Re: [dm-devel] [PATCH V10 18/19] block: kill QUEUE_FLAG_NO_SG_MERGE

2018-11-21 Thread Omar Sandoval
On Fri, Nov 16, 2018 at 02:59:22PM +0100, Christoph Hellwig wrote: > On Thu, Nov 15, 2018 at 06:18:11PM -0800, Omar Sandoval wrote: > > This commit message wasn't very clear. Is it the case that > > QUEUE_FLAG_NO_SG_MERGE is no longer set by any drivers? > > I think he wants to say that not doing

Re: [dm-devel] [PATCH V10 18/19] block: kill QUEUE_FLAG_NO_SG_MERGE

2018-11-19 Thread Ming Lei
On Fri, Nov 16, 2018 at 02:58:03PM +0100, Christoph Hellwig wrote: > On Thu, Nov 15, 2018 at 04:53:05PM +0800, Ming Lei wrote: > > Since bdced438acd83ad83a6c ("block: setup bi_phys_segments after > > splitting"), > > physical segment number is mainly figured out in blk_queue_split() for > > fast

Re: [dm-devel] [PATCH V10 18/19] block: kill QUEUE_FLAG_NO_SG_MERGE

2018-11-19 Thread Ming Lei
On Thu, Nov 15, 2018 at 06:18:11PM -0800, Omar Sandoval wrote: > On Thu, Nov 15, 2018 at 04:53:05PM +0800, Ming Lei wrote: > > Since bdced438acd83ad83a6c ("block: setup bi_phys_segments after > > splitting"), > > physical segment number is mainly figured out in blk_queue_split() for > > fast

Re: [dm-devel] [PATCH V10 18/19] block: kill QUEUE_FLAG_NO_SG_MERGE

2018-11-16 Thread Christoph Hellwig
On Thu, Nov 15, 2018 at 06:18:11PM -0800, Omar Sandoval wrote: > This commit message wasn't very clear. Is it the case that > QUEUE_FLAG_NO_SG_MERGE is no longer set by any drivers? I think he wants to say that not doing S/G merging is rather pointless with the current setup of the I/O path, as

Re: [dm-devel] [PATCH V10 18/19] block: kill QUEUE_FLAG_NO_SG_MERGE

2018-11-16 Thread Christoph Hellwig
On Thu, Nov 15, 2018 at 04:53:05PM +0800, Ming Lei wrote: > Since bdced438acd83ad83a6c ("block: setup bi_phys_segments after splitting"), > physical segment number is mainly figured out in blk_queue_split() for > fast path, and the flag of BIO_SEG_VALID is set there too. > > Now only

Re: [dm-devel] [PATCH V10 18/19] block: kill QUEUE_FLAG_NO_SG_MERGE

2018-11-16 Thread Omar Sandoval
On Thu, Nov 15, 2018 at 04:53:05PM +0800, Ming Lei wrote: > Since bdced438acd83ad83a6c ("block: setup bi_phys_segments after splitting"), > physical segment number is mainly figured out in blk_queue_split() for > fast path, and the flag of BIO_SEG_VALID is set there too. > > Now only

[dm-devel] [PATCH V10 18/19] block: kill QUEUE_FLAG_NO_SG_MERGE

2018-11-15 Thread Ming Lei
Since bdced438acd83ad83a6c ("block: setup bi_phys_segments after splitting"), physical segment number is mainly figured out in blk_queue_split() for fast path, and the flag of BIO_SEG_VALID is set there too. Now only blk_recount_segments() and blk_recalc_rq_segments() use this flag. Basically