From: Jeff Garzik <jeff@garzik.org>
To: John Stoffel <john@stoffel.org>
Cc: Jens Axboe <jens.axboe@oracle.com>,
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 12:52:47 -0400 [thread overview]
Message-ID: <4A92C55F.6080506@garzik.org> (raw)
In-Reply-To: <19090.50074.62901.633104@stoffel.org>
On 08/24/2009 12:45 PM, John Stoffel wrote:
>>>>>> "Jeff" == Jeff Garzik<jeff@garzik.org> writes:
> Jeff> No objections to the code, operationally...
>
> Jeff> But it is disappointing that the "1 thread on UP" problem is not
> Jeff> solved while changing this libata area. Is there no way to
> Jeff> specify a minimum lazy-thread count?
>
> Jeff> A key problem continues to be tying to the number of CPUs, which
> Jeff> is quite inappropriate for libata.
>
> So should the minimum number be the NumATADisks on the system? Actual
> or potential? I've got a system with dual CPUs and two IDE disk, two
> SATA disks and two SCSI disks, plus two SCSI Tape drives. All on
> seperate controllers... how would that work?
Technically speaking, the maximum is the number of PIO-polling devices.
Theoretically this can change with hotplugging, but that is _very_ rare
-- mainly PATA+media bay situations, or bridged SATA with an ancient
PATA device.
Jeff
next prev parent reply other threads:[~2009-08-24 16:52 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
2009-08-24 18:16 ` Jens Axboe
2009-08-24 16:45 ` John Stoffel
2009-08-24 16:52 ` Jeff Garzik [this message]
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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