Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758007AbYLLCIt (ORCPT ); Thu, 11 Dec 2008 21:08:49 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1756980AbYLLCId (ORCPT ); Thu, 11 Dec 2008 21:08:33 -0500 Received: from smtp108.mail.mud.yahoo.com ([209.191.85.218]:32750 "HELO smtp108.mail.mud.yahoo.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with SMTP id S1756953AbYLLCIc (ORCPT ); Thu, 11 Dec 2008 21:08:32 -0500 DomainKey-Signature: a=rsa-sha1; q=dns; c=nofws; s=s1024; d=yahoo.com.au; h=Received:X-YMail-OSG:X-Yahoo-Newman-Property:From:To:Subject:Date:User-Agent:Cc:References:In-Reply-To:MIME-Version:Content-Type:Content-Transfer-Encoding:Content-Disposition:Message-Id; b=0Hko8H8lh1AytvRMOu7ZsgMRh88xAOLNTv+D1+iS3HA66cPARrtFOtXHCm4IMv7MbsBQdj5F5/1Nctu30290IgWXHqJQr+PGsWjZTdVAVt6MhbyJB5ujUEhsHFZtdA7jl6j77kLVCsEzw+WKFzPeOPbTyelHP89p1YPpGxfGY0M= ; X-YMail-OSG: o1ikndYVM1kWNR5IwScgonUTk62jrppJQBzKlC_oKMLZx6G6mlVtcs8x4Xftdj6hnE8kyZdsJo9_.OzavQJCsTkMP6XTYG24HzjfHzUqU2efyauyh90iND0NhqXR1BmwSdlI7VSN4z3ad12suOPUKdFbf_VMaBK7b3tj1IL51aeO1.pTa6lQB9ElWrAn X-Yahoo-Newman-Property: ymail-3 From: Nick Piggin To: Eric Dumazet Subject: Re: [PATCH v3 2/7] fs: Use a percpu_counter to track nr_inodes Date: Tue, 24 Jul 2007 11:30:55 +1000 User-Agent: KMail/1.9.5 Cc: Andrew Morton , Ingo Molnar , Christoph Hellwig , David Miller , "Rafael J. Wysocki" , linux-kernel@vger.kernel.org, "kernel-testers@vger.kernel.org >> Kernel Testers List" , Mike Galbraith , Peter Zijlstra , Linux Netdev List , Christoph Lameter , linux-fsdevel@vger.kernel.org, Al Viro , "Paul E. McKenney" References: <493100B0.6090104@cosmosbay.com> <4941968E.3020201@cosmosbay.com> In-Reply-To: <4941968E.3020201@cosmosbay.com> MIME-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: 7bit Content-Disposition: inline Message-Id: <200707241130.56767.nickpiggin@yahoo.com.au> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 886 Lines: 22 On Friday 12 December 2008 09:39, Eric Dumazet wrote: > Avoids cache line ping pongs between cpus and prepare next patch, > because updates of nr_inodes dont need inode_lock anymore. > > (socket8 bench result : no difference at this point) Looks good. But.... If we never actually need fast access to the approximate total, (which seems to apply to this and the previous patch) we could use something much simpler which does not have the spinlock or all this batching stuff that percpu counters have. I'd prefer that because it will be faster in a straight line... (BTW. percpu counters can't be used in interrupt context? That's nice.) -- 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/