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* Merge tag 'split-asm_system_h-for-linus-20120328' of ↵Linus Torvalds2012-03-281-1/+0
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-asm_system Pull "Disintegrate and delete asm/system.h" from David Howells: "Here are a bunch of patches to disintegrate asm/system.h into a set of separate bits to relieve the problem of circular inclusion dependencies. I've built all the working defconfigs from all the arches that I can and made sure that they don't break. The reason for these patches is that I recently encountered a circular dependency problem that came about when I produced some patches to optimise get_order() by rewriting it to use ilog2(). This uses bitops - and on the SH arch asm/bitops.h drags in asm-generic/get_order.h by a circuituous route involving asm/system.h. The main difficulty seems to be asm/system.h. It holds a number of low level bits with no/few dependencies that are commonly used (eg. memory barriers) and a number of bits with more dependencies that aren't used in many places (eg. switch_to()). These patches break asm/system.h up into the following core pieces: (1) asm/barrier.h Move memory barriers here. This already done for MIPS and Alpha. (2) asm/switch_to.h Move switch_to() and related stuff here. (3) asm/exec.h Move arch_align_stack() here. Other process execution related bits could perhaps go here from asm/processor.h. (4) asm/cmpxchg.h Move xchg() and cmpxchg() here as they're full word atomic ops and frequently used by atomic_xchg() and atomic_cmpxchg(). (5) asm/bug.h Move die() and related bits. (6) asm/auxvec.h Move AT_VECTOR_SIZE_ARCH here. Other arch headers are created as needed on a per-arch basis." Fixed up some conflicts from other header file cleanups and moving code around that has happened in the meantime, so David's testing is somewhat weakened by that. We'll find out anything that got broken and fix it.. * tag 'split-asm_system_h-for-linus-20120328' of git://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-asm_system: (38 commits) Delete all instances of asm/system.h Remove all #inclusions of asm/system.h Add #includes needed to permit the removal of asm/system.h Move all declarations of free_initmem() to linux/mm.h Disintegrate asm/system.h for OpenRISC Split arch_align_stack() out from asm-generic/system.h Split the switch_to() wrapper out of asm-generic/system.h Move the asm-generic/system.h xchg() implementation to asm-generic/cmpxchg.h Create asm-generic/barrier.h Make asm-generic/cmpxchg.h #include asm-generic/cmpxchg-local.h Disintegrate asm/system.h for Xtensa Disintegrate asm/system.h for Unicore32 [based on ver #3, changed by gxt] Disintegrate asm/system.h for Tile Disintegrate asm/system.h for Sparc Disintegrate asm/system.h for SH Disintegrate asm/system.h for Score Disintegrate asm/system.h for S390 Disintegrate asm/system.h for PowerPC Disintegrate asm/system.h for PA-RISC Disintegrate asm/system.h for MN10300 ...
| * Remove all #inclusions of asm/system.hDavid Howells2012-03-281-1/+0
| | | | | | | | | | | | | | | | | | Remove all #inclusions of asm/system.h preparatory to splitting and killing it. Performed with the following command: perl -p -i -e 's!^#\s*include\s*<asm/system[.]h>.*\n!!' `grep -Irl '^#\s*include\s*<asm/system[.]h>' *` Signed-off-by: David Howells <dhowells@redhat.com>
* | prctl: add PR_{SET,GET}_CHILD_SUBREAPER to allow simple process supervisionLennart Poettering2012-03-231-0/+12
|/ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Userspace service managers/supervisors need to track their started services. Many services daemonize by double-forking and get implicitly re-parented to PID 1. The service manager will no longer be able to receive the SIGCHLD signals for them, and is no longer in charge of reaping the children with wait(). All information about the children is lost at the moment PID 1 cleans up the re-parented processes. With this prctl, a service manager process can mark itself as a sort of 'sub-init', able to stay as the parent for all orphaned processes created by the started services. All SIGCHLD signals will be delivered to the service manager. Receiving SIGCHLD and doing wait() is in cases of a service-manager much preferred over any possible asynchronous notification about specific PIDs, because the service manager has full access to the child process data in /proc and the PID can not be re-used until the wait(), the service-manager itself is in charge of, has happened. As a side effect, the relevant parent PID information does not get lost by a double-fork, which results in a more elaborate process tree and 'ps' output: before: # ps afx 253 ? Ss 0:00 /bin/dbus-daemon --system --nofork 294 ? Sl 0:00 /usr/libexec/polkit-1/polkitd 328 ? S 0:00 /usr/sbin/modem-manager 608 ? Sl 0:00 /usr/libexec/colord 658 ? Sl 0:00 /usr/libexec/upowerd 819 ? Sl 0:00 /usr/libexec/imsettings-daemon 916 ? Sl 0:00 /usr/libexec/udisks-daemon 917 ? S 0:00 \_ udisks-daemon: not polling any devices after: # ps afx 294 ? Ss 0:00 /bin/dbus-daemon --system --nofork 426 ? Sl 0:00 \_ /usr/libexec/polkit-1/polkitd 449 ? S 0:00 \_ /usr/sbin/modem-manager 635 ? Sl 0:00 \_ /usr/libexec/colord 705 ? Sl 0:00 \_ /usr/libexec/upowerd 959 ? Sl 0:00 \_ /usr/libexec/udisks-daemon 960 ? S 0:00 | \_ udisks-daemon: not polling any devices 977 ? Sl 0:00 \_ /usr/libexec/packagekitd This prctl is orthogonal to PID namespaces. PID namespaces are isolated from each other, while a service management process usually requires the services to live in