On 05/11/2015 03:50 PM, Christoph Hellwig wrote: > On Mon, May 11, 2015 at 11:59:16AM +0200, Hannes Reinecke wrote: >> This is just an intermediate step, before the entire thing moves off >> to a workqueue and becomes asynchronous again. >> It's not meant to be as a standalone patch; I've just split it off >> for easier review. > > It actually made the review a bit harder. Also I don't really undertand > what the benfit of running a synchronous STPG in a workqueue is over > running it asynchronously. > Because STPG might fail, at which point we need to re-run RTPG to figure out the current status. But that might clash with a scheduled RTPG from another task. _And_ issuing RTPG while STPG is active is pointless, too, as the information is pretty much guaranteed to be incorrect. Hence the use of a workqueue to serialize RTPG and STPG against each other. Cheers, Hannes -- Dr. Hannes Reinecke zSeries & Storage hare@xxxxxxx +49 911 74053 688 SUSE LINUX GmbH, Maxfeldstr. 5, 90409 Nürnberg GF: F. Imendörffer, J. Smithard, J. Guild, D. Upmanyu, G. Norton HRB 21284 (AG Nürnberg) -- dm-devel mailing list dm-devel@xxxxxxxxxx https://www.redhat.com/mailman/listinfo/dm-devel
