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2009-09-02sched: Provide iowait countersArjan van de Ven
For counting how long an application has been waiting for (disk) IO, there currently is only the HZ sample driven information available, while for all other counters in this class, a high resolution version is available via CONFIG_SCHEDSTATS. In order to make an improved bootchart tool possible, we also need a higher resolution version of the iowait time. This patch below adds this scheduler statistic to the kernel. Signed-off-by: Arjan van de Ven <arjan@linux.intel.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <4A64B813.1080506@linux.intel.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-09-02Merge commit 'v2.6.31-rc8' into sched/coreIngo Molnar
Merge reason: bump from rc5 to rc8, but also pick up TP_perf_assign() API, a patch will be queued that depends on it. Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-08-29rcu: Changes from reviews: avoid casts, fix/add warnings, improve commentsPaul E. McKenney
Changes suggested by review comments from Josh Triplett and Mathieu Desnoyers. Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Acked-by: Josh Triplett <josh@joshtriplett.org> Acked-by: Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca> Cc: laijs@cn.fujitsu.com Cc: dipankar@in.ibm.com Cc: akpm@linux-foundation.org Cc: dvhltc@us.ibm.com Cc: niv@us.ibm.com Cc: peterz@infradead.org Cc: rostedt@goodmis.org LKML-Reference: <20090827220012.GA30525@linux.vnet.ibm.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-08-29rcu: Create rcutree plugins to handle hotplug CPU for multi-level treesPaul E. McKenney
When offlining CPUs from a multi-level tree, there is the possibility of offlining the last CPU from a given node when there are preempted RCU read-side critical sections that started life on one of the CPUs on that node. In this case, the corresponding tasks will be enqueued via the task_struct's rcu_node_entry list_head onto one of the rcu_node's blocked_tasks[] lists. These tasks need to be moved somewhere else so that they will prevent the current grace period from ending. That somewhere is the root rcu_node. Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: laijs@cn.fujitsu.com Cc: dipankar@in.ibm.com Cc: akpm@linux-foundation.org Cc: mathieu.desnoyers@polymtl.ca Cc: josht@linux.vnet.ibm.com Cc: dvhltc@us.ibm.com Cc: niv@us.ibm.com Cc: peterz@infradead.org Cc: rostedt@goodmis.org LKML-Reference: <20090827215816.GA30472@linux.vnet.ibm.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-08-23rcu: Remove CONFIG_PREEMPT_RCUPaul E. McKenney
Now that CONFIG_TREE_PREEMPT_RCU is in place, there is no further need for CONFIG_PREEMPT_RCU. Remove it, along with whatever subtle bugs it may (or may not) contain. Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: laijs@cn.fujitsu.com Cc: dipankar@in.ibm.com Cc: akpm@linux-foundation.org Cc: mathieu.desnoyers@polymtl.ca Cc: josht@linux.vnet.ibm.com Cc: dvhltc@us.ibm.com Cc: niv@us.ibm.com Cc: peterz@infradead.org Cc: rostedt@goodmis.org LKML-Reference: <125097461396-git-send-email-> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-08-23rcu: Merge preemptable-RCU functionality into hierarchical RCUPaul E. McKenney
Create a kernel/rcutree_plugin.h file that contains definitions for preemptable RCU (or, under the #else branch of the #ifdef, empty definitions for the classic non-preemptable semantics). These definitions fit into plugins defined in kernel/rcutree.c for this purpose. This variant of preemptable RCU uses a new algorithm whose read-side expense is roughly that of classic hierarchical RCU under CONFIG_PREEMPT. This new algorithm's update-side expense is similar to that of classic hierarchical RCU, and, in absence of read-side preemption or blocking, is exactly that of classic hierarchical RCU. Perhaps more important, this new algorithm has a much simpler implementation, saving well over 1,000 lines of code compared to mainline's implementation of preemptable RCU, which will hopefully be retired in favor of this new algorithm. The simplifications are obtained by maintaining per-task nesting state for running tasks, and using a simple lock-protected algorithm to handle accounting when tasks block within RCU read-side critical sections, making use of lessons learned while creating numerous user-level RCU implementations over the past 18 months. Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: laijs@cn.fujitsu.com Cc: dipankar@in.ibm.com Cc: akpm@linux-foundation.org Cc: mathieu.desnoyers@polymtl.ca Cc: josht@linux.vnet.ibm.com Cc: dvhltc@us.ibm.com Cc: niv@us.ibm.com Cc: peterz@infradead.org Cc: rostedt@goodmis.org LKML-Reference: <12509746134003-git-send-email-> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-08-20Merge branch 'master' into nextJames Morris
