From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751331Ab1HPHnR (ORCPT ); Tue, 16 Aug 2011 03:43:17 -0400 Received: from mail.skyhub.de ([78.46.96.112]:35413 "EHLO mail.skyhub.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750789Ab1HPHnP (ORCPT ); Tue, 16 Aug 2011 03:43:15 -0400 Date: Tue, 16 Aug 2011 09:43:10 +0200 From: Borislav Petkov To: melwyn lobo Cc: Denys Vlasenko , Ingo Molnar , linux-kernel@vger.kernel.org, "H. Peter Anvin" , Thomas Gleixner , Linus Torvalds , Peter Zijlstra , borislav.petkov@amd.com Subject: Re: x86 memcpy performance Message-ID: <20110816074309.GA31781@liondog.tnic> Mail-Followup-To: Borislav Petkov , melwyn lobo , Denys Vlasenko , Ingo Molnar , linux-kernel@vger.kernel.org, "H. Peter Anvin" , Thomas Gleixner , Linus Torvalds , Peter Zijlstra , borislav.petkov@amd.com References: MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.20 (2009-06-14) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Aug 16, 2011 at 12:49:28PM +0530, melwyn lobo wrote: > We would rather use the 32 bit patch. Have you already got a 32 bit > patch. Nope, only 64-bit for now, sorry. > How can I use sse3 for 32 bit. Well, OTTOMH, you have only 8 xmm regs in 32-bit instead of 16, which should halve the performance of the 64-bit version in a perfect world. However, we don't know how the performance of a 32-bit SSE memcpy version behaves vs the gcc builtin one - that would require benchmarking too. But other than that, I don't see a problem with having a 32-bit version. > I don't think you have submitted 64 bit patch in the mainline. > Is there still work ongoing on this. Yeah, we are currently benchmarking it to see whether it actually makes sense to even have SSE memcpy in the kernel. -- Regards/Gruss, Boris.