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* oom: fix constraint deadlockDavid Rientjes2007-05-07
| | | | | | | | | | | | | | | | | | | | | | | | | | | | Fixes a deadlock in the OOM killer for allocations that are not __GFP_HARDWALL. Before the OOM killer checks for the allocation constraint, it takes callback_mutex. constrained_alloc() iterates through each zone in the allocation zonelist and calls cpuset_zone_allowed_softwall() to determine whether an allocation for gfp_mask is possible. If a zone's node is not in the OOM-triggering task's mems_allowed, it is not exiting, and we did not fail on a __GFP_HARDWALL allocation, cpuset_zone_allowed_softwall() attempts to take callback_mutex to check the nearest exclusive ancestor of current's cpuset. This results in deadlock. We now take callback_mutex after iterating through the zonelist since we don't need it yet. Cc: Andi Kleen <ak@suse.de> Cc: Nick Piggin <npiggin@suse.de> Cc: Christoph Lameter <clameter@engr.sgi.com> Cc: Martin J. Bligh <mbligh@mbligh.org> Signed-off-by: David Rientjes <rientjes@google.com> Cc: <stable@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* mm: fix handling of panic_on_oom when cpusets are in useYasunori Goto2007-05-07
| | | | | | | | | | | | | | | | | | The current panic_on_oom may not work if there is a process using cpusets/mempolicy, because other nodes' memory may remain. But some people want failover by panic ASAP even if they are used. This patch makes new setting for its request. This is tested on my ia64 box which has 3 nodes. Signed-off-by: Yasunori Goto <y-goto@jp.fujitsu.com> Signed-off-by: Benjamin LaHaise <bcrl@kvack.org> Cc: Christoph Lameter <clameter@sgi.com> Cc: Paul Jackson <pj@sgi.com> Cc: Ethan Solomita <solo@google.com> Cc: David Rientjes <rientjes@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* allow oom_adj of saintly processesJoshua N Pritikin2007-05-07
| | | | | | | | | | | If the badness of a process is zero then oom_adj>0 has no effect. This patch makes sure that the oom_adj shift actually increases badness points appropriately. Signed-off-by: Joshua N. Pritikin <jpritikin@pobox.com> Cc: Andrea Arcangeli <andrea@novell.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* fix OOM killing processes wrongly thought MPOL_BINDHugh Dickins2007-04-24
| | | | | | | | | | | | | | | I only have CONFIG_NUMA=y for build testing: surprised when trying a memhog to see lots of other processes killed with "No available memory (MPOL_BIND)". memhog is killed correctly once we initialize nodemask in constrained_alloc(). Signed-off-by: Hugh Dickins <hugh@veritas.com> Acked-by: Christoph Lameter <clameter@sgi.com> Acked-by: William Irwin <bill.irwin@oracle.com> Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: <stable@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* oom: kill all threads that share mm with killed taskDavid Rientjes2007-04-24
| | | | | | | | | | | | | | | | oom_kill_task() calls __oom_kill_task() to OOM kill a selected task. When finding other threads that share an mm with that task, we need to kill those individual threads and not the same one. (Bug introduced by f2a2a7108aa0039ba7a5fe7a0d2ecef2219a7584) Acked-by: William Irwin <bill.irwin@oracle.com> Acked-by: Christoph Lameter <clameter@engr.sgi.com> Cc: Nick Piggin <npiggin@suse.de> Cc: Andrew Morton <akpm@osdl.org> Cc: Andi Kleen <ak@suse.de> Signed-off-by: David Rientjes <rientjes@google.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* [PATCH] oom fix: prevent oom from killing a process with children/sibling ↵Ankita Garg2007-03-16
| | | | | | | | | | | | | | unkillable Looking at oom_kill.c, found that the intention to not kill the selected process if any of its children/siblings has OOM_DISABLE set, is not being met. Signed-off-by: Ankita Garg <ankita@in.ibm.com> Acked-by: Nick Piggin <npiggin@suse.de> Acked-by: William Irwin <wli@holomorphy.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* [PATCH] fix OOM killing of swapoffHugh Dickins2007-01-06
| | | | | | | | | | | | | These days, if you swapoff when there isn't enough memory, OOM killer gives "BUG: scheduling while atomic" and the machine hangs: badness() needs to do its PF_SWAPOFF return after the task_unlock (tasklist_lock is also held here, so p isn't going to be freed: PF_SWAPOFF might get turned off at any moment, but that doesn't really matter). Signed-off-by: Hugh Dickins <hugh@veritas.com> Cc: <stable@kernel.org> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] fix oom killer kills current every time if there is memory-less-node ↵KAMEZAWA Hiroyuki2006-12-30
