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From: Andi Kleen <ak@linux.intel.com>
To: Namhyung Kim <namhyung@kernel.org>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>,
	Jiri Olsa <jolsa@redhat.com>, Ingo Molnar <mingo@kernel.org>,
	Peter Zijlstra <peterz@infradead.org>,
	Mark Rutland <mark.rutland@arm.com>,
	Alexander Shishkin <alexander.shishkin@linux.intel.com>,
	LKML <linux-kernel@vger.kernel.org>,
	Stephane Eranian <eranian@google.com>,
	Ian Rogers <irogers@google.com>
Subject: Re: [PATCH 0/3] perf tools: Minor improvements in event synthesis
Date: Fri, 12 Mar 2021 07:09:33 -0800	[thread overview]
Message-ID: <20210312150933.GN203350@tassilo.jf.intel.com> (raw)
In-Reply-To: <20201221070029.1451176-1-namhyung@kernel.org>

On Mon, Dec 21, 2020 at 04:00:26PM +0900, Namhyung Kim wrote:
> Hello,
> 
> This is to optimize the event synthesis during perf record.
> 
> The first patch is to reduce memory usage when many threads are used.
> The second is to avoid unncessary syscalls for kernel threads.  And
> the last one is to reduce the number of threads to iterate when new
> threads are being created at the same time.
> 
> Unfortunately there's no dramatic improvement here but I can see ~5%
> gain in the 'perf bench internals synthesize' on a big machine.
> (The numbers are not stable though)

Looks all good to me. The VmPeak assumption might be slightly
fragile, but I guess there's nothing better currently.

Reviewed-by: Andi Kleen <ak@linux.intel.com>

-Andi

      parent reply	other threads:[~2021-03-12 15:10 UTC|newest]

Thread overview: 7+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-12-21  7:00 [PATCH 0/3] perf tools: Minor improvements in event synthesis Namhyung Kim
2020-12-21  7:00 ` [PATCH 1/3] perf tools: Use /proc/<PID>/task/<TID>/status for synthesis Namhyung Kim
2020-12-21  7:00 ` [PATCH 2/3] perf tools: Skip MMAP record synthesis for kernel threads Namhyung Kim
2020-12-28 11:50   ` Jiri Olsa
2020-12-29  5:35     ` Namhyung Kim
2020-12-21  7:00 ` [PATCH 3/3] perf tools: Use scandir() to iterate threads Namhyung Kim
2021-03-12 15:09 ` Andi Kleen [this message]

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