From: Vince Weaver <vincent.weaver@maine.edu>
To: Peter Zijlstra <peterz@infradead.org>
Cc: Jiri Olsa <jolsa@redhat.com>,
Vegard Nossum <vegard.nossum@gmail.com>,
Thomas Gleixner <tglx@linutronix.de>,
Stephane Eranian <eranian@google.com>,
Vince Weaver <vincent.weaver@maine.edu>,
Ingo Molnar <mingo@kernel.org>,
David Carrillo-Cisneros <davidcc@google.com>,
"H. Peter Anvin" <hpa@zytor.com>, Kan Liang <kan.liang@intel.com>,
Arnaldo Carvalho de Melo <acme@redhat.com>,
Paul Turner <pjt@google.com>,
Linus Torvalds <torvalds@linux-foundation.org>,
LKML <linux-kernel@vger.kernel.org>,
Alexander Shishkin <alexander.shishkin@linux.intel.com>,
linux-tip-commits@vger.kernel.org
Subject: Re: [tip:perf/core] perf/core: Check return value of the perf_event_read() IPI
Date: Mon, 29 Aug 2016 09:14:46 -0400 (EDT) [thread overview]
Message-ID: <alpine.DEB.2.20.1608290910110.22153@macbook-air> (raw)
In-Reply-To: <20160829130213.GF10168@twins.programming.kicks-ass.net>
On Mon, 29 Aug 2016, Peter Zijlstra wrote:
>
> The best I can come up with is something like:
>
>
> do {
> state = READ_ONCE(event->state);
> if (state != ACTIVE)
> break;
> smp_rmb();
> cpu = READ_ONCE(event->cpu);
> smp_rmb();
> } while (READ_ONCE(event->state) != state);
>
>
> And I suppose perf_event_restart() should do the same thing... Let me
> ponder this a wee bit more.
the perf_fuzzer trips over this warning fairly regularly too, so once you
have a patch you're happy with I can give it a test.
I ordered a whole crate of null modem cables so I've got a whole bunch of
serial consoles ready and raring to go. Maybe I can find out how the
fuzzer crashes the new skylake machine, it doesn't leave anything useful
in the syslog.
Vince
next prev parent reply other threads:[~2016-08-29 13:14 UTC|newest]
Thread overview: 24+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-08-17 20:55 [PATCH v3 0/4] remove unnecessary IPI reading uncore events David Carrillo-Cisneros
2016-08-17 20:55 ` [PATCH v3 1/4] perf/core: check return value of perf_event_read IPI David Carrillo-Cisneros
2016-08-18 10:52 ` [tip:perf/core] perf/core: Check return value of the perf_event_read() IPI tip-bot for David Carrillo-Cisneros
2016-08-21 12:10 ` Vegard Nossum
2016-08-22 7:17 ` Jiri Olsa
2016-08-22 8:29 ` Jiri Olsa
2016-08-22 10:38 ` Jiri Olsa
2016-08-28 18:09 ` Jiri Olsa
2016-08-29 10:03 ` Peter Zijlstra
2016-08-29 13:02 ` Peter Zijlstra
2016-08-29 13:14 ` Vince Weaver [this message]
2016-08-29 18:58 ` Jiri Olsa
2016-08-30 6:47 ` Peter Zijlstra
2016-08-30 7:26 ` Peter Zijlstra
2016-08-30 9:47 ` Jiri Olsa
2016-08-30 16:26 ` Stephane Eranian
2016-09-02 8:33 ` Peter Zijlstra
2016-10-09 7:09 ` [lkp] [perf/core] 412929295f: WARNING: CPU: 2 PID: 600 at kernel/events/core.c:3530 perf_event_read+0x17d/0x190 kernel test robot
2016-08-17 20:55 ` [PATCH v3 2/4] perf/core: generalize event->group_flags David Carrillo-Cisneros
2016-08-18 10:53 ` [tip:perf/core] perf/core: Generalize event->group_flags tip-bot for David Carrillo-Cisneros
2016-08-17 20:55 ` [PATCH v3 3/4] perf/core: introduce PMU_EV_CAP_READ_ACTIVE_PKG David Carrillo-Cisneros
2016-08-18 10:54 ` [tip:perf/core] perf/core: Introduce PMU_EV_CAP_READ_ACTIVE_PKG tip-bot for David Carrillo-Cisneros
2016-08-17 20:55 ` [PATCH v3 4/4] perf/x86: use PMUEF_READ_CPU_PKG in uncore events David Carrillo-Cisneros
2016-08-18 10:54 ` [tip:perf/core] perf/x86: Use " tip-bot for David Carrillo-Cisneros
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