Conflicts: security/Kconfig Manual fix. Signed-off-by: James Morris <jmorris@namei.org>
2009-08-18mm: revert "oom: move oom_adj value"KOSAKI Motohiro
The commit 2ff05b2b (oom: move oom_adj value) moveed the oom_adj value to the mm_struct. It was a very good first step for sanitize OOM. However Paul Menage reported the commit makes regression to his job scheduler. Current OOM logic can kill OOM_DISABLED process. Why? His program has the code of similar to the following. ... set_oom_adj(OOM_DISABLE); /* The job scheduler never killed by oom */ ... if (vfork() == 0) { set_oom_adj(0); /* Invoked child can be killed */ execve("foo-bar-cmd"); } .... vfork() parent and child are shared the same mm_struct. then above set_oom_adj(0) doesn't only change oom_adj for vfork() child, it's also change oom_adj for vfork() parent. Then, vfork() parent (job scheduler) lost OOM immune and it was killed. Actually, fork-setting-exec idiom is very frequently used in userland program. We must not break this assumption. Then, this patch revert commit 2ff05b2b and related commit. Reverted commit list --------------------- - commit 2ff05b2b4e (oom: move oom_adj value from task_struct to mm_struct) - commit 4d8b9135c3 (oom: avoid unnecessary mm locking and scanning for OOM_DISABLE) - commit 8123681022 (oom: only oom kill exiting tasks with attached memory) - commit 933b787b57 (mm: copy over oom_adj value at fork time) Signed-off-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Cc: Paul Menage <menage@google.com> Cc: David Rientjes <rientjes@google.com> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Rik van Riel <riel@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Nick Piggin <npiggin@suse.de> Cc: Mel Gorman <mel@csn.ul.ie> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-08-18sched, task_struct: stack_canary is not needed without CC_STACKPROTECTORHiroshi Shimamoto
The field stack_canary is only used with CC_STACKPROTECTOR. This patch reduces task_struct size without CC_STACKPROTECTOR. Signed-off-by: Hiroshi Shimamoto <h-shimamoto@ct.jp.nec.com> LKML-Reference: <4A8A44CA.2020701@ct.jp.nec.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-08-06Merge branch 'master' into nextJames Morris
2009-08-03itimers: Fix periodic tics precisionStanislaw Gruszka
Measure ITIMER_PROF and ITIMER_VIRT timers interval error between real ticks and requested by user. Take it into account when scheduling next tick. This patch introduce possibility where time between two consecutive tics is smaller then requested interval, it preserve however dependency that n tick is generated not earlier than n*interval time - counting from the beginning of periodic signal generation. Signed-off-by: Stanislaw Gruszka <sgruszka@redhat.com> Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Acked-by: Thomas Gleixner <tglx@linutronix.de> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Paul Mackerras <paulus@samba.org> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> LKML-Reference: <1248862529-6063-3-git-send-email-sgruszka@redhat.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-08-03itimers: Merge ITIMER_VIRT and ITIMER_PROFStanislaw Gruszka
Both cpu itimers have same data flow in the few places, this patch make unification of code related with VIRT and PROF itimers. Signed-off-by: Stanislaw Gruszka <sgruszka@redhat.com> Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Acked-by: Thomas Gleixner <tglx@linutronix.de> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Paul Mackerras <paulus@samba.org> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> LKML-Reference: <1248862529-6063-2-git-send-email-sgruszka@redhat.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-08-02sched: Enhance the pre/post scheduling logicGregory Haskins
We currently have an explicit "needs_post" vtable method which returns a stack variable for whether we should later run post-schedule. This leads to an awkward exchange of the variable as it bubbles back up out of the context switch. Peter Zijlstra observed that this information could be stored in the run-queue itself instead of handled on the stack. Therefore, we revert to the method of having context_switch return void, and update an internal rq->post_schedule variable when we require further processing. In addition, we fix a race condition where we try to access current->sched_class without holding the rq->lock. This is technically racy, as the sched-class could change out from under us. Instead, we reference the per-rq post_schedule variable with the runqueue unlocked, but with preemption disabled to see if we need to reacquire the rq->lock. Finally, we clean the code up slightly by removing the #ifdef CONFIG_SMP conditionals from the schedule() call, and implement some inline helper functions instead. This patch passes checkpatch, and rt-migrate. Signed-off-by: Gregory Haskins <ghaskins@novell.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <20090729150422.17691.55590.stgit@dev.haskins.net> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-08-02Merge branch 'sched/urgent' into sched/coreIngo Molnar
