From: "Wangnan (F)" <wangnan0@huawei.com>
To: Alexei Starovoitov <alexei.starovoitov@gmail.com>
Cc: Peter Zijlstra <peterz@infradead.org>, <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: Thu, 24 Mar 2016 11:48:54 +0800 [thread overview]
Message-ID: <56F363A6.2010603@huawei.com> (raw)
In-Reply-To: <20160323192521.GA48575@ast-mbp.thefacebook.com>
On 2016/3/24 3:25, Alexei Starovoitov wrote:
> On Wed, Mar 23, 2016 at 06:08:41PM +0800, Wangnan (F) wrote:
>>
>> On 2016/3/23 17:50, Peter Zijlstra wrote:
>>> On Mon, Mar 14, 2016 at 09:59:43AM +0000, Wang Nan wrote:
>>>> Convert perf_output_begin to __perf_output_begin and make the later
>>>> function able to write records from the end of the ring buffer.
>>>> Following commits will utilize the 'backward' flag.
>>>>
>>>> This patch doesn't introduce any extra performance overhead since we
>>>> use always_inline.
>>> So while I agree that with __always_inline and constant propagation we
>>> _should_ end up with the same code, we have:
>>>
>>> $ size defconfig-build/kernel/events/ring_buffer.o.{pre,post}
>>> text data bss dec hex filename
>>> 3785 2 0 3787 ecb defconfig-build/kernel/events/ring_buffer.o.pre
>>> 3673 2 0 3675 e5b defconfig-build/kernel/events/ring_buffer.o.post
>>>
>>> The patch actually makes the file shrink.
>>>
>>> So I think we still want to have some actual performance numbers.
>> There are some numbers. You can find them from:
>>
>> http://lkml.iu.edu/hypermail/linux/kernel/1601.2/03966.html
> Wang, when you respin, please add all perf analysis that you've
> done and the reasons to do it this way to commit log
> to make sure it stays in git history.
>
> I've reviewed it in the past and looks like the patches didn't
> change over the last months. So still ack, I believe
> overwrite buffers is a great feature.
Can I add your Acked-by in all these 5 patches?
Thank you.
next prev parent reply other threads:[~2016-03-24 3:50 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) [this message]
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
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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