From: "Michael S. Tsirkin" <mst@redhat.com>
To: Tejun Heo <tj@kernel.org>
Cc: Or Gerlitz <ogerlitz@mellanox.com>,
Ming Lei <ming.lei@canonical.com>,
Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
David Miller <davem@davemloft.net>,
Roland Dreier <roland@kernel.org>,
netdev <netdev@vger.kernel.org>, Yan Burman <yanb@mellanox.com>,
Jack Morgenstein <jackm@dev.mellanox.co.il>,
Bjorn Helgaas <bhelgaas@google.com>,
linux-pci@vger.kernel.org
Subject: Re: [PATCH repost for-3.9] pci: avoid work_on_cpu for nested SRIOV probes
Date: Thu, 11 Apr 2013 23:30:53 +0300 [thread overview]
Message-ID: <20130411203053.GC25515@redhat.com> (raw)
In-Reply-To: <20130411192005.GN17641@mtj.dyndns.org>
On Thu, Apr 11, 2013 at 12:20:05PM -0700, Tejun Heo wrote:
> On Thu, Apr 11, 2013 at 10:17:17PM +0300, Michael S. Tsirkin wrote:
> > Hmm no, there's a real deadlock here: you are
> > trying to flush from work1 from within work2 running
> > on same workqueue. work2 can't event start running.
> > The problem is not annotation.
>
> No, that has changed years ago with introduction of cmwq. System
> workqueues are now expected to have high enough maximum concurrency to
> not cause deadlock as long as memory for worker creation is available,
> so as long as your work item doesn't directly sit in the memory
> reclaim path, it's safe to flush a different work item running on the
> same workqueue with sufficiently high max_active.
>
> Thanks.
Okay, so you are saying it's a false-positive?
Want to send a patch so Or can try it out?
> --
> tejun
next prev parent reply other threads:[~2013-04-11 20:31 UTC|newest]
Thread overview: 21+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-04-11 15:30 [PATCH repost for-3.9] pci: avoid work_on_cpu for nested SRIOV probes Michael S. Tsirkin
2013-04-11 18:05 ` Tejun Heo
2013-04-11 18:58 ` Michael S. Tsirkin
2013-04-11 19:04 ` Tejun Heo
2013-04-11 19:17 ` Michael S. Tsirkin
2013-04-11 19:20 ` Tejun Heo
2013-04-11 20:30 ` Michael S. Tsirkin [this message]
2013-04-11 20:41 ` Tejun Heo
2013-04-11 21:52 ` Or Gerlitz
[not found] ` <516AA80F.7040505@mellanox.com>
2013-04-14 13:43 ` Tejun Heo
2013-04-18 8:33 ` Michael S. Tsirkin
2013-04-18 9:40 ` Jack Morgenstein
2013-04-18 8:48 ` Michael S. Tsirkin
2013-04-18 9:57 ` Jack Morgenstein
2013-04-18 14:49 ` Or Gerlitz
2013-04-18 13:54 ` Michael S. Tsirkin
2013-04-18 18:19 ` Tejun Heo
2013-04-18 18:25 ` Bjorn Helgaas
2013-04-18 20:11 ` Michael S. Tsirkin
2013-04-18 18:41 ` Or Gerlitz
2013-04-18 20:03 ` Michael S. Tsirkin
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