Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754089Ab2BAQ65 (ORCPT ); Wed, 1 Feb 2012 11:58:57 -0500 Received: from mail-vw0-f46.google.com ([209.85.212.46]:52615 "EHLO mail-vw0-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753852Ab2BAQ6z convert rfc822-to-8bit (ORCPT ); Wed, 1 Feb 2012 11:58:55 -0500 MIME-Version: 1.0 In-Reply-To: <1327961644-6886-6-git-send-email-zohar@linux.vnet.ibm.com> References: <1327961644-6886-1-git-send-email-zohar@linux.vnet.ibm.com> <1327961644-6886-6-git-send-email-zohar@linux.vnet.ibm.com> Date: Wed, 1 Feb 2012 11:58:54 -0500 Message-ID: Subject: Re: [RFC][PATCH v1 5/9] ima: allocating iint improvements From: Eric Paris To: Mimi Zohar Cc: linux-security-module@vger.kernel.org, Dmitry Kasatkin , linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org, David Safford , Mimi Zohar Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 8BIT Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 920 Lines: 19 On Mon, Jan 30, 2012 at 5:14 PM, Mimi Zohar wrote: > From: Dmitry Kasatkin > > ?static struct rb_root integrity_iint_tree = RB_ROOT; > -static DEFINE_SPINLOCK(integrity_iint_lock); > +static DEFINE_RWLOCK(integrity_iint_lock); > ?static struct kmem_cache *iint_cache __read_mostly; Has any profiling been done here? rwlocks have been shown to actually be slower on multi processor systems in a number of cases due to the cache line bouncing required. I believe the current kernel logic is that if you have a short critical section and you can't show profile data the rwlocks are better, just stick with a spinlock. -- 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/