Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754914AbbFCRmN (ORCPT ); Wed, 3 Jun 2015 13:42:13 -0400 Received: from www.linutronix.de ([62.245.132.108]:56946 "EHLO Galois.linutronix.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754319AbbFCRmB (ORCPT ); Wed, 3 Jun 2015 13:42:01 -0400 Date: Wed, 3 Jun 2015 19:41:43 +0200 (CEST) From: Thomas Gleixner To: Peter Zijlstra cc: umgwanakikbuti@gmail.com, mingo@elte.hu, ktkhai@parallels.com, rostedt@goodmis.org, juri.lelli@gmail.com, pang.xunlei@linaro.org, oleg@redhat.com, wanpeng.li@linux.intel.com, linux-kernel@vger.kernel.org Subject: Re: [PATCH 8/9] hrtimer: Allow hrtimer::function() to free the timer In-Reply-To: <20150603134023.156059118@infradead.org> Message-ID: References: <20150603132903.203333087@infradead.org> <20150603134023.156059118@infradead.org> User-Agent: Alpine 2.11 (DEB 23 2013-08-11) MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII X-Linutronix-Spam-Score: -1.0 X-Linutronix-Spam-Level: - X-Linutronix-Spam-Status: No , -1.0 points, 5.0 required, ALL_TRUSTED=-1,SHORTCIRCUIT=-0.0001 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 994 Lines: 29 On Wed, 3 Jun 2015, Peter Zijlstra wrote: > /** > * struct hrtimer - the basic hrtimer structure > @@ -153,6 +144,7 @@ struct hrtimer_clock_base { > struct timerqueue_head active; > ktime_t (*get_time)(void); > ktime_t offset; > + struct hrtimer *running; Aside of lacking a KernelDoc comment, it expands the struct size on 32bit from 32 bytes to 36 bytes which undoes some of the recent cache line optimizations I did. Mooo! So we might think about storing the running timer pointer in cpu_base instead for 32bit, which increases the foot print of the migration base and the extra cost for the additional indirection, but it would keep cache line tight for the hot pathes. Other than that, this looks pretty good. Thanks, tglx -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/