From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mga11.intel.com (mga11.intel.com [192.55.52.93]) by dpdk.org (Postfix) with ESMTP id 9ABAC58D4 for ; Wed, 25 Feb 2015 12:17:04 +0100 (CET) Received: from orsmga001.jf.intel.com ([10.7.209.18]) by fmsmga102.fm.intel.com with ESMTP; 25 Feb 2015 03:16:47 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.09,644,1418112000"; d="scan'208";a="656946132" Received: from bricha3-mobl3.ger.corp.intel.com ([10.243.20.32]) by orsmga001.jf.intel.com with SMTP; 25 Feb 2015 03:16:46 -0800 Received: by (sSMTP sendmail emulation); Wed, 25 Feb 2015 11:16:44 +0025 Date: Wed, 25 Feb 2015 11:16:44 +0000 From: Bruce Richardson To: Robert Sanford Message-ID: <20150225111643.GC4896@bricha3-MOBL3> References: <1422996127-64370-1-git-send-email-rsanford2@gmail.com> <1424837389-56276-1-git-send-email-rsanford2@gmail.com> <54ED8EC1.3030108@6wind.com> <1519667.hoeNh6GYxK@xps13> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Organization: Intel Shannon Ltd. User-Agent: Mutt/1.5.23 (2014-03-12) Cc: "dev@dpdk.org" Subject: Re: [dpdk-dev] [PATCH v2 0/3] timer: fix rte_timer_reset X-BeenThere: dev@dpdk.org X-Mailman-Version: 2.1.15 Precedence: list List-Id: patches and discussions about DPDK List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Wed, 25 Feb 2015 11:17:05 -0000 On Wed, Feb 25, 2015 at 06:02:24AM -0500, Robert Sanford wrote: > Hi Thomas, > > Yes, I'm interested in becoming a maintainer of rte_timer. What are the > responsibilities? > > > One question about lib rte_timer that's been troubling me for a while: How > are skip lists better than BSD-style timer wheels? > > -- The skip list may not be any better than a timer wheel - it's just what is used now, and it does give pretty good performance (insert O(log n) [up to a few million timers per core], expiry O(1)). Originally in DPDK, the timers were maintained in a regular sorted linked list, but that suffered from scalability issues when starting timers, or stopped before expiry. The skip-list was therefore a big improvement on that, and gave us much greater scalability in timers, without any regressions in performance. I don't know if anyone has tried to implement and benchmark a timer-wheel based rte_timer library replacement. I'd be interested to see a performance comparison between the two implementations! :-) Regards, /Bruce > Regards, > Robert > > > On Wed, Feb 25, 2015 at 4:46 AM, Thomas Monjalon > wrote: > > > > > Changes in v2: > > > > - split into multiple patches > > > > - minor coding-style changes > > > > > > > > Robert Sanford (3): > > > > timer: fix return value of rte_timer_reset(), > > > > insert rte_pause() into rte_timer_reset_sync() wait-loop > > > > app/test: fix timer stress test to succeed on multiple runs, > > > > display number of times that rte_timer_reset() fails > > > > (expected) due to races with other cores > > > > > > Series: > > > Acked-by: Olivier Matz > > > > Applied, thanks > > > > Robert, as you well know rte_timer and you work on it, > > maybe you are interested in becoming maintainer? > >