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From: Anton Blanchard <anton@samba.org>
To: Hugh Dickins <hugh@veritas.com>
Cc: Christoph Lameter <clameter@sgi.com>,
	Andrew Morton <akpm@linux-foundation.org>,
	Badari Pulavarty <pbadari@us.ibm.com>,
	netdev@vger.kernel.org, lkml <linux-kernel@vger.kernel.org>,
	sfr@canb.auug.org.au, ak@suse.de
Subject: Re: select(0, ..) is valid ?
Date: Wed, 16 May 2007 10:37:03 -0500	[thread overview]
Message-ID: <20070516153703.GA26912@kryten> (raw)
In-Reply-To: <Pine.LNX.4.64.0705151927360.28895@blonde.wat.veritas.com>


Hi Hugh,

> It's interesting that compat_core_sys_select() shows this kmalloc(0)
> failure but core_sys_select() does not.  That's because core_sys_select()
> avoids kmalloc by using a buffer on the stack for small allocations (and
> 0 sure is small).  Shouldn't compat_core_sys_select() do just the same?
> Or is SLUB going to be so efficient that doing so is a waste of time?

Nice catch, the original optimisation from Andi is:

http://git.kernel.org/git-new/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commit;h=70674f95c0a2ea694d5c39f4e514f538a09be36f

And I think it makes sense for the compat code to do it too.

Anton

  reply	other threads:[~2007-05-16 15:37 UTC|newest]

Thread overview: 18+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2007-05-15 17:29 select(0, ..) is valid ? Badari Pulavarty
2007-05-15 17:34 ` Mark Glines
2007-05-15 17:36 ` Jiri Slaby
2007-05-15 17:42 ` H. Peter Anvin
2007-05-15 17:43 ` Alan Cox
2007-05-15 17:44 ` Andrew Morton
2007-05-15 17:57   ` Badari Pulavarty
2007-05-15 18:10   ` Christoph Lameter
2007-05-15 18:30     ` Andrew Morton
2007-05-15 18:36       ` Christoph Lameter
2007-05-15 18:44     ` Hugh Dickins
2007-05-16 15:37       ` Anton Blanchard [this message]
2007-05-17  0:59         ` Badari Pulavarty
2007-05-22 14:16           ` Steve Fox
2007-05-22 14:34             ` Nishanth Aravamudan
2007-05-22 17:49               ` Steve Fox
2007-05-18 13:21         ` Andi Kleen
2007-05-22  1:21           ` Nish Aravamudan

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