From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from psmtp.com (na3sys010amx144.postini.com [74.125.245.144]) by kanga.kvack.org (Postfix) with SMTP id E6F576B0044 for ; Wed, 21 Mar 2012 10:49:49 -0400 (EDT) Received: by dadv6 with SMTP id v6so2079436dad.14 for ; Wed, 21 Mar 2012 07:49:49 -0700 (PDT) Subject: Re: Patch workqueue: create new slab cache instead of hacking From: Eric Dumazet In-Reply-To: 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> Content-Type: text/plain; charset="UTF-8" Date: Wed, 21 Mar 2012 07:49:41 -0700 Message-ID: <1332341381.7893.17.camel@edumazet-glaptop> Mime-Version: 1.0 Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org List-ID: To: Christoph Lameter Cc: Tejun Heo , Lai Jiangshan , Pekka Enberg , Matt Mackall , Andrew Morton , linux-kernel@vger.kernel.org, linux-mm@kvack.org On Wed, 2012-03-21 at 09:12 -0500, Christoph Lameter wrote: > How about this instead? > > Subject: workqueues: Use new kmem cache to get aligned memory for workqueues > > The workqueue logic currently improvises by doing a kmalloc allocation and > then aligning the object. Create a slab cache for that purpose with the > proper alignment instead. > > Cleans up the code and makes things much simpler. No need anymore to carry > an additional pointer to the beginning of the kmalloc object. > > Signed-off-by: Christoph Lameter Creating a dedicated cache for few objects ? Thats a lot of overhead, at least for SLAB (no merges of caches) By the way network stack also wants to align struct net_device (in function alloc_netdev_mqs(), and uses a custom code. In this case, as the size of net_device is not constant, we use standard kzalloc(). No idea why NETDEV_ALIGN is 32 ... Oh well, some old constant instead of L1_CACHE_BYTES ... -- 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