From: Peter Zijlstra <peterz@infradead.org> To: Leo Yan <leo.yan@linaro.org> Cc: Arnaldo Carvalho de Melo <acme@kernel.org>, Ingo Molnar <mingo@redhat.com>, Mark Rutland <mark.rutland@arm.com>, Alexander Shishkin <alexander.shishkin@linux.intel.com>, Jiri Olsa <jolsa@redhat.com>, Namhyung Kim <namhyung@kernel.org>, Thomas Gleixner <tglx@linutronix.de>, x86@kernel.org, "H. Peter Anvin" <hpa@zytor.com>, Mathieu Poirier <mathieu.poirier@linaro.org>, Suzuki K Poulose <suzuki.poulose@arm.com>, Mike Leach <mike.leach@linaro.org>, Adrian Hunter <adrian.hunter@intel.com>, Andi Kleen <ak@linux.intel.com>, linux-perf-users@vger.kernel.org, linux-kernel@vger.kernel.org, coresight@lists.linaro.org, linux-arm-kernel@lists.infradead.org Subject: Re: [PATCH v2 7/8] perf auxtrace: Use WRITE_ONCE() for updating aux_tail Date: Mon, 7 Jun 2021 17:31:01 +0200 [thread overview] Message-ID: <YL47tdD0ygaErZu+@hirez.programming.kicks-ass.net> (raw) In-Reply-To: <20210602103007.184993-8-leo.yan@linaro.org> On Wed, Jun 02, 2021 at 06:30:06PM +0800, Leo Yan wrote: > Use WRITE_ONCE() for updating aux_tail, so can avoid unexpected memory > behaviour. > > Signed-off-by: Leo Yan <leo.yan@linaro.org> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> > --- > tools/perf/util/auxtrace.h | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/tools/perf/util/auxtrace.h b/tools/perf/util/auxtrace.h > index e625bc76cdde..abc4282f5272 100644 > --- a/tools/perf/util/auxtrace.h > +++ b/tools/perf/util/auxtrace.h > @@ -458,7 +458,7 @@ static inline void auxtrace_mmap__write_tail(struct auxtrace_mmap *mm, u64 tail) > > /* Ensure all reads are done before we write the tail out */ > smp_mb(); > - pc->aux_tail = tail; > + WRITE_ONCE(pc->aux_tail, tail); > } > > int auxtrace_mmap__mmap(struct auxtrace_mmap *mm, > -- > 2.25.1 >
WARNING: multiple messages have this Message-ID (diff)
From: Peter Zijlstra <peterz@infradead.org> To: Leo Yan <leo.yan@linaro.org> Cc: Arnaldo Carvalho de Melo <acme@kernel.org>, Ingo Molnar <mingo@redhat.com>, Mark Rutland <mark.rutland@arm.com>, Alexander Shishkin <alexander.shishkin@linux.intel.com>, Jiri Olsa <jolsa@redhat.com>, Namhyung Kim <namhyung@kernel.org>, Thomas Gleixner <tglx@linutronix.de>, x86@kernel.org, "H. Peter Anvin" <hpa@zytor.com>, Mathieu Poirier <mathieu.poirier@linaro.org>, Suzuki K Poulose <suzuki.poulose@arm.com>, Mike Leach <mike.leach@linaro.org>, Adrian Hunter <adrian.hunter@intel.com>, Andi Kleen <ak@linux.intel.com>, linux-perf-users@vger.kernel.org, linux-kernel@vger.kernel.org, coresight@lists.linaro.org, linux-arm-kernel@lists.infradead.org Subject: Re: [PATCH v2 7/8] perf auxtrace: Use WRITE_ONCE() for updating aux_tail Date: Mon, 7 Jun 2021 17:31:01 +0200 [thread overview] Message-ID: <YL47tdD0ygaErZu+@hirez.programming.kicks-ass.net> (raw) In-Reply-To: <20210602103007.184993-8-leo.yan@linaro.org> On Wed, Jun 02, 2021 at 06:30:06PM +0800, Leo Yan wrote: > Use WRITE_ONCE() for updating aux_tail, so can avoid unexpected memory > behaviour. > > Signed-off-by: Leo Yan <leo.yan@linaro.org> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> > --- > tools/perf/util/auxtrace.h | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/tools/perf/util/auxtrace.h b/tools/perf/util/auxtrace.h > index e625bc76cdde..abc4282f5272 100644 > --- a/tools/perf/util/auxtrace.h > +++ b/tools/perf/util/auxtrace.h > @@ -458,7 +458,7 @@ static inline void auxtrace_mmap__write_tail(struct auxtrace_mmap *mm, u64 tail) > > /* Ensure all reads are done before we write the tail out */ > smp_mb(); > - pc->aux_tail = tail; > + WRITE_ONCE(pc->aux_tail, tail); > } > > int auxtrace_mmap__mmap(struct auxtrace_mmap *mm, > -- > 2.25.1 > _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
next prev parent reply other threads:[~2021-06-07 15:32 UTC|newest] Thread overview: 56+ messages / expand[flat|nested] mbox.gz Atom feed top 2021-06-02 10:29 [PATCH v2 0/8] perf: Refine barriers for AUX ring buffer Leo Yan 2021-06-02 10:29 ` Leo Yan 2021-06-02 10:30 ` [PATCH v2 1/8] perf/ring_buffer: Add comment for barriers on " Leo Yan 2021-06-02 10:30 ` Leo Yan 2021-06-07 15:27 ` Peter Zijlstra 2021-06-07 15:27 ` Peter Zijlstra 2021-06-02 10:30 ` [PATCH v2 2/8] coresight: tmc-etr: Add barrier after updating " Leo Yan 2021-06-02 10:30 ` Leo Yan 2021-06-02 10:30 ` [PATCH v2 3/8] coresight: tmc-etf: Add comment for store ordering Leo Yan 2021-06-02 10:30 ` Leo Yan 2021-06-02 10:30 ` [PATCH v2 4/8] perf/x86: Add barrier after updating bts Leo Yan 2021-06-02 10:30 ` Leo Yan 2021-06-07 15:29 ` Peter Zijlstra 2021-06-07 15:29 ` Peter Zijlstra 2021-06-02 10:30 ` [PATCH v2 5/8] perf auxtrace: Change to use SMP memory barriers Leo Yan 2021-06-02 10:30 ` Leo Yan 2021-06-07 10:02 ` Adrian Hunter 2021-06-07 10:02 ` Adrian Hunter 2021-06-07 15:29 ` Peter Zijlstra 2021-06-07 15:29 ` Peter Zijlstra 2021-06-08 16:45 ` Arnaldo Carvalho de Melo 2021-06-08 16:45 ` Arnaldo Carvalho de Melo 2021-06-02 10:30 ` [PATCH v2 6/8] perf auxtrace: Drop legacy __sync functions Leo Yan 2021-06-02 10:30 ` Leo Yan 2021-06-02 10:47 ` Adrian Hunter 2021-06-02 10:47 ` Adrian Hunter 2021-06-02 11:16 ` Leo Yan 2021-06-02 11:16 ` Leo Yan 2021-06-02 11:21 ` Adrian Hunter 2021-06-02 11:21 ` Adrian Hunter 2021-06-02 13:01 ` Leo Yan 2021-06-02 13:01 ` Leo Yan 2021-06-02 10:30 ` [PATCH v2 7/8] perf auxtrace: Use WRITE_ONCE() for updating aux_tail Leo Yan 2021-06-02 10:30 ` Leo Yan 2021-06-07 10:03 ` Adrian Hunter 2021-06-07 10:03 ` Adrian Hunter 2021-06-07 15:31 ` Peter Zijlstra [this message] 2021-06-07 15:31 ` Peter Zijlstra 2021-06-08 17:04 ` Arnaldo Carvalho de Melo 2021-06-08 17:04 ` Arnaldo Carvalho de Melo 2021-06-09 0:21 ` Leo Yan 2021-06-09 0:21 ` Leo Yan 2021-06-02 10:30 ` [PATCH v2 8/8] perf record: Directly bail out for compat case Leo Yan 2021-06-02 10:30 ` Leo Yan 2021-06-02 11:18 ` Adrian Hunter 2021-06-02 11:18 ` Adrian Hunter 2021-06-02 12:38 ` Leo Yan 2021-06-02 12:38 ` Leo Yan 2021-06-07 10:23 ` Adrian Hunter 2021-06-07 10:23 ` Adrian Hunter 2021-06-07 15:09 ` Leo Yan 2021-06-07 15:09 ` Leo Yan 2021-06-09 8:23 ` Adrian Hunter 2021-06-09 8:23 ` Adrian Hunter 2021-06-09 8:57 ` Leo Yan 2021-06-09 8:57 ` Leo Yan
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