Merge reason: avoid upcoming patch conflict. Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-08-02sched: Fix cond_resched_lock() in !CONFIG_PREEMPTFrederic Weisbecker
The might_sleep() test inside cond_resched_lock() assumes the spinlock is held and then preemption is disabled. This is true with CONFIG_PREEMPT but the preempt_count() doesn't change otherwise. Check by starting from the appropriate preempt offset depending on the config. Reported-by: Li Zefan <lizf@cn.fujitsu.com> Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <1248458723-12146-1-git-send-email-fweisbec@gmail.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-07-18sched: Convert the only user of cond_resched_bkl to use cond_resched()Frederic Weisbecker
fs/locks.c:flock_lock_file() is the only user of cond_resched_bkl() This helper doesn't do anything more than cond_resched(). The latter naming is enough to explain that we are rescheduling if needed. The bkl suffix suggests another semantics but it's actually a synonym of cond_resched(). Reported-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <1247725694-6082-7-git-send-email-fweisbec@gmail.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-07-18sched: Pull up the might_sleep() check into cond_resched()Frederic Weisbecker
might_sleep() is called late-ish in cond_resched(), after the need_resched()/preempt enabled/system running tests are checked. It's better to check the sleeps while atomic earlier and not depend on some environment datas that reduce the chances to detect a problem. Also define cond_resched_*() helpers as macros, so that the FILE/LINE reported in the sleeping while atomic warning displays the real origin and not sched.h Changes in v2: - Call __might_sleep() directly instead of might_sleep() which may call cond_resched() - Turn cond_resched() into a macro so that the file:line couple reported refers to the caller of cond_resched() and not __cond_resched() itself. Changes in v3: - Also propagate this __might_sleep() pull up to cond_resched_lock() and cond_resched_softirq() Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <1247725694-6082-6-git-send-email-fweisbec@gmail.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-07-18sched: Remove the CONFIG_PREEMPT_BKL case definition of cond_resched()Frederic Weisbecker
CONFIG_PREEMPT_BKL doesn't exist anymore. So remove this config-on case definition of cond_resched(). Reported-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Reported-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <1247725694-6082-5-git-send-email-fweisbec@gmail.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-07-18Merge branch 'linus' into sched/coreIngo Molnar
Merge reason: branch had an old upstream base (-rc1-ish), but also merge to avoid a conflict. Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-07-18sched: fix nr_uninterruptible accounting of frozen tasks reallyThomas Gleixner
commit e3c8ca8336 (sched: do not count frozen tasks toward load) broke the nr_uninterruptible accounting on freeze/thaw. On freeze the task is excluded from accounting with a check for (task->flags & PF_FROZEN), but that flag is cleared before the task is thawed. So while we prevent that the task with state TASK_UNINTERRUPTIBLE is accounted to nr_uninterruptible on freeze we decrement nr_uninterruptible on thaw. Use a separate flag which is handled by the freezing task itself. Set it before calling the scheduler with TASK_UNINTERRUPTIBLE state and clear it after we return from frozen state. Cc: <stable@kernel.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2009-07-17kernel: rename is_single_threaded(task) to current_is_single_threaded(void)Oleg Nesterov
- is_single_threaded(task) is not safe unless task == current, we can't use task->signal or task->mm. - it doesn't make sense unless task == current, the task can fork right after the check. Rename it to current_is_single_threaded() and kill the argument. Signed-off-by: Oleg Nesterov <oleg@redhat.com> Acked-by: David Howells <dhowells@redhat.com> Signed-off-by: James Morris <jmorris@namei.org>
2009-07-10sched: optimize cond_resched()Peter Zijlstra
Optimize cond_resched() by removing one conditional. Currently cond_resched() checks system_state == SYSTEM_RUNNING in order to avoid scheduling before the scheduler is running. We can however, as per suggestion of Matt, use PREEMPT_ACTIVE to accomplish that very same. Suggested-by: Matt Mackall <mpm@selenic.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Acked-by: Matt Mackall <mpm@selenic.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-07-10sched: INIT_PREEMPT_COUNTPeter Zijlstra
