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2013-04-29fix a leak in /proc/schedstatsAl Viro
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2013-04-29Merge branch 'core-locking-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull locking changes from Ingo Molnar: "The most noticeable change are mutex speedups from Waiman Long, for higher loads. These scalability changes should be most noticeable on larger server systems. There are also cleanups, fixes and debuggability improvements." * 'core-locking-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: lockdep: Consolidate bug messages into a single print_lockdep_off() function lockdep: Print out additional debugging advice when we hit lockdep BUGs mutex: Back out architecture specific check for negative mutex count mutex: Queue mutex spinners with MCS lock to reduce cacheline contention mutex: Make more scalable by doing less atomic operations mutex: Move mutex spinning code from sched/core.c back to mutex.c locking/rtmutex/tester: Set correct permissions on sysfs files lockdep: Remove unnecessary 'hlock_next' variable
2013-04-29nohz: Protect smp_processor_id() in tick_nohz_task_switch()Li Zhong
I saw following error when testing the latest nohz code on Power: [ 85.295384] BUG: using smp_processor_id() in preemptible [00000000] code: rsyslogd/3493 [ 85.295396] caller is .tick_nohz_task_switch+0x1c/0xb8 [ 85.295402] Call Trace: [ 85.295408] [c0000001fababab0] [c000000000012dc4] .show_stack+0x110/0x25c (unreliable) [ 85.295420] [c0000001fababba0] [c0000000007c4b54] .dump_stack+0x20/0x30 [ 85.295430] [c0000001fababc10] [c00000000044eb74] .debug_smp_processor_id+0xf4/0x124 [ 85.295438] [c0000001fababca0] [c0000000000d7594] .tick_nohz_task_switch+0x1c/0xb8 [ 85.295447] [c0000001fababd20] [c0000000000b9748] .finish_task_switch+0x13c/0x160 [ 85.295455] [c0000001fababdb0] [c0000000000bbe50] .schedule_tail+0x50/0x124 [ 85.295463] [c0000001fababe30] [c000000000009dc8] .ret_from_fork+0x4/0x54 The code below moves the test into local_irq_save/restore section to avoid the above complaint. Signed-off-by: Li Zhong <zhong@linux.vnet.ibm.com> Acked-by: Frederic Weisbecker <fweisbec@gmail.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Paul McKenney <paulmck@linux.vnet.ibm.com> Link: http://lkml.kernel.org/r/1367119558.6391.34.camel@ThinkPad-T5421.cn.ibm.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2013-04-27cpuset: fix compile warning when CONFIG_SMP=nLi Zefan
Reported by Fengguang's kbuild test robot: kernel/cpuset.c:787: warning: 'generate_sched_domains' defined but not used Introduced by commit e0e80a02e5701c8790bd348ab59edb154fbda60b ("cpuset: use rebuild_sched_domains() in cpuset_hotplug_workfn()), which removed generate_sched_domains() from cpuset_hotplug_workfn(). Reported-by: Fengguang Wu <fengguang.wu@intel.com> Signed-off-by: Li Zefan <lizefan@huawei.com> Signed-off-by: Tejun Heo <tj@kernel.org>
2013-04-28Merge branch 'pm-assorted'Rafael J. Wysocki
* pm-assorted: PM / OPP: add documentation to RCU head in struct opp PM / sleep: invalidate TEST_CPUS and TEST_CORE support for freeze state PM / sleep: add TEST_PLATFORM support for freeze state
2013-04-27Merge branch 'perf-urgent-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull perf fix from Ingo Molnar: "This fix adds missing RCU read protection" * 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: events: Protect access via task_subsys_state_check()
2013-04-27cpuset: fix cpu hotplug vs rebuild_sched_domains() raceLi Zefan
rebuild_sched_domains() might pass doms with offlined cpu to partition_sched_domains(), which results in an oops: general protection fault: 0000 [#1] SMP ... RIP: 0010:[<ffffffff81077a1e>] [<ffffffff81077a1e>] get_group+0x6e/0x90 ... Call Trace: [<ffffffff8107f07c>] build_sched_domains+0x70c/0xcb0 [<ffffffff8107f2a7>] ? build_sched_domains+0x937/0xcb0 [<ffffffff81173f64>] ? kfree+0xe4/0x1b0 [<ffffffff8107f6e0>] ? partition_sched_domains+0xc0/0x470 [<ffffffff8107f905>] partition_sched_domains+0x2e5/0x470 [<ffffffff8107f6e0>] ? partition_sched_domains+0xc0/0x470 [<ffffffff810c9007>] ? generate_sched_domains+0xc7/0x530 [<ffffffff810c94a8>] rebuild_sched_domains_locked+0x38/0x70 [<ffffffff810cb4a4>] cpuset_write_resmask+0x1a4/0x500 [<ffffffff810c8700>] ? cpuset_mount+0xe0/0xe0 [<ffffffff810c7f50>] ? cpuset_read_u64+0x100/0x100 [<ffffffff810be890>] ? cgroup_iter_next+0x90/0x90 [<ffffffff810cb300>] ? cpuset_css_offline+0x70/0x70 [<ffffffff810c1a73>] cgroup_file_write+0x133/0x2e0 [<ffffffff8118995b>] vfs_write+0xcb/0x130 [<ffffffff8118a174>] sys_write+0x64/0xa0 Reported-by: Li Zhong <zhong@linux.vnet.ibm.com> Signed-off-by: Li Zefan <lizefan@huawei.com> Signed-off-by: Tejun Heo <tj@kernel.org>
2013-04-27cpuset: use rebuild_sched_domains() in cpuset_hotplug_workfn()Li Zhong
In cpuset_hotplug_workfn(), partition_sched_domains() is called without hotplug lock held, which is actually needed (stated in the function header of partition_sched_domains()). This patch tries to use rebuild_sched_domains() to solve the above issue, and makes the code looks a little simpler. Signed-off-by: Li Zhong <zhong@linux.vnet.ibm.com> Signed-off-by: Li Zefan <lizefan@huawei.com> Signed-off-by: Tejun Heo <tj@kernel.org>
