Re: [PATCHSET block#for-2.6.36-post] block: replace barrier with sequenced flush

Christoph Hellwig wrote:

On Mon, Aug 23, 2010 at 04:01:15PM +0200, Jens Axboe wrote:

quoted

The problem purely exists on arrays that report write back cache enabled
AND don't implement SYNC_CACHE as a noop. Do any of them exist, or are
they purely urban legend?

I haven't seen it.  I don't care particularly about this case, but once
it a while people want to disable flushing for testing or because they
really don't care.

aacraid for one falls into this category.
SYNC_CACHE is no-oped in the driver. Otherwise you get a _HUGE_
performance loss.

Cheers,

Hannes
-- 
Dr. Hannes Reinecke		      zSeries & Storage
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