> This changes the current behavior, doesn't it? Previously devices with less than 5 hints got streams completely disabled, now they will have streams enabled but ids beyond supported max will be mapped to 0. I'm not against this but I guess it should be spelled out explicitely in the changelog. Yes, that is a change in current behavior. Will add that in next version, thanks. -----Original Message----- From: Jan Kara [mailto:jack@xxxxxxx] Sent: Thursday, April 18, 2019 7:22 PM To: Kanchan Joshi <joshi.k@xxxxxxxxxxx> Cc: linux-kernel@xxxxxxxxxxxxxxx; linux-block@xxxxxxxxxxxxxxx; linux-nvme@xxxxxxxxxxxxxxxxxxx; linux-fsdevel@xxxxxxxxxxxxxxx; linux-ext4@xxxxxxxxxxxxxxx; prakash.v@xxxxxxxxxxx Subject: Re: [PATCH v4 5/7] nvme: register stream info with block layer On Wed 17-04-19 23:20:04, Kanchan Joshi wrote: > Make nvme driver register number of streams with block layer. Block > layer will use that for write-hint to stream-id conversion. > Registration is done for each namespace. Since NVMe spec allow all > available streams (within subsystem) to be used by all namespaces, no > attempt has been made to add reservation at namespace level. > > Signed-off-by: Kanchan Joshi <joshi.k@xxxxxxxxxxx> > --- > drivers/nvme/host/core.c | 23 ++++++----------------- > 1 file changed, 6 insertions(+), 17 deletions(-) > > diff --git a/drivers/nvme/host/core.c b/drivers/nvme/host/core.c index > 2c43e12..81b86fa 100644 > --- a/drivers/nvme/host/core.c > +++ b/drivers/nvme/host/core.c > @@ -464,10 +464,6 @@ static int nvme_toggle_streams(struct nvme_ctrl *ctrl, bool enable) > return nvme_submit_sync_cmd(ctrl->admin_q, &c, NULL, 0); } > > -static int nvme_disable_streams(struct nvme_ctrl *ctrl) -{ > - return nvme_toggle_streams(ctrl, false); > -} > > static int nvme_enable_streams(struct nvme_ctrl *ctrl) { @@ -510,14 > +506,7 @@ static int nvme_configure_directives(struct nvme_ctrl *ctrl) > return ret; > > ctrl->nssa = le16_to_cpu(s.nssa); > - if (ctrl->nssa < BLK_MAX_WRITE_HINTS - 1) { > - dev_info(ctrl->device, "too few streams (%u) available\n", > - ctrl->nssa); > - nvme_disable_streams(ctrl); > - return 0; > - } > - > - ctrl->nr_streams = min_t(unsigned, ctrl->nssa, BLK_MAX_WRITE_HINTS - 1); > + ctrl->nr_streams = ctrl->nssa; > dev_info(ctrl->device, "Using %u streams\n", ctrl->nr_streams); > return 0; > } This changes the current behavior, doesn't it? Previously devices with less than 5 hints got streams completely disabled, now they will have streams enabled but ids beyond supported max will be mapped to 0. I'm not against this but I guess it should be spelled out explicitely in the changelog. Honza -- Jan Kara <jack@xxxxxxxx> SUSE Labs, CR
