LKML Archive on lore.kernel.org
help / color / mirror / Atom feed
From: Nick Piggin <nickpiggin@yahoo.com.au>
To: Christoph Lameter <clameter@sgi.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>,
	Andrew Morton <akpm@linux-foundation.org>,
	LKML <linux-kernel@vger.kernel.org>,
	linux-mm@kvack.org
Subject: Re: [git pull] more SLUB updates for 2.6.25
Date: Fri, 8 Feb 2008 18:12:21 +1100	[thread overview]
Message-ID: <200802081812.22513.nickpiggin@yahoo.com.au> (raw)
In-Reply-To: <Pine.LNX.4.64.0802071755580.7473@schroedinger.engr.sgi.com>

On Friday 08 February 2008 13:13, Christoph Lameter wrote:
> are available in the git repository at:
>
>   git://git.kernel.org/pub/scm/linux/kernel/git/christoph/vm.git slub-linus
>
> (includes the cmpxchg_local fastpath since the cmpxchg_local work
> by Matheiu is in now, and the non atomic unlock by Nick. Verified that
> this is not doing any harm after some other patches had been removed.

Ah, good. I think it is always a good thing to be able to remove atomics.
They place quite a bit of burden on the CPU, especially x86 where it also
has implicit memory ordering semantics (although x86 can speculatively
get around much of the problem, it's obviously worse than no restriction)

Even if perhaps some cache coherency or timing quirk makes the non-atomic
version slower (all else being equal), then I'd still say that the non
atomic version should be preferred.

Thanks,
Nick


  reply	other threads:[~2008-02-08  7:13 UTC|newest]

Thread overview: 7+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2008-02-08  2:13 Christoph Lameter
2008-02-08  7:12 ` Nick Piggin [this message]
2008-02-08  7:29   ` Eric Dumazet
2008-02-08  8:08     ` Nick Piggin
2008-02-08  8:10     ` Christoph Lameter
2008-02-09 11:25       ` Eric Dumazet
2008-02-08 14:58     ` Andi Kleen

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=200802081812.22513.nickpiggin@yahoo.com.au \
    --to=nickpiggin@yahoo.com.au \
    --cc=akpm@linux-foundation.org \
    --cc=clameter@sgi.com \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linux-mm@kvack.org \
    --cc=torvalds@linux-foundation.org \
    --subject='Re: [git pull] more SLUB updates for 2.6.25' \
    /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

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).