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2015-02-06Merge branch 'core-urgent-for-linus' of ↵Linus Torvalds1-0/+2
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull core kernel fixes from Ingo Molnar: "Two liblockdep fixes and a CPU hotplug race fix" * 'core-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: tools/liblockdep: don't include host headers tools/liblockdep: ignore generated .so file smpboot: Add missing get_online_cpus() in smpboot_register_percpu_thread()
2015-02-06livepatch: add missing newline to error messageJosh Poimboeuf1-1/+1
Signed-off-by: Josh Poimboeuf <[email protected]> Signed-off-by: Jiri Kosina <[email protected]>
2015-02-06module: Remove double spaces in module verification taint messageMarcel Holtmann1-1/+1
The warning message when loading modules with a wrong signature has two spaces in it: "module verification failed: signature and/or required key missing" Signed-off-by: Marcel Holtmann <[email protected]> Signed-off-by: Rusty Russell <[email protected]>
2015-02-06kernel/module.c: Free lock-classes if parse_args failedAndrey Tsyvarev1-0/+3
parse_args call module parameters' .set handlers, which may use locks defined in the module. So, these classes should be freed in case parse_args returns error(e.g. due to incorrect parameter passed). Signed-off-by: Andrey Tsyvarev <[email protected]> Signed-off-by: Rusty Russell <[email protected]>
2015-02-05Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/netDavid S. Miller2-5/+15
Conflicts: drivers/net/vxlan.c drivers/vhost/net.c include/linux/if_vlan.h net/core/dev.c The net/core/dev.c conflict was the overlap of one commit marking an existing function static whilst another was adding a new function. In the include/linux/if_vlan.h case, the type used for a local variable was changed in 'net', whereas the function got rewritten to fix a stacked vlan bug in 'net-next'. In drivers/vhost/net.c, Al Viro's iov_iter conversions in 'net-next' overlapped with an endainness fix for VHOST 1.0 in 'net'. In drivers/net/vxlan.c, vxlan_find_vni() added a 'flags' parameter in 'net-next' whereas in 'net' there was a bug fix to pass in the correct network namespace pointer in calls to this function. Signed-off-by: David S. Miller <[email protected]>
2015-02-05resources: Move struct resource_list_entry from ACPI into resource coreJiang Liu1-0/+25
Currently ACPI, PCI and pnp all implement the same resource list management with different data structure. We need to transfer from one data structure into another when passing resources from one subsystem into another subsystem. So move struct resource_list_entry from ACPI into resource core and rename it as resource_entry, then it could be reused by different subystems and avoid the data structure conversion. Introduce dedicated header file resource_ext.h instead of embedding it into ioport.h to avoid header file inclusion order issues. Signed-off-by: Jiang Liu <[email protected]> Acked-by: Vinod Koul <[email protected]> Signed-off-by: Rafael J. Wysocki <[email protected]>
2015-02-05hrtimer: Fix incorrect tai offset calculation for non high-res timer systemsJohn Stultz1-1/+1
I noticed some CLOCK_TAI timer test failures on one of my less-frequently used configurations. And after digging in I found in 76f4108892d9 (Cleanup hrtimer accessors to the timekepeing state), the hrtimer_get_softirq_time tai offset calucation was incorrectly rewritten, as the tai offset we return shold be from CLOCK_MONOTONIC, and not CLOCK_REALTIME. This results in CLOCK_TAI timers expiring early on non-highres capable machines. This patch fixes the issue, calculating the tai time properly from the monotonic base. Signed-off-by: John Stultz <[email protected]> Cc: Thomas Gleixner <[email protected]> Cc: stable <[email protected]> # 3.17+ Link: http://lkml.kernel.org/r/[email protected] Signed-off-by: Ingo Molnar <[email protected]>
2015-02-04livepatch: rename config to CONFIG_LIVEPATCHJosh Poimboeuf2-4/+4
Rename CONFIG_LIVE_PATCHING to CONFIG_LIVEPATCH to make the naming of the config and the code more consistent. Signed-off-by: Josh Poimboeuf <[email protected]> Reviewed-by: Jingoo Han <[email protected]> Signed-off-by: Jiri Kosina <[email protected]>
2015-02-04perf: Decouple unthrottling and rotatingMark Rutland1-52/+29
