From mboxrd@z Thu Jan 1 00:00:00 1970 Received: by nproxy.gmail.com with SMTP id l35so53794nfa for ; Wed, 25 Jan 2006 23:41:28 -0800 (PST) Message-ID: <84144f020601252341k62c0c6fck57f3baa290f4430@mail.gmail.com> Date: Thu, 26 Jan 2006 09:41:27 +0200 From: Pekka Enberg Subject: Re: [patch 8/9] slab - Add *_mempool slab variants In-Reply-To: <1138218020.2092.8.camel@localhost.localdomain> MIME-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 8BIT Content-Disposition: inline References: <20060125161321.647368000@localhost.localdomain> <1138218020.2092.8.camel@localhost.localdomain> Sender: owner-linux-mm@kvack.org Return-Path: To: colpatch@us.ibm.com Cc: linux-kernel@vger.kernel.org, sri@us.ibm.com, andrea@suse.de, pavel@suse.cz, linux-mm@kvack.org List-ID: Hi Matthew, On 1/25/06, Matthew Dobson wrote: > +extern void *__kmalloc(size_t, gfp_t, mempool_t *); If you really need to do this, please ntoe that you're adding an extra parameter push for the nominal case where mempool is not required. The compiler is unable to optimize it away. It's better that you create a new entry point for the mempool case in mm/slab.c rather than overloading __kmalloc() et al. See the following patch that does that sort of thing: http://www.kernel.org/pub/linux/kernel/people/akpm/patches/2.6/2.6.16-rc1/2.6.16-rc1-mm3/broken-out/slab-fix-kzalloc-and-kstrdup-caller-report-for-config_debug_slab.patch Now as for the rest of the patch, are you sure you want to reserve whole pages for each critical allocation that cannot be satisfied by the slab allocator? Wouldn't it be better to use something like the slob allocator to allocate from the mempool pages? That way you wouldn't have to make the slab allocator mempool aware at all, simply make your kmalloc_mempool first try the slab allocator and if it returns NULL, go for the critical pool. All this in preferably separate file so you don't make mm/slab.c any more complex than it is now. 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/ . Don't email: email@kvack.org