linux-mm.kvack.org archive mirror
 help / color / mirror / Atom feed
From: Mateusz Guzik <mjguzik@gmail.com>
To: "Liam R. Howlett" <Liam.Howlett@oracle.com>,
	Mateusz Guzik <mjguzik@gmail.com>,
	ebiederm@xmission.com,  oleg@redhat.com, brauner@kernel.org,
	akpm@linux-foundation.org,  linux-mm@kvack.org,
	linux-kernel@vger.kernel.org
Subject: Re: [PATCH v4 3/5] pid: sprinkle tasklist_lock asserts
Date: Wed, 5 Feb 2025 21:58:11 +0100	[thread overview]
Message-ID: <CAGudoHGUvBCJaY=hnCXLo8r=GFs9wMiM4qf=0_8-rBXqexFqDg@mail.gmail.com> (raw)
In-Reply-To: <jamcxevfeuzsqhsj7b5o7jt2avfqpqmcahwadiwnayj6cwqpvf@psksqzyktksg>

On Wed, Feb 5, 2025 at 9:42 PM Liam R. Howlett <Liam.Howlett@oracle.com> wrote:
>
> * Mateusz Guzik <mjguzik@gmail.com> [250205 15:34]:
> > For this specific case I don't know what can be written in the body
> > given the really self-explanatory nature of the change, other than to
> > spell it out(?).
>
> You could say why you added it?  Is this something that was seen
> happening?
>

I guess this is a cultural discrepancy, if you will.

I spent most of my time in a codebase which is very assert-heavy and
if anything you would need to justify *not* adding some, let alone for
locking.

Plugging a gap of the sort would not require any explanation.

The kernel has numerous examples of mere comments stating that a given
lock is required or no information whatsoever, which one can only
infer from context. I'm assuming this predates lockdep. Given that
lockdep asserts are nops on production kernels there is no legitimate
reason to continue like that (or *avoid* asserting on lock state) that
I can see.

I'm going to sleep on it, type up a sentence or two, maybe reword
other commit messages and resend.

-- 
Mateusz Guzik <mjguzik gmail.com>


  reply	other threads:[~2025-02-05 20:58 UTC|newest]

Thread overview: 12+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2025-02-05 19:32 [PATCH v4 0/5] reduce tasklist_lock hold time on exit and do some pid cleanup Mateusz Guzik
2025-02-05 19:32 ` [PATCH v4 1/5] exit: perform add_device_randomness() without tasklist_lock Mateusz Guzik
2025-02-05 19:55   ` Oleg Nesterov
2025-02-05 20:00     ` Mateusz Guzik
2025-02-05 19:32 ` [PATCH v4 2/5] exit: hoist get_pid() in release_task() outside of tasklist_lock Mateusz Guzik
2025-02-05 19:32 ` [PATCH v4 3/5] pid: sprinkle tasklist_lock asserts Mateusz Guzik
2025-02-05 20:26   ` Liam R. Howlett
2025-02-05 20:34     ` Mateusz Guzik
2025-02-05 20:42       ` Liam R. Howlett
2025-02-05 20:58         ` Mateusz Guzik [this message]
2025-02-05 19:32 ` [PATCH v4 4/5] pid: perform free_pid() calls outside of tasklist_lock Mateusz Guzik
2025-02-05 19:32 ` [PATCH v4 5/5] pid: drop irq disablement around pidmap_lock Mateusz Guzik

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='CAGudoHGUvBCJaY=hnCXLo8r=GFs9wMiM4qf=0_8-rBXqexFqDg@mail.gmail.com' \
    --to=mjguzik@gmail.com \
    --cc=Liam.Howlett@oracle.com \
    --cc=akpm@linux-foundation.org \
    --cc=brauner@kernel.org \
    --cc=ebiederm@xmission.com \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linux-mm@kvack.org \
    --cc=oleg@redhat.com \
    /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