2013-04-27Merge branch 'timers/nohz-v2' of ↵Ingo Molnar
git://git.kernel.org/pub/scm/linux/kernel/git/frederic/linux-dynticks into timers/nohz Pull more full-dynticks updates from Frederic Weisbecker: * Get rid of the passive dependency on VIRT_CPU_ACCOUNTING_GEN (finally!) * Preparation patch to remove the dependency on CONFIG_64BITS Signed-off-by: Ingo Molnar <mingo@kernel.org>
2013-04-26cgroup: restore the call to eventfd->poll()Li Zefan
I mistakenly removed the call to eventfd->poll() while I was actually intending to remove the return value... Calling evenfd->poll() will hook cgroup_event_wake() to the poll waitqueue, which will be called to unregister eventfd when rmdir a cgroup or close eventfd. Signed-off-by: Li Zefan <lizefan@huawei.com> Signed-off-by: Tejun Heo <tj@kernel.org>
2013-04-26cgroup: fix use-after-free when umounting cgroupfsLi Zefan
Try: # mount -t cgroup xxx /cgroup # mkdir /cgroup/sub && rmdir /cgroup/sub && umount /cgroup And you might see this: ida_remove called for id=1 which is not allocated. It's because cgroup_kill_sb() is called to destroy root->cgroup_ida and free cgrp->root before ida_simple_removed() is called. What's worse is we're accessing cgrp->root while it has been freed. Signed-off-by: Li Zefan <lizefan@huawei.com> Signed-off-by: Tejun Heo <tj@kernel.org>
2013-04-26nohz: Select VIRT_CPU_ACCOUNTING_GEN from full dynticks configFrederic Weisbecker
Turn the full dynticks passive dependency on VIRT_CPU_ACCOUNTING_GEN to an active one. The full dynticks Kconfig is currently hidden behind the full dynticks cputime accounting, which is an awkward and counter-intuitive layout: the user first has to select the dynticks cputime accounting in order to make the full dynticks feature to be visible. We definetly want it the other way around. The usual way to perform this kind of active dependency is use "select" on the depended target. Now we can't use the Kconfig "select" instruction when the target is a "choice". So this patch inspires on how the RCU subsystem Kconfig interact with its dependencies on SMP and PREEMPT: we make sure that cputime accounting can't propose another option than VIRT_CPU_ACCOUNTING_GEN when NO_HZ_FULL is selected by using the right "depends on" instruction for each cputime accounting choices. v2: Keep full dynticks cputime accounting available even without full dynticks, as per Paul McKenney's suggestion. Reported-by: Ingo Molnar <mingo@kernel.org> Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Cc: Christoph Lameter <cl@linux.com> Cc: Hakan Akkan <hakanakkan@gmail.com> Cc: Ingo Molnar <mingo@kernel.org> Cc: Kevin Hilman <khilman@linaro.org> Cc: Li Zhong <zhong@linux.vnet.ibm.com> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Paul Gortmaker <paul.gortmaker@windriver.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Thomas Gleixner <tglx@linutronix.de>
2013-04-26sched: Fix init NOHZ_IDLE flagVincent Guittot
On my SMP platform which is made of 5 cores in 2 clusters, I have the nr_busy_cpu field of sched_group_power struct that is not null when the platform is fully idle - which makes the scheduler unhappy. The root cause is: During the boot sequence, some CPUs reach the idle loop and set their NOHZ_IDLE flag while waiting for others CPUs to boot. But the nr_busy_cpus field is initialized later with the assumption that all CPUs are in the busy state whereas some CPUs have already set their NOHZ_IDLE flag. More generally, the NOHZ_IDLE flag must be initialized when new sched_domains are created in order to ensure that NOHZ_IDLE and nr_busy_cpus are aligned. This condition can be ensured by adding a synchronize_rcu() between the destruction of old sched_domains and the creation of new ones so the NOHZ_IDLE flag will not be updated with old sched_domain once it has been initialized. But this solution introduces a additionnal latency in the rebuild sequence that is called during cpu hotplug. As suggested by Frederic Weisbecker, another solution is to have the same rcu lifecycle for both NOHZ_IDLE and sched_domain struct. A new nohz_idle field is added to sched_domain so both status and sched_domain will share the same RCU lifecycle and will be always synchronized. In addition, there is no more need to protect nohz_idle against concurrent access as it is only modified by 2 exclusive functions called by local cpu. This solution has been prefered to the creation of a new struct with an extra pointer indirection for sched_domain. The synchronization is done at the cost of : - An additional indirection and a rcu_dereference for accessing nohz_idle. - We use only the nohz_idle field of the top sched_domain. Signed-off-by: Vincent Guittot <vincent.guittot@linaro.org> Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: linaro-kernel@lists.linaro.org Cc: peterz@infradead.org Cc: fweisbec@gmail.com Cc: pjt@google.com Cc: rostedt@goodmis.org Cc: efault@gmx.de Link: http://lkml.kernel.org/r/1366729142-14662-1-git-send-email-vincent.guittot@linaro.org [ Fixed !NO_HZ build bug. ] Signed-off-by: Ingo Molnar <mingo@kernel.org>
2013-04-26nohz: Reduce overhead under high-freq idling patternsIngo Molnar
