From mboxrd@z Thu Jan 1 00:00:00 1970 From: Andi Kleen Subject: Re: Multi-device update Date: Wed, 16 Apr 2008 20:10:28 +0200 Message-ID: <48064114.5080304@firstfloor.org> References: <200804161134.19237.chris.mason@oracle.com> <200804161254.09414.chris.mason@oracle.com> <87fxtlitle.fsf@basil.nowhere.org> <200804161404.04202.chris.mason@oracle.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Cc: linux-btrfs@vger.kernel.org To: Chris Mason Return-path: In-Reply-To: <200804161404.04202.chris.mason@oracle.com> List-ID: Chris Mason wrote: > On Wednesday 16 April 2008, Andi Kleen wrote: >> Chris Mason writes: >>> On Wednesday 16 April 2008, Andi Kleen wrote: >>>> Chris Mason writes: >>>>> The async work queues include code to checksum data pages without the >>>>> FS mutex >>>> Are they able to distribute work to other cores? >>> Yes, it just uses a workqueue. >> Unfortunately work queues don't do that by default currently. They >> tend to process on the current CPU only. > > Well, I see multiple work queue threads using CPU time, but I haven't spent > much time optimizing it. There's definitely room for improvement. That's likely because you submit from multiple CPUs. But with a single submitter running on a single CPU there shouldn't be any load balancing currently. -Andi