the same namespace, to be able to talk to each other. Users of this will be the systemd per-user instance, which provides init-like functionality for the user's login session and D-Bus, which activates bus services on-demand. Both need init-like capabilities to be able to properly keep track of the services they start. Many thanks to Oleg for several rounds of review and insights. [akpm@linux-foundation.org: fix comment layout and spelling] [akpm@linux-foundation.org: add lengthy code comment from Oleg] Reviewed-by: Oleg Nesterov <oleg@redhat.com> Signed-off-by: Lennart Poettering <lennart@poettering.net> Signed-off-by: Kay Sievers <kay.sievers@vrfy.org> Acked-by: Valdis Kletnieks <Valdis.Kletnieks@vt.edu> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* cpuset: mm: reduce large amounts of memory barrier related damage v3Mel Gorman2012-03-211-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Commit c0ff7453bb5c ("cpuset,mm: fix no node to alloc memory when changing cpuset's mems") wins a super prize for the largest number of memory barriers entered into fast paths for one commit. [get|put]_mems_allowed is incredibly heavy with pairs of full memory barriers inserted into a number of hot paths. This was detected while investigating at large page allocator slowdown introduced some time after 2.6.32. The largest portion of this overhead was shown by oprofile to be at an mfence introduced by this commit into the page allocator hot path. For extra style points, the commit introduced the use of yield() in an implementation of what looks like a spinning mutex. This patch replaces the full memory barriers on both read and write sides with a sequence counter with just read barriers on the fast path side. This is much cheaper on some architectures, including x86. The main bulk of the patch is the retry logic if the nodemask changes in a manner that can cause a false failure. While updating the nodemask, a check is made to see if a false failure is a risk. If it is, the sequence number gets bumped and parallel allocators will briefly stall while the nodemask update takes place. In a page fault test microbenchmark, oprofile samples from __alloc_pages_nodemask went from 4.53% of all samples to 1.15%. The actual results were 3.3.0-rc3 3.3.0-rc3 rc3-vanilla nobarrier-v2r1 Clients 1 UserTime 0.07 ( 0.00%) 0.08 (-14.19%) Clients 2 UserTime 0.07 ( 0.00%) 0.07 ( 2.72%) Clients 4 UserTime 0.08 ( 0.00%) 0.07 ( 3.29%) Clients 1 SysTime 0.70 ( 0.00%) 0.65 ( 6.65%) Clients 2 SysTime 0.85 ( 0.00%) 0.82 ( 3.65%) Clients 4 SysTime 1.41 ( 0.00%) 1.41 ( 0.32%) Clients 1 WallTime 0.77 ( 0.00%) 0.74 ( 4.19%) Clients 2 WallTime 0.47 ( 0.00%) 0.45 ( 3.73%) Clients 4 WallTime 0.38 ( 0.00%) 0.37 ( 1.58%) Clients 1 Flt/sec/cpu 497620.28 ( 0.00%) 520294.53 ( 4.56%) Clients 2 Flt/sec/cpu 414639.05 ( 0.00%) 429882.01 ( 3.68%) Clients 4 Flt/sec/cpu 257959.16 ( 0.00%) 258761.48 ( 0.31%) Clients 1 Flt/sec 495161.39 ( 0.00%) 517292.87 ( 4.47%) Clients 2 Flt/sec 820325.95 ( 0.00%) 850289.77 ( 3.65%) Clients 4 Flt/sec 1020068.93 ( 0.00%) 1022674.06 ( 0.26%) MMTests Statistics: duration Sys Time Running Test (seconds) 135.68 132.17 User+Sys Time Running Test (seconds) 164.2 160.13 Total Elapsed Time (seconds) 123.46 120.87 The overall improvement is small but the System CPU time is much improved and roughly in correlation to what oprofile reported (these performance figures are without profiling so skew is expected). The actual number of page faults is noticeably improved. For benchmarks like kernel builds, the overall benefit is marginal but the system CPU time is slightly reduced. To test the actual bug the commit fixed I opened two terminals. The first ran within a cpuset and continually ran a small program that faulted 100M of anonymous data. In a second window, the nodemask of the cpuset was continually randomised in a loop. Without the commit, the program would fail every so often (usually within 10 seconds) and obviously with the commit everything worked fine. With this patch applied, it also worked fine so the fix should be functionally equivalent. Signed-off-by: Mel Gorman <mgorman@suse.de> Cc: Miao Xie <miaox@cn.fujitsu.com> Cc: David Rientjes <rientjes@google.com> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Christoph Lameter <cl@linux.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* Merge branch 'sched-core-for-linus' of ↵Linus Torvalds2012-03-201-7/+34
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull scheduler changes for v3.4 from Ingo Molnar * 'sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (27 commits) printk: Make it compile with !CONFIG_PRINTK sched/x86: Fix overflow in cyc2ns_offset sched: Fix nohz load accounting -- again! sched: Update yield() docs printk/sched: Introduce special printk_sched() for those awkward moments sched/nohz: Correctly initialize 'next_balance' in 'nohz' idle balancer sched: Cleanup cpu_active madness sched: Fix load-balance wreckage sched: Clean up parameter passing of proc_sched_autogroup_set_nice() sched: Ditch per cgroup task lists for load-balancing sched: Rename load-balancing fields sched: Move load-balancing arguments into helper struct sched/rt: Do not submit new work when PI-blocked sched/rt: Prevent idle task boosting sched/wait: Add __wake_up_all_locked() API sched/rt: Document scheduler related skip-resched-check sites sched/rt: Use schedule_preempt_disabled() sched/rt: Add schedule_preempt_disabled() sched/rt: Do not throttle when PI boosting sched/rt: Keep period timer ticking when rt throttling is active ...
