All of lore.kernel.org
 help / color / mirror / Atom feed
From: Jason Gunthorpe <jgg@ziepe.ca>
To: Jann Horn <jannh@google.com>
Cc: Andrew Morton <akpm@linux-foundation.org>,
	linux-mm@kvack.org, linux-kernel@vger.kernel.org,
	"Eric W . Biederman" <ebiederm@xmission.com>,
	Michel Lespinasse <walken@google.com>,
	Mauro Carvalho Chehab <mchehab@kernel.org>,
	Sakari Ailus <sakari.ailus@linux.intel.com>
Subject: Re: [PATCH 1/4] mm/gup_benchmark: Take the mmap lock around GUP
Date: Wed, 30 Sep 2020 09:20:14 -0300	[thread overview]
Message-ID: <20200930122014.GB9916@ziepe.ca> (raw)
In-Reply-To: <CAG48ez3SG6ngZLtasxJ6LABpOnqCz5-QHqb0B4k44TQ8F9n6+w@mail.gmail.com>

On Tue, Sep 29, 2020 at 06:19:59PM -0700, Jann Horn wrote:
> To be safe against concurrent changes to the VMA tree, we must take the
> mmap lock around GUP operations (excluding the GUP-fast family of
> operations, which will take the mmap lock by themselves if necessary).
> 
> This code is only for testing, and it's only reachable by root through
> debugfs, so this doesn't really have any impact; however, if we want to add
> lockdep asserts into the GUP path, we need to have clean locking here.
> 
> Signed-off-by: Jann Horn <jannh@google.com>
> ---

Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>

Jason

  parent reply	other threads:[~2020-09-30 12:20 UTC|newest]

Thread overview: 8+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-09-30  1:19 [PATCH 1/4] mm/gup_benchmark: Take the mmap lock around GUP Jann Horn
2020-09-30  1:19 ` Jann Horn
2020-09-30  1:35 ` Jann Horn
2020-09-30  1:35   ` Jann Horn
2020-09-30 12:20 ` Jason Gunthorpe [this message]
2020-09-30 21:15 ` John Hubbard
2020-09-30 23:21 ` Michel Lespinasse
2020-09-30 23:21   ` Michel Lespinasse

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=20200930122014.GB9916@ziepe.ca \
    --to=jgg@ziepe.ca \
    --cc=akpm@linux-foundation.org \
    --cc=ebiederm@xmission.com \
    --cc=jannh@google.com \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linux-mm@kvack.org \
    --cc=mchehab@kernel.org \
    --cc=sakari.ailus@linux.intel.com \
    --cc=walken@google.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 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.