From nobody Wed Dec 17 21:11:33 2025 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 9FFC428BAAC for ; Sun, 5 Oct 2025 14:52:07 +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=1759675929; cv=none; b=mW46qa2Y33Hkt43ieM63y0wwGbE8F5WoVL7Via1O33SCmIamq/FRnLeFQUNvSsDQ18tw6tgrkvJdXRfI+2UbuXHtIC/nkfXGrsD0nAajGh9Cxwk8fEeDcTayUmP2Sedl3yrRHLx4Rp+g8gn51Ubh9i0Z4cFk8ovOuMzIJYMXaZU= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1759675929; c=relaxed/simple; bh=9UiiJgLfv8sTOHiIZgjN6sokKuWFef4zdJDK9xhs/bY=; h=Date:From:To:Cc:Subject:Message-ID:MIME-Version:Content-Type: Content-Disposition:In-Reply-To; b=msR8Idjz32fleWtdGin94YOTaGhYeC715joKgBMv60W8wENZiTFMEYZunH7IxM27nUga2eOC9SF8w6aE74tjgcL7r0oxEVijeo16xhpNX6viqmcae77AXw0cAwlcXBT/44D5HiJM74FU7sY1tUHt55ws3sBJb1lOa6KP0x6gb4k= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=quarantine 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=VwCkOf9Q; arc=none smtp.client-ip=170.10.129.124 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=quarantine 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="VwCkOf9Q" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1759675926; 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; bh=ZSx5lQ4+7qrnZX1hvWPArhIGF76mwlIvFYhojlX36ik=; b=VwCkOf9QnaqerIXRzENwi+geNvnmvHhOihN/iZ/7R4l7H34KG4O0bqPv5MfH9KkQ2OqQAr lINgDryaPtaaAfmbxJugcEJCFizY+4nGeyBl14wIOtO7dLav/6op7kDjGjjCe6Wi1BZPCv tazElKQwNRszQ2bQ/KB1xR27FE5Z3Po= Received: from mx-prod-mc-05.mail-002.prod.us-west-2.aws.redhat.com (ec2-54-186-198-63.us-west-2.compute.amazonaws.com [54.186.198.63]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-117-k9gnyN4YOhi3jiAyMQi3KQ-1; Sun, 05 Oct 2025 10:52:03 -0400 X-MC-Unique: k9gnyN4YOhi3jiAyMQi3KQ-1 X-Mimecast-MFC-AGG-ID: k9gnyN4YOhi3jiAyMQi3KQ_1759675922 Received: from mx-prod-int-03.mail-002.prod.us-west-2.aws.redhat.com (mx-prod-int-03.mail-002.prod.us-west-2.aws.redhat.com [10.30.177.12]) (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 mx-prod-mc-05.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id A4970195608B; Sun, 5 Oct 2025 14:52:01 +0000 (UTC) Received: from dhcp-27-174.brq.redhat.com (unknown [10.45.224.5]) by mx-prod-int-03.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with SMTP id E34F319560A2; Sun, 5 Oct 2025 14:51:57 +0000 (UTC) Received: by dhcp-27-174.brq.redhat.com (nbSMTP-1.00) for uid 1000 oleg@redhat.com; Sun, 5 Oct 2025 16:50:40 +0200 (CEST) Date: Sun, 5 Oct 2025 16:50:35 +0200 From: Oleg Nesterov To: Alexander Viro , Boqun Feng , David Howells , Ingo Molnar , Li RongQing , Linus Torvalds , Peter Zijlstra , Waiman Long , Will Deacon Cc: linux-kernel@vger.kernel.org Subject: [PATCH 4/5] seqlock: change do_io_accounting() to use SEQLOCK_READ_SECTION() Message-ID: <20251005145035.GA1263@redhat.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <20251005144929.GB1188@redhat.com> User-Agent: Mutt/1.5.24 (2015-08-30) X-Scanned-By: MIMEDefang 3.0 on 10.30.177.12 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" To simplify the code and make it more readable. Signed-off-by: Oleg Nesterov --- fs/proc/base.c | 9 ++------- 1 file changed, 2 insertions(+), 7 deletions(-) diff --git a/fs/proc/base.c b/fs/proc/base.c index 62d35631ba8c..7ec507efbb99 100644 --- a/fs/proc/base.c +++ b/fs/proc/base.c @@ -3041,20 +3041,15 @@ static int do_io_accounting(struct task_struct *tas= k, struct seq_file *m, int wh if (whole) { struct signal_struct *sig =3D task->signal; struct task_struct *t; - unsigned int seq =3D 1; unsigned long flags; =20 rcu_read_lock(); - do { - seq++; /* 2 on the 1st/lockless path, otherwise odd */ - flags =3D read_seqbegin_or_lock_irqsave(&sig->stats_lock, &seq); - + SEQLOCK_READ_SECTION(&sig->stats_lock, &flags) { acct =3D sig->ioac; __for_each_thread(sig, t) task_io_accounting_add(&acct, &t->ioac); =20 - } while (need_seqretry(&sig->stats_lock, seq)); - done_seqretry_irqrestore(&sig->stats_lock, seq, flags); + } rcu_read_unlock(); } else { acct =3D task->ioac; --=20 2.25.1.362.g51ebf55