3.0-stable review patch. If anyone has any objections, please let me know.
------------------ From: Peter Zijlstra <a.p.zijls...@chello.nl> commit 95cf59ea72331d0093010543b8951bb43f262cac upstream. Jiri reported that he could trigger the WARN_ON_ONCE() in perf_cgroup_switch() using sw-events. This is because sw-events share a cpuctx with multiple PMUs. Use the ->unique_pmu pointer to limit the pmu iteration to unique cpuctx instances. Reported-and-Tested-by: Jiri Olsa <jo...@redhat.com> Signed-off-by: Peter Zijlstra <a.p.zijls...@chello.nl> Link: http://lkml.kernel.org/n/tip-so7wi2zf3jjzrwcutm2mk...@git.kernel.org Signed-off-by: Ingo Molnar <mi...@kernel.org> Cc: Li Zefan <lize...@huawei.com> Signed-off-by: Greg Kroah-Hartman <gre...@linuxfoundation.org> --- kernel/events/core.c | 9 ++++++--- 1 file changed, 6 insertions(+), 3 deletions(-) --- a/kernel/events/core.c +++ b/kernel/events/core.c @@ -342,6 +342,8 @@ void perf_cgroup_switch(struct task_stru list_for_each_entry_rcu(pmu, &pmus, entry) { cpuctx = this_cpu_ptr(pmu->pmu_cpu_context); + if (cpuctx->unique_pmu != pmu) + continue; /* ensure we process each cpuctx once */ perf_pmu_disable(cpuctx->ctx.pmu); @@ -365,9 +367,10 @@ void perf_cgroup_switch(struct task_stru if (mode & PERF_CGROUP_SWIN) { WARN_ON_ONCE(cpuctx->cgrp); - /* set cgrp before ctxsw in to - * allow event_filter_match() to not - * have to pass task around + /* + * set cgrp before ctxsw in to allow + * event_filter_match() to not have to pass + * task around */ cpuctx->cgrp = perf_cgroup_from_task(task); cpu_ctx_sched_in(cpuctx, EVENT_ALL, task); -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
