From: Namhyung Kim <namhyung@kernel.org>
To: Ingo Molnar <mingo@kernel.org>
Cc: David Ahern <dsahern@gmail.com>,
acme@ghostprotocols.net, linux-kernel@vger.kernel.org,
Frederic Weisbecker <fweisbec@gmail.com>,
Peter Zijlstra <peterz@infradead.org>,
Jiri Olsa <jolsa@redhat.com>, Mike Galbraith <efault@gmx.de>,
Stephane Eranian <eranian@google.com>
Subject: Re: [PATCH] perf record: mmap output file - v2
Date: Tue, 15 Oct 2013 17:17:42 +0900 [thread overview]
Message-ID: <87ppr79cd5.fsf@sejong.aot.lge.com> (raw)
In-Reply-To: <20131015072540.GE24584@gmail.com> (Ingo Molnar's message of "Tue, 15 Oct 2013 09:25:40 +0200")
On Tue, 15 Oct 2013 09:25:40 +0200, Ingo Molnar wrote:
> * Namhyung Kim <namhyung@kernel.org> wrote:
>> No, st_size is bigger than rec->bytes_written due to the
>> perf_file_header which is written without updating rec->bytes_written.
>
> Since all this is code that executes once during __cmd_record(), is this
> all about the header writeout?
>
> That is what confused me about the stat() call and that's messy really: we
> are the ones who write the file header, we have a very good idea about how
> many bytes we wrote to the file! It should be entirely unnecessary to lose
> that information and then execute a system call to recover that
> information...
Right, I think session->header.data_offset has the info already.
Thanks,
Namhyung
next prev parent reply other threads:[~2013-10-15 8:17 UTC|newest]
Thread overview: 15+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-10-15 2:55 [PATCH] perf record: mmap output file - v2 David Ahern
2013-10-15 6:02 ` Ingo Molnar
2013-10-15 7:09 ` Namhyung Kim
2013-10-15 7:25 ` Ingo Molnar
2013-10-15 8:17 ` Namhyung Kim [this message]
2013-10-15 12:22 ` Jiri Olsa
2013-10-15 13:20 ` Ingo Molnar
2013-10-15 13:25 ` David Ahern
2013-10-16 1:24 ` Namhyung Kim
2013-10-15 7:31 ` Namhyung Kim
2013-10-15 7:44 ` Ingo Molnar
2013-10-15 13:45 ` David Ahern
2013-10-15 13:35 ` David Ahern
2013-10-16 1:52 ` Namhyung Kim
2013-10-16 1:58 ` David Ahern
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=87ppr79cd5.fsf@sejong.aot.lge.com \
--to=namhyung@kernel.org \
--cc=acme@ghostprotocols.net \
--cc=dsahern@gmail.com \
--cc=efault@gmx.de \
--cc=eranian@google.com \
--cc=fweisbec@gmail.com \
--cc=jolsa@redhat.com \
--cc=linux-kernel@vger.kernel.org \
--cc=mingo@kernel.org \
--cc=peterz@infradead.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox