public inbox for linux-scsi@vger.kernel.org
 help / color / mirror / Atom feed
From: "Martin K. Petersen" <martin.petersen@oracle.com>
To: Lars Ellenberg <lars.ellenberg@linbit.com>
Cc: "Martin K. Petersen" <martin.petersen@oracle.com>,
	NeilBrown <neilb@suse.de>,
	linux-raid@vger.kernel.org,
	linux-scsi <linux-scsi@vger.kernel.org>,
	JBottomley@parallels.com, Jens Axboe <axboe@kernel.dk>,
	konrad.wilk@oracle.com, elder@linaro.org,
	Josh Durgin <josh.durgin@inktank.com>,
	Greg KH <gregkh@linuxfoundation.org>
Subject: Re: sd_setup_discard_cmnd: BUG: unable to handle kernel NULL pointer dereference at (null)
Date: Wed, 25 Jun 2014 21:44:11 -0400	[thread overview]
Message-ID: <yq17g44e978.fsf@sermon.lab.mkp.net> (raw)
In-Reply-To: <20140625101421.GE17123@soda.linbit> (Lars Ellenberg's message of "Wed, 25 Jun 2014 12:14:21 +0200")

>>>>> "Lars" == Lars Ellenberg <lars.ellenberg@linbit.com> writes:

Lars> Because the way we do some internal bookkeeping, we announce a max
Lars> discard of 4 MiB.  

Yikes!

Lars> Similar for the WRITE_SAME interface (which we do not properly
Lars> support on the DRBD protocol level yet -- backward compatibility
Lars> concerns -- but intend to support "soon").

Yeah, WRITE SAME can take a long time to complete too. However, we're
typically issuing them 32 megs at a time.

Lars> If we only have a synchronous interface, we will probably have to
Lars> either add some "async wrapper", or defer such submissions to
Lars> worker threads.  I'd prefer to have an async submit path.

OK, I'll chew on it.

-- 
Martin K. Petersen	Oracle Linux Engineering

      reply	other threads:[~2014-06-26  1:44 UTC|newest]

Thread overview: 12+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2014-06-19  7:02 sd_setup_discard_cmnd: BUG: unable to handle kernel NULL pointer dereference at (null) Stefan Priebe - Profihost AG
2014-06-20  3:08 ` Martin K. Petersen
2014-06-20 15:53   ` Lars Ellenberg
2014-06-20 16:49     ` Martin K. Petersen
2014-06-20 18:29       ` Lars Ellenberg
2014-06-21 17:48         ` Stefan Priebe
2014-06-23 13:38           ` Lars Ellenberg
2014-06-23 19:37         ` Martin K. Petersen
2014-06-24 11:53           ` Lars Ellenberg
2014-06-24 23:11             ` Martin K. Petersen
2014-06-25 10:14               ` Lars Ellenberg
2014-06-26  1:44                 ` Martin K. Petersen [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=yq17g44e978.fsf@sermon.lab.mkp.net \
    --to=martin.petersen@oracle.com \
    --cc=JBottomley@parallels.com \
    --cc=axboe@kernel.dk \
    --cc=elder@linaro.org \
    --cc=gregkh@linuxfoundation.org \
    --cc=josh.durgin@inktank.com \
    --cc=konrad.wilk@oracle.com \
    --cc=lars.ellenberg@linbit.com \
    --cc=linux-raid@vger.kernel.org \
    --cc=linux-scsi@vger.kernel.org \
    --cc=neilb@suse.de \
    /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