From: Steven Rostedt <rostedt@goodmis.org>
To: Vincent Donnefort <vdonnefort@google.com>
Cc: mhiramat@kernel.org, linux-kernel@vger.kernel.org,
linux-trace-kernel@vger.kernel.org, kernel-team@android.com
Subject: Re: [PATCH v5 1/2] ring-buffer: Introducing ring-buffer mapping functions
Date: Wed, 2 Aug 2023 07:45:26 -0400 [thread overview]
Message-ID: <20230802074526.2fa479ab@gandalf.local.home> (raw)
In-Reply-To: <20230801132603.0b18c0eb@gandalf.local.home>
On Tue, 1 Aug 2023 13:26:03 -0400
Steven Rostedt <rostedt@goodmis.org> wrote:
> > +
> > + if (READ_ONCE(cpu_buffer->mapped)) {
> > + /* Ensure the meta_page is ready */
> > + smp_rmb();
> > + WRITE_ONCE(cpu_buffer->meta_page->pages_touched,
> > + local_read(&cpu_buffer->pages_touched));
> > + }
>
> I was thinking instead of doing this in the semi fast path, put this logic
> into the rb_wakeup_waiters() code. That is, if a task is mapped, we call
> the irq_work() to do this for us. It could even do more, like handle
> blocked mapped waiters.
I was thinking how to implement this, and I worry that it may cause an irq
storm. Let's keep this (and the other locations) as is, where we do the
updates in place. Then we can look at seeing if it is possible to do it in
a delayed fashion another time.
-- Steve
next prev parent reply other threads:[~2023-08-02 11:45 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-07-28 16:47 [PATCH v5 0/2] Introducing trace buffer mapping by user-space Vincent Donnefort
2023-07-28 16:47 ` [PATCH v5 1/2] ring-buffer: Introducing ring-buffer mapping functions Vincent Donnefort
2023-07-29 1:09 ` kernel test robot
2023-07-29 3:44 ` kernel test robot
2023-08-01 17:26 ` Steven Rostedt
2023-08-02 11:45 ` Steven Rostedt [this message]
2023-08-02 12:30 ` Vincent Donnefort
2023-08-02 15:13 ` Steven Rostedt
2023-08-03 10:33 ` Vincent Donnefort
2023-08-03 14:52 ` Steven Rostedt
2023-07-28 16:47 ` [PATCH v5 2/2] tracing: Allow user-space mapping of the ring-buffer Vincent Donnefort
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=20230802074526.2fa479ab@gandalf.local.home \
--to=rostedt@goodmis.org \
--cc=kernel-team@android.com \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-trace-kernel@vger.kernel.org \
--cc=mhiramat@kernel.org \
--cc=vdonnefort@google.com \
/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;
as well as URLs for NNTP newsgroup(s).