| | | | | | | | | | | | | | | | | | | | | take2 constrained_alloc(), which is called to detect where oom is from, checks passed zone_list(). If zone_list doesn't include all nodes, it thinks oom is from mempolicy. But there is memory-less-node. memory-less-node's zones are never included in zonelist[]. contstrained_alloc() should get memory_less_node into count. Otherwise, it always thinks 'oom is from mempolicy'. This means that current process dies at any time. This patch fix it. Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Paul Jackson <pj@sgi.com> Cc: Christoph Lameter <clameter@engr.sgi.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] cpuset: rework cpuset_zone_allowed apiPaul Jackson2006-12-13
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Elaborate the API for calling cpuset_zone_allowed(), so that users have to explicitly choose between the two variants: cpuset_zone_allowed_hardwall() cpuset_zone_allowed_softwall() Until now, whether or not you got the hardwall flavor depended solely on whether or not you or'd in the __GFP_HARDWALL gfp flag to the gfp_mask argument. If you didn't specify __GFP_HARDWALL, you implicitly got the softwall version. Unfortunately, this meant that users would end up with the softwall version without thinking about it. Since only the softwall version might sleep, this led to bugs with possible sleeping in interrupt context on more than one occassion. The hardwall version requires that the current tasks mems_allowed allows the node of the specified zone (or that you're in interrupt or that __GFP_THISNODE is set or that you're on a one cpuset system.) The softwall version, depending on the gfp_mask, might allow a node if it was allowed in the nearest enclusing cpuset marked mem_exclusive (which requires taking the cpuset lock 'callback_mutex' to evaluate.) This patch removes the cpuset_zone_allowed() call, and forces the caller to explicitly choose between the hardwall and the softwall case. If the caller wants the gfp_mask to determine this choice, they should (1) be sure they can sleep or that __GFP_HARDWALL is set, and (2) invoke the cpuset_zone_allowed_softwall() routine. This adds another 100 or 200 bytes to the kernel text space, due to the few lines of nearly duplicate code at the top of both cpuset_zone_allowed_* routines. It should save a few instructions executed for the calls that turned into calls of cpuset_zone_allowed_hardwall, thanks to not having to set (before the call) then check (within the call) the __GFP_HARDWALL flag. For the most critical call, from get_page_from_freelist(), the same instructions are executed as before -- the old cpuset_zone_allowed() routine it used to call is the same code as the cpuset_zone_allowed_softwall() routine that it calls now. Not a perfect win, but seems worth it, to reduce this chance of hitting a sleeping with irq off complaint again. Signed-off-by: Paul Jackson <pj@sgi.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] oom: less memdieNick Piggin2006-12-07
| | | | | | | | | | | Don't cause all threads in all other thread groups to gain TIF_MEMDIE otherwise we'll get a thundering herd eating our memory reserve. This may not be the optimal scheme, but it fits our policy of allowing just one TIF_MEMDIE in the system at once. Signed-off-by: Nick Piggin <npiggin@suse.de> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] oom: cleanup messagesNick Piggin2006-12-07
| | | | | | | | Clean up the OOM killer messages to be more consistent. Signed-off-by: Nick Piggin <npiggin@suse.de> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] oom: don't kill unkillable children or siblingsNick Piggin2006-12-07
| | | | | | | | | | Abort the kill if any of our threads have OOM_DISABLE set. Having this test here also prevents any OOM_DISABLE child of the "selected" process from being killed. Signed-off-by: Nick Piggin <npiggin@suse.de> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] OOM killer meets userspace headersAlexey Dobriyan2006-10-20
| | | | | | | | | | | | | | | | | | | Despite mm.h is not being exported header, it does contain one thing which is part of userspace ABI -- value disabling OOM killer for given process. So, a) create and export include/linux/oom.h b) move OOM_DISABLE define there. c) turn bounding values of /proc/$PID/oom_adj into defines and export them too. Note: mass __KERNEL__ removal will be done later. Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com> Cc: Nick Piggin <nickpiggin@yahoo.com.au> Cc: David Woodhouse <dwmw2@infradead.org> Cc: Christoph Hellwig <hch@infradead.org> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] oom: don't kill current when another OOM in progressNick Piggin2006-09-29
| | | | | | | | | | | | | | | A previous patch to allow an exiting task to OOM kill itself (and thereby avoid a little deadlock) introduced a problem. We don't want the PF_EXITING task, even if it is 'current', to access mem reserves if there is already a TIF_MEMDIE process in the system sucking up reserves. Also make the commenting a little bit clearer, and note that our current scheme of effectively single threading the OOM killer is not itself perfect. Signed-off-by: Nick Piggin <npiggin@suse.de> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] oom_kill_task(): cleanup ->mm checksOleg Nesterov2006-09-29
