From: Johannes Berg <johannes@sipsolutions.net>
To: Abhinav Kumar <quic_abhinavk@quicinc.com>, linux-kernel@vger.kernel.org
Cc: rafael@kernel.org, linux-arm-msm@vger.kernel.org,
dri-devel@lists.freedesktop.org, swboyd@chromium.org,
khsieh@codeaurora.org, nganji@codeaurora.org,
seanpaul@chromium.org, gregkh@linuxfoundation.org,
dmitry.baryshkov@linaro.org, aravindh@codeaurora.org,
freedreno@lists.freedesktop.org
Subject: Re: [PATCH] devcoredump: increase the device delete timeout to 10 mins
Date: Tue, 08 Feb 2022 22:54:34 +0100 [thread overview]
Message-ID: <c2a6e29063793eecc5c65d32af9d826544404ecc.camel@sipsolutions.net> (raw)
In-Reply-To: <a280fec2-754a-88ec-acc7-337e069e9148@quicinc.com>
On Tue, 2022-02-08 at 13:40 -0800, Abhinav Kumar wrote:
> >
> I am checking what usermode sees and will get back ( I didnt see an
> error do most likely it was EOF ). I didnt follow the second part.
I think probably it got -ENODEV, looking at kernfs_file_read_iter().
> If the file descriptor read returns EOF, even if we consider them
> separate how will it resolve this issue?
>
> My earlier questions were related to fixing it in devcoredump to detect
> and fix it there. Are you suggesting to fix in usermode instead? How?
>
Yeah, no, you cannot fix it in userspace.
But I just followed the rabbit hole down kernfs and all, and it looks
like indeed the read would be cut short with -ENODEV, sorry.
It doesn't look like there's good API for this, but it seems at least
from the underlying kernfs POV it should be possible to get_device() in
open and put_device() in release, so that the device sticks around while
somebody has the file open? It's entirely virtual, so this should be OK?
johannes
next prev parent reply other threads:[~2022-02-08 22:29 UTC|newest]
Thread overview: 22+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-02-08 19:44 Abhinav Kumar
2022-02-08 20:35 ` Johannes Berg
2022-02-08 21:04 ` Abhinav Kumar
2022-02-08 21:12 ` Johannes Berg
2022-02-08 21:40 ` Abhinav Kumar
2022-02-08 21:54 ` Johannes Berg [this message]
2022-02-09 1:55 ` Abhinav Kumar
2022-02-09 7:50 ` Johannes Berg
2022-02-09 16:29 ` Abhinav Kumar
2022-02-11 11:09 ` Greg KH
2022-02-11 11:09 ` Greg KH
2022-02-11 18:59 ` Abhinav Kumar
2022-02-12 7:04 ` Greg KH
2022-02-12 7:52 ` Abhinav Kumar
2022-02-12 8:24 ` Johannes Berg
2022-02-12 8:35 ` Abhinav Kumar
2022-02-28 21:38 ` Abhinav Kumar
2022-03-01 6:48 ` David Laight
2022-03-01 17:45 ` Rob Clark
2022-03-11 11:53 ` Johannes Berg
2022-02-12 8:29 ` Greg KH
2022-02-12 8:33 ` Abhinav Kumar
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=c2a6e29063793eecc5c65d32af9d826544404ecc.camel@sipsolutions.net \
--to=johannes@sipsolutions.net \
--cc=aravindh@codeaurora.org \
--cc=dmitry.baryshkov@linaro.org \
--cc=dri-devel@lists.freedesktop.org \
--cc=freedreno@lists.freedesktop.org \
--cc=gregkh@linuxfoundation.org \
--cc=khsieh@codeaurora.org \
--cc=linux-arm-msm@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=nganji@codeaurora.org \
--cc=quic_abhinavk@quicinc.com \
--cc=rafael@kernel.org \
--cc=seanpaul@chromium.org \
--cc=swboyd@chromium.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
Powered by JetHome