From: Miquel van Smoorenburg <miquels@cistron.nl>
To: Andrew Morton <akpm@osdl.org>
Cc: linux-kernel@vger.kernel.org
Subject: Re: per-cpu blk_plug_list
Date: Wed, 3 Mar 2004 10:45:10 +0100 [thread overview]
Message-ID: <20040303094509.GA8779@cistron.nl> (raw)
In-Reply-To: <20040302211309.500f43fb.akpm@osdl.org>
According to Andrew Morton:
> And also having looked at Miquel's (currently slightly defective)
> implementation of the any_congested() API for devicemapper:
>
> ftp://ftp.kernel.org/pub/linux/kernel/people/akpm/patches/2.6/2.6.4-rc1/2.6.4-rc1-mm1/broken-out/queue-congestion-dm-implementation.patch
>
> I am thinking that an appropriate way of solving the blk_run_queues() lock
> contention problem is to nuke the global plug list altogther and make the
> unplug function a method in struct backing_device_info.
>
> This is conceptually the appropriate place to put it - it is almost always
> the case that when we run blk_run_queues() it is on behalf of an
> address_space, and the few remaining case can be simply deleted -
> mm/mempool.c is the last one I think.
>
> The implementation of backing_dev_info.unplug() would have to run the
> unplug_fn of every queue which contributes to the top-level queue (the
> thing which the address_space is sitting on top of).
But then you need a pointer to the queue. In that case,
you might as well put the congested_fn pointer in the request_queue
too. Then you get something like
https://www.redhat.com/archives/linux-lvm/2004-February/msg00203.html
(though I'd replace "rw" with "bdi_bits" like in the current patch).
Mike.
next prev parent reply other threads:[~2004-03-03 9:45 UTC|newest]
Thread overview: 17+ messages / expand[flat|nested] mbox.gz Atom feed top
2004-03-03 4:20 per-cpu blk_plug_list Chen, Kenneth W
2004-03-03 4:20 ` Chen, Kenneth W
2004-03-03 5:13 ` Andrew Morton
2004-03-03 5:13 ` Andrew Morton
2004-03-03 9:45 ` Miquel van Smoorenburg [this message]
2004-03-03 9:54 ` Andrew Morton
2004-03-03 16:24 ` Miquel van Smoorenburg
2004-03-03 22:37 ` Miquel van Smoorenburg
-- strict thread matches above, loose matches on Subject: below --
2004-03-01 22:28 Chen, Kenneth W
2004-03-01 22:14 Chen, Kenneth W
2004-03-01 21:18 Chen, Kenneth W
2004-03-01 22:06 ` Jens Axboe
2004-03-01 22:17 ` Andrew Morton
2004-03-01 22:31 ` Andrew Morton
[not found] ` <B05667366EE6204181EABE9C1B1C0EB501F2AB4C@scsmsx401.sc.intel.com.suse.lists.linux.kernel>
2004-03-01 22:36 ` Andi Kleen
2004-03-03 3:44 ` Jesse Barnes
2004-03-03 3:55 ` Andrew Morton
[not found] <cistron.B05667366EE6204181EABE9C1B1C0EB50211E5C8@scsmsx401.sc.intel.com>
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