From: Oliver Neukum <oliver@neukum•org>
To: Ming Lei <tom.leiming@gmail•com>
Cc: Dan Williams <dcbw@redhat•com>,
Elina Pasheva <epasheva@sierrawireless•com>,
Network Development <netdev@vger•kernel.org>,
linux-usb <linux-usb@vger•kernel.org>,
Rory Filer <rfiler@sierrawireless•com>, Phil Sutter <phil@nwl•cc>
Subject: Re: [PATCH 1/2 v5] usbnet: allow status interrupt URB to always be active
Date: Fri, 12 Apr 2013 12:02:55 +0200 [thread overview]
Message-ID: <1819986.PZkH8CJNCQ@linux-5eaq.site> (raw)
In-Reply-To: <CACVXFVNyRYzk1Le+QaJr-nnbDCsGqWtx-VJ5X-K6np1+gLzRpA@mail.gmail.com>
On Friday 12 April 2013 17:42:46 Ming Lei wrote:
> On Fri, Apr 12, 2013 at 2:37 PM, Oliver Neukum <oliver@neukum•org> wrote:
> >> The work will complete when memory is reclaimed, and the rx/tx path is
> >> still working, so memory reclaim can continue and the deadlock may not
> >> be caused, may it?
> >
> > Only if the memory allocation goes to the same interface. If the blocking interface
> > is storage, something bad happens (data loss not deadlock)
>
> OK, got it, it should be both since reset can't move on, so
> memory reclaim can't complete to satisfy the allocation.
>
> But I am wondering if it is a case which is worth the consideration.
The remedy is close to trivial, so yes.
> Almost all USB probe() allocate memory with GFP_KERNEL, then
> the similar scenario(data loss only this time) might happen too. Do we
> need to fix all USB drivers?
No. We assume that probing happens before the interfaces are used.
Furthermore, if this turns out to be real, we can reuse your fix for the
general (w.o. work queue) reset case.
> Wrt. the usbnet_status_start() API, looks no good reason to call
> it in another queue context, it should be enough to call it in probe() or
> bind() if init_status() can be put before info->bind() in usbnet_probe().
We are talking about a generic helper. And the fix is really simple.
We just pass mem_flags and all is well. If the API can be made better
at next to no cost, we do it.
> Then looks the mem_flags isn't needed in both cases, and we should
> always take GFP_NOIO inside the API?
We cannot. GFP_ATOMIC may be needed. And no, we atre not going to
unconditionally use GFP_ATOMIC :-;
Regards
Oliver
next prev parent reply other threads:[~2013-04-12 10:02 UTC|newest]
Thread overview: 89+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-07-27 14:12 strange behaviour of MC7700 with sierra_net Phil Sutter
[not found] ` <20110727141246.GC29616-2COwY06ShZsYt6otZODPyA@public.gmane.org>
2011-07-27 19:40 ` Dan Williams
[not found] ` <1311795643.17655.13.camel-wKZy7rqYPVb5EHUCmHmTqw@public.gmane.org>
2011-07-28 16:32 ` Phil Sutter
