From: Peter Zijlstra <peterz@infradead.org>
To: Stephane Eranian <eranian@google.com>
Cc: LKML <linux-kernel@vger.kernel.org>,
"mingo@elte.hu" <mingo@elte.hu>, "Jiri Olsa" <jolsa@redhat.com>,
"Frédéric Weisbecker" <fweisbec@gmail.com>
Subject: Re: [PATCH] perf: fix ring_buffer perf_output_space() boundary calculation
Date: Mon, 18 Mar 2013 14:11:03 +0100 [thread overview]
Message-ID: <1363612263.22553.12.camel@laptop> (raw)
In-Reply-To: <CABPqkBRGutLBC+mO+F8fH5F-Yoe1NL8e_=yF9boxA28jNLO56g@mail.gmail.com>
On Mon, 2013-03-18 at 14:03 +0100, Stephane Eranian wrote:
> On Mon, Mar 18, 2013 at 1:59 PM, Peter Zijlstra <peterz@infradead.org> wrote:
> > On Mon, 2013-03-18 at 13:48 +0100, Stephane Eranian wrote:
> >> if (!rb->writable)
> >> - return true;
> >> + return false;
> >
> >
> > writable means user writable (VM_WRITE); the difference is that a
> > !VM_WRITE buffer will simply over-write its own tail whereas a VM_WRITE
> > buffer will drop events.
> >
> > So returning true for !VM_WRITE makes sense, there's always space.
> >
> Ok, that was not so clear to me. I think this if() statment deserves a comment.
> I will add that in V2.
Thanks; I suppose renaming the entire ->writable thing might be better
though. Something like ->overwrite or so.
next prev parent reply other threads:[~2013-03-18 13:11 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-03-18 12:48 Stephane Eranian
2013-03-18 12:59 ` Peter Zijlstra
2013-03-18 13:03 ` Stephane Eranian
2013-03-18 13:11 ` Peter Zijlstra [this message]
2013-03-18 13:18 ` Stephane Eranian
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=1363612263.22553.12.camel@laptop \
--to=peterz@infradead.org \
--cc=eranian@google.com \
--cc=fweisbec@gmail.com \
--cc=jolsa@redhat.com \
--cc=linux-kernel@vger.kernel.org \
--cc=mingo@elte.hu \
/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
all inboxes | Powered by JetHome®