From: Peter Zijlstra <peterz@infradead.org>
To: Marco Elver <elver@google.com>
Cc: Ingo Molnar <mingo@redhat.com>,
Arnaldo Carvalho de Melo <acme@kernel.org>,
Mark Rutland <mark.rutland@arm.com>,
Alexander Shishkin <alexander.shishkin@linux.intel.com>,
Jiri Olsa <jolsa@kernel.org>, Namhyung Kim <namhyung@kernel.org>,
linux-perf-users@vger.kernel.org, linux-kernel@vger.kernel.org,
kasan-dev@googlegroups.com, Dmitry Vyukov <dvyukov@google.com>
Subject: Re: [PATCH] perf: Fix missing SIGTRAPs
Date: Sat, 8 Oct 2022 14:41:47 +0200 [thread overview]
Message-ID: <Y0FwC1yo1pcyL9J/@hirez.programming.kicks-ass.net> (raw)
In-Reply-To: <Y0E3uG7jOywn7vy3@elver.google.com>
On Sat, Oct 08, 2022 at 10:41:28AM +0200, Marco Elver wrote:
> The below patch to the sigtrap_threads test can repro the issue (when
> run lots of them concurrently again). It also illustrates the original
> problem we're trying to solve, where the event never gets rearmed again
> and the test times out (doesn't happen with the almost-working fix).
Excellent, that helps. Also, I'm an idiot ;-)
The below seems to fix it for me.
---
--- a/kernel/events/core.c
+++ b/kernel/events/core.c
@@ -3441,7 +3448,8 @@ static void perf_event_context_sched_out
perf_pmu_disable(pmu);
/* PMIs are disabled; ctx->nr_pending is stable. */
- if (local_read(&ctx->nr_pending)) {
+ if (local_read(&ctx->nr_pending) ||
+ local_read(&next_ctx->nr_pending)) {
/*
* Must not swap out ctx when there's pending
* events that rely on the ctx->task relation.
next prev parent reply other threads:[~2022-10-08 12:42 UTC|newest]
Thread overview: 27+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-09-27 12:13 [PATCH] perf: Fix missing SIGTRAPs due to pending_disable abuse Marco Elver
2022-09-27 12:30 ` Marco Elver
2022-09-27 18:20 ` Peter Zijlstra
2022-09-27 21:45 ` Marco Elver
2022-09-28 10:06 ` Marco Elver
2022-09-28 14:55 ` Marco Elver
2022-10-04 17:09 ` Peter Zijlstra
2022-10-04 17:21 ` Peter Zijlstra
2022-10-04 17:33 ` Marco Elver
2022-10-05 7:37 ` Peter Zijlstra
2022-10-05 7:49 ` Marco Elver
2022-10-05 8:23 ` Peter Zijlstra
2022-10-06 13:33 ` [PATCH] perf: Fix missing SIGTRAPs Peter Zijlstra
2022-10-06 13:59 ` Marco Elver
2022-10-06 16:02 ` Peter Zijlstra
2022-10-07 9:37 ` Marco Elver
2022-10-07 13:09 ` Peter Zijlstra
2022-10-07 13:58 ` Marco Elver
2022-10-07 16:14 ` Marco Elver
2022-10-08 8:41 ` Marco Elver
2022-10-08 12:41 ` Peter Zijlstra [this message]
2022-10-10 20:52 ` Marco Elver
2022-10-08 13:51 ` Peter Zijlstra
2022-10-08 14:08 ` Peter Zijlstra
2022-10-11 7:44 ` [PATCH v2] " Peter Zijlstra
2022-10-11 12:58 ` Marco Elver
2022-10-11 13:06 ` Peter Zijlstra
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