One testbox of mine (Intel Nehalem, 16-way) uses MWAIT for its idle routine, which apparently can break out of its idle loop rather frequently, with high frequency. In that case NO_HZ_FULL=y kernels show high ksoftirqd overhead and constant context switching, because tick_nohz_stop_sched_tick() will, if delta_jiffies == 0, mis-identify this as a timer event - activating the TIMER_SOFTIRQ, which wakes up ksoftirqd. Fix this by treating delta_jiffies == 0 the same way we treat other short wakeups, delta_jiffies == 1. Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Chris Metcalf <cmetcalf@tilera.com> Cc: Christoph Lameter <cl@linux.com> Cc: Geoff Levand <geoff@infradead.org> Cc: Gilad Ben Yossef <gilad@benyossef.com> Cc: Hakan Akkan <hakanakkan@gmail.com> Cc: Kevin Hilman <khilman@linaro.org> Cc: Li Zhong <zhong@linux.vnet.ibm.com> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Paul Gortmaker <paul.gortmaker@windriver.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Steven Rostedt <rostedt@goodmis.org> Signed-off-by: Ingo Molnar <mingo@kernel.org>
2013-04-26lockdep: Consolidate bug messages into a single print_lockdep_off() functionDave Jones
Also add some missing printk levels. Signed-off-by: Dave Jones <davej@redhat.com> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Link: http://lkml.kernel.org/r/20130425174002.GA26769@redhat.com [ Tweaked the messages a bit. ] Signed-off-by: Ingo Molnar <mingo@kernel.org>
2013-04-26lockdep: Print out additional debugging advice when we hit lockdep BUGsDave Jones
We occasionally get reports of these BUGs being hit, and the stack trace doesn't necessarily always tell us what we need to know about why we are hitting those limits. If users start attaching /proc/lock_stats to reports we may have more of a clue what's going on. Signed-off-by: Dave Jones <davej@redhat.com> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Link: http://lkml.kernel.org/r/20130423163403.GA12839@redhat.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2013-04-25clockevents: Set dummy handler on CPU_DEAD shutdownThomas Gleixner
Vitaliy reported that a per cpu HPET timer interrupt crashes the system during hibernation. What happens is that the per cpu HPET timer gets shut down when the nonboot cpus are stopped. When the nonboot cpus are onlined again the HPET code sets up the MSI interrupt which fires before the clock event device is registered. The event handler is still set to hrtimer_interrupt, which then crashes the machine due to highres mode not being active. See http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=700333 There is no real good way to avoid that in the HPET code. The HPET code alrady has a mechanism to detect spurious interrupts when event handler == NULL for a similar reason. We can handle that in the clockevent/tick layer and replace the previous functional handler with a dummy handler like we do in tick_setup_new_device(). The original clockevents code did this in clockevents_exchange_device(), but that got removed by commit 7c1e76897 (clockevents: prevent clockevent event_handler ending up handler_noop) which forgot to fix it up in tick_shutdown(). Same issue with the broadcast device. Reported-by: Vitaliy Fillipov <vitalif@yourcmc.ru> Cc: Ben Hutchings <ben@decadent.org.uk> Cc: stable@vger.kernel.org Cc: 700333@bugs.debian.org Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2013-04-24Merge branch 'linus' into timers/coreThomas Gleixner
Reason: Get upstream fixes before adding conflicting code. Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2013-04-24nohz: Remove full dynticks' superfluous dependency on RCU treeFrederic Weisbecker
Remove the dependency on (TREE_RCU || TREE_PREEMPT_RCU). The full dynticks option already depends on SMP which implies (whatever flavour of) RCU tree config anyway. Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Cc: Chris Metcalf <cmetcalf@tilera.com> Cc: Christoph Lameter <cl@linux.com> Cc: Geoff Levand <geoff@infradead.org> Cc: Gilad Ben Yossef <gilad@benyossef.com> Cc: Hakan Akkan <hakanakkan@gmail.com> Cc: Ingo Molnar <mingo@kernel.org> Cc: Kevin Hilman <khilman@linaro.org> Cc: Li Zhong <zhong@linux.vnet.ibm.com> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Paul Gortmaker <paul.gortmaker@windriver.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Thomas Gleixner <tglx@linutronix.de>
2013-04-24sched: Prevent to re-select dst-cpu in load_balance()Joonsoo Kim
Commit 88b8dac0 makes load_balance() consider other cpus in its group. But, in that, there is no code for preventing to re-select dst-cpu. So, same dst-cpu can be selected over and over. This patch add functionality to load_balance() in order to exclude cpu which is selected once. We prevent to re-select dst_cpu via env's cpus, so now, env's cpus is a candidate not only for src_cpus, but also dst_cpus. With this patch, we can remove lb_iterations and max_lb_iterations, because we decide whether we can go ahead or not via env's cpus. Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@lge.com> Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Tested-by: Jason Low <jason.low2@hp.com> Cc: Srivatsa Vaddagiri <vatsa@linux.vnet.ibm.com> Cc: Davidlohr Bueso <davidlohr.bueso@hp.com> Cc: Peter Zijlstra <peterz@infradead.org> Link: http://lkml.kernel.org/r/1366705662-3587-7-git-send-email-iamjoonsoo.kim@lge.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2013-04-24sched: Rename load_balance_tmpmask to load_balance_maskJoonsoo Kim
