Hello, On 08/23/2010 04:08 PM, Christoph Hellwig wrote: > On Mon, Aug 23, 2010 at 04:01:15PM +0200, Jens Axboe wrote: >> 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. > > What about adding a sysfs attribue to every request_queue that allows > disabling the cache flushing feature? Compared to the barrier option > this controls the feature at the right level and makes it available > to everyone instead of beeing duplicated. After a while we can then > simply ignore the barrier/nobarrier options. Yeah, that sounds reasonable. blk_queue_flush() can be called anytime without locking anyway, so it should be really easy to implement too. Thanks. -- tejun -- dm-devel mailing list dm-devel@xxxxxxxxxx https://www.redhat.com/mailman/listinfo/dm-devel