Currently the adjusments made as part of perf_event_task_tick() use the percpu rotation lists to iterate over any active PMU contexts, but these are not used by the context rotation code, having been replaced by separate (per-context) hrtimer callbacks. However, some manipulation of the rotation lists (i.e. removal of contexts) has remained in perf_rotate_context(). This leads to the following issues: * Contexts are not always removed from the rotation lists. Removal of PMUs which have been placed in rotation lists, but have not been removed by a hrtimer callback can result in corruption of the rotation lists (when memory backing the context is freed). This has been observed to result in hangs when PMU drivers built as modules are inserted and removed around the creation of events for said PMUs. * Contexts which do not require rotation may be removed from the rotation lists as a result of a hrtimer, and will not be considered by the unthrottling code in perf_event_task_tick. This patch fixes the issue by updating the rotation ist when events are scheduled in/out, ensuring that each rotation list stays in sync with the HW state. As each event holds a refcount on the module of its PMU, this ensures that when a PMU module is unloaded none of its CPU contexts can be in a rotation list. By maintaining a list of perf_event_contexts rather than perf_event_cpu_contexts, we don't need separate paths to handle the cpu and task contexts, which also makes the code a little simpler. As the rotation_list variables are not used for rotation, these are renamed to active_ctx_list, which better matches their current function. perf_pmu_rotate_{start,stop} are renamed to perf_pmu_ctx_{activate,deactivate}. Reported-by: Johannes Jensen <[email protected]> Signed-off-by: Mark Rutland <[email protected]> Signed-off-by: Peter Zijlstra (Intel) <[email protected]> Cc: Will Deacon <[email protected]> Cc: Arnaldo Carvalho de Melo <[email protected]> Cc: Fengguang Wu <[email protected]> Cc: Linus Torvalds <[email protected]> Link: http://lkml.kernel.org/r/20150129134511.GR17721@leverpostej Signed-off-by: Ingo Molnar <[email protected]>
2015-02-04perf: Drop module reference on event init failureMark Rutland1-12/+16
When initialising an event, perf_init_event will call try_module_get() to ensure that the PMU's module cannot be removed for the lifetime of the event, with __free_event() dropping the reference when the event is finally destroyed. If something fails after the event has been initialised, but before the event is installed, perf_event_alloc will drop the reference on the module. However, if we fail to initialise an event for some reason (e.g. we ask an uncore PMU to perform sampling, and it refuses to initialise the event), we do not drop the refcount. If we try to open such a bogus event without a precise IDR type, we will loop over each PMU in the pmus list, incrementing each of their refcounts without decrementing them. This patch adds a module_put when pmu->event_init(event) fails, ensuring that the refcounts are balanced in failure cases. As the innards of the precise and search based initialisation look very similar, this logic is hoisted out into a new helper function. While the early return for the failed try_module_get is removed from the search case, this is handled by the remaining return when ret is not -ENOENT. Signed-off-by: Mark Rutland <[email protected]> Signed-off-by: Peter Zijlstra (Intel) <[email protected]> Cc: Will Deacon <[email protected]> Cc: Arnaldo Carvalho de Melo <[email protected]> Cc: Linus Torvalds <[email protected]> Link: http://lkml.kernel.org/r/[email protected] Signed-off-by: Ingo Molnar <[email protected]>
2015-02-04perf: Use POLLIN instead of POLL_IN for perf poll data in flagJiri Olsa1-1/+2
Currently we flag available data (via poll syscall) on perf fd with POLL_IN macro, which is normally used for SIGIO interface. We've been lucky, because POLLIN (0x1) is subset of POLL_IN (0x20001) and sys_poll (do_pollfd function) cut the extra bit out (0x20000). Signed-off-by: Jiri Olsa <[email protected]> Signed-off-by: Peter Zijlstra (Intel) <[email protected]> Cc: Frederic Weisbecker <[email protected]> Cc: Namhyung Kim <[email protected]> Cc: Stephane Eranian <[email protected]> Cc: Arnaldo Carvalho de Melo <[email protected]> Cc: Linus Torvalds <[email protected]> Link: http://lkml.kernel.org/r/[email protected] Signed-off-by: Ingo Molnar <[email protected]>
2015-02-04perf: Fix put_event() ctx lockPeter Zijlstra1-5/+12
So what I suspect; but I'm in zombie mode today it seems; is that while I initially thought that it was impossible for ctx to change when refcount dropped to 0, I now suspect its possible. Note that until perf_remove_from_context() the event is still active and visible on the lists. So a concurrent sys_perf_event_open() from another task into this task can race. Reported-by: Vince Weaver <[email protected]> Signed-off-by: Peter Zijlstra (Intel) <[email protected]> Cc: Stephane Eranian <[email protected]> Cc: [email protected] Cc: Jiri Olsa <[email protected]> Cc: Arnaldo Carvalho de Melo <[email protected]> Cc: Linus Torvalds <[email protected]> Link: http://lkml.kernel.org/r/[email protected] Signed-off-by: Ingo Molnar <[email protected]>
2015-02-04perf: Fix move_group() orderPeter Zijlstra (Intel)1-9/+47
