From: Eric Dumazet <eric.dumazet@gmail.com>
To: Jonathan Lemon <jonathan.lemon@gmail.com>,
Netdev <netdev@vger.kernel.org>
Subject: Re: rtnl_lock() question
Date: Wed, 4 Sep 2019 09:39:07 +0200 [thread overview]
Message-ID: <3164f8de-de20-44f7-03fb-8bc39ca8449e@gmail.com> (raw)
In-Reply-To: <29EC5179-D939-42CD-8577-682BE4B05916@gmail.com>
On 9/3/19 11:55 PM, Jonathan Lemon wrote:
> How appropriate is it to hold the rtnl_lock() across a sleepable
> memory allocation? On one hand it's just a mutex, but it would
> seem like it could block quite a few things.
>
Sure, all GFP_KERNEL allocations can sleep for quite a while.
On the other hand, we may want to delay stuff if memory is under pressure,
or complex operations like NEWLINK would fail.
RTNL is mostly taken for control path operations, we prefer them to be
mostly reliable, otherwise admins job would be a nightmare.
In some cases, it is relatively easy to pre-allocate memory before rtnl is taken,
but that will only take care of some selected paths.
next prev parent reply other threads:[~2019-09-04 7:39 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-09-03 21:55 rtnl_lock() question Jonathan Lemon
2019-09-04 7:39 ` Eric Dumazet [this message]
2019-09-04 16:38 ` Jonathan Lemon
2019-09-04 23:23 ` Saeed Mahameed
2019-09-05 18:07 ` Rustad, Mark D
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=3164f8de-de20-44f7-03fb-8bc39ca8449e@gmail.com \
--to=eric.dumazet@gmail.com \
--cc=jonathan.lemon@gmail.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 an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.