Pull the initial preempt_count value into a single definition site. Maintainers for: alpha, ia64 and m68k, please have a look, your arch code is funny. The header magic is a bit odd, but similar to the KERNEL_DS one, CPP waits with expanding these macros until the INIT_THREAD_INFO macro itself is expanded, which is in arch/*/kernel/init_task.c where we've already included sched.h so we're good. Cc: tony.luck@intel.com Cc: rth@twiddle.net Cc: geert@linux-m68k.org Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Acked-by: Matt Mackall <mpm@selenic.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-06-30elf: limit max map count to safe valueKAMEZAWA Hiroyuki
With ELF, at generating coredump, some more headers other than used vmas are added. When max_map_count == 65536, a core generated by following kinds of code can be unreadable because the number of ELF's program header is written in 16bit in Ehdr (please see elf.h) and the number overflows. == ... = mmap(); (munmap, mprotect, etc...) if (failed) abort(); == This can happen in mmap/munmap/mprotect/etc...which calls split_vma(). I think 65536 is not safe as _default_ and reduce it to 65530 is good for avoiding unexpected corrupted core. Anyway, max_map_count can be enlarged by sysctl if a user is brave.. Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Hugh Dickins <hugh.dickins@tiscali.co.uk> Cc: Jakub Jelinek <jakub@redhat.com> Acked-by: Roland McGrath <roland@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-06-29Merge branch 'linus' into sched/coreIngo Molnar
Merge reason: we will merge a dependent patch. Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-06-18pids: clean up find_task_by_pid variantsChristoph Hellwig
find_task_by_pid_type_ns is only used to implement find_task_by_vpid and find_task_by_pid_ns, but both of them pass PIDTYPE_PID as first argument. So just fold find_task_by_pid_type_ns into find_task_by_pid_ns and use find_task_by_pid_ns to implement find_task_by_vpid. While we're at it also remove the exports for find_task_by_pid_ns and find_task_by_vpid - we don't have any modular callers left as the only modular caller of he old pre pid namespace find_task_by_pid (gfs2) was switched to pid_task which operates on a struct pid pointer instead of a pid_t. Given the confusion about pid_t values vs namespace that's generally the better option anyway and I think we're better of restricting modules to do it that way. Signed-off-by: Christoph Hellwig <hch@lst.de> Cc: Pavel Emelyanov <xemul@openvz.org> Cc: "Eric W. Biederman" <ebiederm@xmission.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Oleg Nesterov <oleg@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-06-18memcg: remove unneeded forward declaration from sched.hLi Zefan
This forward declaration seems pointless. Signed-off-by: Li Zefan <lizf@cn.fujitsu.com> Cc: Balbir Singh <balbir@linux.vnet.ibm.com> Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-06-16Merge branch 'akpm'Linus Torvalds
* akpm: (182 commits) fbdev: bf54x-lq043fb: use kzalloc over kmalloc/memset fbdev: *bfin*: fix __dev{init,exit} markings fbdev: *bfin*: drop unnecessary calls to memset fbdev: bfin-t350mcqb-fb: drop unused local variables fbdev: blackfin has __raw I/O accessors, so use them in fb.h fbdev: s1d13xxxfb: add accelerated bitblt functions tcx: use standard fields for framebuffer physical address and length fbdev: add support for handoff from firmware to hw framebuffers intelfb: fix a bug when changing video timing fbdev: use framebuffer_release() for freeing fb_info structures radeon: P2G2CLK_ALWAYS_ONb tested twice, should 2nd be P2G2CLK_DAC_ALWAYS_ONb? s3c-fb: CPUFREQ frequency scaling support s3c-fb: fix resource releasing on error during probing carminefb: fix possible access beyond end of carmine_modedb[] acornfb: remove fb_mmap function mb862xxfb: use CONFIG_OF instead of CONFIG_PPC_OF mb862xxfb: restrict compliation of platform driver to PPC Samsung SoC Framebuffer driver: add Alpha Channel support atmel-lcdc: fix pixclock upper bound detection offb: use framebuffer_alloc() to allocate fb_info struct ... Manually fix up conflicts due to kmemcheck in mm/slab.c
2009-06-16oom: move oom_adj value from task_struct to mm_structDavid Rientjes
