] 5335/1: pxa25x_udc: Fix is_vbus_present to return 1 or 0 [ARM] pxa/MioA701: bluetooth resume fix [ARM] pxa/MioA701: fix memory corruption.
2008-11-30Merge branch 'irq-fixes-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip * 'irq-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: irq.h: fix missing/extra kernel-doc genirq: __irq_set_trigger: change pr_warning to pr_debug irq: fix typo x86: apic honour irq affinity which was set in early boot genirq: fix the affinity setting in setup_irq genirq: keep affinities set from userspace across free/request_irq()
2008-11-30Merge branch 'drm-fixes' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/airlied/drm-2.6 * 'drm-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/airlied/drm-2.6: drm/i915: Save/restore HWS_PGA on suspend/resume drm: move drm vblank initialization/cleanup to driver load/unload drm/i915: execbuffer pins objects, no need to ensure they're still in the GTT drm/i915: Always read pipestat in irq_handler drm/i915: Subtract total pinned bytes from available aperture size drm/i915: Avoid BUG_ONs on VT switch with a wedged chipset. drm/i915: Remove IMR masking during interrupt handler, and restart it if needed. drm/i915: Manage PIPESTAT to control vblank interrupts instead of IMR.
2008-11-30Merge branch 'release' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/lenb/linux-acpi-2.6 * 'release' of git://git.kernel.org/pub/scm/linux/kernel/git/lenb/linux-acpi-2.6: toshiba_acpi: close race in toshiba_acpi driver ACPICA: disable _BIF warning ACPI: delete OSI(Linux) DMI dmesg spam ACPICA: Allow _WAK method to return an Integer ACPI: thinkpad-acpi: fix fan sleep/resume path sony-laptop: printk tweak sony-laptop: brightness regression fix Revert "ACPI: don't enable control method power button as wakeup device when Fixed Power button is used" ACPI suspend: Blacklist boxes that require us to set SCI_EN directly on resume ACPI: scheduling in atomic via acpi_evaluate_integer () ACPI: battery: Convert discharge energy rate to current properly ACPI: EC: count interrupts only if called from interrupt handler.
2008-11-30remove __ARCH_WANT_COMPAT_SYS_PTRACEChristoph Hellwig
All architectures now use the generic compat_sys_ptrace, as should every new architecture that needs 32bit compat (if we'll ever get another). Remove the now superflous __ARCH_WANT_COMPAT_SYS_PTRACE define, and also kill a comment about __ARCH_SYS_PTRACE that was added after __ARCH_SYS_PTRACE was already gone. Signed-off-by: Christoph Hellwig <hch@lst.de> Acked-by: David S. Miller <davem@davemloft.net> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-11-30hotplug_memory_notifier section annotationAl Viro
Same as for hotplug_cpu - we want static notifier_block in there in meminitdata, to avoid false positives whenever it's used. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-11-30meminit section warningsAl Viro
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-11-28mlx4_core: Save/restore default port IB capability maskJack Morgenstein
Commit 7ff93f8b ("mlx4_core: Multiple port type support") introduced support for different port types. As part of that support, SET_PORT is invoked to set the port type during driver startup. However, as a side-effect, for IB ports the invocation of this command also sets the port's capability mask to zero (losing the default value set by FW). To fix this, get the default ib port capabilities (via a MAD_IFC Port Info query) during driver startup, and save them for use in the mlx4_SET_PORT command when setting the port-type to Infiniband. This patch fixes problems with subnet manager (SM) failover such as <https://bugs.openfabrics.org/show_bug.cgi?id=1183>, which occurred because the IsTrapSupported bit in the capability mask was zeroed. Signed-off-by: Jack Morgenstein <jackm@dev.mellanox.co.il> Signed-off-by: Roland Dreier <rolandd@cisco.com>
2008-11-27Allow architectures to override copy_user_highpage()Russell King