Jiri reported triggering the new WARN_ON_ONCE in event_sched_out over the weekend: event_sched_out.isra.79+0x2b9/0x2d0 group_sched_out+0x69/0xc0 ctx_sched_out+0x106/0x130 task_ctx_sched_out+0x37/0x70 __perf_install_in_context+0x70/0x1a0 remote_function+0x48/0x60 generic_exec_single+0x15b/0x1d0 smp_call_function_single+0x67/0xa0 task_function_call+0x53/0x80 perf_install_in_context+0x8b/0x110 I think the below should cure this; if we install a group leader it will iterate the (still intact) group list and find its siblings and try and install those too -- even though those still have the old event->ctx -- in the new ctx. Upon installing the first group sibling we'd try and schedule out the group and trigger the above warn. Fix this by installing the group leader last, installing siblings would have no effect, they're not reachable through the group lists and therefore we don't schedule them. Also delay resetting the state until we're absolutely sure the events are quiescent. Reported-by: Jiri Olsa <[email protected]> Reported-by: [email protected] Signed-off-by: Peter Zijlstra (Intel) <[email protected]> Cc: Arnaldo Carvalho de Melo <[email protected]> Cc: Linus Torvalds <[email protected]> Link: http://lkml.kernel.org/r/[email protected] Signed-off-by: Ingo Molnar <[email protected]>
2015-02-04perf: Fix event->ctx lockingPeter Zijlstra1-37/+207
There have been a few reported issues wrt. the lack of locking around changing event->ctx. This patch tries to address those. It avoids the whole rwsem thing; and while it appears to work, please give it some thought in review. What I did fail at is sensible runtime checks on the use of event->ctx, the RCU use makes it very hard. Signed-off-by: Peter Zijlstra (Intel) <[email protected]> Cc: Paul E. McKenney <[email protected]> Cc: Jiri Olsa <[email protected]> Cc: Arnaldo Carvalho de Melo <[email protected]> Cc: Linus Torvalds <[email protected]> Link: http://lkml.kernel.org/r/[email protected] Signed-off-by: Ingo Molnar <[email protected]>
2015-02-04perf: Add a bit of paranoiaPeter Zijlstra1-1/+18
Add a few WARN()s to catch things that should never happen. Signed-off-by: Peter Zijlstra (Intel) <[email protected]> Cc: Arnaldo Carvalho de Melo <[email protected]> Cc: Linus Torvalds <[email protected]> Link: http://lkml.kernel.org/r/[email protected] Signed-off-by: Ingo Molnar <[email protected]>
2015-02-04Merge tag 'v3.19-rc7' into perf/core, to merge fixes before applying new changesIngo Molnar2-11/+19
Signed-off-by: Ingo Molnar <[email protected]>
2015-02-04locking/rtmutex: Optimize setting task running after being blockedDavidlohr Bueso1-4/+3
We explicitly mark the task running after returning from a __rt_mutex_slowlock() call, which does the actual sleeping via wait-wake-trylocking. As such, this patch does two things: (1) refactors the code so that setting current to TASK_RUNNING is done by __rt_mutex_slowlock(), and not by the callers. The downside to this is that it becomes a bit unclear when at what point we block. As such I've added a comment that the task blocks when calling __rt_mutex_slowlock() so readers can figure out when it is running again. (2) relaxes setting current's state through __set_current_state(), instead of it's more expensive barrier alternative. There was no need for the implied barrier as we're obviously not planning on blocking. Signed-off-by: Davidlohr Bueso <[email protected]> Signed-off-by: Peter Zijlstra (Intel) <[email protected]> Cc: Linus Torvalds <[email protected]> Link: http://lkml.kernel.org/r/[email protected] Signed-off-by: Ingo Molnar <[email protected]>
2015-02-04locking/rwsem: Use task->state helpersDavidlohr Bueso2-3/+2
Call __set_task_state() instead of assigning the new state directly. These interfaces also aid CONFIG_DEBUG_ATOMIC_SLEEP environments, keeping track of who last changed the state. Signed-off-by: Davidlohr Bueso <[email protected]> Signed-off-by: Peter Zijlstra (Intel) <[email protected]> Cc: "Paul E. McKenney" <[email protected]> Cc: Jason Low <[email protected]> Cc: Michel Lespinasse <[email protected]> Cc: Tim Chen <[email protected]> Cc: Linus Torvalds <[email protected]> Link: http://lkml.kernel.org/r/[email protected] Signed-off-by: Ingo Molnar <[email protected]>
2015-02-04sched/completion: Add lock-free checking of the blocking caseNicholas Mc Guire1-0/+9
The "thread would block" case can be checked without grabbing ->wait.lock. [ If the check does not return early then grab the lock and recheck. A memory barrier is not needed as complete() and complete_all() imply a barrier. The ACCESS_ONCE() is needed for calls in a loop that, if inlined, could optimize out the re-fetching of x->done. ] Signed-off-by: Nicholas Mc Guire <[email protected]> Signed-off-by: Peter Zijlstra (Intel) <[email protected]> Cc: Linus Torvalds <[email protected]> Link: http://lkml.kernel.org/r/[email protected] Signed-off-by: Ingo Molnar <[email protected]>
2015-02-04sched/completion: Remove unnecessary ->wait.lock serialization when reading ↵Nicholas Mc Guire1-8/+1
completion state Signed-off-by: Nicholas Mc Guire <[email protected]> Signed-off-by: Peter Zijlstra (Intel) <[email protected]> Cc: Linus Torvalds <[email protected]> Link: http://lkml.kernel.org/r/[email protected] Signed-off-by: Ingo Molnar <[email protected]>
