Linux-RDMA Archive on lore.kernel.org
 help / color / Atom feed
From: Eric Dumazet <edumazet@google.com>
To: Jason Gunthorpe <jgg@nvidia.com>
Cc: Doug Ledford <dledford@redhat.com>,
	linux-kernel <linux-kernel@vger.kernel.org>,
	Eric Dumazet <eric.dumazet@gmail.com>,
	linux-rdma <linux-rdma@vger.kernel.org>
Subject: Re: [PATCH net] RDMA/umem: add a schedule point in ib_umem_get()
Date: Fri, 31 Jul 2020 10:21:08 -0700
Message-ID: <CANn89i+SwhK8XKDqKKvL1svnBWKxv28iKzD2nEf2g0pOO0+0qQ@mail.gmail.com> (raw)
In-Reply-To: <20200731171714.GA513060@nvidia.com>

On Fri, Jul 31, 2020 at 10:17 AM Jason Gunthorpe <jgg@nvidia.com> wrote:
>
> On Wed, Jul 29, 2020 at 06:57:55PM -0700, Eric Dumazet wrote:
> > Mapping as little as 64GB can take more than 10 seconds,
> > triggering issues on kernels with CONFIG_PREEMPT_NONE=y.
> >
> > ib_umem_get() already splits the work in 2MB units on x86_64,
> > adding a cond_resched() in the long-lasting loop is enough
> > to solve the issue.
> >
> > Note that sg_alloc_table() can still use more than 100 ms,
> > which is also problematic. This might be addressed later
> > in ib_umem_add_sg_table(), adding new blocks in sgl
> > on demand.
>
> I have seen some patches in progress to do exactly this, the
> motivation is to reduce the memory consumption if a lot of pages are
> combined.

Nice ;)

>
> > Signed-off-by: Eric Dumazet <edumazet@google.com>
> > Cc: Doug Ledford <dledford@redhat.com>
> > Cc: Jason Gunthorpe <jgg@ziepe.ca>
> > Cc: linux-rdma@vger.kernel.org
> > ---
> >  drivers/infiniband/core/umem.c | 1 +
> >  1 file changed, 1 insertion(+)
>
> Why [PATCH net] ?

Sorry, I used a script that I normally use for net submissions, forgot
to remove this tag ;)

>
> Anyhow, applied to rdma for-next

Thanks !

>
> Thanks,
> Jason

      reply index

Thread overview: 3+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-07-30  1:57 Eric Dumazet
2020-07-31 17:17 ` Jason Gunthorpe
2020-07-31 17:21   ` Eric Dumazet [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=CANn89i+SwhK8XKDqKKvL1svnBWKxv28iKzD2nEf2g0pOO0+0qQ@mail.gmail.com \
    --to=edumazet@google.com \
    --cc=dledford@redhat.com \
    --cc=eric.dumazet@gmail.com \
    --cc=jgg@nvidia.com \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linux-rdma@vger.kernel.org \
    /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

Linux-RDMA Archive on lore.kernel.org

Archives are clonable:
	git clone --mirror https://lore.kernel.org/linux-rdma/0 linux-rdma/git/0.git

	# If you have public-inbox 1.1+ installed, you may
	# initialize and index your mirror using the following commands:
	public-inbox-init -V2 linux-rdma linux-rdma/ https://lore.kernel.org/linux-rdma \
		linux-rdma@vger.kernel.org
	public-inbox-index linux-rdma

Example config snippet for mirrors

Newsgroup available over NNTP:
	nntp://nntp.lore.kernel.org/org.kernel.vger.linux-rdma


AGPL code for this site: git clone https://public-inbox.org/public-inbox.git