Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755044AbbLDCSM (ORCPT ); Thu, 3 Dec 2015 21:18:12 -0500 Received: from szxga01-in.huawei.com ([58.251.152.64]:17580 "EHLO szxga01-in.huawei.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754776AbbLDCSI (ORCPT ); Thu, 3 Dec 2015 21:18:08 -0500 From: Li Bin To: , CC: , , , , , Subject: [PATCH v2 1/2] arm64: ftrace: stop using kstop_machine to enable/disable tracing Date: Fri, 4 Dec 2015 10:18:38 +0800 Message-ID: <1449195519-17901-2-git-send-email-huawei.libin@huawei.com> X-Mailer: git-send-email 1.7.1 In-Reply-To: <1449195519-17901-1-git-send-email-huawei.libin@huawei.com> References: <1449195519-17901-1-git-send-email-huawei.libin@huawei.com> MIME-Version: 1.0 Content-Type: text/plain X-Originating-IP: [10.175.100.166] X-CFilter-Loop: Reflected X-Mirapoint-Virus-RAPID-Raw: score=unknown(0), refid=str=0001.0A020204.5660F798.007D,ss=1,re=0.000,recu=0.000,reip=0.000,cl=1,cld=1,fgs=0, ip=0.0.0.0, so=2013-06-18 04:22:30, dmn=2013-03-21 17:37:32 X-Mirapoint-Loop-Id: 8b42cb6ec0251f1a1bc62da956cd9a59 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1286 Lines: 37 For ftrace on arm64, kstop_machine which is hugely disruptive to a running system is not needed to convert nops to ftrace calls or back, because that to be modified instrucions, that NOP, B or BL, are all safe instructions which called "concurrent modification and execution of instructions", that can be executed by one thread of execution as they are being modified by another thread of execution without requiring explicit synchronization. Signed-off-by: Li Bin --- arch/arm64/kernel/ftrace.c | 5 +++++ 1 files changed, 5 insertions(+), 0 deletions(-) diff --git a/arch/arm64/kernel/ftrace.c b/arch/arm64/kernel/ftrace.c index c851be7..9669b33 100644 --- a/arch/arm64/kernel/ftrace.c +++ b/arch/arm64/kernel/ftrace.c @@ -93,6 +93,11 @@ int ftrace_make_nop(struct module *mod, struct dyn_ftrace *rec, return ftrace_modify_code(pc, old, new, true); } +void arch_ftrace_update_code(int command) +{ + ftrace_modify_all_code(command); +} + int __init ftrace_dyn_arch_init(void) { return 0; -- 1.7.1 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/