This name doesn't represent specific meaning. So rename it to imply it's purpose. Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@lge.com> Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Tested-by: Jason Low <jason.low2@hp.com> Cc: Srivatsa Vaddagiri <vatsa@linux.vnet.ibm.com> Cc: Davidlohr Bueso <davidlohr.bueso@hp.com> Cc: Peter Zijlstra <peterz@infradead.org> Link: http://lkml.kernel.org/r/1366705662-3587-6-git-send-email-iamjoonsoo.kim@lge.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2013-04-24sched: Move up affinity check to mitigate useless redoing overheadJoonsoo Kim
Currently, LBF_ALL_PINNED is cleared after affinity check is passed. So, if task migration is skipped by small load value or small imbalance value in move_tasks(), we don't clear LBF_ALL_PINNED. At last, we trigger 'redo' in load_balance(). Imbalance value is often so small that any tasks cannot be moved to other cpus and, of course, this situation may be continued after we change the target cpu. So this patch move up affinity check code and clear LBF_ALL_PINNED before evaluating load value in order to mitigate useless redoing overhead. In addition, re-order some comments correctly. Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@lge.com> Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Tested-by: Jason Low <jason.low2@hp.com> Cc: Srivatsa Vaddagiri <vatsa@linux.vnet.ibm.com> Cc: Davidlohr Bueso <davidlohr.bueso@hp.com> Cc: Peter Zijlstra <peterz@infradead.org> Link: http://lkml.kernel.org/r/1366705662-3587-5-git-send-email-iamjoonsoo.kim@lge.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2013-04-24sched: Don't consider other cpus in our group in case of NEWLY_IDLEJoonsoo Kim
Commit 88b8dac0 makes load_balance() consider other cpus in its group, regardless of idle type. When we do NEWLY_IDLE balancing, we should not consider it, because a motivation of NEWLY_IDLE balancing is to turn this cpu to non idle state if needed. This is not the case of other cpus. So, change code not to consider other cpus for NEWLY_IDLE balancing. With this patch, assign 'if (pulled_task) this_rq->idle_stamp = 0' in idle_balance() is corrected, because NEWLY_IDLE balancing doesn't consider other cpus. Assigning to 'this_rq->idle_stamp' is now valid. Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@lge.com> Tested-by: Jason Low <jason.low2@hp.com> Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Srivatsa Vaddagiri <vatsa@linux.vnet.ibm.com> Cc: Davidlohr Bueso <davidlohr.bueso@hp.com> Cc: Peter Zijlstra <peterz@infradead.org> Link: http://lkml.kernel.org/r/1366705662-3587-4-git-send-email-iamjoonsoo.kim@lge.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2013-04-24sched: Explicitly cpu_idle_type checking in rebalance_domains()Joonsoo Kim
After commit 88b8dac0, dst-cpu can be changed in load_balance(), then we can't know cpu_idle_type of dst-cpu when load_balance() return positive. So, add explicit cpu_idle_type checking. Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@lge.com> Tested-by: Jason Low <jason.low2@hp.com> Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Srivatsa Vaddagiri <vatsa@linux.vnet.ibm.com> Cc: Davidlohr Bueso <davidlohr.bueso@hp.com> Cc: Peter Zijlstra <peterz@infradead.org> Link: http://lkml.kernel.org/r/1366705662-3587-3-git-send-email-iamjoonsoo.kim@lge.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2013-04-24sched: Change position of resched_cpu() in load_balance()Joonsoo Kim
cur_ld_moved is reset if env.flags hit LBF_NEED_BREAK. So, there is possibility that we miss doing resched_cpu(). Correct it as changing position of resched_cpu() before checking LBF_NEED_BREAK. Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@lge.com> Tested-by: Jason Low <jason.low2@hp.com> Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Srivatsa Vaddagiri <vatsa@linux.vnet.ibm.com> Cc: Davidlohr Bueso <davidlohr.bueso@hp.com> Cc: Peter Zijlstra <peterz@infradead.org> Link: http://lkml.kernel.org/r/1366705662-3587-2-git-send-email-iamjoonsoo.kim@lge.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2013-04-22Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/netDavid S. Miller
Conflicts: drivers/net/ethernet/emulex/benet/be_main.c drivers/net/ethernet/intel/igb/igb_main.c drivers/net/wireless/brcm80211/brcmsmac/mac80211_if.c include/net/scm.h net/batman-adv/routing.c net/ipv4/tcp_input.c The e{uid,gid} --> {uid,gid} credentials fix conflicted with the cleanup in net-next to now pass cred structs around. The be2net driver had a bug fix in 'net' that overlapped with the VLAN interface changes by Patrick McHardy in net-next. An IGB conflict existed because in 'net' the build_skb() support was reverted, and in 'net-next' there was a comment style fix within that code. Several batman-adv conflicts were resolved by making sure that all calls to batadv_is_my_mac() are changed to have a new bat_priv first argument. Eric Dumazet's TS ECR fix in TCP in 'net' conflicted with the F-RTO rewrite in 'net-next', mostly overlapping changes. Thanks to Stephen Rothwell and Antonio Quartulli for help with several of these merge resolutions. Signed-off-by: David S. Miller <davem@davemloft.net>
