From patchwork Sat Nov 28 07:50:09 2015 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Li Bin X-Patchwork-Id: 7716341 Return-Path: X-Original-To: patchwork-linux-arm@patchwork.kernel.org Delivered-To: patchwork-parsemail@patchwork2.web.kernel.org Received: from mail.kernel.org (mail.kernel.org [198.145.29.136]) by patchwork2.web.kernel.org (Postfix) with ESMTP id 63A9DBEEE1 for ; Sat, 28 Nov 2015 07:55:22 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id A42952053B for ; Sat, 28 Nov 2015 07:55:21 +0000 (UTC) Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.9]) (using TLSv1.2 with cipher AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id CC6C02053A for ; Sat, 28 Nov 2015 07:55:20 +0000 (UTC) Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.80.1 #2 (Red Hat Linux)) id 1a2aJp-0003Xv-CW; Sat, 28 Nov 2015 07:53:17 +0000 Received: from szxga01-in.huawei.com ([58.251.152.64]) by bombadil.infradead.org with esmtps (Exim 4.80.1 #2 (Red Hat Linux)) id 1a2aJk-0003VL-Uo for linux-arm-kernel@lists.infradead.org; Sat, 28 Nov 2015 07:53:14 +0000 Received: from 172.24.1.47 (EHLO szxeml426-hub.china.huawei.com) ([172.24.1.47]) by szxrg01-dlp.huawei.com (MOS 4.3.7-GA FastPath queued) with ESMTP id CZV02059; Sat, 28 Nov 2015 15:51:51 +0800 (CST) Received: from localhost.localdomain (10.175.100.166) by szxeml426-hub.china.huawei.com (10.82.67.181) with Microsoft SMTP Server id 14.3.235.1; Sat, 28 Nov 2015 15:51:41 +0800 From: Li Bin To: , , , 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 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 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20151127_235313_259170_79251C01 X-CRM114-Status: UNSURE ( 8.62 ) X-CRM114-Notice: Please train this message. X-Spam-Score: -4.2 (----) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.20 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: huawei.libin@huawei.com, dingtianhong@huawei.com, linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, guohanjun@huawei.com Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+patchwork-linux-arm=patchwork.kernel.org@lists.infradead.org X-Spam-Status: No, score=-4.2 required=5.0 tests=BAYES_00, RCVD_IN_DNSWL_MED, T_RP_MATCHES_RCVD, UNPARSEABLE_RELAY autolearn=unavailable version=3.3.1 X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on mail.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP 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;