From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932126AbcAWA4R (ORCPT ); Fri, 22 Jan 2016 19:56:17 -0500 Received: from mail.kernel.org ([198.145.29.136]:38276 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753058AbcAWA4L (ORCPT ); Fri, 22 Jan 2016 19:56:11 -0500 From: Andy Lutomirski To: x86@kernel.org, linux-kernel@vger.kernel.org Cc: Borislav Petkov , Fenghua Yu , Oleg Nesterov , Peter Zijlstra , Sai Praneeth Prakhya , yu-cheng yu , Dave Hansen , Rik van Riel , Linus Torvalds , Andy Lutomirski Subject: [PATCH 0/5] x86/fpu: eagerfpu fixes, speedups, and default enablement Date: Fri, 22 Jan 2016 16:56:01 -0800 Message-Id: X-Mailer: git-send-email 2.5.0 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi all- Patches 1, 2, and 3 are fixes. Patch 4 is probably a small speedup. It also only matters in lazy FPU mode, which means that, most likely, no one cares. Apply or don't -- I don't care much. Patch 5 is, in some sense, a radical change. Currently we select eager or lazy mode depending on CPU type. I think that lazy mode sucks and that we should deprecate and remove it. With patches 1-3 applied, I think that eagerfpu works on all systems. Patch 5 will use it on all systems subject to a chicken flag -- eagerfpu=off will still disable it. I propose that we apply patch 5, let it soak in -next until the 4.6 merge window opens, possibly let it actually land in 4.6, and then remove lazy mode entirely for 4.7. This will open up enormous cleanup possibilities, and it will make the fpu code vastly more comprehensible. Thoughts? Andy Lutomirski (5): x86/fpu: Fix math emulation in eager fpu mode x86/fpu: Fix FNSAVE usage in eagerfpu mode x86/fpu: Fold fpu_copy into fpu__copy x86/fpu: Speed up lazy FPU restores slightly x86/fpu: Default eagerfpu=on on all CPUs arch/x86/include/asm/fpu/internal.h | 3 ++- arch/x86/kernel/fpu/core.c | 52 +++++++++++++++++++------------------ arch/x86/kernel/fpu/init.c | 13 ++++------ arch/x86/kernel/traps.c | 3 +-- 4 files changed, 35 insertions(+), 36 deletions(-) -- 2.5.0