From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752903Ab1LTUpc (ORCPT ); Tue, 20 Dec 2011 15:45:32 -0500 Received: from mail-iy0-f174.google.com ([209.85.210.174]:63069 "EHLO mail-iy0-f174.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751688Ab1LTUp1 (ORCPT ); Tue, 20 Dec 2011 15:45:27 -0500 Date: Tue, 20 Dec 2011 12:45:22 -0800 From: Tejun Heo To: Vivek Goyal Cc: Nate Custer , Jens Axboe , Avi Kivity , Marcelo Tosatti , kvm@vger.kernel.org, linux-kernel Subject: Re: [RFT PATCH] blkio: alloc per cpu data from worker thread context( Re: kvm deadlock) Message-ID: <20111220204522.GI10752@google.com> References: <4EE8C8EA.9070207@kernel.dk> <20111215194712.GA11194@redhat.com> <20111216202907.GH7586@redhat.com> <20111219172717.GB7175@redhat.com> <20111219173519.GL24519@google.com> <20111219182717.GC7175@redhat.com> <20111219225635.GC6256@google.com> <20111220145024.GA16946@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20111220145024.GA16946@redhat.com> User-Agent: Mutt/1.5.20 (2009-06-14) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hello, On Tue, Dec 20, 2011 at 09:50:24AM -0500, Vivek Goyal wrote: > So IIUC, existing mempool implementation is not directly usable for my > requirement and I need to write some code of my own for the caching > layer which always allocates objects from reserve and fills in the > pool asynchronously with the help of a worker thread. I've been looking at it and don't think allowing percpu allocator to be called from no io path is a good idea. The on-demand area filling is tied into vmalloc area management which in turn is tied to arch page table code and I really want to avoid pre-allocating full chunk - it can be huge. I'm trying to extend mempool to cover percpu areas, so please wait a bit. Thanks. -- tejun