From: Peter Zijlstra <peterz@infradead.org>
To: "Wangnan (F)" <wangnan0@huawei.com>
Cc: mingo@redhat.com, linux-kernel@vger.kernel.org,
He Kuang <hekuang@huawei.com>,
Alexei Starovoitov <ast@kernel.org>,
Arnaldo Carvalho de Melo <acme@redhat.com>,
Brendan Gregg <brendan.d.gregg@gmail.com>,
Jiri Olsa <jolsa@kernel.org>,
Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>,
Namhyung Kim <namhyung@kernel.org>, Zefan Li <lizefan@huawei.com>,
pi3orama@163.com
Subject: Re: [PATCH 3/5] perf core: Prepare writing into ring buffer from end
Date: Sun, 27 Mar 2016 17:20:05 +0200 [thread overview]
Message-ID: <20160327152005.GU6356@twins.programming.kicks-ass.net> (raw)
In-Reply-To: <56F547CC.5000408@huawei.com>
On Fri, Mar 25, 2016 at 10:14:36PM +0800, Wangnan (F) wrote:
> >>I think you enabled some unusual config options?
x86_64-defconfig
> >You must enabled CONFIG_OPTIMIZE_INLINING. Now I get similar result:
It has that indeed.
> After enabling CONFIG_OPTIMIZE_INLINING:
>
> Test its performance by calling 'close(-1)' for 3000000 times and
> use 'perf record -o /dev/null -e raw_syscalls:* test-ring-buffer' to
> capture system calls:
>
> MEAN STDVAR
> BASE 800077.1 23448.13
> RAWPERF.PRE 2465858.0 603473.70
> RAWPERF.POST 2471925.0 609437.60
>
> Considering the high stdvar, after applying this patch the performance
> is not change.
Why is your variance so immense? And doesn't that render the
measurements pointless?
next prev parent reply other threads:[~2016-03-27 15:20 UTC|newest]
Thread overview: 34+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-03-14 9:59 [PATCH 0/5] perf core: Support overwrite ring buffer Wang Nan
2016-03-14 9:59 ` [PATCH 1/5] perf core: Introduce new ioctl options to pause and resume " Wang Nan
2016-03-23 9:16 ` Peter Zijlstra
2016-03-23 9:33 ` Wangnan (F)
2016-03-23 9:52 ` Peter Zijlstra
2016-03-23 12:43 ` Vince Weaver
2016-10-21 7:06 ` Michael Kerrisk (man-pages)
2016-10-21 7:13 ` Wangnan (F)
2016-10-21 8:55 ` Michael Kerrisk (man-pages)
2016-03-14 9:59 ` [PATCH 2/5] perf core: Set event's default overflow_handler Wang Nan
2016-03-23 17:50 ` Peter Zijlstra
2016-03-23 18:13 ` Will Deacon
2016-03-23 19:13 ` Peter Zijlstra
2016-03-23 19:29 ` Peter Zijlstra
2016-03-24 9:58 ` Will Deacon
2016-03-24 10:42 ` Peter Zijlstra
2016-03-14 9:59 ` [PATCH 3/5] perf core: Prepare writing into ring buffer from end Wang Nan
2016-03-23 9:50 ` Peter Zijlstra
2016-03-23 10:08 ` Wangnan (F)
2016-03-23 19:25 ` Alexei Starovoitov
2016-03-24 3:48 ` Wangnan (F)
2016-03-24 17:29 ` Alexei Starovoitov
2016-03-25 12:26 ` Wangnan (F)
2016-03-25 12:36 ` Wangnan (F)
2016-03-25 14:14 ` Wangnan (F)
2016-03-27 15:20 ` Peter Zijlstra [this message]
2016-03-27 15:30 ` pi3orama
2016-03-28 1:07 ` Wangnan (F)
2016-03-28 1:58 ` Wangnan (F)
2016-03-28 2:58 ` Wangnan (F)
2016-03-14 9:59 ` [PATCH 4/5] perf core: Add backward attribute to perf event Wang Nan
2016-03-14 9:59 ` [PATCH 5/5] perf core: Reduce perf event output overhead by new overflow handler Wang Nan
2016-03-23 10:02 ` Peter Zijlstra
-- strict thread matches above, loose matches on Subject: below --
2016-01-25 8:33 [PATCH 0/5] perf core: Read from overwrite ring buffer Wang Nan
2016-01-25 8:33 ` [PATCH 3/5] perf core: Prepare writing into ring buffer from end Wang Nan
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