| * Merge tag 'v3.3-rc7' into sched/coreIngo Molnar2012-03-131-2/+1
| |\ | | | | | | | | | | | | | | | Merge reason: merge back final fixes, prepare for the merge window. Signed-off-by: Ingo Molnar <mingo@elte.hu>
| * | sched: Clean up parameter passing of proc_sched_autogroup_set_nice()Hiroshi Shimamoto2012-03-021-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Pass nice as a value to proc_sched_autogroup_set_nice(). No side effect is expected, and the variable err will be overwritten with the return value. Signed-off-by: Hiroshi Shimamoto <h-shimamoto@ct.jp.nec.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Link: http://lkml.kernel.org/r/4F45FBB7.5090607@ct.jp.nec.com Signed-off-by: Ingo Molnar <mingo@elte.hu>
| * | sched/rt: Do not submit new work when PI-blockedThomas Gleixner2012-03-011-0/+8
| | | | | | | | | | | | | | | | | | | | | | | | | | | When we are PI-blocked then we want to get things done ASAP. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Link: http://lkml.kernel.org/n/tip-vw8et3445km5b8mpihf4trae@git.kernel.org Signed-off-by: Ingo Molnar <mingo@elte.hu>
| * | sched/rt: Add schedule_preempt_disabled()Thomas Gleixner2012-03-011-0/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Add helper to get rid of the ever repeating: preempt_enable_no_resched(); schedule(); preempt_disable(); patterns. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Link: http://lkml.kernel.org/n/tip-wxx7btox7coby6ifv5vzhzgp@git.kernel.org Signed-off-by: Ingo Molnar <mingo@elte.hu>
| * | Merge branch 'linus' into sched/coreIngo Molnar2012-03-011-1/+7
| |\ \ | | | | | | | | | | | | | | | | | | | | Merge reason: we'll queue up dependent patches. Signed-off-by: Ingo Molnar <mingo@elte.hu>
| * | | sched: Make initial SCHED_RR timeslace DEF_TIMESLICEHiroshi Shimamoto2012-02-221-0/+6
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Current the initial SCHED_RR timeslice of init_task is HZ, which means 1s, and is not same as the default SCHED_RR timeslice DEF_TIMESLICE. Change that initial timeslice to the DEF_TIMESLICE. Signed-off-by: Hiroshi Shimamoto <h-shimamoto@ct.jp.nec.com> [ s/DEF_TIMESLICE/RR_TIMESLICE/g ] Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Link: http://lkml.kernel.org/r/4F3C9995.3010800@ct.jp.nec.com Signed-off-by: Ingo Molnar <mingo@elte.hu>
| * | | sched: Turn lock_task_sighand() into a static inlineAnton Vorontsov2012-02-111-6/+9
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | It appears that sparse tool understands static inline functions for context balance checking, so let's turn the macros into an inline func. This makes the code a little bit more robust. Suggested-by: Oleg Nesterov <oleg@redhat.com> Signed-off-by: Anton Vorontsov <anton.vorontsov@linaro.org> Cc: KOSAKI Motohiro <kosaki.motohiro@gmail.com> Cc: Greg KH <gregkh@linuxfoundation.org> Cc: Arve <arve@android.com> Cc: San Mehat <san@google.com> Cc: Colin Cross <ccross@android.com> Cc: Eric W. Biederman <ebiederm@xmission.com> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: kernel-team@android.com Cc: linaro-kernel@lists.linaro.org Cc: Peter Zijlstra <peterz@infradead.org> Link: http://lkml.kernel.org/r/20120209164519.GA10266@oksana.dev.rtsoft.ru Signed-off-by: Ingo Molnar <mingo@elte.hu>
| * | | sched: Ensure cpu_power periodic updateVincent Guittot2012-01-271-0/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | With a lot of small tasks, the softirq sched is nearly never called when no_hz is enabled. In this case load_balance() is mainly called with the newly_idle mode which doesn't update the cpu_power. Add a next_update field which ensure a maximum update period when there is short activity. Having stale cpu_power information can skew the load-balancing decisions, this is cured by the guaranteed update. Signed-off-by: Vincent Guittot <vincent.guittot@linaro.org> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Link: http://lkml.kernel.org/r/1323717668-2143-1-git-send-email-vincent.guittot@linaro.org
| * | | sched, block: Unify cache detectionPeter Zijlstra2012-01-271-0/+8
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The block layer has some code trying to determine if two CPUs share a cache, the scheduler has a similar function. Expose the function used by the scheduler and make the block layer use it, thereby removing the block layers usage of CONFIG_SCHED* and topology bits. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Acked-by: Jens Axboe <axboe@kernel.dk> Link: http://lkml.kernel.org/r/1327579450.2446.95.camel@twins
* | | | Merge branch 'irq-core-for-linus' of ↵Linus Torvalds2012-03-201-5/+5
|\ \ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull irq/core changes for v3.4 from Ingo Molnar * 'irq-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: genirq: Remove paranoid warnons and bogus fixups genirq: Flush the irq thread on synchronization genirq: Get rid of unnecessary IRQTF_DIED flag genirq: No need to check IRQTF_DIED before stopping a thread handler genirq: Get rid of unnecessary irqaction field in task_struct genirq: Fix incorrect check for forced IRQ thread handler softirq: Reduce invoke_softirq() code duplication genirq: Fix long-term regression in genirq irq_set_irq_type() handling x86-32/irq: Don't switch to irq stack for a user-mode irq
| * \ \ \ Merge branch 'linus' into irq/coreThomas Gleixner2012-03-131-2/+1
| |\ \ \ \ | | | |_|/ | | |/| | | | | | | | | | | | | | | | | Reason: Get upstream fixes integrated before further modifications. Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
| * | | | genirq: Get rid of unnecessary irqaction field in task_structAlexander Gordeev2012-03-091-5/+5
| | |_|/ | |/| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When a new thread handler is created, an irqaction is passed to it as data. Not only that irqaction is stored in task_struct by the handler for later use, but also a structure associated with the kernel thread keeps this value as long as the thread exists. This fix kicks irqaction out off task_struct. Yes, I introduce new bit field. But it allows not only to eliminate the duplicate, but also shortens size of task_struct. Reported-by: Oleg Nesterov <oleg@redhat.com> Signed-off-by: Alexander Gordeev <agordeev@redhat.com> Link: http://lkml.kernel.org/r/20120309135925.GB2114@dhcp-26-207.brq.redhat.com Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