| | | | | | | | | | | - It is not possible to have task->mm == &init_mm. - task_lock() buys nothing for 'if (!p->mm)' check. Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru> Cc: Nick Piggin <nickpiggin@yahoo.com.au> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] select_bad_process(): cleanup 'releasing' checkOleg Nesterov2006-09-29
| | | | | | | | | No logic changes, but imho easier to read. Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru> Acked-by: Nick Piggin <npiggin@suse.de> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] select_bad_process(): kill a bogus PF_DEAD/TASK_DEAD checkOleg Nesterov2006-09-29
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The only one usage of TASK_DEAD outside of last schedule path, select_bad_process: for_each_task(p) { if (!p->mm) continue; ... if (p->state == TASK_DEAD) continue; ... TASK_DEAD state is set at the end of do_exit(), this means that p->mm was already set == NULL by exit_mm(), so this task was already rejected by 'if (!p->mm)' above. Note also that the caller holds tasklist_lock, this means that p can't pass exit_notify() and then set TASK_DEAD when p->mm != NULL. Also, remove open-coded is_init(). Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru> Cc: Ingo Molnar <mingo@elte.hu> Cc: Nick Piggin <nickpiggin@yahoo.com.au> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] introduce TASK_DEAD stateOleg Nesterov2006-09-29
| | | | | | | | | | | | | | | | I am not sure about this patch, I am asking Ingo to take a decision. task_struct->state == EXIT_DEAD is a very special case, to avoid a confusion it makes sense to introduce a new state, TASK_DEAD, while EXIT_DEAD should live only in ->exit_state as documented in sched.h. Note that this state is not visible to user-space, get_task_state() masks off unsuitable states. Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru> Cc: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] kill PF_DEAD flagOleg Nesterov2006-09-29
| | | | | | | | | | After the previous change (->flags & PF_DEAD) <=> (->state == EXIT_DEAD), we don't need PF_DEAD any longer. Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru> Cc: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] pidspace: is_init()Sukadev Bhattiprolu2006-09-29
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This is an updated version of Eric Biederman's is_init() patch. (http://lkml.org/lkml/2006/2/6/280). It applies cleanly to 2.6.18-rc3 and replaces a few more instances of ->pid == 1 with is_init(). Further, is_init() checks pid and thus removes dependency on Eric's other patches for now. Eric's original description: There are a lot of places in the kernel where we test for init because we give it special properties. Most significantly init must not die. This results in code all over the kernel test ->pid == 1. Introduce is_init to capture this case. With multiple pid spaces for all of the cases affected we are looking for only the first process on the system, not some other process that has pid == 1. Signed-off-by: Eric W. Biederman <ebiederm@xmission.com> Signed-off-by: Sukadev Bhattiprolu <sukadev@us.ibm.com> Cc: Dave Hansen <haveblue@us.ibm.com> Cc: Serge Hallyn <serue@us.ibm.com> Cc: Cedric Le Goater <clg@fr.ibm.com> Cc: <lxc-devel@lists.sourceforge.net> Acked-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] NUMA: Add zone_to_nid functionChristoph Lameter2006-09-26
| | | | | | | | | | | There are many places where we need to determine the node of a zone. Currently we use a difficult to read sequence of pointer dereferencing. Put that into an inline function and use throughout VM. Maybe we can find a way to optimize the lookup in the future. Signed-off-by: Christoph Lameter <clameter@sgi.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] oom-kill: update comments to reflect current codeRam Gupta2006-09-26
| | | | | | | | Update the comments for __oom_kill_task() to reflect the code changes. Signed-off-by: Ram Gupta <r.gupta@astronautics.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] oom: more printkNick Piggin2006-09-26
| | | | | | | | | Print the name of the task invoking the OOM killer. Could make debugging easier. Signed-off-by: Nick Piggin <npiggin@suse.de> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] oom: kthread infinite loop fixNick Piggin2006-09-26
| | | | | | | | | | Skip kernel threads, rather than having them return 0 from badness. Theoretically, badness might truncate all results to 0, thus a kernel thread might be picked first, causing an infinite loop. Signed-off-by: Nick Piggin <npiggin@suse.de> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] oom: swapoff tasks tweakNick Piggin2006-09-26
