From mboxrd@z Thu Jan 1 00:00:00 1970 Subject: Re: [PATCH] slub: reduce total stack usage of slab_err & object_err From: Matt Mackall In-Reply-To: <1222791638.2995.41.camel@castor.localdomain> References: <1222787736.2995.24.camel@castor.localdomain> <48E2480A.9090003@linux-foundation.org> <1222791638.2995.41.camel@castor.localdomain> Content-Type: text/plain Date: Tue, 30 Sep 2008 19:02:42 -0500 Message-Id: <1222819362.13453.9.camel@calx> Mime-Version: 1.0 Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org Return-Path: To: Richard Kennedy Cc: Christoph Lameter , penberg , linux-mm , lkml List-ID: On Tue, 2008-09-30 at 17:20 +0100, Richard Kennedy wrote: > Yes, using vprintk is better but you still have this path : > ( with your patch applied) > > object_err -> slab_bug(208) -> printk(216) > instead of > object_err -> slab_bug_message(8) -> printk(216) > > unfortunately the overhead for having var_args is pretty big, at least > on x86_64. I haven't measured it on 32 bit yet. Looks like this got fixed for x86_64 in gcc 4.4. For most other arches, the overhead should be reasonable. -- Mathematics is the supreme nostalgia of our time. -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org