Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755493Ab0G1QCc (ORCPT ); Wed, 28 Jul 2010 12:02:32 -0400 Received: from waste.org ([173.11.57.241]:58703 "EHLO waste.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751136Ab0G1QCb (ORCPT ); Wed, 28 Jul 2010 12:02:31 -0400 Subject: Re: [PATCH] random: reorder struct entropy_store to remove padding on 64bits From: Matt Mackall To: Richard Kennedy Cc: Herbert Xu , Andrew Morton , lkml In-Reply-To: <1280309521.2029.5.camel@castor.rsk> References: <1280309521.2029.5.camel@castor.rsk> Content-Type: text/plain; charset="UTF-8" Date: Wed, 28 Jul 2010 11:02:28 -0500 Message-ID: <1280332948.11415.705.camel@calx> Mime-Version: 1.0 X-Mailer: Evolution 2.30.2 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 873 Lines: 23 On Wed, 2010-07-28 at 10:32 +0100, Richard Kennedy wrote: > Re-order structure entropy_store to remove 8 bytes of padding on > 64 bit builds, so shrinking this structure from 72 to 64 bytes > and allowing it to fit into one cache line. I have a vague memory that we reordered things so that the r/w bits would be on a separate cache line than the r/o bits. But as we never added the alignment primitives to actually enforce that, I guess it doesn't matter much. > Signed-off-by: Richard Kennedy Signed-off-by: Matt Mackall -- Mathematics is the supreme nostalgia of our time. -- 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/