linux/kernel, branch v3.19

Merge branches 'timers-urgent-for-linus' and 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

2015-02-06T21:56:02Z

Pull timer and x86 fix from Ingo Molnar: "A CLOCK_TAI early expiry fix and an x86 microcode driver oops fix" * 'timers-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: hrtimer: Fix incorrect tai offset calculation for non high-res timer systems * 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86, microcode: Return error from driver init code when loader is disabled

Merge branch 'sched-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

2015-02-06T21:34:26Z

Pull scheduler fixes from Ingo Molnar: "Misc fixes" * 'sched-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: sched/deadline: Fix deadline parameter modification handling sched/wait: Remove might_sleep() from wait_event_cmd() sched: Fix crash if cpuset_cpumask_can_shrink() is passed an empty cpumask sched/fair: Avoid using uninitialized variable in preferred_group_nid()

Merge branch 'core-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

2015-02-06T21:06:10Z

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()

hrtimer: Fix incorrect tai offset calculation for non high-res timer systems

2015-02-05T07:39:37Z

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 Cc: Thomas Gleixner Cc: stable # 3.17+ Link: http://lkml.kernel.org/r/1423097126-10236-1-git-send-email-john.stultz@linaro.org Signed-off-by: Ingo Molnar

sched/deadline: Fix deadline parameter modification handling

2015-02-04T06:42:48Z

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 Acked-by: Juri Lelli Tested-by: Luca Abeni Fixes: 67dfa1b756f2 ("sched/deadline: Implement cancel_dl_timer() to use in switched_from_dl()") Signed-off-by: Peter Zijlstra (Intel) Cc: Cc: Kirill Tkhai Cc: Linus Torvalds Link: http://lkml.kernel.org/r/20150128140803.GF23038@twins.programming.kicks-ass.net Signed-off-by: Ingo Molnar

sched: don't cause task state changes in nested sleep debugging

2015-02-01T20:23:32Z

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 Tested-by: Rafael J Wysocki Acked-by: Oleg Nesterov Cc: Peter Zijlstra Cc: Thomas Gleixner , Cc: Ilya Dryomov , Cc: Mike Galbraith Cc: Ingo Molnar Cc: Peter Hurley , Cc: Davidlohr Bueso , Signed-off-by: Linus Torvalds

Merge branch 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

2015-01-30T22:34:55Z

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

sched: Fix crash if cpuset_cpumask_can_shrink() is passed an empty cpumask

2015-01-28T14:28:15Z

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:[] [] cpuset_cpumask_can_shrink+0x56/0xb0 [...] Call Trace: [] validate_change+0x18a/0x200 [] cpuset_write_resmask+0x3b7/0x720 [] cgroup_file_write+0x38/0x100 [] kernfs_fop_write+0x12a/0x180 [] vfs_write+0xb3/0x1d0 [] SyS_write+0x46/0xb0 [] system_call_fastpath+0x16/0x1b Signed-off-by: Mike Galbraith Acked-by: Zefan Li Fixes: f82f80426f7a ("sched/deadline: Ensure that updates to exclusive cpusets don't break AC") Signed-off-by: Peter Zijlstra (Intel) Cc: Linus Torvalds Link: http://lkml.kernel.org/r/1422417235.5716.5.camel@marge.simpson.net Signed-off-by: Ingo Molnar

perf: Tighten (and fix) the grouping condition

2015-01-28T12:17:35Z

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) Cc: Arnaldo Carvalho de Melo Cc: Jiri Olsa Cc: Linus Torvalds Link: http://lkml.kernel.org/r/20150123125834.090683288@infradead.org Signed-off-by: Ingo Molnar

sched/fair: Avoid using uninitialized variable in preferred_group_nid()

2015-01-28T12:14:12Z

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 Signed-off-by: Peter Zijlstra (Intel) Cc: Rik van Riel Cc: Linus Torvalds Link: http://lkml.kernel.org/r/54C2139202000078000588F7@mail.emea.novell.com Signed-off-by: Ingo Molnar