From patchwork Tue Mar 22 15:40:21 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Christophe Leroy X-Patchwork-Id: 1608257 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Authentication-Results: ozlabs.org; spf=pass (sender SPF authorized) smtp.mailfrom=lists.ozlabs.org (client-ip=2404:9400:2:0:216:3eff:fee1:b9f1; helo=lists.ozlabs.org; envelope-from=linuxppc-dev-bounces+incoming=patchwork.ozlabs.org@lists.ozlabs.org; receiver=) Received: from lists.ozlabs.org (lists.ozlabs.org [IPv6:2404:9400:2:0:216:3eff:fee1:b9f1]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits)) (No client certificate requested) by bilbo.ozlabs.org (Postfix) with ESMTPS id 4KNG156TV2z9s0r for ; Wed, 23 Mar 2022 02:41:13 +1100 (AEDT) Received: from boromir.ozlabs.org (localhost [IPv6:::1]) by lists.ozlabs.org (Postfix) with ESMTP id 4KNG155FwCz3bbF for ; Wed, 23 Mar 2022 02:41:13 +1100 (AEDT) X-Original-To: linuxppc-dev@lists.ozlabs.org Delivered-To: linuxppc-dev@lists.ozlabs.org Authentication-Results: lists.ozlabs.org; spf=pass (sender SPF authorized) smtp.mailfrom=csgroup.eu (client-ip=93.17.235.10; helo=pegase2.c-s.fr; envelope-from=christophe.leroy@csgroup.eu; receiver=) Received: from pegase2.c-s.fr (pegase2.c-s.fr [93.17.235.10]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits)) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id 4KNG0c14zxz308h for ; Wed, 23 Mar 2022 02:40:47 +1100 (AEDT) Received: from localhost (mailhub3.si.c-s.fr [172.26.127.67]) by localhost (Postfix) with ESMTP id 4KNG0P1xBBz9sTJ; Tue, 22 Mar 2022 16:40:37 +0100 (CET) X-Virus-Scanned: amavisd-new at c-s.fr Received: from pegase2.c-s.fr ([172.26.127.65]) by localhost (pegase2.c-s.fr [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id fyuRthqRyGhe; Tue, 22 Mar 2022 16:40:37 +0100 (CET) Received: from messagerie.si.c-s.fr (messagerie.si.c-s.fr [192.168.25.192]) by pegase2.c-s.fr (Postfix) with ESMTP id 4KNG0N09Bfz9sTN; Tue, 22 Mar 2022 16:40:36 +0100 (CET) Received: from localhost (localhost [127.0.0.1]) by messagerie.si.c-s.fr (Postfix) with ESMTP id E6A2B8B778; Tue, 22 Mar 2022 16:40:35 +0100 (CET) X-Virus-Scanned: amavisd-new at c-s.fr Received: from messagerie.si.c-s.fr ([127.0.0.1]) by localhost (messagerie.si.c-s.fr [127.0.0.1]) (amavisd-new, port 10023) with ESMTP id DASnUpcyQiCP; Tue, 22 Mar 2022 16:40:35 +0100 (CET) Received: from PO20335.IDSI0.si.c-s.fr (unknown [192.168.203.14]) by messagerie.si.c-s.fr (Postfix) with ESMTP id 9AFE58B774; Tue, 22 Mar 2022 16:40:35 +0100 (CET) Received: from PO20335.IDSI0.si.c-s.fr (localhost [127.0.0.1]) by PO20335.IDSI0.si.c-s.fr (8.17.1/8.16.1) with ESMTPS id 22MFeU4I1513378 (version=TLSv1.3 cipher=TLS_AES_256_GCM_SHA384 bits=256 verify=NOT); Tue, 22 Mar 2022 16:40:30 +0100 Received: (from chleroy@localhost) by PO20335.IDSI0.si.c-s.fr (8.17.1/8.17.1/Submit) id 22MFeUuq1513377; Tue, 22 Mar 2022 16:40:30 +0100 X-Authentication-Warning: PO20335.IDSI0.si.c-s.fr: chleroy set sender to christophe.leroy@csgroup.eu using -f From: Christophe Leroy To: Benjamin Herrenschmidt , Paul Mackerras , Michael Ellerman Subject: [PATCH v1 4/4] powerpc/code-patching: Use jump_label to check if poking_init() is done Date: Tue, 22 Mar 2022 16:40:21 +0100 Message-Id: <8d6088aca7b63247377b6d9e4897d08d935fbe93.1647962456.git.christophe.leroy@csgroup.eu> X-Mailer: git-send-email 2.35.1 In-Reply-To: References: MIME-Version: 1.0 X-Developer-Signature: v=1; a=ed25519-sha256; t=1647963619; l=1657; s=20211009; h=from:subject:message-id; bh=VpCvKObwtwt586zecmpLYRX0hNgaFguYgIynvmw/m08=; b=6g96jp94nOECf9453iw6yW4xXNCjIbsZcPV9VpQOZT5CHAxxbybhTCDWxioVRHhOYBl7Q7CXK5xL 9Io9NWy6DhdpnjrZtNfLAVvAqesW4m13bQIuubUf5UGoGjPsamUM X-Developer-Key: i=christophe.leroy@csgroup.eu; a=ed25519; pk=HIzTzUj91asvincQGOFx6+ZF5AoUuP9GdOtQChs7Mm0= X-BeenThere: linuxppc-dev@lists.ozlabs.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: linuxppc-dev@lists.ozlabs.org, linux-kernel@vger.kernel.org Errors-To: linuxppc-dev-bounces+incoming=patchwork.ozlabs.org@lists.ozlabs.org Sender: "Linuxppc-dev" It's only during early startup that poking_init() is not done yet, for instance when calling ftrace_init(). Once poking_init() has been called there must be a poking area, no need to check it everytime patch_instruction() is called. ftrace activation time is reduced by 7% with the change on an 8xx. Signed-off-by: Christophe Leroy --- arch/powerpc/lib/code-patching.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) diff --git a/arch/powerpc/lib/code-patching.c b/arch/powerpc/lib/code-patching.c index ab434c3853c9..8bd74bbe8b8d 100644 --- a/arch/powerpc/lib/code-patching.c +++ b/arch/powerpc/lib/code-patching.c @@ -79,6 +79,8 @@ static int text_area_cpu_down(unsigned int cpu) return 0; } +static __ro_after_init DEFINE_STATIC_KEY_FALSE(poking_init_done); + /* * Although BUG_ON() is rude, in this case it should only happen if ENOMEM, and * we judge it as being preferable to a kernel that will crash later when @@ -89,6 +91,7 @@ void __init poking_init(void) BUG_ON(!cpuhp_setup_state(CPUHP_AP_ONLINE_DYN, "powerpc/text_poke:online", text_area_cpu_up, text_area_cpu_down)); + static_branch_enable(&poking_init_done); } static unsigned long get_patch_pfn(void *addr) @@ -176,7 +179,7 @@ static int do_patch_instruction(u32 *addr, ppc_inst_t instr) * when text_poke_area is not ready, but we still need * to allow patching. We just do the plain old patching */ - if (!this_cpu_read(text_poke_area)) + if (!static_branch_likely(&poking_init_done)) return raw_patch_instruction(addr, instr); local_irq_save(flags);