Path: csiph.com!news.mixmin.net!news.unit0.net!news.panservice.it!bofh.it!news.nic.it!robomod From: "George Spelvin" Newsgroups: linux.kernel Subject: Re: [patch 13/20] timer: Switch to a non cascading wheel Date: Tue, 14 Jun 2016 22:00:02 +0200 Message-ID: References: X-Original-To: linux@sciencehorizons.net, tglx@linutronix.de Sender: robomod@news.nic.it List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Approved: robomod@news.nic.it Lines: 27 Organization: linux.* mail to news gateway X-Original-Cc: edumazet@google.com, linux-kernel@vger.kernel.org, peterz@infradead.org, richardcochran@gmail.com X-Original-Date: 14 Jun 2016 15:56:53 -0400 X-Original-Message-ID: <20160614195653.16933.qmail@ns.sciencehorizons.net> X-Original-References: X-Original-Sender: linux-kernel-owner@vger.kernel.org Xref: csiph.com linux.kernel:1422269 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.