From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933221Ab1JDTSa (ORCPT ); Tue, 4 Oct 2011 15:18:30 -0400 Received: from claw.goop.org ([74.207.240.146]:56758 "EHLO claw.goop.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S933191Ab1JDTSV (ORCPT ); Tue, 4 Oct 2011 15:18:21 -0400 From: Jeremy Fitzhardinge To: Steven Rostedt Cc: "David S. Miller" , David Daney , Michael Ellerman , Jan Glauber , Jason Baron , the arch/x86 maintainers , Xen Devel , Linux Kernel Mailing List , Jeremy Fitzhardinge Subject: [PATCH RFC V3 0/8] jump-label: allow early jump_label_enable() Date: Tue, 4 Oct 2011 12:18:01 -0700 Message-Id: X-Mailer: git-send-email 1.7.6.4 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Jeremy Fitzhardinge [ Change from V2: add arch_jump_label_transform_static() for use on code which can't possibly be currently executing (ie, a freshly loaded module), which can avoid heavyweight things like stop_machine. The default implementation is simply arch_jump_label_transform(), so only architectures which would particularly benefit need implement it (x86 and s390 in this series). ] While trying to use the jump-label stuff for my PV ticketlock changes, I had some problems using jump labels early in the kernel's lifetime (pre-SMP). The basic problem is that even if I enable a jump_label_key, the jump_label_init() initializer ends up nopping out all the code sites. This series enables early use of jump labels by making jump_label_init() respect already-enabled keys. To do this, I've dropped arch_jump_label_poke_text_early() and replaced it with arch_jump_label_transform(), allowing it to either insert an optimal nop, or leave the jump in place. Part of this series makes sure that stop_machine() is safe to call in an early pre-SMP environment, by making it just call the function with interrupts disabled. git://github.com/jsgf/linux-xen upstream/jump-label-noearly Jeremy Fitzhardinge (8): jump_label: use proper atomic_t initializer stop_machine: make stop_machine safe and efficient to call early jump_label: if a key has already been initialized, don't nop it out x86/jump_label: drop arch_jump_label_text_poke_early() sparc/jump_label: drop arch_jump_label_text_poke_early() jump_label: add arch_jump_label_transform_static() to optimise non-live code updates s390/jump-label: add arch_jump_label_transform_static() x86/jump_label: add arch_jump_label_transform_static() arch/s390/kernel/jump_label.c | 51 ++++++++++++++++++++++++--------------- arch/sparc/kernel/jump_label.c | 8 ------ arch/x86/kernel/jump_label.c | 20 +++++++++++---- include/linux/jump_label.h | 9 ++++--- kernel/jump_label.c | 32 +++++++++++++++--------- kernel/stop_machine.c | 22 +++++++++++++++++ 6 files changed, 92 insertions(+), 50 deletions(-) -- 1.7.6.4