2013-04-22nohz: Add basic tracingFrederic Weisbecker
It's not obvious to find out why the full dynticks subsystem doesn't always stop the tick: whether this is due to kthreads, posix timers, perf events, etc... These new tracepoints are here to help the user diagnose the failures and test this feature. Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Cc: Chris Metcalf <cmetcalf@tilera.com> Cc: Christoph Lameter <cl@linux.com> Cc: Geoff Levand <geoff@infradead.org> Cc: Gilad Ben Yossef <gilad@benyossef.com> Cc: Hakan Akkan <hakanakkan@gmail.com> Cc: Ingo Molnar <mingo@kernel.org> Cc: Kevin Hilman <khilman@linaro.org> Cc: Li Zhong <zhong@linux.vnet.ibm.com> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Paul Gortmaker <paul.gortmaker@windriver.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Thomas Gleixner <tglx@linutronix.de>
2013-04-22nohz: Select wide RCU nocb for full dynticksFrederic Weisbecker
It makes testing and implementation much easier as we know in advance that all CPUs are RCU nocbs. Also this prepares to remove the dynamic check for nohz_full= boot mask to be a subset of rcu_nocbs= Eventually this should also help removing the requirement for the boot CPU to be outside the full dynticks range. Suggested-by: Christoph Lameter <cl@linux.com> Suggested-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Cc: Chris Metcalf <cmetcalf@tilera.com> Cc: Christoph Lameter <cl@linux.com> Cc: Geoff Levand <geoff@infradead.org> Cc: Gilad Ben Yossef <gilad@benyossef.com> Cc: Hakan Akkan <hakanakkan@gmail.com> Cc: Ingo Molnar <mingo@kernel.org> Cc: Kevin Hilman <khilman@linaro.org> Cc: Li Zhong <zhong@linux.vnet.ibm.com> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Paul Gortmaker <paul.gortmaker@windriver.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Thomas Gleixner <tglx@linutronix.de>
2013-04-22nohz: Disable the tick when irq resume in full dynticks CPUFrederic Weisbecker
Eventually try to disable tick on irq exit, now that the fundamental infrastructure is in place. Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Cc: Chris Metcalf <cmetcalf@tilera.com> Cc: Christoph Lameter <cl@linux.com> Cc: Geoff Levand <geoff@infradead.org> Cc: Gilad Ben Yossef <gilad@benyossef.com> Cc: Hakan Akkan <hakanakkan@gmail.com> Cc: Ingo Molnar <mingo@kernel.org> Cc: Kevin Hilman <khilman@linaro.org> Cc: Li Zhong <zhong@linux.vnet.ibm.com> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Paul Gortmaker <paul.gortmaker@windriver.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Thomas Gleixner <tglx@linutronix.de>
2013-04-22nohz: Re-evaluate the tick for the new task after a context switchFrederic Weisbecker
When a task is scheduled in, it may have some properties of its own that could make the CPU reconsider the need for the tick: posix cpu timers, perf events, ... So notify the full dynticks subsystem when a task gets scheduled in and re-check the tick dependency at this stage. This is done through a self IPI to avoid messing up with any current lock scenario. Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Cc: Chris Metcalf <cmetcalf@tilera.com> Cc: Christoph Lameter <cl@linux.com> Cc: Geoff Levand <geoff@infradead.org> Cc: Gilad Ben Yossef <gilad@benyossef.com> Cc: Hakan Akkan <hakanakkan@gmail.com> Cc: Ingo Molnar <mingo@kernel.org> Cc: Kevin Hilman <khilman@linaro.org> Cc: Li Zhong <zhong@linux.vnet.ibm.com> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Paul Gortmaker <paul.gortmaker@windriver.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Thomas Gleixner <tglx@linutronix.de>
2013-04-22nohz: Prepare to stop the tick on irq exitFrederic Weisbecker
Interrupt exit is a natural place to stop the tick: it happens after all events happening before and during the irq which are liable to update the dependency on the tick occured. Also it makes sure that any check on tick dependency is well ordered against dynticks kick IPIs. Bring in the infrastructure that performs the tick dependency checks on irq exit and shut it down if these checks show that we can do it safely. Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Cc: Chris Metcalf <cmetcalf@tilera.com> Cc: Christoph Lameter <cl@linux.com> Cc: Geoff Levand <geoff@infradead.org> Cc: Gilad Ben Yossef <gilad@benyossef.com> Cc: Hakan Akkan <hakanakkan@gmail.com> Cc: Ingo Molnar <mingo@kernel.org> Cc: Kevin Hilman <khilman@linaro.org> Cc: Li Zhong <zhong@linux.vnet.ibm.com> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Paul Gortmaker <paul.gortmaker@windriver.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Thomas Gleixner <tglx@linutronix.de>
2013-04-22nohz: Implement full dynticks kickFrederic Weisbecker
Implement the full dynticks kick that is performed from IPIs sent by various subsystems (scheduler, posix timers, ...) when they want to notify about a new event that may reconsider the dependency on the tick. Most of the time, such an event end up restarting the tick. (Part of the design with subsystems providing *_can_stop_tick() helpers suggested by Peter Zijlstra a while ago). Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Cc: Chris Metcalf <cmetcalf@tilera.com> Cc: Christoph Lameter <cl@linux.com> Cc: Geoff Levand <geoff@infradead.org> Cc: Gilad Ben Yossef <gilad@benyossef.com> Cc: Hakan Akkan <hakanakkan@gmail.com> Cc: Ingo Molnar <mingo@kernel.org> Cc: Kevin Hilman <khilman@linaro.org> Cc: Li Zhong <zhong@linux.vnet.ibm.com> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Paul Gortmaker <paul.gortmaker@windriver.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Thomas Gleixner <tglx@linutronix.de>
