From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:39653) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1YpaCj-0005Ja-VF for qemu-devel@nongnu.org; Tue, 05 May 2015 06:35:58 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1YpaCe-0007jP-Ru for qemu-devel@nongnu.org; Tue, 05 May 2015 06:35:57 -0400 Received: from mx1.redhat.com ([209.132.183.28]:54103) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1YpaCe-0007jB-Kc for qemu-devel@nongnu.org; Tue, 05 May 2015 06:35:52 -0400 Message-ID: <55489D00.7050303@redhat.com> Date: Tue, 05 May 2015 12:35:44 +0200 From: Paolo Bonzini MIME-Version: 1.0 References: <1430510112-30474-1-git-send-email-jsnow@redhat.com> <1430510112-30474-5-git-send-email-jsnow@redhat.com> <5543E688.6020703@redhat.com> <554416B2.50904@redhat.com> In-Reply-To: <554416B2.50904@redhat.com> Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: 7bit Subject: Re: [Qemu-devel] [PATCH v2 4/4] libqos/ahci: Swap memread/write with bufread/write List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: John Snow , qemu-devel@nongnu.org Cc: marc.mari.barcelo@gmail.com, afaerber@suse.de, stefanha@redhat.com On 02/05/2015 02:13, John Snow wrote: >> > > I wrote a loop to batch the ascii-hex conversion instead of letting > printf do it; then ran some more very, very scientific tests: > > memset alone: > real 0m10.888s > user 0m9.303s > sys 0m9.146s > > send-batching: > real 0m6.541s > user 0m5.027s > sys 0m4.941s > > memset+batching+b64: > real 0m3.675s > user 0m2.582s > sys 0m1.718s > > So it still seems as if the b64 batching is a strict improvement > speed-wise. I'll send the non-b64 batching patch separately later, > unless you have thoughts otherwise. Ok, this is more similar to what I'd expect (3.6 * 6 / 4 = 5.4, I'm not sure if you have the memset optimization in the send-batching test). Hex is obviously more debuggable compared to Base64 (unless you starred in the Matrix movies), so I'm a bit undecided about this one. Anyone can break the tie? Paolo