2015-02-04locking/mutex: Explicitly mark task as running after wakeupDavidlohr Bueso1-0/+2
By the time we wake up and get the lock after being asleep in the slowpath, we better be running. As good practice, be explicit about this and avoid any mischief. Signed-off-by: Davidlohr Bueso <[email protected]> Signed-off-by: Peter Zijlstra (Intel) <[email protected]> Cc: "Paul E. McKenney" <[email protected]> Cc: Linus Torvalds <[email protected]> Link: http://lkml.kernel.org/r/[email protected] Signed-off-by: Ingo Molnar <[email protected]>
2015-02-04Merge tag 'v3.19-rc7' into locking/core, to refresh the branch before ↵Ingo Molnar17-85/+235
applying new changes Signed-off-by: Ingo Molnar <[email protected]>
2015-02-04sched/Documentation: Remove unneeded wordSharon Dvir1-1/+1
The second 'mutex' shouldn't be there, it can't be about the mutex, as the mutex can't be freed, but unlocked, the memory where the mutex resides however, can be freed. Signed-off-by: Sharon Dvir <[email protected]> Signed-off-by: Peter Zijlstra (Intel) <[email protected]> Cc: Linus Torvalds <[email protected]> Link: http://lkml.kernel.org/r/[email protected] Signed-off-by: Ingo Molnar <[email protected]>
2015-02-04sched: Pull resched loop to __schedule() callersFrederic Weisbecker1-4/+7
__schedule() disables preemption during its job and re-enables it afterward without doing a preemption check to avoid recursion. But if an event happens after the context switch which requires rescheduling, we need to check again if a task of a higher priority needs the CPU. A preempt irq can raise such a situation. To handle that, __schedule() loops on need_resched(). But preempt_schedule_*() functions, which call __schedule(), also loop on need_resched() to handle missed preempt irqs. Hence we end up with the same loop happening twice. Lets simplify that by attributing the need_resched() loop responsibility to all __schedule() callers. There is a risk that the outer loop now handles reschedules that used to be handled by the inner loop with the added overhead of caller details (inc/dec of PREEMPT_ACTIVE, irq save/restore) but assuming those inner rescheduling loop weren't too frequent, this shouldn't matter. Especially since the whole preemption path is now losing one loop in any case. Suggested-by: Linus Torvalds <[email protected]> Signed-off-by: Frederic Weisbecker <[email protected]> Signed-off-by: Peter Zijlstra (Intel) <[email protected]> Cc: Steven Rostedt <[email protected]> Link: http://lkml.kernel.org/r/[email protected] Signed-off-by: Ingo Molnar <[email protected]>
2015-02-04sched/deadline: Remove cpu_active_mask from cpudl_find()Xunlei Pang1-2/+1
cpu_active_mask is rarely changed (only on hotplug), so remove this operation to gain a little performance. If there is a change in cpu_active_mask, rq_online_dl() and rq_offline_dl() should take care of it normally, so cpudl::free_cpus carries enough information for us. For the rare case when a task is put onto a dying cpu (which rq_offline_dl() can't handle in a timely fashion), it will be handled through _cpu_down()->...->multi_cpu_stop()->migration_call() ->migrate_tasks(), preventing the task from hanging on the dead cpu. Cc: Juri Lelli <[email protected]> Signed-off-by: Xunlei Pang <[email protected]> [peterz: changelog] Signed-off-by: Peter Zijlstra (Intel) <[email protected]> Link: http://lkml.kernel.org/r/[email protected] Cc: Linus Torvalds <[email protected]> Cc: [email protected] Signed-off-by: Ingo Molnar <[email protected]>
2015-02-04sched: Fix hrtick_start() on UPWanpeng Li1-0/+5
The commit 177ef2a6315e ("sched/deadline: Fix a precision problem in the microseconds range") forgot to change the UP version of hrtick_start(), do so now. Signed-off-by: Wanpeng Li <[email protected]> Fixes: 177ef2a6315e ("sched/deadline: Fix a precision problem in the microseconds range") [ Fixed the changelog. ] Signed-off-by: Peter Zijlstra (Intel) <[email protected]> Cc: Juri Lelli <[email protected]> Cc: Kirill Tkhai <[email protected]> Cc: Linus Torvalds <[email protected]> Link: http://lkml.kernel.org/r/[email protected] Signed-off-by: Ingo Molnar <[email protected]>
2015-02-04sched/deadline: Avoid pointless __setscheduler()Wanpeng Li1-1/+15
There is no need to dequeue/enqueue and push/pull if there are no scheduling parameters changed for the DL class. Both fair and RT classes already check if parameters changed for them to avoid unnecessary overhead. This patch add the parameters changed test for the DL class in order to reduce overhead. Signed-off-by: Wanpeng Li <[email protected]> [ Fixed up the changelog. ] Signed-off-by: Peter Zijlstra (Intel) <[email protected]> Cc: Juri Lelli <[email protected]> Cc: Kirill Tkhai <[email protected]> Cc: Linus Torvalds <[email protected]> Link: http://lkml.kernel.org/r/[email protected] Signed-off-by: Ingo Molnar <[email protected]>
