From nobody Fri Dec 19 22:02:54 2025 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 5AC6D64CEF; Wed, 13 Mar 2024 16:43:41 +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=1710348221; cv=none; b=NE+lHSxefdICLwsgvWNnx12z6ET0HxUQSLEcX7eeTHOBSqqeG/4oTLSLy5pZnmP94AFgeIj1cLYMw5V6VihSoBSf4OAhc+oD8QkWIkXKbtz87+pgaps1w7kS3mwa35MasG9niZcOTwp22CC2jeODeP9S7bYtCFcb8ZTB0Y2YSxM= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1710348221; c=relaxed/simple; bh=WAUj8o87Jtl9FY8pDymI7DWVAEqnJiixd48oKquu4iI=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=SeyYb92Hyq0eW9gsdfE3xx0sQBIIRwFS/aIH4Q+1WNpL/bVTqK8yYC/y10y5GsXLFDWO07hVZP1HOtk0eLgoOUiWq3Jh/2QQXT+GinBTITL61qRB5DMcPc77EqlqRb9+OlLOfHGLY/NwQH4qpSsYPScny3NiKyiyxXlGOIe9BSI= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=o7TY/Ia2; 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="o7TY/Ia2" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 4F1D7C433C7; Wed, 13 Mar 2024 16:43:40 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1710348221; bh=WAUj8o87Jtl9FY8pDymI7DWVAEqnJiixd48oKquu4iI=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=o7TY/Ia2kdis+532dlECAIEuQdXX6Oj/lZoreuoVRvGf0a9AhK0ra/IR3EMdewWHe msy4j4uXbo2mCzFS0USbOury7NGEu6AYwWrO3Pi1CM7W2TBDPU7BKyJ6vgjJYQeFLX vyDovPuRQji7/4DhbqzpUcDJlxztGR5qDSa5O711JsnwXEkTaVMjnOpAf/jukj5pcm RlOOxe1djo70tVsWox/2JvVkaWMEup04LxJF/C+uwOyWedYoYPYq/fp7p2WqrRaTFJ aPmp5vGTOsdmJId5ia6WDKnRgs6LdQBpdgUxxGXbYv4udrYCK2dXTodxPhfGgyNtmc njiet83lDu1zQ== From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Oleg Nesterov , Dylan Hatch , "Eric W . Biederman" , Andrew Morton , Sasha Levin Subject: [PATCH 5.15 67/76] exit: wait_task_zombie: kill the no longer necessary spin_lock_irq(siglock) Date: Wed, 13 Mar 2024 12:42:14 -0400 Message-ID: <20240313164223.615640-68-sashal@kernel.org> X-Mailer: git-send-email 2.43.0 In-Reply-To: <20240313164223.615640-1-sashal@kernel.org> References: <20240313164223.615640-1-sashal@kernel.org> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-KernelTest-Patch: http://kernel.org/pub/linux/kernel/v5.x/stable-review/patch-5.15.152-rc1.gz X-KernelTest-Tree: git://git.kernel.org/pub/scm/linux/kernel/git/stable/linux-stable-rc.git X-KernelTest-Branch: linux-5.15.y X-KernelTest-Patches: git://git.kernel.org/pub/scm/linux/kernel/git/stable/stable-queue.git X-KernelTest-Version: 5.15.152-rc1 X-KernelTest-Deadline: 2024-03-15T16:42+00:00 X-stable: review X-Patchwork-Hint: Ignore Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" From: Oleg Nesterov [ Upstream commit c1be35a16b2f1fe21f4f26f9de030ad6eaaf6a25 ] After the recent changes nobody use siglock to read the values protected by stats_lock, we can kill spin_lock_irq(¤t->sighand->siglock) and update the comment. With this patch only __exit_signal() and thread_group_start_cputime() take stats_lock under siglock. Link: https://lkml.kernel.org/r/20240123153359.GA21866@redhat.com Signed-off-by: Oleg Nesterov Signed-off-by: Dylan Hatch Cc: Eric W. Biederman Cc: Signed-off-by: Andrew Morton Signed-off-by: Sasha Levin --- kernel/exit.c | 10 +++------- 1 file changed, 3 insertions(+), 7 deletions(-) diff --git a/kernel/exit.c b/kernel/exit.c index e982111c489a9..85baaa31b2997 100644 --- a/kernel/exit.c +++ b/kernel/exit.c @@ -1120,17 +1120,14 @@ static int wait_task_zombie(struct wait_opts *wo, s= truct task_struct *p) * and nobody can change them. * * psig->stats_lock also protects us from our sub-threads - * which can reap other children at the same time. Until - * we change k_getrusage()-like users to rely on this lock - * we have to take ->siglock as well. + * which can reap other children at the same time. * * We use thread_group_cputime_adjusted() to get times for * the thread group, which consolidates times for all threads * in the group including the group leader. */ thread_group_cputime_adjusted(p, &tgutime, &tgstime); - spin_lock_irq(¤t->sighand->siglock); - write_seqlock(&psig->stats_lock); + write_seqlock_irq(&psig->stats_lock); psig->cutime +=3D tgutime + sig->cutime; psig->cstime +=3D tgstime + sig->cstime; psig->cgtime +=3D task_gtime(p) + sig->gtime + sig->cgtime; @@ -1153,8 +1150,7 @@ static int wait_task_zombie(struct wait_opts *wo, str= uct task_struct *p) psig->cmaxrss =3D maxrss; task_io_accounting_add(&psig->ioac, &p->ioac); task_io_accounting_add(&psig->ioac, &sig->ioac); - write_sequnlock(&psig->stats_lock); - spin_unlock_irq(¤t->sighand->siglock); + write_sequnlock_irq(&psig->stats_lock); } =20 if (wo->wo_rusage) --=20 2.43.0