2013-04-22timekeeping: Update tk->cycle_last in resumeThomas Gleixner
commit 7ec98e15aa (timekeeping: Delay update of clock->cycle_last) forgot to update tk->cycle_last in the resume path. This results in a stale value versus clock->cycle_last and prevents resume in the worst case. Reported-by: Jiri Slaby <jslaby@suse.cz> Reported-and-tested-by: Borislav Petkov <bp@alien8.de> Acked-by: John Stultz <john.stultz@linaro.org> Cc: Linux-pm mailing list <linux-pm@lists.linux-foundation.org> Link: http://lkml.kernel.org/r/alpine.LFD.2.02.1304211648150.21884@ionos Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2013-04-22nohz: Re-evaluate the tick from the scheduler IPIFrederic Weisbecker
The scheduler IPI is used by the scheduler to kick full dynticks CPUs asynchronously when more than one task are running or when a new timer list timer is enqueued. This way the destination CPU can decide to restart the tick to handle this new situation. Now let's call that kick in the scheduler IPI. (Reusing the scheduler IPI rather than implementing a new IPI was suggested by Peter Zijlstra a while ago) Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Cc: Chris Metcalf <cmetcalf@tilera.com> Cc: Christoph Lameter <cl@linux.com> Cc: Geoff Levand <geoff@infradead.org> Cc: Gilad Ben Yossef <gilad@benyossef.com> Cc: Hakan Akkan <hakanakkan@gmail.com> Cc: Ingo Molnar <mingo@kernel.org> Cc: Kevin Hilman <khilman@linaro.org> Cc: Li Zhong <zhong@linux.vnet.ibm.com> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Paul Gortmaker <paul.gortmaker@windriver.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Thomas Gleixner <tglx@linutronix.de>
2013-04-22sched: New helper to prevent from stopping the tick in full dynticksFrederic Weisbecker
Provide a new helper to be called from the full dynticks engine before stopping the tick in order to make sure we don't stop it when there is more than one task running on the CPU. This way we make sure that the tick stays alive to maintain fairness. Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Cc: Chris Metcalf <cmetcalf@tilera.com> Cc: Christoph Lameter <cl@linux.com> Cc: Geoff Levand <geoff@infradead.org> Cc: Gilad Ben Yossef <gilad@benyossef.com> Cc: Hakan Akkan <hakanakkan@gmail.com> Cc: Ingo Molnar <mingo@kernel.org> Cc: Kevin Hilman <khilman@linaro.org> Cc: Li Zhong <zhong@linux.vnet.ibm.com> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Paul Gortmaker <paul.gortmaker@windriver.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Thomas Gleixner <tglx@linutronix.de>
2013-04-22sched: Kick full dynticks CPU that have more than one task enqueued.Frederic Weisbecker
Kick the tick on full dynticks CPUs when they get more than one task running on their queue. This makes sure that local fairness is maintained by the tick on the destination. This is done regardless of these tasks' class. We should be able to be more clever in the future depending on these. eg: a CPU that runs a SCHED_FIFO task doesn't need to maintain fairness against local pending tasks of the fair class. But keep things simple for now. Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Cc: Chris Metcalf <cmetcalf@tilera.com> Cc: Christoph Lameter <cl@linux.com> Cc: Geoff Levand <geoff@infradead.org> Cc: Gilad Ben Yossef <gilad@benyossef.com> Cc: Hakan Akkan <hakanakkan@gmail.com> Cc: Ingo Molnar <mingo@kernel.org> Cc: Kevin Hilman <khilman@linaro.org> Cc: Li Zhong <zhong@linux.vnet.ibm.com> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Paul Gortmaker <paul.gortmaker@windriver.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Thomas Gleixner <tglx@linutronix.de>
2013-04-22perf: New helper to prevent full dynticks CPUs from stopping tickFrederic Weisbecker
Provide a new helper that help full dynticks CPUs to prevent from stopping their tick in case there are events in the local rotation list. This way we make sure that perf_event_task_tick() is serviced on demand. Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Cc: Chris Metcalf <cmetcalf@tilera.com> Cc: Christoph Lameter <cl@linux.com> Cc: Geoff Levand <geoff@infradead.org> Cc: Gilad Ben Yossef <gilad@benyossef.com> Cc: Hakan Akkan <hakanakkan@gmail.com> Cc: Ingo Molnar <mingo@kernel.org> Cc: Kevin Hilman <khilman@linaro.org> Cc: Li Zhong <zhong@linux.vnet.ibm.com> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Paul Gortmaker <paul.gortmaker@windriver.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Stephane Eranian <eranian@google.com> Cc: Jiri Olsa <jolsa@redhat.com>
2013-04-22perf: Kick full dynticks CPU if events rotation is neededFrederic Weisbecker