| | | | | | | | | | PF_SWAPOFF processes currently cause select_bad_process to return straight away. Instead, give them high priority, so we will kill them first, however we also first ensure no parallel OOM kills are happening at the same time. Signed-off-by: Nick Piggin <npiggin@suse.de> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] oom: handle oom_disable exitingNick Piggin2006-09-26
| | | | | | | | | | | | | | | Having the oomkilladj == OOM_DISABLE check before the releasing check means that oomkilladj == OOM_DISABLE tasks exiting will not stop the OOM killer. Moving the test down will give the desired behaviour. Also: it will allow them to "OOM-kill" themselves if they are exiting. As per the previous patch, this is required to prevent OOM killer deadlocks (and they don't actually get killed, because they're already exiting -- they're simply allowed access to memory reserves). Signed-off-by: Nick Piggin <npiggin@suse.de> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] oom: handle current exitingNick Piggin2006-09-26
| | | | | | | | | | | | | | | | | | | If current *is* exiting, it should actually be allowed to access reserved memory rather than OOM kill something else. Can't do this via a straight check in page_alloc.c because that would allow multiple tasks to use up reserves. Instead cause current to OOM-kill itself which will mark it as TIF_MEMDIE. The current procedure of simply aborting the OOM-kill if a task is exiting can lead to OOM deadlocks. In the case of killing a PF_EXITING task, don't make a lot of noise about it. This becomes more important in future patches, where we can "kill" OOM_DISABLE tasks. Signed-off-by: Nick Piggin <npiggin@suse.de> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] oom: cpuset hintNick Piggin2006-09-26
| | | | | | | | | | | | | cpuset_excl_nodes_overlap does not always indicate that killing a task will not free any memory we for us. For example, we may be asking for an allocation from _anywhere_ in the machine, or the task in question may be pinning memory that is outside its cpuset. Fix this by just causing cpuset_excl_nodes_overlap to reduce the badness rather than disallow it. Signed-off-by: Nick Piggin <npiggin@suse.de> Acked-by: Paul Jackson <pj@sgi.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] out of memory notifierMartin Schwidefsky2006-09-26
| | | | | | | | | | | | | | | | | | Add a notifer chain to the out of memory killer. If one of the registered callbacks could release some memory, do not kill the process but return and retry the allocation that forced the oom killer to run. The purpose of the notifier is to add a safety net in the presence of memory ballooners. If the resource manager inflated the balloon to a size where memory allocations can not be satisfied anymore, it is better to deflate the balloon a bit instead of killing processes. The implementation for the s390 ballooner is included. [akpm@osdl.org: cleanups] Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] sched: cleanup, remove task_t, convert to struct task_structIngo Molnar2006-07-03
| | | | | | | | | | | | cleanup: remove task_t and convert all the uses to struct task_struct. I introduced it for the scheduler anno and it was a mistake. Conversion was mostly scripted, the result was reviewed and all secondary whitespace and style impact (if any) was fixed up by hand. Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] mm: fix typos in comments in mm/oom_kill.cDave Peterson2006-06-23
| | | | | | | | This fixes a few typos in the comments in mm/oom_kill.c. Signed-off-by: David S. Peterson <dsp@llnl.gov> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] support for panic at OOMKAMEZAWA Hiroyuki2006-06-23
| | | | | | | | | | | | | | | | | This patch adds panic_on_oom sysctl under sys.vm. When sysctl vm.panic_on_oom = 1, the kernel panics intead of killing rogue processes. And if vm.panic_on_oom is 0 the kernel will do oom_kill() in the same way as it does today. Of course, the default value is 0 and only root can modifies it. In general, oom_killer works well and kill rogue processes. So the whole system can survive. But there are environments where panic is preferable rather than kill some processes. Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] mm: fix mm_struct reference counting bugs in mm/oom_kill.cDave Peterson2006-04-19
| | | | | | | | | Fix oom_kill_task() so it doesn't call mmput() (which may sleep) while holding tasklist_lock. Signed-off-by: David S. Peterson <dsp@llnl.gov> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] oom-kill: mm locking fixAndrew Morton2006-04-19
