From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S936522Ab0GSShh (ORCPT ); Mon, 19 Jul 2010 14:37:37 -0400 Received: from mga09.intel.com ([134.134.136.24]:1264 "EHLO mga09.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S936510Ab0GSShK (ORCPT ); Mon, 19 Jul 2010 14:37:10 -0400 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="4.55,228,1278313200"; d="scan'208";a="639823102" Message-Id: <20100719181941.971215286@sbs-t61.sc.intel.com> User-Agent: quilt/0.47-1 Date: Mon, 19 Jul 2010 11:35:41 -0700 From: Suresh Siddha To: "H. Peter Anvin" , Ingo Molnar , Thomas Gleixner Cc: LKML , Suresh Siddha Subject: [patch 0/3] x86: xsaveopt kernel enabling patches Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org AVX Programming Reference (June, 2010 version) located at http://software.intel.com/en-us/avx/ refers to the optimized extended state save instruction "xsaveopt". xsaveopt is similar to xsave and incorporates optimizations specifically targeted for speeding up context switch save, like: a. if a state is in an INIT state, the instruction may clear the corresponding bit in the xheader.bv with out writing the actual state in to the memory. b. if the state hasn't been modified since the last xrstor, the instruction may not write out the state to the save area. Following patches enable the use of xsaveopt for context switch save/restore of the extended state. Signed-off-by: Suresh Siddha