From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail6.bemta8.messagelabs.com (mail6.bemta8.messagelabs.com [216.82.243.55]) by kanga.kvack.org (Postfix) with ESMTP id 6F2DD6B004A for ; Wed, 20 Jul 2011 09:42:41 -0400 (EDT) Received: by eyg7 with SMTP id 7so1139773eyg.41 for ; Wed, 20 Jul 2011 06:42:39 -0700 (PDT) Date: Wed, 20 Jul 2011 16:42:25 +0300 (EEST) From: Pekka Enberg Subject: Re: [PATCH] mm-slab: allocate kmem_cache with __GFP_REPEAT In-Reply-To: <4E26D7EA.3000902@parallels.com> Message-ID: References: <20110720121612.28888.38970.stgit@localhost6> <4E26D7EA.3000902@parallels.com> MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII; format=flowed Sender: owner-linux-mm@kvack.org List-ID: To: Konstantin Khlebnikov Cc: Andrew Morton , "linux-mm@kvack.org" , Christoph Lameter , "linux-kernel@vger.kernel.org" , Matt Mackall , "mgorman@suse.de" On Wed, 20 Jul 2011, Konstantin Khlebnikov wrote: >> The changelog isn't that convincing, really. This is kmem_cache_create() >> so I'm surprised we'd ever get NULL here in practice. Does this fix some >> problem you're seeing? If this is really an issue, I'd blame the page >> allocator as GFP_KERNEL should just work. > > nf_conntrack creates separate slab-cache for each net-namespace, > this patch of course not eliminates the chance of failure, but makes it more > acceptable. I'm still surprised you are seeing failures. mm/slab.c hasn't changed significantly in a long time. Why hasn't anyone reported this before? I'd still be inclined to shift the blame to the page allocator... Mel, Christoph? On Wed, 20 Jul 2011, Konstantin Khlebnikov wrote: > struct kmem_size for slub is more compact, it uses pecpu-pointers instead of > dumb NR_CPUS-size array. > probably better to fix this side... So how big is 'struct kmem_cache' for your configuration anyway? Fixing the per-cpu data structures would be nice but I'm guessing it'll be slightly painful for mm/slab.c. Pekka -- 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/ . Fight unfair telecom internet charges in Canada: sign http://stopthemeter.ca/ Don't email: email@kvack.org