linux-rdma.vger.kernel.org archive mirror
 help / color / mirror / Atom feed
From: Gal Pressman <galpress@amazon.com>
To: Jason Gunthorpe <jgg@nvidia.com>
Cc: Leon Romanovsky <leon@kernel.org>,
	Doug Ledford <dledford@redhat.com>, <linux-rdma@vger.kernel.org>,
	Alexander Matushevsky <matua@amazon.com>,
	Firas JahJah <firasj@amazon.com>,
	Yossi Leybovich <sleybo@amazon.com>
Subject: Re: [PATCH for-next 4/4] RDMA/efa: CQ notifications
Date: Thu, 9 Sep 2021 14:00:00 +0300	[thread overview]
Message-ID: <002ea7b9-42b1-84f0-a094-638215ee23b9@amazon.com> (raw)
In-Reply-To: <20210907113135.GE2505917@nvidia.com>

On 07/09/2021 14:31, Jason Gunthorpe wrote:
> On Sun, Sep 05, 2021 at 05:36:23PM +0300, Gal Pressman wrote:
> 
>>> I can't say if it is needed or not, just wanted to understand why you need
>>> complexity in destroy_cq path.
>>
>> Well, as I said, I don't think the restrack protection is enough in this case as
>> it isn't aware of the concurrent eq flow.
>>
>> I guess I can put a synchronize_irq() on destroy_cq flow to get rid of the race.
> 
> That is a better choice that synchronize_rcu(), IIRC
> 
> synchronize_rcu should be avoided compared to all other forms of
> synchronization because it can take seconds per call to complete, and
> in a reasonable verbs app this means potentially minutes to close the
> verbs FD and destroy many CQs.

Got it, will use synchronize_irq, thanks.

  reply	other threads:[~2021-09-09 11:00 UTC|newest]

Thread overview: 27+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-08-11 15:11 [PATCH for-next 0/4] EFA CQ notifications Gal Pressman
2021-08-11 15:11 ` [PATCH for-next 1/4] RDMA/efa: Free IRQ vectors on error flow Gal Pressman
2021-08-20 18:34   ` Jason Gunthorpe
2021-08-11 15:11 ` [PATCH for-next 2/4] RDMA/efa: Remove unused cpu field from irq struct Gal Pressman
2021-08-11 15:11 ` [PATCH for-next 3/4] RDMA/efa: Rename vector field in efa_irq struct to irqn Gal Pressman
2021-08-11 15:11 ` [PATCH for-next 4/4] RDMA/efa: CQ notifications Gal Pressman
2021-08-20 18:27   ` Jason Gunthorpe
2021-09-01 11:50     ` Gal Pressman
2021-09-01 11:57       ` Jason Gunthorpe
2021-09-01 14:24         ` Gal Pressman
2021-09-01 15:36           ` Jason Gunthorpe
2021-09-02  7:03             ` Gal Pressman
2021-09-02 13:02               ` Jason Gunthorpe
2021-09-02 15:09                 ` Gal Pressman
2021-09-02 15:10                   ` Jason Gunthorpe
2021-09-02 15:17                     ` Gal Pressman
2021-09-02 15:41                       ` Jason Gunthorpe
2021-09-05  7:25                         ` Gal Pressman
2021-09-05  7:59                           ` Leon Romanovsky
2021-09-05 10:45                             ` Gal Pressman
2021-09-05 10:54                               ` Leon Romanovsky
2021-09-05 11:05                                 ` Gal Pressman
2021-09-05 13:14                                   ` Leon Romanovsky
2021-09-05 14:36                                     ` Gal Pressman
2021-09-07 11:31                                       ` Jason Gunthorpe
2021-09-09 11:00                                         ` Gal Pressman [this message]
2021-08-20 18:36 ` [PATCH for-next 0/4] EFA " Jason Gunthorpe

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=002ea7b9-42b1-84f0-a094-638215ee23b9@amazon.com \
    --to=galpress@amazon.com \
    --cc=dledford@redhat.com \
    --cc=firasj@amazon.com \
    --cc=jgg@nvidia.com \
    --cc=leon@kernel.org \
    --cc=linux-rdma@vger.kernel.org \
    --cc=matua@amazon.com \
    --cc=sleybo@amazon.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;
as well as URLs for NNTP newsgroup(s).