Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751355AbbK1Hv6 (ORCPT ); Sat, 28 Nov 2015 02:51:58 -0500 Received: from szxga01-in.huawei.com ([58.251.152.64]:38276 "EHLO szxga01-in.huawei.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750793AbbK1Hv4 (ORCPT ); Sat, 28 Nov 2015 02:51:56 -0500 From: Li Bin To: , , , CC: , , , , Subject: [PATCH] arm64: ftrace: stop using kstop_machine to enable/disable tracing Date: Sat, 28 Nov 2015 15:50:09 +0800 Message-ID: <1448697009-17211-1-git-send-email-huawei.libin@huawei.com> X-Mailer: git-send-email 1.7.1 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=0001.0A020206.56595D17.00BC,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: 787ab8866635a8d38c7b81ff300f0a16 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1172 Lines: 36 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 modifed code is a single 32bit instructions which is impossible to cross cache (or page) boundaries, and the used str instruction is single-copy atomic. Cc: # 3.18+ 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/