Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) client-ip=23.128.96.18;
Content-Type: text/plain; charset=utf-8
Content-Transfer-Encoding: quoted-printable
From:   Qian Cai <cai@lca.pw>
Mime-Version: 1.0 (1.0)
Subject: Re: [RFC PATCH] mm: silence soft lockups from unlock_page
Date:   Tue, 21 Jul 2020 07:10:14 -0400
Message-Id: <FCC3EB2D-9F11-4E9E-88F4-40B2926B35CC@lca.pw>
References: <20200721063258.17140-1-mhocko@kernel.org>
Cc:     linux-mm@kvack.org, LKML <linux-kernel@vger.kernel.org>,
        Andrew Morton <akpm@linux-foundation.org>,
        Linus Torvalds <torvalds@linux-foundation.org>,
        Tim Chen <tim.c.chen@linux.intel.com>,
        Michal Hocko <mhocko@suse.com>
In-Reply-To: <20200721063258.17140-1-mhocko@kernel.org>
To:     Michal Hocko <mhocko@kernel.org>
Sender: linux-kernel-owner@vger.kernel.org
Precedence: bulk


> On Jul 21, 2020, at 2:33 AM, Michal Hocko <mhocko@kernel.org> wrote:
>=20
> on a large ppc machine. The very likely cause is a suboptimal
> configuration when systed-udev spawns way too many workders to bring the
> system up.

This is strange. The problem description is missing quite a few important de=
tails. For example, what systems exactly are those? How many CPUs, memory an=
d NUMA nodes were you talking about? Which kernel version was it reported? H=
ow many workers from systemd-udev was =E2=80=9Cmisconfigured=E2=80=9D?=