* | | | Merge branch 'core-rcu-for-linus' of ↵Linus Torvalds2012-03-201-2/+1
|\ \ \ \ | |_|/ / |/| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull RCU changes for v3.4 from Ingo Molnar. The major features of this series are: - making RCU more aggressive about entering dyntick-idle mode in order to improve energy efficiency - converting a few more call_rcu()s to kfree_rcu()s - applying a number of rcutree fixes and cleanups to rcutiny - removing CONFIG_SMP #ifdefs from treercu - allowing RCU CPU stall times to be set via sysfs - adding CPU-stall capability to rcutorture - adding more RCU-abuse diagnostics - updating documentation - fixing yet more issues located by the still-ongoing top-to-bottom inspection of RCU, this time with a special focus on the CPU-hotplug code path. * 'core-rcu-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (48 commits) rcu: Stop spurious warnings from synchronize_sched_expedited rcu: Hold off RCU_FAST_NO_HZ after timer posted rcu: Eliminate softirq-mediated RCU_FAST_NO_HZ idle-entry loop rcu: Add RCU_NONIDLE() for idle-loop RCU read-side critical sections rcu: Allow nesting of rcu_idle_enter() and rcu_idle_exit() rcu: Remove redundant check for rcu_head misalignment PTR_ERR should be called before its argument is cleared. rcu: Convert WARN_ON_ONCE() in rcu_lock_acquire() to lockdep rcu: Trace only after NULL-pointer check rcu: Call out dangers of expedited RCU primitives rcu: Rework detection of use of RCU by offline CPUs lockdep: Add CPU-idle/offline warning to lockdep-RCU splat rcu: No interrupt disabling for rcu_prepare_for_idle() rcu: Move synchronize_sched_expedited() to rcutree.c rcu: Check for illegal use of RCU from offlined CPUs rcu: Update stall-warning documentation rcu: Add CPU-stall capability to rcutorture rcu: Make documentation give more realistic rcutorture duration rcutorture: Permit holding off CPU-hotplug operations during boot rcu: Print scheduling-clock information on RCU CPU stall-warning messages ...
| * | | rcu: Simplify unboosting checksPaul E. McKenney2012-02-211-2/+1
| |/ / | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This is a port of commit #82e78d80 from TREE_PREEMPT_RCU to TINY_PREEMPT_RCU. This commit uses the fact that current->rcu_boost_mutex is set any time that the RCU_READ_UNLOCK_BOOSTED flag is set in the current->rcu_read_unlock_special bitmask. This allows tests of the bit to be changed to tests of the pointer, which in turn allows the RCU_READ_UNLOCK_BOOSTED flag to be eliminated. Please note that the check of current->rcu_read_unlock_special need not change because any time that RCU_READ_UNLOCK_BOOSTED was set, so was RCU_READ_UNLOCK_BLOCKED. Therefore, __rcu_read_unlock() can continue testing current->rcu_read_unlock_special for non-zero, as before. Signed-off-by: Paul E. McKenney <paul.mckenney@linaro.org> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
* | | vfork: kill PF_STARTINGOleg Nesterov2012-03-051-1/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Previously it was (ab)used by utrace. Then it was wrongly used by the scheduler code. Currently it is not used, kill it before it finds the new erroneous user. Signed-off-by: Oleg Nesterov <oleg@redhat.com> Acked-by: Tejun Heo <tj@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | | coredump_wait: don't call complete_vfork_done()Oleg Nesterov2012-03-051-1/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Now that CLONE_VFORK is killable, coredump_wait() no longer needs complete_vfork_done(). zap_threads() should find and kill all tasks with the same ->mm, this includes our parent if ->vfork_done is set. mm_release() becomes the only caller, unexport complete_vfork_done(). Signed-off-by: Oleg Nesterov <oleg@redhat.com> Acked-by: Tejun Heo <tj@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | | vfork: make it killableOleg Nesterov2012-03-051-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Make vfork() killable. Change do_fork(CLONE_VFORK) to do wait_for_completion_killable(). If it fails we do not return to the user-mode and never touch the memory shared with our child. However, in this case we should clear child->vfork_done before return, we use task_lock() in do_fork()->wait_for_vfork_done() and complete_vfork_done() to serialize with each other. Note: now that we use task_lock() we don't really need completion, we could turn task->vfork_done into "task_struct *wake_up_me" but this needs some complications. NOTE: this and the next patches do not affect in-kernel users of CLONE_VFORK, kernel threads run with all signals ignored including SIGKILL/SIGSTOP. However this is obviously the user-visible change. Not only a fatal signal can kill the vforking parent, a sub-thread can do execve or exit_group() and kill the thread sleeping in vfork(). Signed-off-by: Oleg Nesterov <oleg@redhat.com> Acked-by: Tejun Heo <tj@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | | vfork: introduce complete_vfork_done()Oleg Nesterov2012-03-051-0/+1
|/ / | | | | | | | | | | | | | | | | | | | | | | No functional changes. Move the clear-and-complete-vfork_done code into the new trivial helper, complete_vfork_done(). Signed-off-by: Oleg Nesterov <oleg@redhat.com> Acked-by: Tejun Heo <tj@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | Fix race in process_vm_rw_coreChristopher Yeoh2012-02-021-0/+6
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This fixes the race in process_vm_core found by Oleg (see http://article.gmane.org/gmane.linux.kernel/1235667/ for details). This has been updated since I last sent it as the creation of the new mm_access() function did almost exactly the same thing as parts of the previous version of this patch did. In order to use mm_access() even when /proc isn't enabled, we move it to kernel/fork.c where other related process mm access functions already are. Signed-off-by: Chris Yeoh <yeohc@au1.ibm.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | Merge branch 'core-urgent-for-linus' of ↵Linus Torvalds2012-01-261-1/+1
|\ \ | |/ |/| | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip * 'core-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: rcu: Add missing __cpuinit annotation in rcutorture code sched: Add "const" to is_idle_task() parameter rcu: Make rcutorture bool parameters really bool (core code) memblock: Fix alloc failure due to dumb underflow protection in memblock_find_in_range_node()