The per-task oom_adj value is a characteristic of its mm more than the task itself since it's not possible to oom kill any thread that shares the mm. If a task were to be killed while attached to an mm that could not be freed because another thread were set to OOM_DISABLE, it would have needlessly been terminated since there is no potential for future memory freeing. This patch moves oomkilladj (now more appropriately named oom_adj) from struct task_struct to struct mm_struct. This requires task_lock() on a task to check its oom_adj value to protect against exec, but it's already necessary to take the lock when dereferencing the mm to find the total VM size for the badness heuristic. This fixes a livelock if the oom killer chooses a task and another thread sharing the same memory has an oom_adj value of OOM_DISABLE. This occurs because oom_kill_task() repeatedly returns 1 and refuses to kill the chosen task while select_bad_process() will repeatedly choose the same task during the next retry. Taking task_lock() in select_bad_process() to check for OOM_DISABLE and in oom_kill_task() to check for threads sharing the same memory will be removed in the next patch in this series where it will no longer be necessary. Writing to /proc/pid/oom_adj for a kthread will now return -EINVAL since these threads are immune from oom killing already. They simply report an oom_adj value of OOM_DISABLE. Cc: Nick Piggin <npiggin@suse.de> Cc: Rik van Riel <riel@redhat.com> Cc: Mel Gorman <mel@csn.ul.ie> Signed-off-by: David Rientjes <rientjes@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-06-16cpuset,mm: update tasks' mems_allowed in timeMiao Xie
Fix allocating page cache/slab object on the unallowed node when memory spread is set by updating tasks' mems_allowed after its cpuset's mems is changed. In order to update tasks' mems_allowed in time, we must modify the code of memory policy. Because the memory policy is applied in the process's context originally. After applying this patch, one task directly manipulates anothers mems_allowed, and we use alloc_lock in the task_struct to protect mems_allowed and memory policy of the task. But in the fast path, we didn't use lock to protect them, because adding a lock may lead to performance regression. But if we don't add a lock,the task might see no nodes when changing cpuset's mems_allowed to some non-overlapping set. In order to avoid it, we set all new allowed nodes, then clear newly disallowed ones. [lee.schermerhorn@hp.com: The rework of mpol_new() to extract the adjusting of the node mask to apply cpuset and mpol flags "context" breaks set_mempolicy() and mbind() with MPOL_PREFERRED and a NULL nodemask--i.e., explicit local allocation. Fix this by adding the check for MPOL_PREFERRED and empty node mask to mpol_new_mpolicy(). Remove the now unneeded 'nodes = NULL' from mpol_new(). Note that mpol_new_mempolicy() is always called with a non-NULL 'nodes' parameter now that it has been removed from mpol_new(). Therefore, we don't need to test nodes for NULL before testing it for 'empty'. However, just to be extra paranoid, add a VM_BUG_ON() to verify this assumption.] [lee.schermerhorn@hp.com: I don't think the function name 'mpol_new_mempolicy' is descriptive enough to differentiate it from mpol_new(). This function applies cpuset set context, usually constraining nodes to those allowed by the cpuset. However, when the 'RELATIVE_NODES flag is set, it also translates the nodes. So I settled on 'mpol_set_nodemask()', because the comment block for mpol_new() mentions that we need to call this function to "set nodes". Some additional minor line length, whitespace and typo cleanup.] Signed-off-by: Miao Xie <miaox@cn.fujitsu.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Christoph Lameter <cl@linux-foundation.org> Cc: Paul Menage <menage@google.com> Cc: Nick Piggin <nickpiggin@yahoo.com.au> Cc: Yasunori Goto <y-goto@jp.fujitsu.com> Cc: Pekka Enberg <penberg@cs.helsinki.fi> Cc: David Rientjes <rientjes@google.com> Signed-off-by: Lee Schermerhorn <lee.schermerhorn@hp.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-06-15sched: delayed cleanup of user_structKay Sievers
During bootup performance tracing we see repeated occurrences of /sys/kernel/uid/* events for the same uid, leading to a, in this case, rather pointless userspace processing for the same uid over and over. This is usually caused by tools which change their uid to "nobody", to run without privileges to read data supplied by untrusted users. This change delays the execution of the (already existing) scheduled work, to cleanup the uid after one second, so the allocated and announced uid can possibly be re-used by another process. This is the current behavior, where almost every invocation of a binary, which changes the uid, creates two events: $ read START < /sys/kernel/uevent_seqnum; \ for i in `seq 100`; do su --shell=/bin/true bin; done; \ read END < /sys/kernel/uevent_seqnum; \ echo $(($END - $START)) 178 With the delayed cleanup, we get only two events, and userspace finishes a bit faster too: $ read START < /sys/kernel/uevent_seqnum; \ for i in `seq 100`; do su --shell=/bin/true bin; done; \ read END < /sys/kernel/uevent_seqnum; \ echo $(($END - $START)) 1 Acked-by: Dhaval Giani <dhaval@linux.vnet.ibm.com> Signed-off-by: Kay Sievers <kay.sievers@vrfy.org> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2009-06-15Merge branch 'timers-for-linus-migration' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip * 'timers-for-linus-migration' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: timers: Logic to move non pinned timers timers: /proc/sys sysctl hook to enable timer migration timers: Identifying the existing pinned timers timers: Framework for identifying pinned timers timers: allow deferrable timers for intervals tv2-tv5 to be deferred Fix up conflicts in kernel/sched.c and kernel/timer.c manually