2015-02-04sched/deadline: Fix stale yield statePeter Zijlstra1-19/+19
When we fail to start the deadline timer in update_curr_dl(), we forget to clear ->dl_yielded, resulting in wrecked time keeping. Since the natural place to clear both ->dl_yielded and ->dl_throttled is in replenish_dl_entity(); both are after all waiting for that event; make it so. Luckily since 67dfa1b756f2 ("sched/deadline: Implement cancel_dl_timer() to use in switched_from_dl()") the task_on_rq_queued() condition in dl_task_timer() must be true, and can therefore call enqueue_task_dl() unconditionally. Reported-by: Wanpeng Li <[email protected]> Signed-off-by: Peter Zijlstra (Intel) <[email protected]> Cc: Kirill Tkhai <[email protected]> Cc: Juri Lelli <[email protected]> Cc: Linus Torvalds <[email protected]> Link: http://lkml.kernel.org/r/[email protected] Signed-off-by: Ingo Molnar <[email protected]>
2015-02-04sched/deadline: Fix hrtick for a non-leftmost taskWanpeng Li1-1/+7
After update_curr_dl() the current task might not be the leftmost task anymore. In that case do not start a new hrtick for it. In this case NEED_RESCHED will be set and the next schedule will start the hrtick for the new task if and when appropriate. Signed-off-by: Wanpeng Li <[email protected]> Acked-by: Juri Lelli <[email protected]> [ Rewrote the changelog and comment. ] Signed-off-by: Peter Zijlstra (Intel) <[email protected]> Cc: Kirill Tkhai <[email protected]> Cc: Linus Torvalds <[email protected]> Link: http://lkml.kernel.org/r/[email protected] Signed-off-by: Ingo Molnar <[email protected]>
2015-02-04Merge branch 'sched/urgent' into sched/core, to merge fixes before applying ↵Ingo Molnar2-6/+30
new patches Signed-off-by: Ingo Molnar <[email protected]>
2015-02-04sched/deadline: Fix deadline parameter modification handlingPeter Zijlstra2-6/+30
Commit 67dfa1b756f2 ("sched/deadline: Implement cancel_dl_timer() to use in switched_from_dl()") removed the hrtimer_try_cancel() function call out from init_dl_task_timer(), which gets called from __setparam_dl(). The result is that we can now re-init the timer while its active -- this is bad and corrupts timer state. Furthermore; changing the parameters of an active deadline task is tricky in that you want to maintain guarantees, while immediately effective change would allow one to circumvent the CBS guarantees -- this too is bad, as one (bad) task should not be able to affect the others. Rework things to avoid both problems. We only need to initialize the timer once, so move that to __sched_fork() for new tasks. Then make sure __setparam_dl() doesn't affect the current running state but only updates the parameters used to calculate the next scheduling period -- this guarantees the CBS functions as expected (albeit slightly pessimistic). This however means we need to make sure __dl_clear_params() needs to reset the active state otherwise new (and tasks flipping between classes) will not properly (re)compute their first instance. Todo: close class flipping CBS hole. Todo: implement delayed BW release. Reported-by: Luca Abeni <[email protected]> Acked-by: Juri Lelli <[email protected]> Tested-by: Luca Abeni <[email protected]> Fixes: 67dfa1b756f2 ("sched/deadline: Implement cancel_dl_timer() to use in switched_from_dl()") Signed-off-by: Peter Zijlstra (Intel) <[email protected]> Cc: <[email protected]> Cc: Kirill Tkhai <[email protected]> Cc: Linus Torvalds <[email protected]> Link: http://lkml.kernel.org/r/[email protected] Signed-off-by: Ingo Molnar <[email protected]>
2015-02-03PM / hibernate: exclude freed pages from allocated pages printoutWonhong Kwon1-3/+6
hibernate_preallocate_memory() prints out that how many pages are allocated, but it doesn't take into consideration the pages freed by free_unnecessary_pages(). Therefore, it always shows the count more than actually allocated. Signed-off-by: Wonhong Kwon <[email protected]> [ rjw: Subject ] Signed-off-by: Rafael J. Wysocki <[email protected]>
2015-02-02tracing: Separate out initializing top level dir from instancesSteven Rostedt (Red Hat)1-21/+30
The top level trace array is treated a little different than the instances, as it has to deal with more of the general tracing. The tr->dir is the tracing directory, which is an immutable dentry, where as the tr->dir of instances are the dentry that was created, and can be destroyed later. These should have different functions accessing them. As only tracing_init_dentry() deals with the top level array, fold the code for it into that function, and remove the trace_init_dentry_tr() that was also used by the instances to get their directory dentry. Add a tracing_get_dentry() to just get the tracing dir entry for instances as well as the top level array. Signed-off-by: Steven Rostedt <[email protected]>
2015-02-02tracing: Make tracing_init_dentry_tr() staticSteven Rostedt (Red Hat)2-2/+1
tracing_init_dentry_tr() is not used outside of trace.c, it should be static. Signed-off-by: Steven Rostedt <[email protected]>
