Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752284AbaJCMHt (ORCPT ); Fri, 3 Oct 2014 08:07:49 -0400 Received: from resqmta-po-12v.sys.comcast.net ([96.114.154.171]:34076 "EHLO resqmta-po-12v.sys.comcast.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751454AbaJCMHs (ORCPT ); Fri, 3 Oct 2014 08:07:48 -0400 Date: Fri, 3 Oct 2014 07:07:46 -0500 (CDT) From: Christoph Lameter X-X-Sender: cl@gentwo.org To: Richard Cochran cc: Thomas Gleixner , linux-kernel@vger.kernel.org Subject: Re: Why do we still have 32 bit counters? Interrupt counters overflow within 50 days In-Reply-To: <20141003120345.GA6652@localhost.localdomain> Message-ID: References: <20141003120345.GA6652@localhost.localdomain> Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, 3 Oct 2014, Richard Cochran wrote: > > DECLARE_PER_CPU(char *, irq_stack_ptr); > > -DECLARE_PER_CPU(unsigned int, irq_count); > > +DECLARE_PER_CPU(unsigned long, irq_count); > > Still 32 bit on 32 bit machines... 64 bit counters on 32 bit machines are not an easy thing and could be expensive to handle in particular because these counters are used in performance critical hotpaths. I thought I better leave it alone on 32 bit. -- 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/