From: Nick Piggin <npiggin@suse.de>
To: Christoph Lameter <clameter@sgi.com>
Cc: netdev@vger.kernel.org,
Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
yanmin_zhang@linux.intel.com, David Miller <davem@davemloft.net>,
Eric Dumazet <dada1@cosmosbay.com>
Subject: Re: [rfc][patch 1/3] slub: fix small HWCACHE_ALIGN alignment
Date: Mon, 3 Mar 2008 21:06:13 +0100 [thread overview]
Message-ID: <20080303200613.GC8974@wotan.suse.de> (raw)
In-Reply-To: <Pine.LNX.4.64.0803031107130.6917@schroedinger.engr.sgi.com>
On Mon, Mar 03, 2008 at 11:08:44AM -0800, Christoph Lameter wrote:
> On Mon, 3 Mar 2008, Nick Piggin wrote:
>
> > SLUB should pack even small objects nicely into cachelines if that is what
> > has been asked for. Use the same algorithm as SLAB for this.
>
> Why? SLAB does not cacheline align objects smaller than cache_line_size()
> /2.
It still doesn't after this patch.
> If they are already not cache line aligned then we can make them as
> dense as possible. That is what SLUB does.
Because when you specify HWCACHE_ALIGN, it means that you want the object
not to cross cacheline boundaries for at least cache_line_size() bytes.
SLAB does this. SLUB does not without this patch.
next prev parent reply other threads:[~2008-03-03 20:06 UTC|newest]
Thread overview: 68+ messages / expand[flat|nested] mbox.gz Atom feed top
2008-03-03 9:34 [rfc][patch 1/3] slub: fix small HWCACHE_ALIGN alignment Nick Piggin
2008-03-03 9:35 ` [rfc][patch 2/3] slab: introduce SMP alignment Nick Piggin
2008-03-03 19:06 ` Christoph Lameter
2008-03-03 20:03 ` Nick Piggin
2008-03-03 20:09 ` Christoph Lameter
2008-03-03 20:12 ` Nick Piggin
2008-03-03 20:17 ` Christoph Lameter
2008-03-03 20:24 ` Nick Piggin
2008-03-03 20:41 ` Pekka Enberg
2008-03-03 21:23 ` Christoph Lameter
2008-03-03 21:31 ` Christoph Lameter
2008-03-05 0:16 ` Nick Piggin
2008-03-07 4:37 ` Nick Piggin
2008-03-07 5:11 ` Christoph Lameter
2008-03-07 5:19 ` Nick Piggin
2008-03-07 5:26 ` Christoph Lameter
2008-03-07 5:37 ` Nick Piggin
2008-03-11 7:13 ` Nick Piggin
2008-03-12 6:21 ` Christoph Lameter
2008-03-03 9:36 ` [rfc][patch 3/3] use SLAB_ALIGN_SMP Nick Piggin
2008-03-03 9:53 ` Eric Dumazet
2008-03-03 12:41 ` Nick Piggin
2008-03-03 13:00 ` Eric Dumazet
2008-03-03 13:46 ` Nick Piggin
2008-03-03 13:53 ` Pekka Enberg
2008-03-03 14:15 ` Eric Dumazet
2008-03-03 19:10 ` Christoph Lameter
2008-03-03 19:09 ` Christoph Lameter
2008-03-03 20:10 ` Nick Piggin
2008-03-03 20:12 ` Christoph Lameter
2008-03-03 20:18 ` Nick Piggin
2008-03-03 21:14 ` Christoph Lameter
2008-03-03 9:44 ` [rfc][patch 1/3] slub: fix small HWCACHE_ALIGN alignment Pekka Enberg
2008-03-03 12:28 ` Nick Piggin
2008-03-03 19:08 ` Christoph Lameter
2008-03-03 20:06 ` Nick Piggin [this message]
2008-03-03 20:10 ` Christoph Lameter
2008-03-03 20:17 ` Nick Piggin
2008-03-03 21:16 ` Christoph Lameter
2008-03-03 21:30 ` Pekka Enberg
2008-03-03 21:32 ` Christoph Lameter
2008-03-03 21:35 ` Pekka Enberg
2008-03-05 0:28 ` Nick Piggin
2008-03-05 20:56 ` Christoph Lameter
2008-03-06 2:49 ` Nick Piggin
2008-03-06 22:53 ` Christoph Lameter
2008-03-07 2:04 ` Nick Piggin
2008-03-07 2:20 ` Christoph Lameter
2008-03-07 2:25 ` Nick Piggin
2008-03-07 2:27 ` Christoph Lameter
2008-03-07 2:33 ` Nick Piggin
2008-03-07 2:33 ` Christoph Lameter
2008-03-07 5:23 ` Nick Piggin
2008-03-05 0:08 ` Nick Piggin
2008-03-05 0:06 ` Nick Piggin
2008-03-05 0:10 ` David Miller
2008-03-05 21:06 ` Christoph Lameter
2008-03-06 2:57 ` Nick Piggin
2008-03-06 22:56 ` Christoph Lameter
2008-03-07 2:23 ` Nick Piggin
2008-03-07 2:26 ` Christoph Lameter
2008-03-07 2:32 ` Nick Piggin
2008-03-07 2:54 ` Christoph Lameter
2008-03-07 3:10 ` Nick Piggin
2008-03-07 3:18 ` Christoph Lameter
2008-03-07 3:22 ` Nick Piggin
2008-03-07 3:58 ` Christoph Lameter
2008-03-07 4:05 ` Nick Piggin
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