From: "Jonathan Lemon" <jonathan.lemon@gmail.com>
To: "Jesper Dangaard Brouer" <brouer@redhat.com>
Cc: "Grygorii Strashko" <grygorii.strashko@ti.com>,
netdev@vger.kernel.org, davem@davemloft.net, kernel-team@fb.com,
"Ilias Apalodimas" <ilias.apalodimas@linaro.org>
Subject: Re: [net PATCH] xdp: obtain the mem_id mutex before trying to remove an entry.
Date: Wed, 04 Dec 2019 09:30:18 -0800 [thread overview]
Message-ID: <49A0ABFF-32CD-4F21-B091-0997DC805B7B@gmail.com> (raw)
In-Reply-To: <20191204123829.2af45813@carbon>
On 4 Dec 2019, at 3:38, Jesper Dangaard Brouer wrote:
> On Wed, 4 Dec 2019 12:07:22 +0200
> Grygorii Strashko <grygorii.strashko@ti.com> wrote:
>
>> On 04/12/2019 10:32, Jesper Dangaard Brouer wrote:
>>> On Tue, 3 Dec 2019 14:01:14 -0800
>>> Jonathan Lemon <jonathan.lemon@gmail.com> wrote:
>>>
>>>> A lockdep splat was observed when trying to remove an xdp memory
>>>> model from the table since the mutex was obtained when trying to
>>>> remove the entry, but not before the table walk started:
>>>>
>>>> Fix the splat by obtaining the lock before starting the table walk.
>>>>
>>>> Fixes: c3f812cea0d7 ("page_pool: do not release pool until inflight
>>>> == 0.")
>>>> Reported-by: Grygorii Strashko <grygorii.strashko@ti.com>
>>>> Signed-off-by: Jonathan Lemon <jonathan.lemon@gmail.com>
>>>
>>> Have you tested if this patch fix the problem reported by Grygorii?
Yes, I reproduced the problem locally, and confirmed that the patch
resolves the issue.
--
Jonathan
>>>
>>> Link:
>>> https://lore.kernel.org/netdev/c2de8927-7bca-612f-cdfd-e9112fee412a@ti.com
>>>
>>> Grygorii can you test this?
>>
>> Thanks.
>> I do not see this trace any more and networking is working after if
>> down/up
>>
>> Tested-by: Grygorii Strashko <grygorii.strashko@ti.com>
>>
>
> Well if it fixes you issue, then I guess its okay.
>
> Acked-by: Jesper Dangaard Brouer <brouer@redhat.com>
>
> I just though it was related to the rcu_read_lock() around the
> page_pool_destroy() call. Guess, I was wrong.
>
> --
> Best regards,
> Jesper Dangaard Brouer
> MSc.CS, Principal Kernel Engineer at Red Hat
> LinkedIn: http://www.linkedin.com/in/brouer
next prev parent reply other threads:[~2019-12-04 17:30 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-12-03 22:01 [net PATCH] xdp: obtain the mem_id mutex before trying to remove an entry Jonathan Lemon
2019-12-04 8:32 ` Jesper Dangaard Brouer
2019-12-04 10:07 ` Grygorii Strashko
2019-12-04 11:38 ` Jesper Dangaard Brouer
2019-12-04 17:30 ` Jonathan Lemon [this message]
2019-12-04 20:28 ` Ilias Apalodimas
2019-12-05 0:36 ` David Miller
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=49A0ABFF-32CD-4F21-B091-0997DC805B7B@gmail.com \
--to=jonathan.lemon@gmail.com \
--cc=brouer@redhat.com \
--cc=davem@davemloft.net \
--cc=grygorii.strashko@ti.com \
--cc=ilias.apalodimas@linaro.org \
--cc=kernel-team@fb.com \
--cc=netdev@vger.kernel.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).