| * Merge branch 'rcu/urgent' of ↵Ingo Molnar2012-01-171-1/+1
| |\ | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/paulmck/linux-rcu into core/urgent
| | * sched: Add "const" to is_idle_task() parameterPaul E. McKenney2012-01-161-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | This patch fixes a build warning in -next due to a const pointer being passed to is_idle_task(). Because is_idle_task() does not modify anything, this commit adds the "const" to is_idle_task()'s argument declaration. Reported-by: Stephen Rothwell <sfr@canb.auug.org.au> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
* | | kernel-doc: fix kernel-doc warnings in schedRandy Dunlap2012-01-231-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Fix new kernel-doc notation warnings: Warning(include/linux/sched.h:2094): No description found for parameter 'p' Warning(include/linux/sched.h:2094): Excess function parameter 'tsk' description in 'is_idle_task' Warning(kernel/sched/cpupri.c:139): No description found for parameter 'newpri' Warning(kernel/sched/cpupri.c:139): Excess function parameter 'pri' description in 'cpupri_set' Warning(kernel/sched/cpupri.c:208): Excess function parameter 'bootmem' description in 'cpupri_init' Signed-off-by: Randy Dunlap <rdunlap@xenotime.net> Cc: Ingo Molnar <mingo@elte.hu> Cc: Peter Zijlstra <peterz@infradead.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | | treewide: remove useless NORET_TYPE macro and usesJoe Perches2012-01-121-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | It's a very old and now unused prototype marking so just delete it. Neaten panic pointer argument style to keep checkpatch quiet. Signed-off-by: Joe Perches <joe@perches.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Haavard Skinnemoen <hskinnemoen@gmail.com> Cc: Hans-Christian Egtvedt <egtvedt@samfundet.no> Cc: Tony Luck <tony.luck@intel.com> Cc: Fenghua Yu <fenghua.yu@intel.com> Acked-by: Geert Uytterhoeven <geert@linux-m68k.org> Acked-by: Ralf Baechle <ralf@linux-mips.org> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Paul Mackerras <paulus@samba.org> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: Chris Metcalf <cmetcalf@tilera.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | | Merge branch 'writeback-for-linus' of ↵Linus Torvalds2012-01-101-0/+1
|\ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/wfg/linux * 'writeback-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/wfg/linux: writeback: move MIN_WRITEBACK_PAGES to fs-writeback.c writeback: balanced_rate cannot exceed write bandwidth writeback: do strict bdi dirty_exceeded writeback: avoid tiny dirty poll intervals writeback: max, min and target dirty pause time writeback: dirty ratelimit - think time compensation btrfs: fix dirtied pages accounting on sub-page writes writeback: fix dirtied pages accounting on redirty writeback: fix dirtied pages accounting on sub-page writes writeback: charge leaked page dirties to active tasks writeback: Include all dirty inodes in background writeback
| * | | writeback: dirty ratelimit - think time compensationWu Fengguang2011-12-181-0/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Compensate the task's think time when computing the final pause time, so that ->dirty_ratelimit can be executed accurately. think time := time spend outside of balance_dirty_pages() In the rare case that the task slept longer than the 200ms period time (result in negative pause time), the sleep time will be compensated in the following periods, too, if it's less than 1 second. Accumulated errors are carefully avoided as long as the max pause area is not hitted. Pseudo code: period = pages_dirtied / task_ratelimit; think = jiffies - dirty_paused_when; pause = period - think; 1) normal case: period > think pause = period - think dirty_paused_when = jiffies + pause nr_dirtied = 0 period time |===============================>| think time pause time |===============>|==============>| ------|----------------|---------------|------------------------ dirty_paused_when jiffies 2) no pause case: period <= think don't pause; reduce future pause time by: dirty_paused_when += period nr_dirtied = 0 period time |===============================>| think time |===================================================>| ------|--------------------------------+-------------------|---- dirty_paused_when jiffies Acked-by: Jan Kara <jack@suse.cz> Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Wu Fengguang <fengguang.wu@intel.com>
* | | | Merge branch 'for-3.3' of ↵Linus Torvalds2012-01-091-19/+54
|\ \ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup * 'for-3.3' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup: (21 commits) cgroup: fix to allow mounting a hierarchy by name cgroup: move assignement out of condition in cgroup_attach_proc() cgroup: Remove task_lock() from cgroup_post_fork() cgroup: add sparse annotation to cgroup_iter_start() and cgroup_iter_end() cgroup: mark cgroup_rmdir_waitq and cgroup_attach_proc() as static cgroup: only need to check oldcgrp==newgrp once cgroup: remove redundant get/put of task struct cgroup: remove redundant get/put of old css_set from migrate cgroup: Remove unnecessary task_lock before fetching css_set on migration cgroup: Drop task_lock(parent) on cgroup_fork() cgroups: remove redundant get/put of css_set from css_set_check_fetched() resource cgroups: remove bogus cast cgroup: kill subsys->can_attach_task(), pre_attach() and attach_task() cgroup, cpuset: don't use ss->pre_attach() cgroup: don't use subsys->can_attach_task() or ->attach_task() cgroup: introduce cgroup_taskset and use it in subsys->can_attach(), cancel_attach() and attach() cgroup: improve old cgroup handling in cgroup_attach_proc() cgroup: always lock threadgroup during migration threadgroup: extend threadgroup_lock() to cover exit and exec threadgroup: rename signal->threadgroup_fork_lock to ->group_rwsem ... Fix up conflict in kernel/cgroup.c due to commit e0197aae59e5: "cgroups: fix a css_set not found bug in cgroup_attach_proc" that already mentioned that the bug is fixed (differently) in Tejun's cgroup patchset. This one, in other words.
