> Why not just use the bio write hint? We already disallow merging of dissimilar write hints, so req->bio->bi_write_hint is known to be identical with the rest of the bio's in that chain. Yes, that is better. Thanks for suggesting it. -----Original Message----- From: Jens Axboe [mailto:axboe@xxxxxxxxx] Sent: Wednesday, April 17, 2019 11:28 PM To: Kanchan Joshi <joshi.k@xxxxxxxxxxx>; linux-kernel@xxxxxxxxxxxxxxx; linux-block@xxxxxxxxxxxxxxx; linux-nvme@xxxxxxxxxxxxxxxxxxx; linux-fsdevel@xxxxxxxxxxxxxxx; linux-ext4@xxxxxxxxxxxxxxx Cc: prakash.v@xxxxxxxxxxx Subject: Re: [PATCH v4 4/7] block: introduce write-hint to stream-id conversion On 4/17/19 11:50 AM, Kanchan Joshi wrote: > This patch moves write-hint-to-stream-id conversion in block-layer. > Earlier this was done by driver (nvme). Current conversion is of the > form "streamid = write-hint - 1", for both user and kernel streams. > Conversion takes stream limit (maintained in request queue) into > account. Write-hints beyond the exposed limit turn to 0. > A new field 'streamid' has been added in request. While 'write-hint' > field continues to exist. It keeps original value passed from upper > layer, and used during merging checks. Why not just use the bio write hint? We already disallow merging of dissimilar write hints, so req->bio->bi_write_hint is known to be identical with the rest of the bio's in that chain. -- Jens Axboe
