Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932322AbYBHO6U (ORCPT ); Fri, 8 Feb 2008 09:58:20 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1757027AbYBHO6J (ORCPT ); Fri, 8 Feb 2008 09:58:09 -0500 Received: from smtp-out04.alice-dsl.net ([88.44.63.6]:61939 "EHLO smtp-out04.alice-dsl.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756506AbYBHO6I (ORCPT ); Fri, 8 Feb 2008 09:58:08 -0500 To: Eric Dumazet Cc: Nick Piggin , Christoph Lameter , Linus Torvalds , Andrew Morton , LKML , linux-mm@kvack.org Subject: Re: [git pull] more SLUB updates for 2.6.25 References: <200802081812.22513.nickpiggin@yahoo.com.au> <47AC04CD.9090407@cosmosbay.com> From: Andi Kleen Date: 08 Feb 2008 15:58:05 +0100 In-Reply-To: <47AC04CD.9090407@cosmosbay.com> Message-ID: <87ve4z1on6.fsf@basil.nowhere.org> User-Agent: Gnus/5.09 (Gnus v5.9.0) Emacs/21.3 MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii X-OriginalArrivalTime: 08 Feb 2008 14:51:45.0563 (UTC) FILETIME=[1FF63EB0:01C86A62] Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 828 Lines: 20 Eric Dumazet writes: > > What about IRQ masking then ? > > Many CPU pay high cost for cli/sti pair... Many? In the x86 world only P4. On the other cores cli/sti (and even pushf ; cli ; popf) is reasonably fast. > > And SLAB/SLUB allocators, even if only used from process context, want > to disable/re-enable interrupts... > > I understand kmalloc() want generic pools, but dedicated pools could > avoid this cli/sti While there are a lot of P4s around they are obsolete by now and I would advise against major redesigns for tuning obsolete CPUs. -Andi -- 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/