[not found] ` <8F90F944E50427428C60E12A34A309D23424BB0F25@carmd-exchmb01.sierrawireless.local>
[not found] ` <8F90F944E50427428C60E12A34A309D23424BB0F25-3qf8vkpM5jTbmvMHnzRVpW3Pdy6AhKVLXbPIYa3/oNjDOqzlkpFKJg@public.gmane.org>
2011-08-04 16:38 ` Phil Sutter
2013-01-04 16:48 ` [PATCH 1/2] usbnet: allow status interrupt URB to always be active Dan Williams
2013-01-04 16:51 ` [PATCH 2/2] sierra_net: keep status interrupt URB active over netdev open/close Dan Williams
[not found] ` <1357318289.5370.19.camel-wKZy7rqYPVb5EHUCmHmTqw@public.gmane.org>
2013-02-06 18:42 ` [PATCH 2/2 v2] sierra_net: fix issues with SYNC/RESTART messages and interrupt pipe setup Dan Williams
[not found] ` <1360176176.11742.16.camel-wKZy7rqYPVb5EHUCmHmTqw@public.gmane.org>
2013-02-06 20:17 ` Oliver Neukum
2013-02-07 21:09 ` Dan Williams
2013-02-06 21:11 ` Bjørn Mork
2013-02-07 17:06 ` Dan Williams
2013-02-13 11:44 ` Bjørn Mork
2013-02-13 16:34 ` Dan Williams
2013-01-04 22:16 ` [PATCH 1/2] usbnet: allow status interrupt URB to always be active Oliver Neukum
2013-01-05 1:26 ` Dan Williams
[not found] ` <1357349193.19684.3.camel-wKZy7rqYPVb5EHUCmHmTqw@public.gmane.org>
2013-01-05 10:59 ` Bjørn Mork
[not found] ` <87y5g7nbej.fsf-lbf33ChDnrE/G1V5fR+Y7Q@public.gmane.org>
2013-01-07 7:40 ` Oliver Neukum
2013-01-07 15:21 ` Dan Williams
2013-01-11 3:06 ` Ming Lei
2013-01-14 17:23 ` Dan Williams
2013-01-15 1:13 ` Ming Lei
2013-01-05 11:01 ` Oliver Neukum
2013-01-05 11:44 ` Bjørn Mork
2013-01-07 15:25 ` Dan Williams
2013-01-14 17:52 ` Dan Williams
2013-02-06 18:36 ` [PATCH 1/2 v2] " Dan Williams
2013-02-06 20:19 ` Oliver Neukum
2013-03-28 16:30 ` [PATCH 1/2 v3] " Dan Williams
[not found] ` <1364488207.1877.20.camel-wKZy7rqYPVb5EHUCmHmTqw@public.gmane.org>
2013-03-28 16:32 ` [PATCH 2/2 v3] sierra_net: keep status interrupt URB active Dan Williams
[not found] ` <1364488327.1877.22.camel-wKZy7rqYPVb5EHUCmHmTqw@public.gmane.org>
2013-03-29 19:21 ` David Miller
2013-03-29 19:20 ` [PATCH 1/2 v3] usbnet: allow status interrupt URB to always be active David Miller
[not found] ` <CACVXFVMBAzTYZKiE_uSTqr_yB4f7c5_PSnK=LBP6=oWdWwYHfg@mail.gmail.com>
[not found] ` <CACVXFVMBAzTYZKiE_uSTqr_yB4f7c5_PSnK=LBP6=oWdWwYHfg-JsoAwUIsXosN+BqQ9rBEUg@public.gmane.org>
2013-04-01 16:04 ` Dan Williams
2013-04-09 23:02 ` [PATCH 1/2 v4] " Dan Williams
2013-04-09 23:05 ` [PATCH 2/2 v4] sierra_net: keep status interrupt URB active Dan Williams
2013-04-10 7:15 ` Oliver Neukum
2013-04-10 14:57 ` Dan Williams
2013-04-10 15:01 ` Oliver Neukum
2013-04-10 7:23 ` [PATCH 1/2 v4] usbnet: allow status interrupt URB to always be active Oliver Neukum
[not found] ` <2328167.HJRXSHNhKT-7ztolUikljGernLeA6q8OA@public.gmane.org>
2013-04-10 12:49 ` Dan Williams
