linux-kernel - Re: [ANNOUNCE] kmod 30

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Date:   Thu, 30 Jun 2022 15:09:32 -0700
From:   Luis Chamberlain <mcgrof@...nel.org>
To:     Lucas De Marchi <lucas.demarchi@...el.com>
Cc:     linux-modules <linux-modules@...r.kernel.org>,
        lkml <linux-kernel@...r.kernel.org>
Subject: Re: [ANNOUNCE] kmod 30

On Thu, Jun 30, 2022 at 08:36:21AM -0700, Lucas De Marchi wrote:
>         - modprobe learned a --wait <MSEC> option to be used together with -r
>           when removing a module. This allows modprobe to keep trying the
>           removal if it fails because the module is still in use. An exponential backoff
>           time is used for further retries.
> 
>           The wait behavior provided by the kernel when not passing O_NONBLOCK
>           to delete_module() was removed in v3.13 due to not be used and the
>           consequences of having to support it in the kernel. However there may
>           be some users, particularly on testsuites for individual susbsystems, that
>           would want that. So provide a userspace implementation inside modprobe for
>           such users. "rmmod" doesn't have a --wait as it remains a bare minimal over
>           the API provided by the kernel. In future the --wait behavior can be added
>           to libkmod for testsuites not exec'ing modprobe for module removal.

Sorry for the super late review, I was swamped. OK so the only issue
I can think of is that rmmod *used* to support the kernel wait support
with $(rmmod --wait) so wouldn't this be odd?

It is why I had gone with:

 -p | --remove-patiently   patiently removes the module
 -t | --timeout            timeout in ms to remove the module

You would know better though.

Also just curious, is it really terrible to just support waiting
forever?

  Luis