From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from psmtp.com (na3sys010amx109.postini.com [74.125.245.109]) by kanga.kvack.org (Postfix) with SMTP id 0E02D6B0044 for ; Wed, 21 Mar 2012 13:54:41 -0400 (EDT) Date: Wed, 21 Mar 2012 12:54:38 -0500 (CDT) From: Christoph Lameter Subject: Re: Patch workqueue: create new slab cache instead of hacking In-Reply-To: <1332345859.5330.8.camel@edumazet-glaptop> Message-ID: References: <1332238884-6237-1-git-send-email-laijs@cn.fujitsu.com> <1332238884-6237-7-git-send-email-laijs@cn.fujitsu.com> <20120320154619.GA5684@google.com> <4F6944D9.5090002@cn.fujitsu.com> <1332341381.7893.17.camel@edumazet-glaptop> <1332345859.5330.8.camel@edumazet-glaptop> MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: owner-linux-mm@kvack.org List-ID: To: Eric Dumazet Cc: Tejun Heo , Lai Jiangshan , Pekka Enberg , Matt Mackall , Andrew Morton , linux-kernel@vger.kernel.org, linux-mm@kvack.org On Wed, 21 Mar 2012, Eric Dumazet wrote: > On Wed, 2012-03-21 at 10:03 -0500, Christoph Lameter wrote: > > On Wed, 21 Mar 2012, Eric Dumazet wrote: > > > > > Creating a dedicated cache for few objects ? Thats a lot of overhead, at > > > least for SLAB (no merges of caches) > > > > Its some overhead for SLAB (a lot is what? If you tune down the per cpu > > caches it should be a couple of pages) but its none for SLUB. > > SLAB overhead per cache is O(CPUS * nr_node_ids) (unless alien caches > are disabled) nr_node_ids==2 in the standard case these days. Alien caches are minimal. > For few in flight objects, its just better to use standard kmalloc-xxxx > caches. Its easier to use a custom slab cache. Avoids hackery like we have in workqueue.c -- 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