From: Theodore Tso Subject: Re: [PATCH 01/42] percpu counter: clean up percpu_counter_sum_and_set() Date: Thu, 9 Oct 2008 12:52:33 -0400 Message-ID: <20081009165233.GH17512@mit.edu> References: <1223525160-9887-1-git-send-email-tytso@mit.edu> <1223525160-9887-2-git-send-email-tytso@mit.edu> <1223542372.7382.30.camel@lappy.programming.kicks-ass.net> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: linux-ext4@vger.kernel.org, linux-kernel@vger.kernel.org, Mingming Cao , Andrew Morton To: Peter Zijlstra Return-path: Received: from www.church-of-our-saviour.org ([69.25.196.31]:52508 "EHLO thunker.thunk.org" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1752861AbYJIQwg (ORCPT ); Thu, 9 Oct 2008 12:52:36 -0400 Content-Disposition: inline In-Reply-To: <1223542372.7382.30.camel@lappy.programming.kicks-ass.net> Sender: linux-ext4-owner@vger.kernel.org List-ID: On Thu, Oct 09, 2008 at 10:52:52AM +0200, Peter Zijlstra wrote: > On Thu, 2008-10-09 at 00:05 -0400, Theodore Ts'o wrote: > > From: Mingming Cao > > > > percpu_counter_sum_and_set() and percpu_counter_sum() is the same except > > the former updates the global counter after accounting. Since we are > > taking the fbc->lock to calculate the precise value of the counter in > > percpu_counter_sum() anyway, it should simply set fbc->count too, as the > > percpu_counter_sum_and_set() does. > > > > This patch merge these two interfaces into one. > > I totally missed the patch introducing this _and_set() horror, but this > does look like a good cleanup. Note: this patch was in the -mm tree (Andrew signed off on it), but given that a number of ext4 patches depend on it, we have a copy of it in the ext4 tree. - Ted