| | | | | | | | | | | Dave Peterson <dsp@llnl.gov> points out that badness() is playing with mm_structs without taking a reference on them. mmput() can sleep, so taking a reference here (inside tasklist_lock) is hard. Fix it up via task_lock() instead. Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] out_of_memory() locking fixAndrew Morton2006-03-02
| | | | | | | | | | | I seem to have lost this read_unlock(). While we're there, let's turn that interruptible sleep unto uninterruptible, so we don't get a busywait if signal_pending(). (Again. We seem to have a habit of doing this). Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] out_of_memory(): use of uninitialisedAndrew Morton2006-02-28
| | | | | | | | Under some circumstances `points' can get printed before it's initialised. Spotted by Carlos Martin <carlos@cmartin.tk>. Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] Terminate process that fails on a constrained allocationChristoph Lameter2006-02-20
| | | | | | | | | | | | | | | | | | | | | | | | | | | | Some allocations are restricted to a limited set of nodes (due to memory policies or cpuset constraints). If the page allocator is not able to find enough memory then that does not mean that overall system memory is low. In particular going postal and more or less randomly shooting at processes is not likely going to help the situation but may just lead to suicide (the whole system coming down). It is better to signal to the process that no memory exists given the constraints that the process (or the configuration of the process) has placed on the allocation behavior. The process may be killed but then the sysadmin or developer can investigate the situation. The solution is similar to what we do when running out of hugepages. This patch adds a check before we kill processes. At that point performance considerations do not matter much so we just scan the zonelist and reconstruct a list of nodes. If the list of nodes does not contain all online nodes then this is a constrained allocation and we should kill the current process. Signed-off-by: Christoph Lameter <clameter@sgi.com> Cc: Nick Piggin <nickpiggin@yahoo.com.au> Cc: Andi Kleen <ak@muc.de> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] OOM kill: children accountingKurt Garloff2006-02-20
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | In the badness() calculation, there's currently this piece of code: /* * Processes which fork a lot of child processes are likely * a good choice. We add the vmsize of the children if they * have an own mm. This prevents forking servers to flood the * machine with an endless amount of children */ list_for_each(tsk, &p->children) { struct task_struct *chld; chld = list_entry(tsk, struct task_struct, sibling); if (chld->mm = p->mm && chld->mm) points += chld->mm->total_vm; } The intention is clear: If some server (apache) keeps spawning new children and we run OOM, we want to kill the father rather than picking a child. This -- to some degree -- also helps a bit with getting fork bombs under control, though I'd consider this a desirable side-effect rather than a feature. There's one problem with this: No matter how many or few children there are, if just one of them misbehaves, and all others (including the father) do everything right, we still always kill the whole family. This hits in real life; whether it's javascript in konqueror resulting in kdeinit (and thus the whole KDE session) being hit or just a classical server that spawns children. Sidenote: The killer does kill all direct children as well, not only the selected father, see oom_kill_process(). The idea in attached patch is that we do want to account the memory consumption of the (direct) children to the father -- however not fully. This maintains the property that fathers with too many children will still very likely be picked, whereas a single misbehaving child has the chance to be picked by the OOM killer. In the patch I account only half (rounded up) of the children's vm_size to the parent. This means that if one child eats more mem than the rest of the family, it will be picked, otherwise it's still the father and thus the whole family that gets selected. This is heuristics -- we could debate whether accounting for a fourth would be better than for half of it. Or -- if people would consider it worth the trouble -- make it a sysctl. For now I sticked to accounting for half, which should IMHO be a significant improvement. The patch does one more thing: As users tend to be irritated by the choice of killed processes (mainly because the children are killed first, despite some of them having a very low OOM score), I added some more output: The selected (father) process will be reported first and it's oom_score printed to syslog. Description: Only account for half of children's vm size in oom score calculation This should still give the parent enough point in case of fork bombs. If any child however has more than 50% of the vm size of all children together, it'll get a higher score and be elected. This patch also makes the kernel display the oom_score. Signed-off-by: Kurt Garloff <garloff@suse.de> Cc: Rik van Riel <riel@redhat.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] dump_stack() in oom handlerAndrew Morton2006-02-01
