Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753894AbbDMKi1 (ORCPT ); Mon, 13 Apr 2015 06:38:27 -0400 Received: from casper.infradead.org ([85.118.1.10]:48816 "EHLO casper.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753642AbbDMKi0 (ORCPT ); Mon, 13 Apr 2015 06:38:26 -0400 Date: Mon, 13 Apr 2015 12:38:16 +0200 From: Peter Zijlstra To: George Spelvin Cc: linux-kernel@vger.kernel.org Subject: Re: Two other ways to do latched seqcounts Message-ID: <20150413103816.GE5029@twins.programming.kicks-ass.net> References: <20150413073510.GC5029@twins.programming.kicks-ass.net> <20150413092605.2469.qmail@ns.horizon.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20150413092605.2469.qmail@ns.horizon.com> User-Agent: Mutt/1.5.21 (2012-12-30) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 874 Lines: 19 On Mon, Apr 13, 2015 at 05:26:05AM -0400, George Spelvin wrote: > > I'm assuming you're writing to me because of the latched rb-tree; > > because that's the most recent related thing I posted ;-) > > Basically yes, although it was the documentation you added to the > latched seqlock code in particular. > > I haven't checked the users of your rb-tree code to see how large and > frequently read the trees are, but if a read is expensive, then avoiding > retries by incrementing the seqlock twice per update starts to become > interesting. Right, so I use it for modules, and updates are near non existent under normal usage. -- 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/