From mboxrd@z Thu Jan 1 00:00:00 1970 Subject: Re: [PATCH 0/5] make slab gfp fair From: Peter Zijlstra In-Reply-To: References: <20070514131904.440041502@chello.nl> <20070514161224.GC11115@waste.org> <1179164453.2942.26.camel@lappy> <1179170912.2942.37.camel@lappy> <1179172994.2942.49.camel@lappy> Content-Type: text/plain Date: Mon, 14 May 2007 22:12:36 +0200 Message-Id: <1179173556.2942.54.camel@lappy> Mime-Version: 1.0 Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org Return-Path: To: Christoph Lameter Cc: Matt Mackall , linux-kernel@vger.kernel.org, linux-mm@kvack.org, Thomas Graf , David Miller , Andrew Morton , Daniel Phillips , Pekka Enberg List-ID: On Mon, 2007-05-14 at 13:06 -0700, Christoph Lameter wrote: > On Mon, 14 May 2007, Peter Zijlstra wrote: > > > > Hmmm.. Maybe we could do that.... But what I had in mind was simply to > > > set a page flag (DebugSlab()) if you know in alloc_slab that the slab > > > should be only used for emergency allocation. If DebugSlab is set then the > > > fastpath will not be called. You can trap all allocation attempts and > > > insert whatever fancy logic you want in the debug path since its not > > > performance critical. > > > > I might have missed some detail when I looked at SLUB, but I did not see > > how setting SlabDebug would trap subsequent allocations to that slab. > > Ok its not evident in slab_alloc. But if SlabDebug is set then > page->lockless_list is always NULL and we always fall back to > __slab_alloc. Ah, indeed, that is the detail I missed. Yes that would work out. > There we check for SlabDebug and go to the debug: label. > There you can insert any fancy processing you want. -- 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