| * | | | threadgroup: extend threadgroup_lock() to cover exit and execTejun Heo2011-12-121-6/+41
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | threadgroup_lock() protected only protected against new addition to the threadgroup, which was inherently somewhat incomplete and problematic for its only user cgroup. On-going migration could race against exec and exit leading to interesting problems - the symmetry between various attach methods, task exiting during method execution, ->exit() racing against attach methods, migrating task switching basic properties during exec and so on. This patch extends threadgroup_lock() such that it protects against all three threadgroup altering operations - fork, exit and exec. For exit, threadgroup_change_begin/end() calls are added to exit_signals around assertion of PF_EXITING. For exec, threadgroup_[un]lock() are updated to also grab and release cred_guard_mutex. With this change, threadgroup_lock() guarantees that the target threadgroup will remain stable - no new task will be added, no new PF_EXITING will be set and exec won't happen. The next patch will update cgroup so that it can take full advantage of this change. -v2: beefed up comment as suggested by Frederic. -v3: narrowed scope of protection in exit path as suggested by Frederic. Signed-off-by: Tejun Heo <tj@kernel.org> Reviewed-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Acked-by: Li Zefan <lizf@cn.fujitsu.com> Acked-by: Frederic Weisbecker <fweisbec@gmail.com> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Paul Menage <paul@paulmenage.org> Cc: Linus Torvalds <torvalds@linux-foundation.org>
| * | | | threadgroup: rename signal->threadgroup_fork_lock to ->group_rwsemTejun Heo2011-12-121-15/+15
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Make the following renames to prepare for extension of threadgroup locking. * s/signal->threadgroup_fork_lock/signal->group_rwsem/ * s/threadgroup_fork_read_lock()/threadgroup_change_begin()/ * s/threadgroup_fork_read_unlock()/threadgroup_change_end()/ * s/threadgroup_fork_write_lock()/threadgroup_lock()/ * s/threadgroup_fork_write_unlock()/threadgroup_unlock()/ This patch doesn't cause any behavior change. -v2: Rename threadgroup_change_done() to threadgroup_change_end() per KAMEZAWA's suggestion. Signed-off-by: Tejun Heo <tj@kernel.org> Reviewed-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Acked-by: Li Zefan <lizf@cn.fujitsu.com> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Paul Menage <paul@paulmenage.org>
* | | | | Merge branch 'pm-for-linus' of ↵Linus Torvalds2012-01-081-3/+1
|\ \ \ \ \ | |/ / / / | | | / / | |_|/ / |/| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm * 'pm-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm: (76 commits) PM / Hibernate: Implement compat_ioctl for /dev/snapshot PM / Freezer: fix return value of freezable_schedule_timeout_killable() PM / shmobile: Allow the A4R domain to be turned off at run time PM / input / touchscreen: Make st1232 use device PM QoS constraints PM / QoS: Introduce dev_pm_qos_add_ancestor_request() PM / shmobile: Remove the stay_on flag from SH7372's PM domains PM / shmobile: Don't include SH7372's INTCS in syscore suspend/resume PM / shmobile: Add support for the sh7372 A4S power domain / sleep mode PM: Drop generic_subsys_pm_ops PM / Sleep: Remove forward-only callbacks from AMBA bus type PM / Sleep: Remove forward-only callbacks from platform bus type PM: Run the driver callback directly if the subsystem one is not there PM / Sleep: Make pm_op() and pm_noirq_op() return callback pointers PM/Devfreq: Add Exynos4-bus device DVFS driver for Exynos4210/4212/4412. PM / Sleep: Merge internal functions in generic_ops.c PM / Sleep: Simplify generic system suspend callbacks PM / Hibernate: Remove deprecated hibernation snapshot ioctls PM / Sleep: Fix freezer failures due to racy usermodehelper_is_disabled() ARM: S3C64XX: Implement basic power domain support PM / shmobile: Use common always on power domain governor ... Fix up trivial conflict in fs/xfs/xfs_buf.c due to removal of unused XBT_FORCE_SLEEP bit
| * | | Merge branch 'pm-freezer' of ↵Rafael J. Wysocki2011-11-231-3/+1
| |\ \ \ | | |/ / | |/| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tj/misc into pm-freezer * 'pm-freezer' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/misc: (24 commits) freezer: fix wait_event_freezable/__thaw_task races freezer: kill unused set_freezable_with_signal() dmatest: don't use set_freezable_with_signal() usb_storage: don't use set_freezable_with_signal() freezer: remove unused @sig_only from freeze_task() freezer: use lock_task_sighand() in fake_signal_wake_up() freezer: restructure __refrigerator() freezer: fix set_freezable[_with_signal]() race freezer: remove should_send_signal() and update frozen() freezer: remove now unused TIF_FREEZE freezer: make freezing() test freeze conditions in effect instead of TIF_FREEZE cgroup_freezer: prepare for removal of TIF_FREEZE freezer: clean up freeze_processes() failure path freezer: kill PF_FREEZING freezer: test freezable conditions while holding freezer_lock freezer: make freezing indicate freeze condition in effect freezer: use dedicated lock instead of task_lock() + memory barrier freezer: don't distinguish nosig tasks on thaw freezer: remove racy clear_freeze_flag() and set PF_NOFREEZE on dead tasks freezer: rename thaw_process() to __thaw_task() and simplify the implementation ...
