From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752712AbcFNT44 (ORCPT ); Tue, 14 Jun 2016 15:56:56 -0400 Received: from ns.sciencehorizons.net ([71.41.210.147]:63829 "HELO ns.sciencehorizons.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with SMTP id S1751765AbcFNT4z (ORCPT ); Tue, 14 Jun 2016 15:56:55 -0400 Date: 14 Jun 2016 15:56:53 -0400 Message-ID: <20160614195653.16933.qmail@ns.sciencehorizons.net> From: "George Spelvin" To: linux@sciencehorizons.net, tglx@linutronix.de Subject: Re: [patch 13/20] timer: Switch to a non cascading wheel Cc: edumazet@google.com, linux-kernel@vger.kernel.org, peterz@infradead.org, richardcochran@gmail.com In-Reply-To: Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Thomas Gleixner wrote: > On Tue, 14 Jun 2016, George Spelvin wrote: >> If you need to shrink TIMER_ARRAYMASK to fit another flag bit, > > We can accomodate wheel with 512 buckets with the current ARRAYMASK and that > really should be enough. You're absolutely correct, but I was referring to the possible development in the future of the need for another flag bit for some purpose *other* than encoding a bucket number. There's no need now, but if next year someone finds and urgent need for another flag bit, there's a way to proceed. (Although you could just enlarge "flags"; the removal of "slack" has left a 32-bit alignment hole.) > The expiry code uses the pending_map already in patch 13 to avoid looking at > the bucket if its empty. My bad, I'm sorry! I was quickly re-reading it and missed that. Given the quality of the patch series, I should have expected that and looked harder. > Thanks, Thank *you*. It really is a pleasure to read. I can't find anything but the most insignificant issues to complain about.