On 02/29/2016 12:13 AM, Christoph Hellwig wrote: > I was still hoping we'd get your slicing patches in ASAP at least. > But there are couple more topics here, so I think it would > still be useful in that case. > Actually I have been pondering an alternative approach. In most cases submit_bio() / submit_bh() is called in a loop, submitting several bios in one go. These bios typically refer to a larger piece of memory, so merging should be trivial here. However, both submit_bh() and submit_bio() will never convey this information, so they will be placed on the queue as individual bios. If we manage to link the generated bios together we can trivially implement merging, even for the mq case. One idea here is to add plugging around the callers, or to allow for linked bios to be submitted. I see if I can make some tests here. Cheers, Hannes -- Dr. Hannes Reinecke zSeries & Storage hare@xxxxxxx +49 911 74053 688 SUSE LINUX Products GmbH, Maxfeldstr. 5, 90409 Nürnberg GF: J. Hawn, J. Guild, F. Imendörffer, HRB 16746 (AG Nürnberg) -- To unsubscribe from this list: send the line "unsubscribe linux-block" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
