From patchwork Tue Oct 22 07:31:40 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Liao, Chang" X-Patchwork-Id: 13845237 X-Patchwork-Delegate: bpf@iogearbox.net Received: from szxga05-in.huawei.com (szxga05-in.huawei.com [45.249.212.191]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 1A6A814EC6E; Tue, 22 Oct 2024 07:42:26 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=45.249.212.191 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1729582950; cv=none; b=jaxxGHxVWb5qJln76Qhiq/nrmuVblHxRsVW0J8YUmXV1L0Jbr/hE0wsUOTqZclOmko0A4vvX4nk3OPlsJvLV2F0MQHLlFpNxU3VL/yay3gwtngufU5xkU51IaCvjm5DRtfBXGwQ2fGS/2tNrUofkp1llOWt3/3aV6HAe6wk9ji8= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1729582950; c=relaxed/simple; bh=ZTESNk0TwpnCiaPAZD8hbpu4RXeK4V6ATOv6HmarPTY=; h=From:To:CC:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=hjU57IkHqvpl1mbbEtKDZMqriELDMXCj/nrHH4hPA8BVjUb8Do+qToB4KTUWyzPML7EX5Svzp152xDu8fx7pOKcr6IDK7dVXhgKzAN8fLVbzkYOMK+PHaYxjD65IscvDJUlFO4Cxf/yowBL9FCHPCWSWofaLlCq3A2jcNeeBKXc= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=huawei.com; spf=pass smtp.mailfrom=huawei.com; arc=none smtp.client-ip=45.249.212.191 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=huawei.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=huawei.com Received: from mail.maildlp.com (unknown [172.19.88.234]) by szxga05-in.huawei.com (SkyGuard) with ESMTP id 4XXkYR5FMlz1HLL0; Tue, 22 Oct 2024 15:38:03 +0800 (CST) Received: from kwepemd200013.china.huawei.com (unknown [7.221.188.133]) by mail.maildlp.com (Postfix) with ESMTPS id 6A84814010D; Tue, 22 Oct 2024 15:42:23 +0800 (CST) Received: from huawei.com (10.67.174.28) by kwepemd200013.china.huawei.com (7.221.188.133) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.2.1258.34; Tue, 22 Oct 2024 15:42:22 +0800 From: Liao Chang To: , , , , , , , , , , , , CC: , , , Subject: [PATCH v4 1/2] uprobes: Remove redundant spinlock in uprobe_deny_signal() Date: Tue, 22 Oct 2024 07:31:40 +0000 Message-ID: <20241022073141.3291245-2-liaochang1@huawei.com> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20241022073141.3291245-1-liaochang1@huawei.com> References: <20241022073141.3291245-1-liaochang1@huawei.com> Precedence: bulk X-Mailing-List: bpf@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-ClientProxiedBy: dggems703-chm.china.huawei.com (10.3.19.180) To kwepemd200013.china.huawei.com (7.221.188.133) Since clearing a bit in thread_info is an atomic operation, the spinlock is redundant and can be removed, reducing lock contention is good for performance. Acked-by: Masami Hiramatsu (Google) Acked-by: Oleg Nesterov Signed-off-by: Liao Chang --- kernel/events/uprobes.c | 2 -- 1 file changed, 2 deletions(-) diff --git a/kernel/events/uprobes.c b/kernel/events/uprobes.c index 2a0059464383..196366c013f2 100644 --- a/kernel/events/uprobes.c +++ b/kernel/events/uprobes.c @@ -1986,9 +1986,7 @@ bool uprobe_deny_signal(void) WARN_ON_ONCE(utask->state != UTASK_SSTEP); if (task_sigpending(t)) { - spin_lock_irq(&t->sighand->siglock); clear_tsk_thread_flag(t, TIF_SIGPENDING); - spin_unlock_irq(&t->sighand->siglock); if (__fatal_signal_pending(t) || arch_uprobe_xol_was_trapped(t)) { utask->state = UTASK_SSTEP_TRAPPED;