| | | | | | | Sometimes it's nice to know who's calling. Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] cpuset oom lock fixPaul Jackson2006-01-14
| | | | | | | | | | | | | | | | | | | | | | | | | The problem, reported in: http://bugzilla.kernel.org/show_bug.cgi?id=5859 and by various other email messages and lkml posts is that the cpuset hook in the oom (out of memory) code can try to take a cpuset semaphore while holding the tasklist_lock (a spinlock). One must not sleep while holding a spinlock. The fix seems easy enough - move the cpuset semaphore region outside the tasklist_lock region. This required a few lines of mechanism to implement. The oom code where the locking needs to be changed does not have access to the cpuset locks, which are internal to kernel/cpuset.c only. So I provided a couple more cpuset interface routines, available to the rest of the kernel, which simple take and drop the lock needed here (cpusets callback_sem). Signed-off-by: Paul Jackson <pj@sgi.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] Optimise oom kill of current taskKirill Korotaev2006-01-08
| | | | | | | | | | When oom_killer kills current there's no need to call schedule_timeout_interruptible() since task must die ASAP. Signed-Off-By: Pavel Emelianov <xemul@sw.ru> Signed-Off-By: Kirill Korotaev <dev@openvz.org> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] gfp flags annotations - part 1Al Viro2005-10-08
| | | | | | | | | | | | - added typedef unsigned int __nocast gfp_t; - replaced __nocast uses for gfp flags with gfp_t - it gives exactly the same warnings as far as sparse is concerned, doesn't change generated code (from gcc point of view we replaced unsigned int with typedef) and documents what's going on far better. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] mm: fix-up schedule_timeout() usageNishanth Aravamudan2005-09-10
| | | | | | | | | Use schedule_timeout_{,un}interruptible() instead of set_current_state()/schedule_timeout() to reduce kernel size. Signed-off-by: Nishanth Aravamudan <nacc@us.ibm.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] cpusets: confine oom_killer to mem_exclusive cpusetPaul Jackson2005-09-07
| | | | | | | | | | | | | | | | | | | | | Now the real motivation for this cpuset mem_exclusive patch series seems trivial. This patch keeps a task in or under one mem_exclusive cpuset from provoking an oom kill of a task under a non-overlapping mem_exclusive cpuset. Since only interrupt and GFP_ATOMIC allocations are allowed to escape mem_exclusive containment, there is little to gain from oom killing a task under a non-overlapping mem_exclusive cpuset, as almost all kernel and user memory allocation must come from disjoint memory nodes. This patch enables configuring a system so that a runaway job under one mem_exclusive cpuset cannot cause the killing of a job in another such cpuset that might be using very high compute and memory resources for a prolonged time. Signed-off-by: Paul Jackson <pj@sgi.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] cpusets: oom_kill tweaksPaul Jackson2005-09-07
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch series extends the use of the cpuset attribute 'mem_exclusive' to support cpuset configurations that: 1) allow GFP_KERNEL allocations to come from a potentially larger set of memory nodes than GFP_USER allocations, and 2) can constrain the oom killer to tasks running in cpusets in a specified subtree of the cpuset hierarchy. Here's an example usage scenario. For a few hours or more, a large NUMA system at a University is to be divided in two halves, with a bunch of student jobs running in half the system under some form of batch manager, and with a big research project running in the other half. Each of the student jobs is placed in a small cpuset, but should share the classic Unix time share facilities, such as buffered pages of files in /bin and /usr/lib. The big research project wants no interference whatsoever from the student jobs, and has highly tuned, unusual memory and i/o patterns that intend to make full use of all the main memory on the nodes available to it. In this example, we have two big sibling cpusets, one of which is further divided into a more dynamic set of child cpusets. We want kernel memory allocations constrained by the two big cpusets, and user allocations constrained by the smaller child cpusets where present. And we require that the oom killer not operate across the two halves of this system, or else the first time a student