linux-mm.kvack.org archive mirror
 help / color / mirror / Atom feed
From: Catalin Marinas <catalin.marinas@arm.com>
To: Davidlohr Bueso <dave@stgolabs.net>
Cc: akpm@linux-foundation.org, oleg@redhat.com, linux-mm@kvack.org,
	linux-kernel@vger.kernel.org, Davidlohr Bueso <dbueso@suse.de>
Subject: Re: [PATCH] mm/kmemleak: rely on rcu for task stack scanning
Date: Fri, 21 Aug 2020 19:09:31 +0100	[thread overview]
Message-ID: <20200821180931.GF6823@gaia> (raw)
In-Reply-To: <20200820203902.11308-1-dave@stgolabs.net>

On Thu, Aug 20, 2020 at 01:39:02PM -0700, Davidlohr Bueso wrote:
> kmemleak_scan() currently relies on the big tasklist_lock
> hammer to stabilize iterating through the tasklist. Instead,
> this patch proposes simply using rcu along with the rcu-safe
> for_each_process_thread flavor (without changing scan semantics),
> which doesn't make use of next_thread/p->thread_group and thus
> cannot race with exit. Furthermore, any races with fork()
> and not seeing the new child should be benign as it's not
> running yet and can also be detected by the next scan.
> 
> Signed-off-by: Davidlohr Bueso <dbueso@suse.de>

As long as the kernel thread stack is still around (kmemleak does use
try_get_task_stack()), I'm fine with the change:

Acked-by: Catalin Marinas <catalin.marinas@arm.com>


      parent reply	other threads:[~2020-08-21 18:09 UTC|newest]

Thread overview: 4+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-08-20 20:39 Davidlohr Bueso
     [not found] ` <20200821002554.GB4622@lca.pw>
2020-08-21  1:27   ` Davidlohr Bueso
2020-08-21 11:20 ` Oleg Nesterov
2020-08-21 18:09 ` Catalin Marinas [this message]

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=20200821180931.GF6823@gaia \
    --to=catalin.marinas@arm.com \
    --cc=akpm@linux-foundation.org \
    --cc=dave@stgolabs.net \
    --cc=dbueso@suse.de \
    --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