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From: Jeff Garzik <jeff@garzik.org>
To: Jens Axboe <jens.axboe@oracle.com>
Cc: linux-kernel@vger.kernel.org, benh@kernel.crashing.org,
	htejun@gmail.com, bzolnier@gmail.com, alan@lxorguk.ukuu.org.uk,
	akpm@linux-foundation.org
Subject: Re: [PATCH 4/7] libata: use lazy workqueues for the pio task
Date: Mon, 24 Aug 2009 12:51:12 -0400	[thread overview]
Message-ID: <4A92C500.4030109@garzik.org> (raw)
In-Reply-To: <20090824164214.GO12579@kernel.dk>

On 08/24/2009 12:42 PM, Jens Axboe wrote:
> On Mon, Aug 24 2009, Jeff Garzik wrote:
>> No objections to the code, operationally...
>>
>> But it is disappointing that the "1 thread on UP" problem is not solved
>> while changing this libata area.  Is there no way to specify a minimum
>> lazy-thread count?
>>
>> A key problem continues to be tying to the number of CPUs, which is
>> quite inappropriate for libata.
>
> We'll solve that next, the first problem is reducing the per-cpu
> threads. Lots of places use per-cpu workqueues because that is what is
> available, not necessarily because it's an appropriate choice. Like the
> ata_wq above, it's not even a good fit.

Agreed + sounds great.

Thanks -- both for hacking libata for this, and more generally, for 
attacking the too-many-kthreads problem!  :)  It's just sad how many 
unused workqueue threads hang about, on every modern Linux box.

	Jeff




  reply	other threads:[~2009-08-24 16:51 UTC|newest]

Thread overview: 14+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2009-08-24  7:56 [PATCH 0/7] Lazy workqueues v2 Jens Axboe
2009-08-24  7:56 ` [PATCH 1/7] workqueue: replace singlethread/freezable/rt parameters and variables with flags Jens Axboe
2009-08-24  7:56 ` [PATCH 2/7] workqueue: add support for lazy workqueues Jens Axboe
2009-08-24  7:56 ` [PATCH 3/7] crypto: use " Jens Axboe
2009-08-24  7:56 ` [PATCH 4/7] libata: use lazy workqueues for the pio task Jens Axboe
2009-08-24 16:32   ` Jeff Garzik
2009-08-24 16:42     ` Jens Axboe
2009-08-24 16:51       ` Jeff Garzik [this message]
2009-08-24 18:16         ` Jens Axboe
2009-08-24 16:45     ` John Stoffel
2009-08-24 16:52       ` Jeff Garzik
2009-08-24  7:56 ` [PATCH 5/7] aio: use lazy workqueues Jens Axboe
2009-08-24  7:56 ` [PATCH 6/7] sunrpc: " Jens Axboe
2009-08-24  7:56 ` [PATCH 7/7] bio: convert integrity to " Jens Axboe

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