public inbox for linux-next@vger.kernel.org 
 help / color / mirror / Atom feed
From: Sebastian Andrzej Siewior <bigeasy@linutronix•de>
To: Vlastimil Babka <vbabka@suse•cz>
Cc: "Paul E. McKenney" <paulmck@kernel•org>,
	Marco Elver <elver@google•com>,
	linux-next@vger•kernel.org, linux-kernel@vger•kernel.org,
	kasan-dev@googlegroups•com, linux-mm@kvack•org,
	sfr@canb•auug.org.au, longman@redhat•com, boqun.feng@gmail•com,
	cl@linux•com, penberg@kernel•org, rientjes@google•com,
	iamjoonsoo.kim@lge•com, akpm@linux-foundation•org
Subject: Re: [BUG] -next lockdep invalid wait context
Date: Thu, 31 Oct 2024 08:55:09 +0100	[thread overview]
Message-ID: <20241031075509.hCS9Amov@linutronix.de> (raw)
In-Reply-To: <cca52eaa-28c2-4ed5-9870-b2531ec8b2bc@suse.cz>

On 2024-10-31 08:35:45 [+0100], Vlastimil Babka wrote:
> On 10/31/24 08:21, Sebastian Andrzej Siewior wrote:
> > On 2024-10-30 16:10:58 [-0700], Paul E. McKenney wrote:
> >> 
> >> So I need to avoid calling kfree() within an smp_call_function() handler?
> > 
> > Yes. No kmalloc()/ kfree() in IRQ context.
> 
> However, isn't this the case that the rule is actually about hardirq context
> on RT, and most of these operations that are in IRQ context on !RT become
> the threaded interrupt context on RT, so they are actually fine? Or is smp
> call callback a hardirq context on RT and thus it really can't do those
> operations?

interrupt handlers as of request_irq() are forced-threaded on RT so you
can do kmalloc()/ kfree() there. smp_call_function.*() on the other hand
are not threaded and invoked directly within the IRQ context.

> Vlastimil
> 
Sebastian


  reply	other threads:[~2024-10-31  7:55 UTC|newest]

Thread overview: 16+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2024-10-30 21:05 [BUG] -next lockdep invalid wait context Paul E. McKenney
2024-10-30 21:48 ` Vlastimil Babka
2024-10-30 22:34   ` Marco Elver
2024-10-30 23:04     ` Boqun Feng
2024-10-30 23:10     ` Paul E. McKenney
2024-10-31  7:21       ` Sebastian Andrzej Siewior
2024-10-31  7:35         ` Vlastimil Babka
2024-10-31  7:55           ` Sebastian Andrzej Siewior [this message]
2024-10-31  8:18             ` Vlastimil Babka
2024-11-01 17:14               ` Paul E. McKenney
2024-10-31 17:50             ` Paul E. McKenney
2024-11-01 19:50               ` Boqun Feng
2024-11-01 19:54                 ` [PATCH] scftorture: Use workqueue to free scf_check Boqun Feng
2024-11-01 23:35                   ` Paul E. McKenney
2024-11-03  3:35                     ` Boqun Feng
2024-11-03 15:03                       ` Paul E. McKenney

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=20241031075509.hCS9Amov@linutronix.de \
    --to=bigeasy@linutronix$(echo .)de \
    --cc=akpm@linux-foundation$(echo .)org \
    --cc=boqun.feng@gmail$(echo .)com \
    --cc=cl@linux$(echo .)com \
    --cc=elver@google$(echo .)com \
    --cc=iamjoonsoo.kim@lge$(echo .)com \
    --cc=kasan-dev@googlegroups$(echo .)com \
    --cc=linux-kernel@vger$(echo .)kernel.org \
    --cc=linux-mm@kvack$(echo .)org \
    --cc=linux-next@vger$(echo .)kernel.org \
    --cc=longman@redhat$(echo .)com \
    --cc=paulmck@kernel$(echo .)org \
    --cc=penberg@kernel$(echo .)org \
    --cc=rientjes@google$(echo .)com \
    --cc=sfr@canb$(echo .)auug.org.au \
    --cc=vbabka@suse$(echo .)cz \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html
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