On Wed, May 13, 2020 at 05:27:53AM -0700, Christoph Hellwig wrote: > On Wed, May 13, 2020 at 05:54:37PM +0800, Ming Lei wrote: > > .commit_rqs() is supposed to handle partial dispatch when driver may not > > see .last of flag passed to .queue_rq(). > > > > We have added .commit_rqs() in case of partial dispatch and all consumers > > of bd->last have implemented .commit_rqs() callback, so it is perfect to > > pass real .last flag of the request list to .queue_rq() instead of faking > > it by trying to allocate driver tag for next request in the batching list. > > The current case still seems like a nice optimization to avoid an extra > indirect function call. So if you want to get rid of it I think it at > least needs a better rationale. You mean marking .last by trying to allocate for next request can replace .commit_rqs()? No, it can't because .commit_rqs() can be called no matter .last is set or not, both two are independent. Removing it can avoid to pre-allocate one extra driver tag, and improve driver tag's utilization. Thanks, Ming