2009-06-15sched: Introduce SCHED_RESET_ON_FORK scheduling policy flagLennart Poettering
This patch introduces a new flag SCHED_RESET_ON_FORK which can be passed to the kernel via sched_setscheduler(), ORed in the policy parameter. If set this will make sure that when the process forks a) the scheduling priority is reset to DEFAULT_PRIO if it was higher and b) the scheduling policy is reset to SCHED_NORMAL if it was either SCHED_FIFO or SCHED_RR. Why have this? Currently, if a process is real-time scheduled this will 'leak' to all its child processes. For security reasons it is often (always?) a good idea to make sure that if a process acquires RT scheduling this is confined to this process and only this process. More specifically this makes the per-process resource limit RLIMIT_RTTIME useful for security purposes, because it makes it impossible to use a fork bomb to circumvent the per-process RLIMIT_RTTIME accounting. This feature is also useful for tools like 'renice' which can then change the nice level of a process without having this spill to all its child processes. Why expose this via sched_setscheduler() and not other syscalls such as prctl() or sched_setparam()? prctl() does not take a pid parameter. Due to that it would be impossible to modify this flag for other processes than the current one. The struct passed to sched_setparam() can unfortunately not be extended without breaking compatibility, since sched_setparam() lacks a size parameter. How to use this from userspace? In your RT program simply replace this: sched_setscheduler(pid, SCHED_FIFO, &param); by this: sched_setscheduler(pid, SCHED_FIFO|SCHED_RESET_ON_FORK, &param); Signed-off-by: Lennart Poettering <lennart@poettering.net> Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <20090615152714.GA29092@tango.0pointer.de> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-06-15Merge branch 'master' of ↵David S. Miller
master.kernel.org:/pub/scm/linux/kernel/git/torvalds/linux-2.6 Conflicts: Documentation/feature-removal-schedule.txt drivers/scsi/fcoe/fcoe.c net/core/drop_monitor.c net/core/net-traces.c
2009-06-11Merge branch 'perfcounters-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip * 'perfcounters-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: (574 commits) perf_counter: Turn off by default perf_counter: Add counter->id to the throttle event perf_counter: Better align code perf_counter: Rename L2 to LL cache perf_counter: Standardize event names perf_counter: Rename enums perf_counter tools: Clean up u64 usage perf_counter: Rename perf_counter_limit sysctl perf_counter: More paranoia settings perf_counter: powerpc: Implement generalized cache events for POWER processors perf_counters: powerpc: Add support for POWER7 processors perf_counter: Accurate period data perf_counter: Introduce struct for sample data perf_counter tools: Normalize data using per sample period data perf_counter: Annotate exit ctx recursion perf_counter tools: Propagate signals properly perf_counter tools: Small frequency related fixes perf_counter: More aggressive frequency adjustment perf_counter/x86: Fix the model number of Intel Core2 processors perf_counter, x86: Correct some event and umask values for Intel processors ...
2009-06-11Merge branch 'for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/security-testing-2.6 * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/security-testing-2.6: (44 commits) nommu: Provide mmap_min_addr definition. TOMOYO: Add description of lists and structures. TOMOYO: Remove unused field. integrity: ima audit dentry_open failure TOMOYO: Remove unused parameter. security: use mmap_min_addr indepedently of security models TOMOYO: Simplify policy reader. TOMOYO: Remove redundant markers. SELinux: define audit permissions for audit tree netlink messages TOMOYO: Remove unused mutex. tomoyo: avoid get+put of task_struct smack: Remove redundant initialization. integrity: nfsd imbalance bug fix rootplug: Remove redundant initialization. smack: do not beyond ARRAY_SIZE of data integrity: move ima_counts_get integrity: path_check update IMA: Add __init notation to ima functions IMA: Minimal IMA policy and boot param for TCB IMA policy selinux: remove obsolete read buffer limit from sel_read_bool ...
