From patchwork Fri Aug 9 06:10:03 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Liao, Chang" X-Patchwork-Id: 13758436 Received: from szxga06-in.huawei.com (szxga06-in.huawei.com [45.249.212.32]) (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 DA25B3D6D; Fri, 9 Aug 2024 06:19:17 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=45.249.212.32 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1723184361; cv=none; b=ToQJzZBBbY+MfEr+M+5hT+BFbAhtX1WgA8MvgtNzrqqxiBR0pMh09PAnXSVn5xBqMwsQ5lkAFmFf8yJ+mglRgHtaO5UUd13/M5Inwx+D8zp29+agEVWPR2aXwtl9msuqV5cOSsqDTlM49DnQf5eYwxjaGX5zPgvUR4C6vHkzWH4= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1723184361; c=relaxed/simple; bh=nj2pyoZqJqmHJU2rzvoQJXs0NBPBSP422jfhghGWovU=; h=From:To:CC:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=Prvzh1Tdpw2S35NfPQgRNf0sun8MwGR+W05LKFok2CyNAcBKZJWbJF7dG1V76oLq2FsMfWx94omh6vpIYkqJ6voL4fg5vSGr1r3J/EtnNkgi7CYoFkZUfKcR35oISkExuxjWmfXwVw2IxGdef2ku9xf5YED42cJwNUu8oxmMplk= 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=45.249.212.32 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 [172.19.88.163]) by szxga06-in.huawei.com (SkyGuard) with ESMTP id 4WgDGZ1xZPz3743B; Fri, 9 Aug 2024 14:17:26 +0800 (CST) Received: from kwepemd200013.china.huawei.com (unknown [7.221.188.133]) by mail.maildlp.com (Postfix) with ESMTPS id 59A7718002B; Fri, 9 Aug 2024 14:19:15 +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; Fri, 9 Aug 2024 14:19:14 +0800 From: Liao Chang To: , , , , , , , , , , , , , CC: , , , Subject: [PATCH v2 1/2] uprobes: Remove redundant spinlock in uprobe_deny_signal() Date: Fri, 9 Aug 2024 06:10:03 +0000 Message-ID: <20240809061004.2112369-2-liaochang1@huawei.com> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20240809061004.2112369-1-liaochang1@huawei.com> References: <20240809061004.2112369-1-liaochang1@huawei.com> Precedence: bulk X-Mailing-List: bpf@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-ClientProxiedBy: dggems706-chm.china.huawei.com (10.3.19.183) 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: 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 73cc47708679..76a51a1f51e2 100644 --- a/kernel/events/uprobes.c +++ b/kernel/events/uprobes.c @@ -1979,9 +1979,7 @@ 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;