From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.129.124]) (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 458101509E6 for ; Wed, 13 Mar 2024 17:04:52 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=170.10.129.124 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1710349495; cv=none; b=Y23pBuMZ5cLFNxJ4vo8jXuOAbmflLK3BxjC3NWHi79x1CN/SRD2zxUuis64Ll10/hCsbLPrDN6Zp42uziN/jzjVB/epXZGsjDDhEn3p1PAQ7FYExiuUTObXyEhhjay/EPE802Tqfh8JWSOqS85++Ggjexj2isLILYlmRvrScKUw= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1710349495; c=relaxed/simple; bh=NVVCPsRTH9aJFP5INYUA1mg6ri8jiYYeK/20kRzivhs=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=pUy24khgNjdJioQgkRnwD1AusHYz3Y8lDtGJ0jGxwkNfP0b+yd5GpWhECT5ILcArWB1IRM4wsx0PcK8DJ6TkcYUEMdx2DUcfnhZnPLdwDPUlJqgVYk2DWICFhfzgrPojFdVDARglRmas2lkXgxxUWjuspa++ydRqpb3kXQBi4iY= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=redhat.com; spf=pass smtp.mailfrom=redhat.com; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b=eoa/I07o; arc=none smtp.client-ip=170.10.129.124 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=redhat.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=redhat.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="eoa/I07o" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1710349492; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=+Xbn72BYWl9q5M69bjzFR6tOEN9CO/5oxYSGxU1c8D8=; b=eoa/I07ouZIHn+PEuEjZ9w3yw9tvuNHo63pze0T1mocf7QGixRihYt61EO1or/obE3n6WN woLh8xUXuHQTi7O4Gm3M1EeiwlONbrICxA4wF5NhXRS5qFe/Cuo3rVUofeRBjbp99EN6s+ jDAl1rSfbPTzeRYiO5KoTY4X0Qdbv78= Received: from mimecast-mx02.redhat.com (mx-ext.redhat.com [66.187.233.73]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-643-Vgj_NRLtPQiJww3MCVkOQQ-1; Wed, 13 Mar 2024 13:04:49 -0400 X-MC-Unique: Vgj_NRLtPQiJww3MCVkOQQ-1 Received: from smtp.corp.redhat.com (int-mx01.intmail.prod.int.rdu2.redhat.com [10.11.54.1]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id 7D8111C07F3A; Wed, 13 Mar 2024 17:04:48 +0000 (UTC) Received: from dhcp-27-174.brq.redhat.com (unknown [10.45.225.233]) by smtp.corp.redhat.com (Postfix) with SMTP id CF26F3C21; Wed, 13 Mar 2024 17:04:46 +0000 (UTC) Received: by dhcp-27-174.brq.redhat.com (nbSMTP-1.00) for uid 1000 oleg@redhat.com; Wed, 13 Mar 2024 18:03:27 +0100 (CET) Date: Wed, 13 Mar 2024 18:03:24 +0100 From: Oleg Nesterov To: Sasha Levin Cc: linux-kernel@vger.kernel.org, stable@vger.kernel.org, Dylan Hatch , "Eric W . Biederman" , Andrew Morton Subject: Re: [PATCH 5.10 65/73] exit: wait_task_zombie: kill the no longer necessary spin_lock_irq(siglock) Message-ID: <20240313170324.GC25452@redhat.com> References: <20240313164640.616049-1-sashal@kernel.org> <20240313164640.616049-66-sashal@kernel.org> Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20240313164640.616049-66-sashal@kernel.org> User-Agent: Mutt/1.5.24 (2015-08-30) X-Scanned-By: MIMEDefang 3.4.1 on 10.11.54.1 I do not know what does 5.10 mean. Does this tree has all the changes this patch depends on? Say, 1df4bd83cdfdbd0720dd ("do_io_accounting: use sig->stats_lock") ? In any case please remove this patch from all your queues, it got the "stable" tag by mistake. Oleg. On 03/13, Sasha Levin wrote: > > 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, struct 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 += tgutime + sig->cutime; > psig->cstime += tgstime + sig->cstime; > psig->cgtime += task_gtime(p) + sig->gtime + sig->cgtime; > @@ -1139,8 +1136,7 @@ static int wait_task_zombie(struct wait_opts *wo, struct task_struct *p) > psig->cmaxrss = 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); > } > > if (wo->wo_rusage) > -- > 2.43.0 >