From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751293Ab2E2Min (ORCPT ); Tue, 29 May 2012 08:38:43 -0400 Received: from merlin.infradead.org ([205.233.59.134]:38103 "EHLO merlin.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750715Ab2E2Mim convert rfc822-to-8bit (ORCPT ); Tue, 29 May 2012 08:38:42 -0400 Message-ID: <1338295111.26856.57.camel@twins> Subject: Re: [PATCH 2/2] block: Convert BDI proportion calculations to flexible proportions From: Peter Zijlstra To: Jan Kara Cc: Sasha Levin , Wu Fengguang , linux-mm@kvack.org, LKML Date: Tue, 29 May 2012 14:38:31 +0200 In-Reply-To: <20120529123408.GA23991@quack.suse.cz> References: <1337878751-22942-1-git-send-email-jack@suse.cz> <1337878751-22942-3-git-send-email-jack@suse.cz> <1338220185.4284.19.camel@lappy> <20120529123408.GA23991@quack.suse.cz> Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7BIT X-Mailer: Evolution 3.2.2- Mime-Version: 1.0 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, 2012-05-29 at 14:34 +0200, Jan Kara wrote: > The only safe solution seems to be to create a variant of percpu counters > that can be used from an interrupt. Or do you have other idea Peter? > > [ 20.680186] [] _raw_spin_lock+0x3b/0x70 > > [ 20.680186] [] ? __percpu_counter_sum+0x17/0xc0 > > [ 20.680186] [] __percpu_counter_sum+0x17/0xc0 > > [ 20.680186] [] ? init_timer_deferrable_key+0x20/0x20 > > [ 20.680186] [] fprop_new_period+0x12/0x60 > > [ 20.680186] [] writeout_period+0x3d/0xa0 > > [ 20.680186] [] call_timer_fn+0x12f/0x260 > > [ 20.680186] [] ? init_timer_deferrable_key+0x20/0x20 Yeah, just make sure IRQs are disabled around doing that ;-)