2009-06-11Merge branch 'linus' into perfcounters/coreIngo Molnar
Conflicts: arch/x86/kernel/irqinit.c arch/x86/kernel/irqinit_64.c arch/x86/kernel/traps.c arch/x86/mm/fault.c include/linux/sched.h kernel/exit.c
2009-06-10Merge branch 'tracing-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip * 'tracing-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: (244 commits) Revert "x86, bts: reenable ptrace branch trace support" tracing: do not translate event helper macros in print format ftrace/documentation: fix typo in function grapher name tracing/events: convert block trace points to TRACE_EVENT(), fix !CONFIG_BLOCK tracing: add protection around module events unload tracing: add trace_seq_vprint interface tracing: fix the block trace points print size tracing/events: convert block trace points to TRACE_EVENT() ring-buffer: fix ret in rb_add_time_stamp ring-buffer: pass in lockdep class key for reader_lock tracing: add annotation to what type of stack trace is recorded tracing: fix multiple use of __print_flags and __print_symbolic tracing/events: fix output format of user stack tracing/events: fix output format of kernel stack tracing/trace_stack: fix the number of entries in the header ring-buffer: discard timestamps that are at the start of the buffer ring-buffer: try to discard unneeded timestamps ring-buffer: fix bug in ring_buffer_discard_commit ftrace: do not profile functions when disabled tracing: make trace pipe recognize latency format flag ...
2009-06-10Merge branch 'rcu-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip * 'rcu-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: rcu: rcu_sched_grace_period(): kill the bogus flush_signals() rculist: use list_entry_rcu in places where it's appropriate rculist.h: introduce list_entry_rcu() and list_first_entry_rcu() rcu: Update RCU tracing documentation for __rcu_pending rcu: Add __rcu_pending tracing to hierarchical RCU RCU: make treercu be default
2009-06-11Merge branch 'next' into for-linusJames Morris
2009-05-24perf_counter: Change pctrl() behaviourPeter Zijlstra
Instead of en/dis-abling all counters acting on a particular task, en/dis- able all counters we created. [ v2: fix crash on first counter enable ] Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Paul Mackerras <paulus@samba.org> Cc: Corey Ashford <cjashfor@linux.vnet.ibm.com> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: John Kacur <jkacur@redhat.com> LKML-Reference: <20090523163012.916937244@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-05-22perf_counter: Dynamically allocate tasks' perf_counter_context structPaul Mackerras
This replaces the struct perf_counter_context in the task_struct with a pointer to a dynamically allocated perf_counter_context struct. The main reason for doing is this is to allow us to transfer a perf_counter_context from one task to another when we do lazy PMU switching in a later patch. This has a few side-benefits: the task_struct becomes a little smaller, we save some memory because only tasks that have perf_counters attached get a perf_counter_context allocated for them, and we can remove the inclusion of <linux/perf_counter.h> in sched.h, meaning that we don't end up recompiling nearly everything whenever perf_counter.h changes. The perf_counter_context structures are reference-counted and freed when the last reference is dropped. A context can have references from its task and the counters on its task. Counters can outlive the task so it is possible that a context will be freed well after its task has exited. Contexts are allocated on fork if the parent had a context, or otherwise the first time that a per-task counter is created on a task. In the latter case, we set the context pointer in the task struct locklessly using an atomic compare-and-exchange operation in case we raced with some other task in creating a context for the subject task. This also removes the task pointer from the perf_counter struct. The task pointer was not used anywhere and would make it harder to move a context from one task to another. Anything that needed to know which task a counter was attached to was already using counter->ctx->task. The __perf_counter_init_context function moves up in perf_counter.c so that it can be called from find_get_context, and now initializes the refcount, but is otherwise unchanged. We were potentially calling list_del_counter twice: once from __perf_counter_exit_task when the task exits and once from __perf_counter_remove_from_context when the counter's fd gets closed. This adds a check in list_del_counter so it doesn't do anything if the counter has already been removed from the lists. Since perf_counter_task_sched_in doesn't do anything if the task doesn't have a context, and leaves cpuctx->task_ctx = NULL, this adds code to __perf_install_in_context to set cpuctx->task_ctx if necessary, i.e. in the case where the current task adds the first counter to itself and thus creates a context for itself. This also adds similar code to __perf_counter_enable to handle a similar situation which can arise when the counters have been disabled using prctl; that also leaves cpuctx->task_ctx = NULL. [ Impact: refactor counter context management to prepare for new feature ] Signed-off-by: Paul Mackerras <paulus@samba.org> Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Corey Ashford <cjashfor@linux.vnet.ibm.com> Cc: Marcelo Tosatti <mtosatti@redhat.com> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> LKML-Reference: <18966.10075.781053.231153@cargo.ozlabs.ibm.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-05-19sched: properly define the sched_group::cpumask and sched_domain::span fieldsIngo Molnar
