From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:43093) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1bz8SK-0008TF-Ib for qemu-devel@nongnu.org; Tue, 25 Oct 2016 16:36:21 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1bz8SJ-00028d-Vb for qemu-devel@nongnu.org; Tue, 25 Oct 2016 16:36:20 -0400 Received: from mail-yw0-x22c.google.com ([2607:f8b0:4002:c05::22c]:36418) by eggs.gnu.org with esmtps (TLS1.0:RSA_AES_128_CBC_SHA1:16) (Exim 4.71) (envelope-from ) id 1bz8SJ-00028P-P6 for qemu-devel@nongnu.org; Tue, 25 Oct 2016 16:36:19 -0400 Received: by mail-yw0-x22c.google.com with SMTP id u124so13770916ywg.3 for ; Tue, 25 Oct 2016 13:36:19 -0700 (PDT) MIME-Version: 1.0 In-Reply-To: <5190ece5-7167-dbe1-5b5a-38247cba5be3@redhat.com> References: <20161025153507.27110-1-bobby.prani@gmail.com> <5b91345d-fea6-8d98-69a9-eda1e256c3e1@redhat.com> <54c9a235-4ab4-1731-b076-116ecde91442@redhat.com> <87shrkckfv.fsf@gmail.com> <5190ece5-7167-dbe1-5b5a-38247cba5be3@redhat.com> From: Pranith Kumar Date: Tue, 25 Oct 2016 16:35:48 -0400 Message-ID: Content-Type: text/plain; charset=UTF-8 Subject: Re: [Qemu-devel] [RFC PATCH] qht: Align sequence lock to cache line List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Paolo Bonzini Cc: "open list:All patches CC here" , "Emilio G. Cota" , =?UTF-8?B?QWxleCBCZW5uw6ll?= , Markus Armbruster , Richard Henderson On Tue, Oct 25, 2016 at 4:02 PM, Paolo Bonzini wrote: > > >> I've written a patch (see below) to take the per-bucket sequence locks. > > What's the performance like? > Applying only this patch, the perf numbers are similar to the 128 cache line alignment you suggested. 0 4 10 9.70 20 8.09 30 7.13 40 6.49 I am not sure why only 100% reader case is so low. Applying the sequence lock cache alignment patch brings it back up to 13 MT/s/thread. -- Pranith