From nobody Mon Feb 9 01:44:51 2026 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 5442B7602C; Wed, 13 Mar 2024 16:38:15 +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=1710347896; cv=none; b=ciM7SJcyBdVjuuEXzaHPIDViYZ4wnPUnrmBDm8BYTSrG5e/ucWh3fiNamE9fhDXVUyKBVZENhzbHql+z9JQY3cy23ERDBj9EIOKLxZ8tysaunVvF9Px9W50X8TzMdboVgJprMXL5I7BIz3js5uT2IFb6q6qq63COp6H0q24NG6Y= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1710347896; c=relaxed/simple; bh=uys9znSgCeHdgzitYvSe3FISZB4ZDmHwLt7pJPKCqpk=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=e3m3GOKtvxbYeLxtqpYCoHlsGR+gstsesSxsl9YxO4CNClENHTdcGtriqQj7Ynz7yt6weSGX5dtMVPEt2vDELrfRKTb3eswNA6VBRryHfQ6jtD5GVkGUVVViQyX7gfeX/LlpUw9eOjeS8j61wYC+21axfVqpiPCMz0XAavFFz+w= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=RoeXHWXP; 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="RoeXHWXP" Received: by smtp.kernel.org (Postfix) with ESMTPSA id D7BC3C433C7; Wed, 13 Mar 2024 16:38:14 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1710347895; bh=uys9znSgCeHdgzitYvSe3FISZB4ZDmHwLt7pJPKCqpk=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=RoeXHWXPeOzN7sF+8vM/ZIDj115CSlP4BeIcnBFFDLz7WA+XQdfeonX3rqkwtJYBx F2eS3JLffeU6TyYE823k+Qo0uUJpIjDCdxMatthHrS9s9hWwl1YdPijVIWbQotxkPI KJ1lFG+rFBaYsNH6//EqQUETjnVErDgXtlGp2Yk9Q9f/241k3mEMA9d16Odyg5kuyi AAXE1TXs17tp+DZYnnADL4rIvjir3slJLJT0LX59WC/9xC44ZISv8DekuuPK5NUDZw QP5Ei7qU/woLFyOVWMciUn/fVcp44SP5XkVpYaq3wxxK4xxpfiLvsPKgKmMotJGXpl ZrmGu5yor9pdQ== 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 6.6 55/60] exit: wait_task_zombie: kill the no longer necessary spin_lock_irq(siglock) Date: Wed, 13 Mar 2024 12:37:02 -0400 Message-ID: <20240313163707.615000-56-sashal@kernel.org> X-Mailer: git-send-email 2.43.0 In-Reply-To: <20240313163707.615000-1-sashal@kernel.org> References: <20240313163707.615000-1-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/v6.x/stable-review/patch-6.6.22-rc1.gz X-KernelTest-Tree: git://git.kernel.org/pub/scm/linux/kernel/git/stable/linux-stable-rc.git X-KernelTest-Branch: linux-6.6.y X-KernelTest-Patches: git://git.kernel.org/pub/scm/linux/kernel/git/stable/stable-queue.git X-KernelTest-Version: 6.6.22-rc1 X-KernelTest-Deadline: 2024-03-15T16:36+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 21a59a6e1f2e8..1867d420c36c4 100644 --- a/kernel/exit.c +++ b/kernel/exit.c @@ -1148,17 +1148,14 @@ 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; @@ -1181,8 +1178,7 @@ 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