2013-04-10 13:06 ` Oliver Neukum
2013-04-10 13:18 ` Dan Williams
2013-04-10 13:29 ` Oliver Neukum
[not found] ` <1542762.9EJvNHlBNo-7ztolUikljGernLeA6q8OA@public.gmane.org>
2013-04-10 13:54 ` Dan Williams
[not found] ` <1365602083.28888.40.camel-wKZy7rqYPVb5EHUCmHmTqw@public.gmane.org>
2013-04-10 13:58 ` Oliver Neukum
2013-04-10 15:01 ` Dan Williams
2013-04-10 18:10 ` Oliver Neukum
2013-04-10 20:30 ` [PATCH 1/2 v5] " Dan Williams
[not found] ` <1365625850.22411.1.camel-wKZy7rqYPVb5EHUCmHmTqw@public.gmane.org>
2013-04-10 20:33 ` [PATCH 2/2 v5] sierra_net: keep status interrupt URB active Dan Williams
2013-04-11 2:31 ` [PATCH 1/2 v5] usbnet: allow status interrupt URB to always be active Ming Lei
2013-04-11 6:50 ` Oliver Neukum
2013-04-11 8:06 ` Bjørn Mork
2013-04-11 8:37 ` Ming Lei
2013-04-11 9:59 ` Oliver Neukum
2013-04-11 10:04 ` Bjørn Mork
2013-04-11 10:09 ` Ming Lei
2013-04-11 10:19 ` Ming Lei
[not found] ` <CACVXFVNn9MQr6JLdin=u642Jb-2ZPfVk8YaBmNdhU0_2e7WJqQ-JsoAwUIsXosN+BqQ9rBEUg@public.gmane.org>
2013-04-11 10:26 ` Bjørn Mork
2013-04-11 10:30 ` Ming Lei
2013-04-11 11:08 ` Bjørn Mork
[not found] ` <87d2u1wci6.fsf-lbf33ChDnrE/G1V5fR+Y7Q@public.gmane.org>
2013-04-11 11:42 ` Ming Lei
[not found] ` <CACVXFVO13tG606nDHth5rEA9jexj1iFHnry5ktrMpm_aGGTSvw-JsoAwUIsXosN+BqQ9rBEUg@public.gmane.org>
2013-04-11 11:54 ` Oliver Neukum
2013-04-11 12:16 ` Ming Lei
2013-04-11 8:09 ` Ming Lei
2013-04-11 9:53 ` Oliver Neukum
2013-04-11 10:03 ` Ming Lei
2013-04-11 11:14 ` Oliver Neukum
2013-04-11 12:11 ` Ming Lei
2013-04-11 12:28 ` Oliver Neukum
2013-04-11 12:59 ` Ming Lei
[not found] ` <CACVXFVPPzva+EwjNdxWsg4FufCc0zzzzvhGH_nLv479vT8VcxQ-JsoAwUIsXosN+BqQ9rBEUg@public.gmane.org>
2013-04-12 6:37 ` Oliver Neukum
2013-04-12 9:42 ` Ming Lei
2013-04-12 10:02 ` Oliver Neukum [this message]
2013-04-12 10:08 ` Ming Lei
2013-04-12 10:13 ` Bjørn Mork
2013-04-11 15:28 ` Dan Williams
2013-04-12 7:28 ` Oliver Neukum
2013-04-10 21:35 ` Oliver Neukum
2013-04-15 15:59 ` Dan Williams
2013-04-16 1:15 ` Ming Lei
2013-04-16 7:57 ` Oliver Neukum
[not found] ` <1637650.tuYfvStuVJ-7ztolUikljGernLeA6q8OA@public.gmane.org>
2013-04-17 1:56 ` Ming Lei
2013-04-17 6:55 ` Oliver Neukum
[not found] ` <5581442.KzM2iaDSQ0-7ztolUikljGernLeA6q8OA@public.gmane.org>
2013-04-18 3:51 ` Ming Lei
2013-04-19 8:25 ` Oliver Neukum
2013-04-24 12:31 ` Dan Williams
2013-04-25 13:00 ` Oliver Neukum
[not found] ` <1365548547.23372.2.camel-wKZy7rqYPVb5EHUCmHmTqw@public.gmane.org>
2013-04-10 13:25 ` [PATCH 1/2 v4] " Bjørn Mork
2013-04-10 13:31 ` Oliver Neukum
[not found] ` <1365604263.28888.56.camel@dcbw.foobar.com>
2013-04-10 15:21 ` Bjørn Mork
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