From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (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 4B99D200CD; Tue, 22 Oct 2024 04:01:38 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1729569698; cv=none; b=ZiKiF9tI/s7H4ryB/1M9Y+UjjL63fIitcfOsKWiAn0vXon4Vbl9nZCHUqcKK0NgA0CpmjT6Goz73LM0knVKM8wuDwLHNeuBCvUvwWSg4mswQ9eqfY+lth8LB4fMHZK8Rfpe41r42/tgmJcjwI92Bi9CJ1gkrrlEQgl7ztOotmdg= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1729569698; c=relaxed/simple; bh=fPXbsF4kyNIhImmlGQ3JVWmhC8p/wdo0pc+43o7C9Y4=; h=Date:From:To:Cc:Subject:Message-Id:In-Reply-To:References: Mime-Version:Content-Type; b=rYOIShOkWyfC47NbdlWD+bs98y6I4denzeSU/9O7RFEtSRRc8SblyIq6Tdf5U6LenovqwlL9B0nfokfvKoL+LZtGtdR+QLwgd57Ty2SPrCA/YaqV/v71RKwHl7/2a9u2ZONGqmZ5FOp9oamd78k3oBATcLSkKINK8RpFcs3YdNU= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=Vze4eSMH; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="Vze4eSMH" Received: by smtp.kernel.org (Postfix) with ESMTPSA id C582FC4CEC3; Tue, 22 Oct 2024 04:01:35 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1729569697; bh=fPXbsF4kyNIhImmlGQ3JVWmhC8p/wdo0pc+43o7C9Y4=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=Vze4eSMH3jmHsdKtGswJpBgjlcovOtHJFXKDP39vCXc9KhG5goYmV7+D815zluuan kykhjjAnq8V8bbcO212RAtz/+jEd1AjHwM+Q+P0aEpRl/3BqH5JeIMerzUvtnTBzM5 7hBlBLQJeZFmAL9AgnaVDuokUrBCRXTk5KJey+RYFKe36tcSLebNmuvoOq+XyQuZNX uhDbzJJjCcJIVM9DHTGRtp5LSu27ecYJcVKYjg592VZqc8+MehgRt9Oi2PPPVLkTVl ca39n6riB265anzmnyue7snGHpGEbzLK14vpp7TVIiOmYNvSL/TXF5FjhOQrC68AET 8swa+1tsWgnPg== Date: Tue, 22 Oct 2024 13:01:34 +0900 From: Masami Hiramatsu (Google) To: Liao Chang Cc: , , , , , , , , , , , , , , Subject: Re: [PATCH v3 1/2] uprobes: Remove redundant spinlock in uprobe_deny_signal() Message-Id: <20241022130134.baf9e1f140b2664dba15d410@kernel.org> In-Reply-To: <20240815014629.2685155-2-liaochang1@huawei.com> References: <20240815014629.2685155-1-liaochang1@huawei.com> <20240815014629.2685155-2-liaochang1@huawei.com> X-Mailer: Sylpheed 3.8.0beta1 (GTK+ 2.24.33; x86_64-pc-linux-gnu) Precedence: bulk X-Mailing-List: linux-perf-users@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit On Thu, 15 Aug 2024 01:46:28 +0000 Liao Chang wrote: > 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. > Looks good to me. Acked-by: Masami Hiramatsu (Google) Thanks! > 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; > -- > 2.34.1 > > -- Masami Hiramatsu (Google)