With aliasing VIPT cache support, the ARM implementation of clear_user_page() and copy_user_page() sets up a temporary kernel space mapping such that we have the same cache colour as the userspace page. This avoids having to consider any userspace aliases from this operation. However, when highmem is enabled, kmap_atomic() have to setup mappings. The copy_user_highpage() and clear_user_highpage() call these functions before delegating the copies to copy_user_page() and clear_user_page(). The effect of this is that each of the *_user_highpage() functions setup their own kmap mapping, followed by the *_user_page() functions setting up another mapping. This is rather wasteful. Thankfully, copy_user_highpage() can be overriden by architectures by defining __HAVE_ARCH_COPY_USER_HIGHPAGE. However, replacement of clear_user_highpage() is more difficult because its inline definition is not conditional. It seems that you're expected to define __HAVE_ARCH_ALLOC_ZEROED_USER_HIGHPAGE and provide a replacement __alloc_zeroed_user_highpage() implementation instead. The allocation itself is fine, so we don't want to override that. What we really want to do is to override clear_user_highpage() with our own version which doesn't kmap_atomic() unnecessarily. Other VIPT architectures (PARISC and SH) would also like to override this function as well. Acked-by: Hugh Dickins <hugh@veritas.com> Acked-by: James Bottomley <James.Bottomley@HansenPartnership.com> Acked-by: Paul Mundt <lethal@linux-sh.org> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2008-11-27ACPICA: disable _BIF warningLin Ming
A generic work-around from ACPICA is in the queue, but since Linux has a work-around in its battery driver, we can disable this warning now. Allow _BIF method to return an Package with Buffer elements http://bugzilla.kernel.org/show_bug.cgi?id=11822 Signed-off-by: Lin Ming <ming.m.lin@intel.com> Signed-off-by: Len Brown <len.brown@intel.com>
2008-11-27ACPICA: Allow _WAK method to return an IntegerBob Moore
This can happen if the _WAK method returns nothing (as per ACPI 1.0) but does return an integer if the implicit return mechanism is enabled. This is the only method that has this problem, since it is also defined to return a package of two integers (ACPI 1.0b+). In all other cases, if a method returns an object when one was not expected, no warning is issued. Signed-off-by: Bob Moore <robert.moore@intel.com> Signed-off-by: Lin Ming <ming.m.lin@intel.com> Signed-off-by: Len Brown <len.brown@intel.com>
2008-11-26net: Fix soft lockups/OOM issues w/ unix garbage collectordann frazier
This is an implementation of David Miller's suggested fix in: https://bugzilla.redhat.com/show_bug.cgi?id=470201 It has been updated to use wait_event() instead of wait_event_interruptible(). Paraphrasing the description from the above report, it makes sendmsg() block while UNIX garbage collection is in progress. This avoids a situation where child processes continue to queue new FDs over a AF_UNIX socket to a parent which is in the exit path and running garbage collection on these FDs. This contention can result in soft lockups and oom-killing of unrelated processes. Signed-off-by: dann frazier <dannf@hp.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2008-11-24netfilter: xtables: add missing const qualifier to xt_tgchk_paramJan Engelhardt
When entryinfo was a standalone parameter to functions, it used to be "const void *". Put the const back in. Signed-off-by: Jan Engelhardt <jengelh@medozas.de> Signed-off-by: Patrick McHardy <kaber@trash.net> Signed-off-by: David S. Miller <davem@davemloft.net>
2008-11-25drm: move drm vblank initialization/cleanup to driver load/unloadKeith Packard
drm vblank initialization keeps track of the changes in driver-supplied frame counts across vt switch and mode setting, but only if you let it by not tearing down the drm vblank structure. Signed-off-by: Keith Packard <keithp@keithp.com> Signed-off-by: Dave Airlie <airlied@redhat.com>
2008-11-23irq.h: fix missing/extra kernel-docRandy Dunlap
Impact: fix kernel-doc build Fix missing & excess irq.h kernel-doc: Warning(include/linux/irq.h:182): No description found for parameter 'irq' Warning(include/linux/irq.h:182): Excess struct/union/enum/typedef member 'affinity_entry' description in 'irq_desc' Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com> Cc: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-11-23Merge commit 'v2.6.28-rc6' into irq/urgentIngo Molnar
2008-11-21net: Fix memory leak in the proto_register functionCatalin Marinas
If the slub allocator is used, kmem_cache_create() may merge two or more kmem_cache's into one but the cache name pointer is not updated and kmem_cache_name() is no longer guaranteed to return the pointer passed to the former function. This patch stores the kmalloc'ed pointers in the corresponding request_sock_ops and timewait_sock_ops structures. Signed-off-by: Catalin Marinas <catalin.marinas@arm.com> Acked-by: Arnaldo Carvalho de Melo <acme@redhat.com> Reviewed-by: Christoph Lameter <cl@linux-foundation.org> Signed-off-by: David S. Miller <davem@davemloft.net>