From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([208.118.235.92]:40676) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1UKQ3q-00023y-2S for qemu-devel@nongnu.org; Tue, 26 Mar 2013 05:20:58 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1UKQ3l-0006mB-8l for qemu-devel@nongnu.org; Tue, 26 Mar 2013 05:20:53 -0400 Received: from mx1.redhat.com ([209.132.183.28]:54169) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1UKQ3k-0006m6-SX for qemu-devel@nongnu.org; Tue, 26 Mar 2013 05:20:49 -0400 Message-ID: <51516862.5060906@redhat.com> Date: Tue, 26 Mar 2013 10:20:34 +0100 From: Paolo Bonzini MIME-Version: 1.0 References: <972929461.13095041.1364216522903.JavaMail.root@redhat.com> <4E89AD05-F328-493A-9C31-E52A033420B1@kamp.de> <806A8BFB-FF1F-482C-B679-2B1B10D06D7C@kamp.de> <51506068.5080103@redhat.com> In-Reply-To: Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: 7bit Subject: Re: [Qemu-devel] [PATCHv4 0/9] buffer_is_zero / migration optimizations List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Peter Lieven Cc: Stefan Hajnoczi , Orit Wasserman , qemu-devel@nongnu.org, quintela@redhat.com Il 26/03/2013 09:14, Peter Lieven ha scritto: > If noone objects I would use is_zero_page_2 and continue with v5 of > the patch set. As I am ooo for the next 8 days from tomorrow. i > prefer v3 as it has better performance if the non-zeroness is within > the 8*sizeof(VECTYPE) bytes and not in the first 256-bit. Either v2 or v3 is fine. v3 has slightly simpler code and v2 optimizes for a rare case, but v2 is indeed a bit faster and your benchmarking effort should be rewarded. :) > Paolo, with the version that has lower setup costs in mind shall I > use the vectorized or the unrolled version of patch 4 (find_next_bit > optimization)? I think for that we should, at least for now, use the version we discussed a few weeks ago (with no SIMD and just unrolling). Paolo