Kick the current CPU's tick by sending it a self IPI when an event is queued on the rotation list and it is the first element inserted. This makes sure that perf_event_task_tick() works on full dynticks CPUs. Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Cc: Chris Metcalf <cmetcalf@tilera.com> Cc: Christoph Lameter <cl@linux.com> Cc: Geoff Levand <geoff@infradead.org> Cc: Gilad Ben Yossef <gilad@benyossef.com> Cc: Hakan Akkan <hakanakkan@gmail.com> Cc: Ingo Molnar <mingo@kernel.org> Cc: Kevin Hilman <khilman@linaro.org> Cc: Li Zhong <zhong@linux.vnet.ibm.com> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Paul Gortmaker <paul.gortmaker@windriver.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Stephane Eranian <eranian@google.com> Cc: Jiri Olsa <jolsa@redhat.com>
2013-04-22posix_timers: Fix pre-condition to stop the tick on full dynticksFrederic Weisbecker
The test that checks if a CPU can stop its tick from posix CPU timers angle was mistakenly inverted. What we want is to prevent the tick from being stopped as long as the current CPU's task runs a posix CPU timer. Fix this. Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Cc: Chris Metcalf <cmetcalf@tilera.com> Cc: Christoph Lameter <cl@linux.com> Cc: Geoff Levand <geoff@infradead.org> Cc: Gilad Ben Yossef <gilad@benyossef.com> Cc: Hakan Akkan <hakanakkan@gmail.com> Cc: Ingo Molnar <mingo@kernel.org> Cc: Kevin Hilman <khilman@linaro.org> Cc: Li Zhong <zhong@linux.vnet.ibm.com> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Paul Gortmaker <paul.gortmaker@windriver.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Thomas Gleixner <tglx@linutronix.de>
2013-04-22kernel/hz.bc: ignore.Rusty Russell
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-04-21Merge branch 'perf-urgent-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull perf fixes from Ingo Molnar: "Misc fixes" * 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: perf/x86: Fix offcore_rsp valid mask for SNB/IVB perf: Treat attr.config as u64 in perf_swevent_init()
2013-04-21sched: Fix wrong rq's runnable_avg update with rt tasksVincent Guittot
The current update of the rq's load can be erroneous when RT tasks are involved. The update of the load of a rq that becomes idle, is done only if the avg_idle is less than sysctl_sched_migration_cost. If RT tasks and short idle duration alternate, the runnable_avg will not be updated correctly and the time will be accounted as idle time when a CFS task wakes up. A new idle_enter function is called when the next task is the idle function so the elapsed time will be accounted as run time in the load of the rq, whatever the average idle time is. The function update_rq_runnable_avg is removed from idle_balance. When a RT task is scheduled on an idle CPU, the update of the rq's load is not done when the rq exit idle state because CFS's functions are not called. Then, the idle_balance, which is called just before entering the idle function, updates the rq's load and makes the assumption that the elapsed time since the last update, was only running time. As a consequence, the rq's load of a CPU that only runs a periodic RT task, is close to LOAD_AVG_MAX whatever the running duration of the RT task is. A new idle_exit function is called when the prev task is the idle function so the elapsed time will be accounted as idle time in the rq's load. Signed-off-by: Vincent Guittot <vincent.guittot@linaro.org> Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Acked-by: Steven Rostedt <rostedt@goodmis.org> Cc: linaro-kernel@lists.linaro.org Cc: peterz@infradead.org Cc: pjt@google.com Cc: fweisbec@gmail.com Cc: efault@gmx.de Link: http://lkml.kernel.org/r/1366302867-5055-1-git-send-email-vincent.guittot@linaro.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2013-04-21events: Protect access via task_subsys_state_check()Paul E. McKenney
The following RCU splat indicates lack of RCU protection: [ 953.267649] =============================== [ 953.267652] [ INFO: suspicious RCU usage. ] [ 953.267657] 3.9.0-0.rc6.git2.4.fc19.ppc64p7 #1 Not tainted [ 953.267661] ------------------------------- [ 953.267664] include/linux/cgroup.h:534 suspicious rcu_dereference_check() usage! [ 953.267669] [ 953.267669] other info that might help us debug this: [ 953.267669] [ 953.267675] [ 953.267675] rcu_scheduler_active = 1, debug_locks = 0 [ 953.267680] 1 lock held by glxgears/1289: [ 953.267683] #0: (&sig->cred_guard_mutex){+.+.+.}, at: [<c00000000027f884>] .prepare_bprm_creds+0x34/0xa0 [ 953.267700] [ 953.267700] stack backtrace: [ 953.267704] Call Trace: [ 953.267709] [c0000001f0d1b6e0] [c000000000016e30] .show_stack+0x130/0x200 (unreliable) [ 953.267717] [c0000001f0d1b7b0] [c0000000001267f8] .lockdep_rcu_suspicious+0x138/0x180 [ 953.267724] [c0000001f0d1b840] [c0000000001d43a4] .perf_event_comm+0x4c4/0x690 [ 953.267731] [c0000001f0d1b950] [c00000000027f6e4] .set_task_comm+0x84/0x1f0 [ 953.267737] [c0000001f0d1b9f0] [c000000000280414] .setup_new_exec+0x94/0x220 [ 953.267744] [c0000001f0d1ba70] [c0000000002f665c] .load_elf_binary+0x58c/0x19b0 ... This commit therefore adds the required RCU read-side critical section to perf_event_comm(). Reported-by: Adam Jackson <ajax@redhat.com> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: a.p.zijlstra@chello.nl Cc: paulus@samba.org Cc: acme@ghostprotocols.net Link: http://lkml.kernel.org/r/20130419190124.GA8638@linux.vnet.ibm.com Signed-off-by: Ingo Molnar <mingo@kernel.org> Tested-by: Gustavo Luiz Duarte <gusld@br.ibm.com>
