From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from psmtp.com (na3sys010amx181.postini.com [74.125.245.181]) by kanga.kvack.org (Postfix) with SMTP id 173CB6B00D0 for ; Thu, 6 Dec 2012 13:34:05 -0500 (EST) From: Jeff Moyer Subject: Re: [patch,v2] bdi: add a user-tunable cpu_list for the bdi flusher threads References: <50BE5988.3050501@fusionio.com> <50BE5C99.6070703@fusionio.com> <20121206180150.GQ19802@htj.dyndns.org> <50C0E1B6.5060602@fusionio.com> <20121206182239.GS19802@htj.dyndns.org> Date: Thu, 06 Dec 2012 13:33:57 -0500 In-Reply-To: <20121206182239.GS19802@htj.dyndns.org> (Tejun Heo's message of "Thu, 6 Dec 2012 10:22:39 -0800") Message-ID: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Sender: owner-linux-mm@kvack.org List-ID: To: Tejun Heo Cc: Jens Axboe , "linux-kernel@vger.kernel.org" , "linux-mm@kvack.org" , Zach Brown , Peter Zijlstra , Ingo Tejun Heo writes: > Hello, Jens. > > On Thu, Dec 06, 2012 at 07:19:34PM +0100, Jens Axboe wrote: >> We need to expose it. Once the binding is set from the kernel side on a >> kernel thread, it can't be modified. > > That's only if kthread_bind() is used. Caling set_cpus_allowed_ptr() > doesn't set PF_THREAD_BOUND and userland can adjust affinity like any > other tasks. > >> Binding either for performance reasons or for ensuring that we >> explicitly don't run in some places is a very useful feature. > > Sure, but I think this is too specific. Something more generic would > be much better. It can be as simple as generating a uevent. I'm in favor of a more general approach. For now, I'm still going to push a patch that at least binds to the proper numa node. I'll post that after I've tested it. Cheers, Jeff -- 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