Properly document the variable-size structure tricks we are doing wrt. struct sched_group and sched_domain, and use the field[0] GCC extension instead of defining a vla array. Dont use unions for this, as pointed out by Linus. [ Impact: cleanup, un-confuse Sparse and LLVM ] Reported-by: Jeff Garzik <jeff@garzik.org> Acked-by: Linus Torvalds <torvalds@linux-foundation.org> LKML-Reference: <alpine.LFD.2.01.0905180850110.3301@localhost.localdomain> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-05-18syscall: Implement a convinience function restart_syscallEric W. Biederman
Currently when we have a signal pending we have the functionality to restart that the current system call. There are other cases such as nasty lock ordering issues where it makes sense to have a simple fix that uses try lock and restarts the system call. Buying time to figure out how to rework the locking strategy. Signed-off-by: Eric W. Biederman <ebiederm@aristanetworks.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2009-05-15sched, timers: cleanup avenrun usersThomas Gleixner
avenrun is an rough estimate so we don't have to worry about consistency of the three avenrun values. Remove the xtime lock dependency and provide a function to scale the values. Cleanup the users. [ Impact: cleanup ] Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Peter Zijlstra <peterz@infradead.org>
2009-05-15sched, timers: move calc_load() to schedulerThomas Gleixner
Dimitri Sivanich noticed that xtime_lock is held write locked across calc_load() which iterates over all online CPUs. That can cause long latencies for xtime_lock readers on large SMP systems. The load average calculation is an rough estimate anyway so there is no real need to protect the readers vs. the update. It's not a problem when the avenrun array is updated while a reader copies the values. Instead of iterating over all online CPUs let the scheduler_tick code update the number of active tasks shortly before the avenrun update happens. The avenrun update itself is handled by the CPU which calls do_timer(). [ Impact: reduce xtime_lock write locked section ] Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Peter Zijlstra <peterz@infradead.org>
2009-05-15perf_counter: per user mlock giftPeter Zijlstra
Instead of a per-process mlock gift for perf-counters, use a per-user gift so that there is less of a DoS potential. [ Impact: allow less worst-case unprivileged memory consumption ] Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Paul Mackerras <paulus@samba.org> Cc: Corey Ashford <cjashfor@linux.vnet.ibm.com> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> LKML-Reference: <20090515132018.496182835@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-05-13timers: Logic to move non pinned timersArun R Bharadwaj
* Arun R Bharadwaj <arun@linux.vnet.ibm.com> [2009-04-16 12:11:36]: This patch migrates all non pinned timers and hrtimers to the current idle load balancer, from all the idle CPUs. Timers firing on busy CPUs are not migrated. While migrating hrtimers, care should be taken to check if migrating a hrtimer would result in a latency or not. So we compare the expiry of the hrtimer with the next timer interrupt on the target cpu and migrate the hrtimer only if it expires *after* the next interrupt on the target cpu. So, added a clockevents_get_next_event() helper function to return the next_event on the target cpu's clock_event_device. [ tglx: cleanups and simplifications ] Signed-off-by: Arun R Bharadwaj <arun@linux.vnet.ibm.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2009-05-13timers: /proc/sys sysctl hook to enable timer migrationArun R Bharadwaj
* Arun R Bharadwaj <arun@linux.vnet.ibm.com> [2009-04-16 12:11:36]: This patch creates the /proc/sys sysctl interface at /proc/sys/kernel/timer_migration Timer migration is enabled by default. To disable timer migration, when CONFIG_SCHED_DEBUG = y, echo 0 > /proc/sys/kernel/timer_migration Signed-off-by: Arun R Bharadwaj <arun@linux.vnet.ibm.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2009-05-11CRED: Rename cred_exec_mutex to reflect that it's a guard against ptraceDavid Howells
Rename cred_exec_mutex to reflect that it's a guard against foreign intervention on a process's credential state, such as is made by ptrace(). The attachment of a debugger to a process affects execve()'s calculation of the new credential state - _and_ also setprocattr()'s calculation of that state. Signed-off-by: David Howells <dhowells@redhat.com> Signed-off-by: James Morris <jmorris@namei.org>