linux-mm.kvack.org archive mirror
 help / color / mirror / Atom feed
From: Dennis Dalessandro <dennis.dalessandro@cornelisnetworks.com>
To: Ira Weiny <ira.weiny@intel.com>
Cc: jgg@ziepe.ca, dledford@redhat.com, Jann Horn <jannh@google.com>,
	linux-rdma@vger.kernel.org,
	Mike Marciniszyn <mike.marciniszyn@cornelisnetworks.com>,
	linux-mm@kvack.org, Jason Gunthorpe <jgg@nvidia.com>
Subject: Re: [PATCH for-rc v2] IB/hfi1: Move cached value of mm into handler
Date: Fri, 13 Nov 2020 08:37:39 -0500	[thread overview]
Message-ID: <d423534f-806d-317c-d51d-46f1f104a7e6@cornelisnetworks.com> (raw)
In-Reply-To: <20201113003357.GW3976735@iweiny-DESK2.sc.intel.com>

On 11/12/2020 7:33 PM, Ira Weiny wrote:
> So I think the final point is the key to fixing the bug.  Keeping any
> current->mm which is not the one we opened the file with...  (or more
> specifically the one which first registered memory).  In some ways this may be
> worse than before because technically the parent could open the fd and hand it
> to the child and have the child register with it's mm.  But that is ok
> really...  May just be odd behavior for some users depending on what operations
> they do and in what order.

I don't think that's worse than before. Before we were letting it 
operate on the wrong mm. That's so much worse. Yes, parent could open fd 
and hand it off, which is OK. The "odd" behavior is up to whoever wrote 
the user space code to do that in the first place.

> [1] Also, you probably should credit Jann for the idea with a suggested by tag.

Will change reported-by to suggested-by.

-Denny



  reply	other threads:[~2020-11-13 13:39 UTC|newest]

Thread overview: 10+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-11-12  2:58 Dennis Dalessandro
2020-11-12 17:14 ` Ira Weiny
2020-11-12 22:06   ` Dennis Dalessandro
2020-11-12 22:08     ` Dennis Dalessandro
2020-11-13  0:02       ` Jason Gunthorpe
2020-11-13  0:33       ` Ira Weiny
2020-11-13 13:37         ` Dennis Dalessandro [this message]
2020-11-13 18:31           ` Ira Weiny
2020-11-13  0:01     ` Jason Gunthorpe
2020-11-13  0:42       ` Ira Weiny

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=d423534f-806d-317c-d51d-46f1f104a7e6@cornelisnetworks.com \
    --to=dennis.dalessandro@cornelisnetworks.com \
    --cc=dledford@redhat.com \
    --cc=ira.weiny@intel.com \
    --cc=jannh@google.com \
    --cc=jgg@nvidia.com \
    --cc=jgg@ziepe.ca \
    --cc=linux-mm@kvack.org \
    --cc=linux-rdma@vger.kernel.org \
    --cc=mike.marciniszyn@cornelisnetworks.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