From nobody Fri Dec 19 20:13:14 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 AB76C18C6EE; Wed, 13 Mar 2024 16:47:55 +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=1710348475; cv=none; b=K3yCj8KPB3qzyHN0E7ei+ileeaLvqimOsujSkfRHX9DhuVv8QeoRvJbnDrVnhEDhttUvRejWmVMfMLvJMUl79x+bBlbwO3rpmDXmkSf1YALQVSA9rvMBavLS0CX5MmUSo6Lxj69PSJueoaFzj8Cyw9GF+mqLadRrqBjvSqQujYc= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1710348475; c=relaxed/simple; bh=Chwo63+CUgFsse9hE2Vrekasq4uLyH88xEX6ey5kJcU=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=MLQgHQVQJo2NdzRSxMRyJWSBaSASJskW4dzDmTcZ7hlrqAqqtRxswLH3VMmme8unY/yAqIskk8LJ3RcUFllwmeuS79+g3hrksNEHzIAHeo4HMIOD2S1IOwQXdWKsQy9dZQB2HlTMXGNj8IZIAKLtAq/6ZzJErmtFmjak0FpMRVQ= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=lG0jEBNT; 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="lG0jEBNT" Received: by smtp.kernel.org (Postfix) with ESMTPSA id A82B5C433F1; Wed, 13 Mar 2024 16:47:54 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1710348475; bh=Chwo63+CUgFsse9hE2Vrekasq4uLyH88xEX6ey5kJcU=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=lG0jEBNTmzTkB+KN+QGY2tNmL3atzF3hneXDsiNymN7Bv+C77/gGt1WSgtld+2CpV sm6S2Yb6vn8qXY49xoos9kY0Dq0h82S7hsWVJmJWxMdjH1DlTbHPRlVZJKScxcQEWQ IE9/i9HBO608j0er31eRg6by3YIeAZ0mA8GZLfwvBuR/t0SU4z/yxZZWQ8gfZipaxG L3ptvEHz09qQxlMvldz8WwQ+DnfxkX/RVDQsrjxgv1pLxaMJvcui5b370ejxrxh1/P NATLhdftlnb8TWH2jSDq0VanxRnU2HoA5ERkZ9YOqfbPWfRZo68LHeFpJntw67Lmj1 keU36DFJ/dktg== 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 5.10 65/73] exit: wait_task_zombie: kill the no longer necessary spin_lock_irq(siglock) Date: Wed, 13 Mar 2024 12:46:32 -0400 Message-ID: <20240313164640.616049-66-sashal@kernel.org> X-Mailer: git-send-email 2.43.0 In-Reply-To: <20240313164640.616049-1-sashal@kernel.org> References: <20240313164640.616049-1-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-5.10.213-rc1.gz X-KernelTest-Tree: git://git.kernel.org/pub/scm/linux/kernel/git/stable/linux-stable-rc.git X-KernelTest-Branch: linux-5.10.y X-KernelTest-Patches: git://git.kernel.org/pub/scm/linux/kernel/git/stable/stable-queue.git X-KernelTest-Version: 5.10.213-rc1 X-KernelTest-Deadline: 2024-03-15T16:46+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 c41bdc0a7f06b..8f25abdd5fa7d 100644 --- a/kernel/exit.c +++ b/kernel/exit.c @@ -1106,17 +1106,14 @@ 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; @@ -1139,8 +1136,7 @@ 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