From nobody Tue Nov 26 02:49:42 2024 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: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable X-ClientProxiedBy: dggems703-chm.china.huawei.com (10.3.19.180) To kwepemd200013.china.huawei.com (7.221.188.133) Content-Type: text/plain; charset="utf-8" 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 !=3D UTASK_SSTEP); =20 if (task_sigpending(t)) { - spin_lock_irq(&t->sighand->siglock); clear_tsk_thread_flag(t, TIF_SIGPENDING); - spin_unlock_irq(&t->sighand->siglock); =20 if (__fatal_signal_pending(t) || arch_uprobe_xol_was_trapped(t)) { utask->state =3D UTASK_SSTEP_TRAPPED; --=20 2.34.1 From nobody Tue Nov 26 02:49:42 2024 Received: from szxga03-in.huawei.com (szxga03-in.huawei.com [45.249.212.189]) (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 8D7D2153565; Tue, 22 Oct 2024 07:42:26 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=45.249.212.189 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1729582950; cv=none; b=IAPZBq2cJA3o1q+rGnllVBx4kpTwY3rwaO8lGzNTc9tT4CYAa6SN0WtiqhPtdWWkDDfJ7gFsHeY5eAyjaCkwAD60kdbCfaOYvKF25LYZUkU07h4tB5qGLOQU2WIgJGBa25F9Do+hiCCHVfpy9uQmuNjb4sGTcnu0MTJ9FAYIAgw= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1729582950; c=relaxed/simple; bh=yV33fE2DgD7soNvvjb7T7dsvRNU15jFdSM/8XAdHvRA=; h=From:To:CC:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=t0aI+P0OF+VANa1PhFG0NkV0kiLhgQF2OoWlSFagY8EtRT7UVipBc0IjTdRKYU5BGUJnS5fE+3E3rmfe6PeBn0AaGOImbi9lONK3kbwgy/HJGyWVuCdaAB8fALzQxLqf2xCqj6V7EUCk1u7GawXNZj55kU91E0oIQSOUWfOcDvM= 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=45.249.212.189 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 [172.19.163.174]) by szxga03-in.huawei.com (SkyGuard) with ESMTP id 4XXkdT24XQzQs17; Tue, 22 Oct 2024 15:41:33 +0800 (CST) Received: from kwepemd200013.china.huawei.com (unknown [7.221.188.133]) by mail.maildlp.com (Postfix) with ESMTPS id 07E2514011A; Tue, 22 Oct 2024 15:42:24 +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 15:42:23 +0800 From: Liao Chang To: , , , , , , , , , , , , CC: , , , Subject: [PATCH v4 2/2] uprobes: Remove the spinlock within handle_singlestep() Date: Tue, 22 Oct 2024 07:31:41 +0000 Message-ID: <20241022073141.3291245-3-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: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: quoted-printable X-ClientProxiedBy: dggems703-chm.china.huawei.com (10.3.19.180) To kwepemd200013.china.huawei.com (7.221.188.133) This patch introduces a flag to track TIF_SIGPENDING is suppress temporarily during the uprobe single-step. Upon uprobe singlestep is handled and the flag is confirmed, it could resume the TIF_SIGPENDING directly without acquiring the siglock in most case, then reducing contention and improving overall performance. I've use the script developed by Andrii in [1] to run benchmark. The CPU used was Kunpeng916 (Hi1616), 4 NUMA nodes, 64 cores@2.4GHz running the kernel on next tree + the optimization for get_xol_insn_slot() [2]. before-opt Acked-by: Masami Hiramatsu (Google) Acked-by: Oleg Nesterov ---------- uprobe-nop ( 1 cpus): 0.907 =C2=B1 0.003M/s ( 0.907M/s/cpu) uprobe-nop ( 2 cpus): 1.676 =C2=B1 0.008M/s ( 0.838M/s/cpu) uprobe-nop ( 4 cpus): 3.210 =C2=B1 0.003M/s ( 0.802M/s/cpu) uprobe-nop ( 8 cpus): 4.457 =C2=B1 0.003M/s ( 0.557M/s/cpu) uprobe-nop (16 cpus): 3.724 =C2=B1 0.011M/s ( 0.233M/s/cpu) uprobe-nop (32 cpus): 2.761 =C2=B1 0.003M/s ( 0.086M/s/cpu) uprobe-nop (64 cpus): 1.293 =C2=B1 0.015M/s ( 0.020M/s/cpu) uprobe-push ( 1 cpus): 0.883 =C2=B1 0.001M/s ( 0.883M/s/cpu) uprobe-push ( 2 cpus): 1.642 =C2=B1 0.005M/s ( 0.821M/s/cpu) uprobe-push ( 4 cpus): 3.086 =C2=B1 0.002M/s ( 0.771M/s/cpu) uprobe-push ( 8 cpus): 3.390 =C2=B1 0.003M/s ( 