2015-02-02perf: provide sysfs_show for struct perf_pmu_events_attrCody P Schafer1-0/+12
(struct perf_pmu_events_attr) is defined in include/linux/perf_event.h, but the only "show" for it is in x86 and contains x86 specific stuff. Make a generic one for those of us who are just using the event_str. Signed-off-by: Cody P Schafer <[email protected]> Signed-off-by: Sukadev Bhattiprolu <[email protected]> Acked-by: Jiri Olsa <[email protected]> Signed-off-by: Michael Ellerman <[email protected]>
2015-02-01sched: don't cause task state changes in nested sleep debuggingLinus Torvalds1-3/+2
Commit 8eb23b9f35aa ("sched: Debug nested sleeps") added code to report on nested sleep conditions, which we generally want to avoid because the inner sleeping operation can re-set the thread state to TASK_RUNNING, but that will then cause the outer sleep loop not actually sleep when it calls schedule. However, that's actually valid traditional behavior, with the inner sleep being some fairly rare case (like taking a sleeping lock that normally doesn't actually need to sleep). And the debug code would actually change the state of the task to TASK_RUNNING internally, which makes that kind of traditional and working code not work at all, because now the nested sleep doesn't just sometimes cause the outer one to not block, but will cause it to happen every time. In particular, it will cause the cardbus kernel daemon (pccardd) to basically busy-loop doing scheduling, converting a laptop into a heater, as reported by Bruno Prémont. But there may be other legacy uses of that nested sleep model in other drivers that are also likely to never get converted to the new model. This fixes both cases: - don't set TASK_RUNNING when the nested condition happens (note: even if WARN_ONCE() only _warns_ once, the return value isn't whether the warning happened, but whether the condition for the warning was true. So despite the warning only happening once, the "if (WARN_ON(..))" would trigger for every nested sleep. - in the cases where we knowingly disable the warning by using "sched_annotate_sleep()", don't change the task state (that is used for all core scheduling decisions), instead use '->task_state_change' that is used for the debugging decision itself. (Credit for the second part of the fix goes to Oleg Nesterov: "Can't we avoid this subtle change in behaviour DEBUG_ATOMIC_SLEEP adds?" with the suggested change to use 'task_state_change' as part of the test) Reported-and-bisected-by: Bruno Prémont <[email protected]> Tested-by: Rafael J Wysocki <[email protected]> Acked-by: Oleg Nesterov <[email protected]> Cc: Peter Zijlstra <[email protected]> Cc: Thomas Gleixner <[email protected]>, Cc: Ilya Dryomov <[email protected]>, Cc: Mike Galbraith <[email protected]> Cc: Ingo Molnar <[email protected]> Cc: Peter Hurley <[email protected]>, Cc: Davidlohr Bueso <[email protected]>, Signed-off-by: Linus Torvalds <[email protected]>
2015-01-30Merge branch 'perf-urgent-for-linus' of ↵Linus Torvalds1-2/+13
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull perf fixes from Ingo Molnar: "Mostly tooling fixes, but also an event groups fix, two PMU driver fixes and a CPU model variant addition" * 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: perf: Tighten (and fix) the grouping condition perf/x86/intel: Add model number for Airmont perf/rapl: Fix crash in rapl_scale() perf/x86/intel/uncore: Move uncore_box_init() out of driver initialization perf probe: Fix probing kretprobes perf symbols: Introduce 'for' method to iterate over the symbols with a given name perf probe: Do not rely on map__load() filter to find symbols perf symbols: Introduce method to iterate symbols ordered by name perf symbols: Return the first entry with a given name in find_by_name method perf annotate: Fix memory leaks in LOCK handling perf annotate: Handle ins parsing failures perf scripting perl: Force to use stdbool perf evlist: Remove extraneous 'was' on error message
2015-01-30sched/deadline: Modify cpudl::free_cpus to reflect rd->onlineXunlei Pang3-7/+28
Currently, cpudl::free_cpus contains all CPUs during init, see cpudl_init(). When calling cpudl_find(), we have to add rd->span to avoid selecting the cpu outside the current root domain, because cpus_allowed cannot be depended on when performing clustered scheduling using the cpuset, see find_later_rq(). This patch adds cpudl_set_freecpu() and cpudl_clear_freecpu() for changing cpudl::free_cpus when doing rq_online_dl()/rq_offline_dl(), so we can avoid the rd->span operation when calling cpudl_find() in find_later_rq(). Signed-off-by: Xunlei Pang <[email protected]> Signed-off-by: Peter Zijlstra (Intel) <[email protected]> Cc: Juri Lelli <[email protected]> Cc: Linus Torvalds <[email protected]> Link: http://lkml.kernel.org/r/[email protected] Signed-off-by: Ingo Molnar <[email protected]>
