All of lore.kernel.org
 help / color / mirror / Atom feed
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

  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 an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.