0.424M/s/cpu) uprobe-push (16 cpus): 2.652 =C2=B1 0.005M/s ( 0.166M/s/cpu) uprobe-push (32 cpus): 2.713 =C2=B1 0.005M/s ( 0.085M/s/cpu) uprobe-push (64 cpus): 1.313 =C2=B1 0.009M/s ( 0.021M/s/cpu) uprobe-ret ( 1 cpus): 1.774 =C2=B1 0.000M/s ( 1.774M/s/cpu) uprobe-ret ( 2 cpus): 3.350 =C2=B1 0.001M/s ( 1.675M/s/cpu) uprobe-ret ( 4 cpus): 6.604 =C2=B1 0.000M/s ( 1.651M/s/cpu) uprobe-ret ( 8 cpus): 6.706 =C2=B1 0.005M/s ( 0.838M/s/cpu) uprobe-ret (16 cpus): 5.231 =C2=B1 0.001M/s ( 0.327M/s/cpu) uprobe-ret (32 cpus): 5.743 =C2=B1 0.003M/s ( 0.179M/s/cpu) uprobe-ret (64 cpus): 4.726 =C2=B1 0.016M/s ( 0.074M/s/cpu) after-opt --------- uprobe-nop ( 1 cpus): 0.985 =C2=B1 0.002M/s ( 0.985M/s/cpu) uprobe-nop ( 2 cpus): 1.773 =C2=B1 0.005M/s ( 0.887M/s/cpu) uprobe-nop ( 4 cpus): 3.304 =C2=B1 0.001M/s ( 0.826M/s/cpu) uprobe-nop ( 8 cpus): 5.328 =C2=B1 0.002M/s ( 0.666M/s/cpu) uprobe-nop (16 cpus): 6.475 =C2=B1 0.002M/s ( 0.405M/s/cpu) uprobe-nop (32 cpus): 4.831 =C2=B1 0.082M/s ( 0.151M/s/cpu) uprobe-nop (64 cpus): 2.564 =C2=B1 0.053M/s ( 0.040M/s/cpu) uprobe-push ( 1 cpus): 0.964 =C2=B1 0.001M/s ( 0.964M/s/cpu) uprobe-push ( 2 cpus): 1.766 =C2=B1 0.002M/s ( 0.883M/s/cpu) uprobe-push ( 4 cpus): 3.290 =C2=B1 0.009M/s ( 0.823M/s/cpu) uprobe-push ( 8 cpus): 4.670 =C2=B1 0.002M/s ( 0.584M/s/cpu) uprobe-push (16 cpus): 5.197 =C2=B1 0.004M/s ( 0.325M/s/cpu) uprobe-push (32 cpus): 5.068 =C2=B1 0.161M/s ( 0.158M/s/cpu) uprobe-push (64 cpus): 2.605 =C2=B1 0.026M/s ( 0.041M/s/cpu) uprobe-ret ( 1 cpus): 1.833 =C2=B1 0.001M/s ( 1.833M/s/cpu) uprobe-ret ( 2 cpus): 3.384 =C2=B1 0.003M/s ( 1.692M/s/cpu) uprobe-ret ( 4 cpus): 6.677 =C2=B1 0.004M/s ( 1.669M/s/cpu) uprobe-ret ( 8 cpus): 6.854 =C2=B1 0.005M/s ( 0.857M/s/cpu) uprobe-ret (16 cpus): 6.508 =C2=B1 0.006M/s ( 0.407M/s/cpu) uprobe-ret (32 cpus): 5.793 =C2=B1 0.009M/s ( 0.181M/s/cpu) uprobe-ret (64 cpus): 4.743 =C2=B1 0.016M/s ( 0.074M/s/cpu) Above benchmark results demonstrates a obivious improvement in the scalability of trig-uprobe-nop and trig-uprobe-push, the peak throughput of which are from 4.5M/s to 6.4M/s and 3.3M/s to 5.1M/s individually. [1] https://lore.kernel.org/all/20240731214256.3588718-1-andrii@kernel.org [2] https://lore.kernel.org/all/20240727094405.1362496-1-liaochang1@huawei.= com Acked-by: Masami Hiramatsu (Google) Acked-by: Oleg Nesterov Signed-off-by: Liao Chang --- include/linux/uprobes.h | 1 + kernel/events/uprobes.c | 8 +++++--- 2 files changed, 6 insertions(+), 3 deletions(-) diff --git a/include/linux/uprobes.h b/include/linux/uprobes.h index 2b294bf1881f..1c5ece4ed55b 100644 --- a/include/linux/uprobes.h +++ b/include/linux/uprobes.h @@ -76,6 +76,7 @@ struct uprobe_task { =20 struct uprobe *active_uprobe; unsigned long xol_vaddr; + bool signal_denied; =20 struct arch_uprobe *auprobe; =20 diff --git a/kernel/events/uprobes.c b/kernel/events/uprobes.c index 196366c013f2..315efbee4353 100644 --- a/kernel/events/uprobes.c +++ b/kernel/events/uprobes.c @@ -1986,6 +1986,7 @@ bool uprobe_deny_signal(void) WARN_ON_ONCE(utask->state !=3D UTASK_SSTEP); =20 if (task_sigpending(t)) { + utask->signal_denied =3D true; clear_tsk_thread_flag(t, TIF_SIGPENDING); =20 if (__fatal_signal_pending(t) || arch_uprobe_xol_was_trapped(t)) { @@ -2302,9 +2303,10 @@ static void handle_singlestep(struct uprobe_task *ut= ask, struct pt_regs *regs) utask->state =3D UTASK_RUNNING; xol_free_insn_slot(utask); =20 - spin_lock_irq(¤t->sighand->siglock); - recalc_sigpending(); /* see uprobe_deny_signal() */ - spin_unlock_irq(¤t->sighand->siglock); + if (utask->signal_denied) { + set_thread_flag(TIF_SIGPENDING); + utask->signal_denied =3D false; + } =20 if (unlikely(err)) { uprobe_warn(current, "execute the probed insn, sending SIGILL."); --=20 2.34.1