2015-01-30sched/idle: Add missing checks to the exit condition of cpu_idle_poll()Preeti U Murthy1-1/+2
cpu_idle_poll() is entered into when either the cpu_idle_force_poll is set or tick_check_broadcast_expired() returns true. The exit condition from cpu_idle_poll() is tif_need_resched(). However this does not take into account scenarios where cpu_idle_force_poll changes or tick_check_broadcast_expired() returns false, without setting the resched flag. So a cpu will be caught in cpu_idle_poll() needlessly, thereby wasting power. Add an explicit check on cpu_idle_force_poll and tick_check_broadcast_expired() to the exit condition of cpu_idle_poll() to avoid this. Signed-off-by: Preeti U Murthy <[email protected]> Reviewed-by: Thomas Gleixner <[email protected]> Signed-off-by: Peter Zijlstra (Intel) <[email protected]> Cc: [email protected] Cc: Linus Torvalds <[email protected]> Link: http://lkml.kernel.org/r/[email protected] Signed-off-by: Ingo Molnar <[email protected]>
2015-01-30sched: Fix missing preemption opportunityFrederic Weisbecker1-21/+19
If an interrupt fires in cond_resched(), between the call to __schedule() and the PREEMPT_ACTIVE count decrementation, and that interrupt sets TIF_NEED_RESCHED, the call to preempt_schedule_irq() will be ignored due to the PREEMPT_ACTIVE count. This kind of scenario, with irq preemption being delayed because it's interrupting a preempt-disabled area, is usually fixed up after preemption is re-enabled back with an explicit call to preempt_schedule(). This is what preempt_enable() does but a raw preempt count decrement as performed by __preempt_count_sub(PREEMPT_ACTIVE) doesn't handle delayed preemption check. Therefore when such a race happens, the rescheduling is going to be delayed until the next scheduler or preemption entrypoint. This can be a problem for scheduler latency sensitive workloads. Lets fix that by consolidating cond_resched() with preempt_schedule() internals. Reported-by: Linus Torvalds <[email protected]> Reported-by: Ingo Molnar <[email protected]> Original-patch-by: Ingo Molnar <[email protected]> Signed-off-by: Frederic Weisbecker <[email protected]> Signed-off-by: Peter Zijlstra (Intel) <[email protected]> Link: http://lkml.kernel.org/r/[email protected] Signed-off-by: Ingo Molnar <[email protected]>
2015-01-30sched/rt: Reduce rq lock contention by eliminating locking of non-feasible ↵Tim Chen1-1/+16
target This patch adds checks that prevens futile attempts to move rt tasks to a CPU with active tasks of equal or higher priority. This reduces run queue lock contention and improves the performance of a well known OLTP benchmark by 0.7%. Signed-off-by: Tim Chen <[email protected]> Signed-off-by: Peter Zijlstra (Intel) <[email protected]> Cc: Shawn Bohrer <[email protected]> Cc: Suruchi Kadu <[email protected]> Cc: Doug Nelson<[email protected]> Cc: Steven Rostedt <[email protected]> Cc: Linus Torvalds <[email protected]> Link: http://lkml.kernel.org/r/[email protected] Signed-off-by: Ingo Molnar <[email protected]>
2015-01-30Merge branch 'sched/urgent' into sched/coreIngo Molnar27-251/+511
Merge all pending fixes and refresh the tree, before applying new changes. Signed-off-by: Ingo Molnar <[email protected]>
2015-01-30PM / sleep: export suspend_resume trace eventTodd E Brandt1-0/+1
Export the suspend_resume tracepoint so it can be used in loadable modules. Signed-off-by: Todd Brandt <[email protected]> Signed-off-by: Rafael J. Wysocki <[email protected]>
2015-01-29ftrace: allow architectures to specify ftrace compile optionsHeiko Carstens5-10/+10
If the kernel is compiled with function tracer support the -pg compile option is passed to gcc to generate extra code into the prologue of each function. This patch replaces the "open-coded" -pg compile flag with a CC_FLAGS_FTRACE makefile variable which architectures can override if a different option should be used for code generation. Acked-by: Steven Rostedt <[email protected]> Signed-off-by: Heiko Carstens <[email protected]> Signed-off-by: Martin Schwidefsky <[email protected]>
2015-01-28trace: Use 64-bit timekeepingTina Ruchandani1-10/+8
The ring_buffer_producer uses 'struct timeval' to measure its start and end times. 'struct timeval' on 32-bit systems will have its tv_sec value overflow in year 2038 and beyond. This patch replaces struct timeval with 'ktime_t' which uses 64-bit representation for nanoseconds. Link: http://lkml.kernel.org/r/20150128141611.GA2701@tinar Suggested-by: Arnd Bergmann <[email protected]> Suggested-by: Steven Rostedt <[email protected]> Signed-off-by: Tina Ruchandani <[email protected]> Signed-off-by: Steven Rostedt <[email protected]>
2015-01-28tracing: Add array printing helperDave Martin1-0/+44