| | * | freezer: kill unused set_freezable_with_signal()Tejun Heo2011-11-231-1/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | There's no in-kernel user of set_freezable_with_signal() left. Mixing TIF_SIGPENDING with kernel threads can lead to nasty corner cases as kernel threads never travel signal delivery path on their own. e.g. the current implementation is buggy in the cancelation path of __thaw_task(). It calls recalc_sigpending_and_wake() in an attempt to clear TIF_SIGPENDING but the function never clears it regardless of sigpending state. This means that signallable freezable kthreads may continue executing with !freezing() && stuck TIF_SIGPENDING, which can be troublesome. This patch removes set_freezable_with_signal() along with PF_FREEZER_NOSIG and recalc_sigpending*() calls in freezer. User tasks get TIF_SIGPENDING, kernel tasks get woken up and the spurious sigpending is dealt with in the usual signal delivery path. Signed-off-by: Tejun Heo <tj@kernel.org> Acked-by: Oleg Nesterov <oleg@redhat.com>
| | * | freezer: kill PF_FREEZINGTejun Heo2011-11-211-2/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | With the previous changes, there's no meaningful difference between PF_FREEZING and PF_FROZEN. Remove PF_FREEZING and use PF_FROZEN instead in task_contributes_to_load(). Signed-off-by: Tejun Heo <tj@kernel.org>
* | | | Merge branch 'sched-core-for-linus' of ↵Linus Torvalds2012-01-061-4/+19
|\ \ \ \ | |_|_|/ |/| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip * 'sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (40 commits) sched/tracing: Add a new tracepoint for sleeptime sched: Disable scheduler warnings during oopses sched: Fix cgroup movement of waking process sched: Fix cgroup movement of newly created process sched: Fix cgroup movement of forking process sched: Remove cfs bandwidth period check in tg_set_cfs_period() sched: Fix load-balance lock-breaking sched: Replace all_pinned with a generic flags field sched: Only queue remote wakeups when crossing cache boundaries sched: Add missing rcu_dereference() around ->real_parent usage [S390] fix cputime overflow in uptime_proc_show [S390] cputime: add sparse checking and cleanup sched: Mark parent and real_parent as __rcu sched, nohz: Fix missing RCU read lock sched, nohz: Set the NOHZ_BALANCE_KICK flag for idle load balancer sched, nohz: Fix the idle cpu check in nohz_idle_balance sched: Use jump_labels for sched_feat sched/accounting: Fix parameter passing in task_group_account_field sched/accounting: Fix user/system tick double accounting sched/accounting: Re-use scheduler statistics for the root cgroup ... Fix up conflicts in - arch/ia64/include/asm/cputime.h, include/asm-generic/cputime.h usecs_to_cputime64() vs the sparse cleanups - kernel/sched/fair.c, kernel/time/tick-sched.c scheduler changes in multiple branches
| * | | Merge branch 'sched/core' of ↵Martin Schwidefsky2011-12-191-2/+17
| |\ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip into cputime-tip Conflicts: drivers/cpufreq/cpufreq_conservative.c drivers/cpufreq/cpufreq_ondemand.c drivers/macintosh/rack-meter.c fs/proc/stat.c fs/proc/uptime.c kernel/sched/core.c
| | * | | sched: Mark parent and real_parent as __rcuKees Cook2011-12-151-2/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The parent and real_parent pointers should be considered __rcu, since they should be held under either tasklist_lock or rcu_read_lock. Signed-off-by: Kees Cook <keescook@chromium.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Link: http://lkml.kernel.org/r/20111214223925.GA27578@www.outflux.net Signed-off-by: Ingo Molnar <mingo@elte.hu>
| | * | | Merge commit 'v3.2-rc5' into sched/coreIngo Molnar2011-12-151-1/+0
| | |\ \ \ | | | |/ / | | | | | | | | | | | | | | | | | | | | Merge reason: Pick up the latest fixes. Signed-off-by: Ingo Molnar <mingo@elte.hu>
| | * | | sched: Fix compile error for UP,!NOHZPeter Zijlstra2011-12-061-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Commit 69e1e811 ("sched, nohz: Track nr_busy_cpus in the sched_group_power") messed up the static inline function definition. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Suresh Siddha <suresh.b.siddha@intel.com> Link: http://lkml.kernel.org/n/tip-abjah8ctq5qrjjtdiabe8lph@git.kernel.org Signed-off-by: Ingo Molnar <mingo@elte.hu>
| | * | | sched, nohz: Track nr_busy_cpus in the sched_group_powerSuresh Siddha2011-12-061-0/+6
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Introduce nr_busy_cpus in the struct sched_group_power [Not in sched_group because sched groups are duplicated for the SD_OVERLAP scheduler domain] and for each cpu that enters and exits idle, this parameter will be updated in each scheduler group of the scheduler domain that this cpu belongs to. To avoid the frequent update of this state as the cpu enters and exits idle, the update of the stat during idle exit is delayed to the first timer tick that happens after the cpu becomes busy. This is done using NOHZ_IDLE flag in the struct rq's nohz_flags. Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/20111202010832.555984323@sbsiddha-desk.sc.intel.com Signed-off-by: Ingo Molnar <mingo@elte.hu>