job runs amuck, the big research project will likely be first inline to get shot. Tweaking /proc/<pid>/oom_adj is not ideal -- if the big research project really does run amuck allocating memory, it should be shot, not some other task outside the research projects mem_exclusive cpuset. I propose to extend the use of the 'mem_exclusive' flag of cpusets to manage such scenarios. Let memory allocations for user space (GFP_USER) be constrained by a tasks current cpuset, but memory allocations for kernel space (GFP_KERNEL) by constrained by the nearest mem_exclusive ancestor of the current cpuset, even though kernel space allocations will still _prefer_ to remain within the current tasks cpuset, if memory is easily available. Let the oom killer be constrained to consider only tasks that are in overlapping mem_exclusive cpusets (it won't help much to kill a task that normally cannot allocate memory on any of the same nodes as the ones on which the current task can allocate.) The current constraints imposed on setting mem_exclusive are unchanged. A cpuset may only be mem_exclusive if its parent is also mem_exclusive, and a mem_exclusive cpuset may not overlap any of its siblings memory nodes. This patch was presented on linux-mm in early July 2005, though did not generate much feedback at that time. It has been built for a variety of arch's using cross tools, and built, booted and tested for function on SN2 (ia64). There are 4 patches in this set: 1) Some minor cleanup, and some improvements to the code layout of one routine to make subsequent patches cleaner. 2) Add another GFP flag - __GFP_HARDWALL. It marks memory requests for USER space, which are tightly confined by the current tasks cpuset. 3) Now memory requests (such as KERNEL) that not marked HARDWALL can if short on memory, look in the potentially larger pool of memory defined by the nearest mem_exclusive ancestor cpuset of the current tasks cpuset. 4) Finally, modify the oom killer to skip any task whose mem_exclusive cpuset doesn't overlap ours. Patch (1), the one time I looked on an SN2 (ia64) build, actually saved 32 bytes of kernel text space. Patch (2) has no affect on the size of kernel text space (it just adds a preprocessor flag). Patches (3) and (4) added about 600 bytes each of kernel text space, mostly in kernel/cpuset.c, which matters only if CONFIG_CPUSET is enabled. This patch: This patch applies a few comment and code cleanups to mm/oom_kill.c prior to applying a few small patches to improve cpuset management of memory placement. The comment changed in oom_kill.c was seriously misleading. The code layout change in select_bad_process() makes room for adding another condition on which a process can be spared the oom killer (see the subsequent cpuset_nodes_overlap patch for this addition). Also a couple typos and spellos that bugged me, while I was here. This patch should have no material affect. Signed-off-by: Paul Jackson <pj@sgi.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] mm: quieten OOM killer noiseAnton Blanchard2005-07-07
| | | | | | | | | | | | | | | | | We now print statistics when invoking the OOM killer, however this information is not rate limited and you can get into situations where the console is continually spammed. For example, when a task is exiting the OOM killer will simply return (waiting for that task to exit and clear up memory). If the VM continually calls back into the OOM killer we get thousands of copies of show_mem() on the console. Use printk_ratelimit() to quieten it. Signed-off-by: Anton Blanchard <anton@samba.org> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] print order information when OOM killingMarcelo Tosatti2005-07-07
| | | | | | | Dump the current allocation order when OOM killing. Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] add OOM debugJanet Morgan2005-06-21
| | | | | | | | | | | | This patch provides more debug info when the system is OOM. It displays memory stats (basically sysrq-m info) from __alloc_pages() when page allocation fails and during OOM kill. Thanks to Dave Jones for coming up with the idea. Signed-off-by: Janet Morgan <janetmor@us.ibm.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] oom-killer disable for iscsi/lvm2/multipath userland critical sectionsAndrea Arcangeli2005-04-16
| | | | | | | | | | | | | iscsi/lvm2/multipath needs guaranteed protection from the oom-killer, so make the magical value of -17 in /proc/<pid>/oom_adj defeat the oom-killer altogether. (akpm: we still need to document oom_adj and friends in Documentation/filesystems/proc.txt!) Signed-off-by: Andrea Arcangeli <andrea@suse.de> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* Linux-2.6.12-rc2v2.6.12-rc2Linus Torvalds2005-04-16
Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
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