From: Jeff Garzik <jeff@garzik.org>
To: Jens Axboe <axboe@kernel.dk>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>,
linux-mm@kvack.org, linux-kernel@vger.kernel.org,
netdev@vger.kernel.org, Linus Torvalds <torvalds@osdl.org>,
Andrew Morton <akpm@osdl.org>, David Miller <davem@davemloft.net>,
Rik van Riel <riel@redhat.com>,
Daniel Phillips <phillips@google.com>,
Pavel Machek <pavel@ucw.cz>
Subject: Re: [PATCH 11/20] nbd: request_fn fixup
Date: Tue, 12 Sep 2006 20:21:06 -0400 [thread overview]
Message-ID: <45074EF2.3080407@garzik.org> (raw)
In-Reply-To: <20060912224710.GB23515@kernel.dk>
Jens Axboe wrote:
> Generally the block device rule is that once you are invoked due to an
> unplug (or whatever) event, it is the responsibility of the block device
> to run the queue until it's done. So if you bail out of queue handling
> for whatever reason (might be resource starvation in hard- or software),
> you must make sure to reenter queue handling since the device will not
> get replugged while it has requests pending. Unless you run into some
> software resource shortage, running of the queue is done
> deterministically when you know resources are available (ie an io
> completes). The device plugging itself is only ever done when you
> encounter a shortage outside of your control (memory shortage, for
> instance) _and_ you don't already have pending work where you can invoke
> queueing from again.
Or he could employ the blk_{start,stop}_queue() functions, if that model
is easier for the driver (and brain).
Jeff
--
To unsubscribe, send a message with 'unsubscribe linux-mm' in
the body to majordomo@kvack.org. For more info on Linux MM,
see: http://www.linux-mm.org/ .
Don't email: <a href=mailto:"dont@kvack.org"> email@kvack.org </a>
next prev parent reply other threads:[~2006-09-13 0:21 UTC|newest]
Thread overview: 37+ messages / expand[flat|nested] mbox.gz Atom feed top
2006-09-12 15:25 [PATCH 00/20] vm deadlock avoidance for NFS, NBD and iSCSI (take 7) Peter Zijlstra
2006-09-12 15:25 ` [PATCH 12/20] nbd: limit blk_queue Peter Zijlstra
2006-09-12 22:47 ` Jens Axboe
2006-09-12 15:25 ` [PATCH 03/20] mm: add support for non block device backed swap files Peter Zijlstra
2006-09-12 15:25 ` [PATCH 09/20] nfs: make swap on NFS robust Peter Zijlstra
2006-09-12 15:25 ` [PATCH 14/20] uml: enable scsi and add iscsi config Peter Zijlstra
2006-09-12 15:25 ` [PATCH 05/20] uml: rename arch/um remove_mapping() Peter Zijlstra
2006-09-12 15:25 ` [PATCH 15/20] iscsi: kernel side tcp connect Peter Zijlstra
2006-09-12 15:25 ` [PATCH 11/20] nbd: request_fn fixup Peter Zijlstra
2006-09-12 22:47 ` Jens Axboe
2006-09-13 0:21 ` Jeff Garzik [this message]
2006-09-13 6:14 ` Jens Axboe
2006-09-12 15:25 ` [PATCH 04/20] mm: methods for teaching filesystems about PG_swapcache pages Peter Zijlstra
2006-09-12 15:25 ` [PATCH 01/20] mm: serialize access to min_free_kbytes Peter Zijlstra
2006-09-12 15:25 ` [PATCH 13/20] nbd: use swapdev hook to make swap deadlock free Peter Zijlstra
2006-09-12 15:25 ` [PATCH 07/20] nfs: add a comment explaining the use of PG_private in the NFS client Peter Zijlstra
2006-09-12 15:25 ` [PATCH 17/20] scsi: propagate the swapdev hook into the scsi stack Peter Zijlstra
2006-09-12 15:25 ` [PATCH 06/20] nfs: teach the NFS client how to treat PG_swapcache pages Peter Zijlstra
2006-09-12 15:25 ` [PATCH 19/20] mm: a process flags to avoid blocking allocations Peter Zijlstra
2006-09-12 15:25 ` [PATCH 08/20] nfs: enable swap on NFS Peter Zijlstra
2006-09-12 15:25 ` [PATCH 16/20] iscsi: add session context to ep_connect Peter Zijlstra
2006-09-12 15:25 ` [PATCH 02/20] net: vm deadlock avoidance core Peter Zijlstra
2006-09-12 15:25 ` [PATCH 18/20] netlink: add SOCK_VMIO support to AF_NETLINK Peter Zijlstra
2006-09-12 15:25 ` [PATCH 20/20] iscsi: support for swapping over iSCSI Peter Zijlstra
2006-09-13 20:50 ` Mike Christie
2006-09-14 6:17 ` Peter Zijlstra
2006-09-14 19:22 ` Mike Christie
2006-09-14 20:35 ` Peter Zijlstra
2006-09-14 20:46 ` Peter Zijlstra
2006-09-14 21:09 ` Mike Christie
2006-09-14 21:28 ` Mike Christie
2006-09-14 21:00 ` Mike Christie
2006-09-14 21:03 ` Mike Christie
2006-09-14 21:18 ` Peter Zijlstra
2006-09-12 15:25 ` [PATCH 10/20] mm: block device swap notification Peter Zijlstra
2006-09-12 16:37 ` [PATCH 00/20] vm deadlock avoidance for NFS, NBD and iSCSI (take 7) Linus Torvalds
2006-09-12 23:58 ` Nate Diller
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=45074EF2.3080407@garzik.org \
--to=jeff@garzik.org \
--cc=a.p.zijlstra@chello.nl \
--cc=akpm@osdl.org \
--cc=axboe@kernel.dk \
--cc=davem@davemloft.net \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-mm@kvack.org \
--cc=netdev@vger.kernel.org \
--cc=pavel@ucw.cz \
--cc=phillips@google.com \
--cc=riel@redhat.com \
--cc=torvalds@osdl.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
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