From mboxrd@z Thu Jan 1 00:00:00 1970 Message-ID: <480DFC8A.8040105@cosmosbay.com> Date: Tue, 22 Apr 2008 16:56:10 +0200 From: Eric Dumazet MIME-Version: 1.0 Subject: Re: [PATCH 01 of 12] Core of mmu notifiers References: In-Reply-To: Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 8BIT Sender: owner-linux-mm@kvack.org Return-Path: To: Andrea Arcangeli Cc: Christoph Lameter , Nick Piggin , Jack Steiner , Peter Zijlstra , kvm-devel@lists.sourceforge.net, Kanoj Sarcar , Roland Dreier , Steve Wise , linux-kernel@vger.kernel.org, Avi Kivity , linux-mm@kvack.org, Robin Holt , general@lists.openfabrics.org, Hugh Dickins , akpm@linux-foundation.org, Rusty Russell List-ID: Andrea Arcangeli a ecrit : > + > +static int mm_lock_cmp(const void *a, const void *b) > +{ > + cond_resched(); > + if ((unsigned long)*(spinlock_t **)a < > + (unsigned long)*(spinlock_t **)b) > + return -1; > + else if (a == b) > + return 0; > + else > + return 1; > +} > + This compare function looks unusual... It should work, but sort() could be faster if the if (a == b) test had a chance to be true eventually... static int mm_lock_cmp(const void *a, const void *b) { unsigned long la = (unsigned long)*(spinlock_t **)a; unsigned long lb = (unsigned long)*(spinlock_t **)b; cond_resched(); if (la < lb) return -1; if (la > lb) return 1; return 0; } -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org