From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933579AbbFVNzV (ORCPT ); Mon, 22 Jun 2015 09:55:21 -0400 Received: from bombadil.infradead.org ([198.137.202.9]:33980 "EHLO bombadil.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754957AbbFVNzQ (ORCPT ); Mon, 22 Jun 2015 09:55:16 -0400 Date: Mon, 22 Jun 2015 15:55:05 +0200 From: Peter Zijlstra To: Rasmus Villemoes Cc: Andrew Morton , Richard Weinberger , Andy Lutomirski , Darren Hart , Oleg Nesterov , Michael Kerrisk , linux-kernel@vger.kernel.org Subject: Re: [PATCH 1/2] futex: eliminate cache miss from futex_hash() Message-ID: <20150622135505.GU3644@twins.programming.kicks-ass.net> References: <1434978981-12831-1-git-send-email-linux@rasmusvillemoes.dk> <20150622133327.GT3644@twins.programming.kicks-ass.net> <87616fluvt.fsf@rasmusvillemoes.dk> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <87616fluvt.fsf@rasmusvillemoes.dk> User-Agent: Mutt/1.5.21 (2012-12-30) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Jun 22, 2015 at 03:45:10PM +0200, Rasmus Villemoes wrote: > On Mon, Jun 22 2015, Peter Zijlstra wrote: > > Does: __aligned(sizeof(__futex_data)), work? > Unfortunately not: > > Because 16 might waste 8 bytes on 32bit. > > Yeah, wasting >= 48 bytes was the reason I didn't make it > ____cacheline_aligned. If 8 bytes is also too much, I suppose one could > just give the struct a tag and then use sizeof(struct futex_data). Nah, its probably fine, just wondering if it could be done better. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in Please read the FAQ at http://www.tux.org/lkml/