2013-04-21Merge branch 'timers/nohz-posix-timers-v2' of ↵Ingo Molnar
git://git.kernel.org/pub/scm/linux/kernel/git/frederic/linux-dynticks into timers/nohz Pull posix cpu timers handling on full dynticks from Frederic Weisbecker. Signed-off-by: Ingo Molnar <mingo@kernel.org>
2013-04-21Merge branch 'perf/urgent' into perf/coreIngo Molnar
Conflicts: arch/x86/kernel/cpu/perf_event_intel.c Merge in the latest fixes before applying new patches, resolve the conflict. Signed-off-by: Ingo Molnar <mingo@kernel.org>
2013-04-20Merge branch 'x86-kdump-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull kdump fixes from Peter Anvin: "The kexec/kdump people have found several problems with the support for loading over 4 GiB that was introduced in this merge cycle. This is partly due to a number of design problems inherent in the way the various pieces of kdump fit together (it is pretty horrifically manual in many places.) After a *lot* of iterations this is the patchset that was agreed upon, but of course it is now very late in the cycle. However, because it changes both the syntax and semantics of the crashkernel option, it would be desirable to avoid a stable release with the broken interfaces." I'm not happy with the timing, since originally the plan was to release the final 3.9 tomorrow. But apparently I'm doing an -rc8 instead... * 'x86-kdump-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: kexec: use Crash kernel for Crash kernel low x86, kdump: Change crashkernel_high/low= to crashkernel=,high/low x86, kdump: Retore crashkernel= to allocate under 896M x86, kdump: Set crashkernel_low automatically
2013-04-19tracepoints: Prevent null probe from being addedSahara
Somehow tracepoint_entry_add_probe() function allows a null probe function. And, this may lead to unexpected results since the number of probe functions in an entry can be counted by checking whether a probe is null or not in the for-loop. This patch prevents a null probe from being added. In tracepoint_entry_remove_probe() function, checking probe parameter within the for-loop is moved out for code efficiency, leaving the null probe feature which removes all probe functions in the entry. Link: http://lkml.kernel.org/r/1365991995-19445-1-git-send-email-kpark3469@gmail.com Reviewed-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Acked-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Signed-off-by: Sahara <keun-o.park@windriver.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2013-04-19posix_timers: New API to prevent from stopping the tick when timers are runningFrederic Weisbecker
Bring a new helper that the full dynticks infrastructure can call in order to know if it can safely stop the tick from the posix cpu timers subsystem point of view. Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Cc: Chris Metcalf <cmetcalf@tilera.com> Cc: Christoph Lameter <cl@linux.com> Cc: Geoff Levand <geoff@infradead.org> Cc: Gilad Ben Yossef <gilad@benyossef.com> Cc: Hakan Akkan <hakanakkan@gmail.com> Cc: Ingo Molnar <mingo@kernel.org> Cc: Kevin Hilman <khilman@linaro.org> Cc: Li Zhong <zhong@linux.vnet.ibm.com> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Paul Gortmaker <paul.gortmaker@windriver.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Thomas Gleixner <tglx@linutronix.de>
2013-04-19posix_timers: Kick full dynticks CPUs when a posix cpu timer is armedFrederic Weisbecker
Kick the full dynticks CPUs when a posix cpu timer is enqueued by way of a standard call to posix_cpu_timer_set() or set_process_cpu_timer(). This also include rescheduled firing timers. This way they can re-evaluate the state of (and possibly restart) their tick against the new expiry modification. Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Cc: Chris Metcalf <cmetcalf@tilera.com> Cc: Christoph Lameter <cl@linux.com> Cc: Geoff Levand <geoff@infradead.org> Cc: Gilad Ben Yossef <gilad@benyossef.com> Cc: Hakan Akkan <hakanakkan@gmail.com> Cc: Ingo Molnar <mingo@kernel.org> Cc: Kevin Hilman <khilman@linaro.org> Cc: Li Zhong <zhong@linux.vnet.ibm.com> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Paul Gortmaker <paul.gortmaker@windriver.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Thomas Gleixner <tglx@linutronix.de>
2013-04-19nohz: New option to default all CPUs in full dynticks rangeFrederic Weisbecker
Provide a new kernel config that defaults all CPUs to be part of the full dynticks range, except the boot one for timekeeping. This default setting is overriden by the nohz_full= boot option if passed by the user. This is helpful for those who don't need a finegrained range of full dynticks CPU and also for automated testing. Suggested-by: Ingo Molnar <mingo@kernel.org> Reviewed-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Chris Metcalf <cmetcalf@tilera.com> Cc: Christoph Lameter <cl@linux.com> Cc: Geoff Levand <geoff@infradead.org> Cc: Gilad Ben Yossef <gilad@benyossef.com> Cc: Hakan Akkan <hakanakkan@gmail.com> Cc: Ingo Molnar <mingo@kernel.org> Cc: Kevin Hilman <khilman@linaro.org> Cc: Li Zhong <zhong@linux.vnet.ibm.com> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Paul Gortmaker <paul.gortmaker@windriver.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Thomas Gleixner <tglx@linutronix.de>