On Sat, Oct 17, 2015 at 03:28:11AM +0200, Stephane Eranian wrote: > > This patch eliminates all known RCU violations detected > by the RCU checker (PROVE_RCU). The impact code paths > were all related to cgroup mode monitoring and involved > access a task's cgrp.
But were they right? This patch provides no clues. > Signed-off-by: Stephane Eranian <[email protected]> > --- > @@ -2094,6 +2104,7 @@ static int __perf_install_in_context(void *info) > cpuctx->task_ctx = task_ctx; > task = task_ctx->task; > } > + rcu_read_lock(); > > cpu_ctx_sched_out(cpuctx, EVENT_ALL); > > @@ -2112,6 +2123,8 @@ static int __perf_install_in_context(void *info) > */ > perf_event_sched_in(cpuctx, task_ctx, task); > > + rcu_read_unlock(); > + > perf_pmu_enable(cpuctx->ctx.pmu); > perf_ctx_unlock(cpuctx, task_ctx); > > @@ -2398,7 +2411,9 @@ static void ctx_sched_out(struct perf_event_context > *ctx, > return; > > update_context_time(ctx); > + rcu_read_lock(); > update_cgrp_time_from_cpuctx(cpuctx); > + rcu_read_unlock(); > if (!ctx->nr_active) > return; > And these impact !cgroup code, and the last looks like it should be inside update_cgrp_time_from_cpuctx() if at all. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