| | * | | sched: Make separate sched*.c translation unitsPeter Zijlstra2011-11-171-0/+9
| | | |/ | | |/| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Since once needs to do something at conferences and fixing compile warnings doesn't actually require much if any attention I decided to break up the sched.c #include "*.c" fest. This further modularizes the scheduler code. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Link: http://lkml.kernel.org/n/tip-x0fcd3mnp8f9c99grcpewmhi@git.kernel.org Signed-off-by: Ingo Molnar <mingo@elte.hu>
| * | | [S390] cputime: add sparse checking and cleanupMartin Schwidefsky2011-12-151-2/+2
| | |/ | |/| | | | | | | | | | | | | | | | | | | Make cputime_t and cputime64_t nocast to enable sparse checking to detect incorrect use of cputime. Drop the cputime macros for simple scalar operations. The conversion macros are still needed. Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
* | | sched: Add is_idle_task() to handle invalidated uses of idle_cpu()Paul E. McKenney2011-12-111-0/+8
|/ / | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Commit 908a3283 (Fix idle_cpu()) invalidated some uses of idle_cpu(), which used to say whether or not the CPU was running the idle task, but now instead says whether or not the CPU is running the idle task in the absence of pending wakeups. Although this new implementation gives a better answer to the question "is this CPU idle?", it also invalidates other uses that were made of idle_cpu(). This commit therefore introduces a new is_idle_task() API member that determines whether or not the specified task is one of the idle tasks, allowing open-coded "->pid == 0" sequences to be replaced by something more meaningful. Suggested-by: Josh Triplett <josh@joshtriplett.org> Suggested-by: Peter Zijlstra <peterz@infradead.org> Signed-off-by: Paul E. McKenney <paul.mckenney@linaro.org> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
* | writeback: remove vm_dirties and task->dirtiesWu Fengguang2011-11-171-1/+0
|/ | | | | | They are not used any more. Signed-off-by: Wu Fengguang <fengguang.wu@intel.com>
* Merge branch 'writeback-for-linus' of ↵Linus Torvalds2011-11-061-0/+7
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/wfg/linux * 'writeback-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/wfg/linux: writeback: Add a 'reason' to wb_writeback_work writeback: send work item to queue_io, move_expired_inodes writeback: trace event balance_dirty_pages writeback: trace event bdi_dirty_ratelimit writeback: fix ppc compile warnings on do_div(long long, unsigned long) writeback: per-bdi background threshold writeback: dirty position control - bdi reserve area writeback: control dirty pause time writeback: limit max dirty pause time writeback: IO-less balance_dirty_pages() writeback: per task dirty rate limit writeback: stabilize bdi->dirty_ratelimit writeback: dirty rate control writeback: add bg_threshold parameter to __bdi_update_bandwidth() writeback: dirty position control writeback: account per-bdi accumulated dirtied pages
| * writeback: per task dirty rate limitWu Fengguang2011-10-031-0/+7
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Add two fields to task_struct. 1) account dirtied pages in the individual tasks, for accuracy 2) per-task balance_dirty_pages() call intervals, for flexibility The balance_dirty_pages() call interval (ie. nr_dirtied_pause) will scale near-sqrt to the safety gap between dirty pages and threshold. The main problem of per-task nr_dirtied is, if 1k+ tasks start dirtying pages at exactly the same time, each task will be assigned a large initial nr_dirtied_pause, so that the dirty threshold will be exceeded long before each task reached its nr_dirtied_pause and hence call balance_dirty_pages(). The solution is to watch for the number of pages dirtied on each CPU in between the calls into balance_dirty_pages(). If it exceeds ratelimit_pages (3% dirty threshold), force call balance_dirty_pages() for a chance to set bdi->dirty_exceeded. In normal situations, this safeguarding condition is not expected to trigger at all. On the sqrt in dirty_poll_interval(): It will serve as an initial guess when dirty pages are still in the freerun area. When dirty pages are floating inside the dirty control scope [freerun, limit], a followup patch will use some refined dirty poll interval to get the desired pause time. thresh-dirty (MB) sqrt 1 16 2 22 4 32 8 45 16 64 32 90 64 128 128 181 256 256 512 362 1024 512 The above table means, given 1MB (or 1GB) gap and the dd tasks polling balance_dirty_pages() on every 16 (or 512) pages, the dirty limit won't be exceeded as long as there are less than 16 (or 512) concurrent dd's. So sqrt naturally leads to less overheads and more safe concurrent tasks for large memory servers, which have large (thresh-freerun) gaps. peter: keep the per-CPU ratelimit for safeguarding the 1k+ tasks case CC: Peter Zijlstra <a.p.zijlstra@chello.nl> Reviewed-by: Andrea Righi <andrea@betterlinux.com> Signed-off-by: Wu Fengguang <fengguang.wu@intel.com>
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