If a trace event contains an array, there is currently no standard way to format this for text output. Drivers are currently hacking around this by a) local hacks that use the trace_seq functionailty directly, or b) just not printing that information. For fixed size arrays, formatting of the elements can be open-coded, but this gets cumbersome for arrays of non-trivial size. These approaches result in non-standard content of the event format description delivered to userspace, so userland tools needs to be taught to understand and parse each array printing method individually. This patch implements a __print_array() helper that tracepoint implementations can use instead of reinventing it. A simple C-style syntax is used to delimit the array and its elements {like,this}. So that the helpers can be used with large static arrays as well as dynamic arrays, they take a pointer and element count: they can be used with __get_dynamic_array() for use with dynamic arrays. Link: http://lkml.kernel.org/r/[email protected] Cc: Ingo Molnar <[email protected]> Signed-off-by: Dave Martin <[email protected]> Signed-off-by: Javi Merino <[email protected]> Signed-off-by: Steven Rostedt <[email protected]>
2015-01-28Merge branch 'perf/urgent' into perf/core, to pick up fixesIngo Molnar15-74/+216
Signed-off-by: Ingo Molnar <[email protected]>
2015-01-28sched: Fix crash if cpuset_cpumask_can_shrink() is passed an empty cpumaskMike Galbraith1-0/+3
While creating an exclusive cpuset, we passed cpuset_cpumask_can_shrink() an empty cpumask (cur), and dl_bw_of(cpumask_any(cur)) made boom with it: CPU: 0 PID: 6942 Comm: shield.sh Not tainted 3.19.0-master #19 Hardware name: MEDIONPC MS-7502/MS-7502, BIOS 6.00 PG 12/26/2007 task: ffff880224552450 ti: ffff8800caab8000 task.ti: ffff8800caab8000 RIP: 0010:[<ffffffff81073846>] [<ffffffff81073846>] cpuset_cpumask_can_shrink+0x56/0xb0 [...] Call Trace: [<ffffffff810cb82a>] validate_change+0x18a/0x200 [<ffffffff810cc877>] cpuset_write_resmask+0x3b7/0x720 [<ffffffff810c4d58>] cgroup_file_write+0x38/0x100 [<ffffffff811d953a>] kernfs_fop_write+0x12a/0x180 [<ffffffff8116e1a3>] vfs_write+0xb3/0x1d0 [<ffffffff8116ed06>] SyS_write+0x46/0xb0 [<ffffffff8159ced6>] system_call_fastpath+0x16/0x1b Signed-off-by: Mike Galbraith <[email protected]> Acked-by: Zefan Li <[email protected]> Fixes: f82f80426f7a ("sched/deadline: Ensure that updates to exclusive cpusets don't break AC") Signed-off-by: Peter Zijlstra (Intel) <[email protected]> Cc: Linus Torvalds <[email protected]> Link: http://lkml.kernel.org/r/[email protected] Signed-off-by: Ingo Molnar <[email protected]>
2015-01-28perf: Tighten (and fix) the grouping conditionPeter Zijlstra1-2/+13
The fix from 9fc81d87420d ("perf: Fix events installation during moving group") was incomplete in that it failed to recognise that creating a group with events for different CPUs is semantically broken -- they cannot be co-scheduled. Furthermore, it leads to real breakage where, when we create an event for CPU Y and then migrate it to form a group on CPU X, the code gets confused where the counter is programmed -- triggered in practice as well by me via the perf fuzzer. Fix this by tightening the rules for creating groups. Only allow grouping of counters that can be co-scheduled in the same context. This means for the same task and/or the same cpu. Fixes: 9fc81d87420d ("perf: Fix events installation during moving group") Signed-off-by: Peter Zijlstra (Intel) <[email protected]> Cc: Arnaldo Carvalho de Melo <[email protected]> Cc: Jiri Olsa <[email protected]> Cc: Linus Torvalds <[email protected]> Link: http://lkml.kernel.org/r/[email protected] Signed-off-by: Ingo Molnar <[email protected]>
2015-01-28sched/fair: Avoid using uninitialized variable in preferred_group_nid()Jan Beulich1-1/+1
At least some gcc versions - validly afaict - warn about potentially using max_group uninitialized: There's no way the compiler can prove that the body of the conditional where it and max_faults get set/ updated gets executed; in fact, without knowing all the details of other scheduler code, I can't prove this either. Generally the necessary change would appear to be to clear max_group prior to entering the inner loop, and break out of the outer loop when it ends up being all clear after the inner one. This, however, seems inefficient, and afaict the same effect can be achieved by exiting the outer loop when max_faults is still zero after the inner loop. [ mingo: changed the solution to zero initialization: uninitialized_var() needs to die, as it's an actively dangerous construct: if in the future a known-proven-good piece of code is changed to have a true, buggy uninitialized variable, the compiler warning is then supressed... The better long term solution is to clean up the code flow, so that even simple minded compilers (and humans!) are able to read it without getting a headache. ] Signed-off-by: Jan Beulich <[email protected]> Signed-off-by: Peter Zijlstra (Intel) <[email protected]> Cc: Rik van Riel <[email protected]> Cc: Linus Torvalds <[email protected]> Link: http://lkml.kernel.org/r/[email protected] Signed-off-by: Ingo Molnar <[email protected]>