From: Richard Henderson <rth@twiddle.net>
To: Siddhesh Poyarekar <siddhesh@redhat.com>
Cc: libc-ports@sourceware.org, libc-alpha@sourceware.org
Subject: Re: PI mutex support for pthread_cond_* now in nptl
Date: Tue, 19 Feb 2013 16:42:00 -0000 [thread overview]
Message-ID: <5123AB55.2070100@twiddle.net> (raw)
In-Reply-To: <20130218105637.GJ32163@spoyarek.pnq.redhat.com>
On 2013-02-18 02:56, Siddhesh Poyarekar wrote:
> Hi arch-maintainers!
>
> The x86 assembly code for pthread_cond_* functions has, since some
> time now, been capable of utilizing PI mutexes (using
> PTHREAD_PRIO_INHERIT when initializing a mutex) optimally by using the
> FUTEX_WAIT_REQUEUE_PI and its companion FUTEX_CMP_REQUEUE_PI to
> requeue waiters woken on pthread_cond_broadcast to the PI mutex while
> waking just one child, hence avoiding the thundering herd effect.
> This code is now available on the default C implementation in master,
> which is used by most non-x86 architectures in glibc.
>
> To allow your architecture to use this, you need to define the
> following:
>
> - lll_futex_wait_requeue_pi macro to call the FUTEX_WAIT_REQUEUE_PI
> operation in a futex syscall.
>
> - lll_futex_timed_wait_requeue_pi, which is the timed equivalent of
> the above.
>
> - lll_futex_cmp_requeue_pi to call FUTEX_CMP_REQUEUE_PI.
>
> I have committed implementations for s390 and powerpc, which can be
> used as examples for implementation on other architectures.
Any chance we can move these macros into a generic linux header?
Given that we're using INTERNAL_SYSCALL macros, the definitions ought to
be the same for all targets.
r~
next prev parent reply other threads:[~2013-02-19 16:42 UTC|newest]
Thread overview: 18+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-02-18 10:56 Siddhesh Poyarekar
2013-02-18 23:50 ` Joseph S. Myers
2013-02-19 0:50 ` Joseph S. Myers
2013-02-19 16:42 ` Richard Henderson [this message]
2013-02-19 16:49 ` Siddhesh Poyarekar
2013-02-19 17:18 ` Joseph S. Myers
2013-02-19 17:21 ` Siddhesh Poyarekar
2013-02-19 20:06 ` Torvald Riegel
2013-02-20 18:13 ` Steven Munroe
2013-02-20 20:25 ` Torvald Riegel
2013-02-20 22:04 ` Roland McGrath
2013-02-20 22:41 ` Steven Munroe
2013-02-21 4:32 ` Siddhesh Poyarekar
[not found] ` <1361304381.581.80.camel__6928.53579898856$1361304432$gmane$org@triegel.csb>
2013-02-22 4:11 ` Andi Kleen
[not found] ` <5123AB55.2070100__45742.2411222526$1361292204$gmane$org@twiddle.net>
2013-02-19 17:01 ` Andreas Schwab
2013-02-19 17:18 ` Siddhesh Poyarekar
2013-02-19 17:39 ` Andreas Schwab
2013-02-19 17:52 ` Siddhesh Poyarekar
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=5123AB55.2070100@twiddle.net \
--to=rth@twiddle.net \
--cc=libc-alpha@sourceware.org \
--cc=libc-ports@sourceware.org \
--cc=siddhesh@redhat.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 read-only IMAP folder(s) and NNTP newsgroup(s).