On 30/11/2020 07:41, Kashyap Desai wrote:
diff --git a/drivers/scsi/scsi_lib.c b/drivers/scsi/scsi_lib.c index
72b12102f777..5a3c383a2bb3 100644
--- a/drivers/scsi/scsi_lib.c
+++ b/drivers/scsi/scsi_lib.c
@@ -1766,6 +1766,19 @@ static void scsi_mq_exit_request(struct
blk_mq_tag_set *set, struct request *rq,
cmd->sense_buffer);
}
+
+static int scsi_mq_poll(struct blk_mq_hw_ctx *hctx) {
+ struct request_queue *q = hctx->queue;
+ struct scsi_device *sdev = q->queuedata;
+ struct Scsi_Host *shost = sdev->host;
could we separately set hctx->driver_data = shost or similar for a quicker
lookup? I don't see hctx->driver_data set for SCSI currently.
Going through the scsi_device looks strange - I know that it is done in
scsi_commit_rqs.
John - I have included your comments. Below is add-on patch which handles
all your comment except one.
Below is just compiled (not tested patch). Please let me know if you like to
handle "scsi_init_hctx" in this patch or shall we do it as a separate patch
(out of this patch series.) ?
It might be better as a separate patch if you also change
scsi_commit_rqs() to use hctx->driver_data, which you are currently not
doing (or showing here).
--- a/drivers/scsi/scsi_lib.c
+++ b/drivers/scsi/scsi_lib.c
@@ -1769,9 +1769,7 @@ static void scsi_mq_exit_request(struct blk_mq_tag_set
*set, struct request *rq,
static int scsi_mq_poll(struct blk_mq_hw_ctx *hctx)
{
- struct request_queue *q = hctx->queue;
- struct scsi_device *sdev = q->queuedata;
- struct Scsi_Host *shost = sdev->host;
+ struct Scsi_Host *shost = hctx->driver_data;
if (shost->hostt->mq_poll)
return shost->hostt->mq_poll(shost, hctx->queue_num);
@@ -1779,6 +1777,14 @@ static int scsi_mq_poll(struct blk_mq_hw_ctx *hctx)
return 0;
}
+static int scsi_init_hctx(struct blk_mq_hw_ctx *hctx, void *data,
+ unsigned int hctx_idx)
+{
+ struct Scsi_Host *shost = data;
+ hctx->driver_data = shost;
+ return 0;
+}
+
static int scsi_map_queues(struct blk_mq_tag_set *set)
{
struct Scsi_Host *shost = container_of(set, struct Scsi_Host,
tag_set);
@@ -1846,6 +1852,7 @@ static const struct blk_mq_ops scsi_mq_ops_no_commit =
{
.cleanup_rq = scsi_cleanup_rq,
.busy = scsi_mq_lld_busy,
.map_queues = scsi_map_queues,
+ .init_hctx = scsi_init_hctx,
.poll = scsi_mq_poll,
};
@@ -1875,6 +1882,7 @@ static const struct blk_mq_ops scsi_mq_ops = {
.cleanup_rq = scsi_cleanup_rq,
.busy = scsi_mq_lld_busy,
.map_queues = scsi_map_queues,
+ .init_hctx = scsi_init_hctx,
.poll = scsi_mq_poll,
};
diff --git a/include/scsi/scsi_cmnd.h b/include/scsi/scsi_cmnd.h
index 5844374a85b1..cc30df96f5f7 100644
--- a/include/scsi/scsi_cmnd.h
+++ b/include/scsi/scsi_cmnd.h
@@ -9,8 +9,8 @@
#include <linux/types.h>
#include <linux/timer.h>
#include <linux/scatterlist.h>
-#include <scsi/scsi_host.h>
#include <scsi/scsi_device.h>
+#include <scsi/scsi_host.h>
#include <scsi/scsi_request.h>
struct Scsi_Host;
diff --git a/include/scsi/scsi_host.h b/include/scsi/scsi_host.h
index 905ee6b00c55..a0cda0f66b84 100644
--- a/include/scsi/scsi_host.h
+++ b/include/scsi/scsi_host.h
@@ -274,7 +274,7 @@ struct scsi_host_template {
* SCSI interface of blk_poll - poll for IO completions.
* Possible interface only if scsi LLD expose multiple h/w queues.
*
- * Return values: Number of completed entries found.
+ * Return value: Number of completed entries found.
*
* Status: OPTIONAL
*/
+
+ if (shost->hostt->mq_poll)
to avoid this check, could we reject if .mq_poll is not set and
HCTX_TYPE_POLL is?
Is this urgent or shall we improve later ? I am not able to figure out how
you want to manage this ? Can you explain little bit ?
I don't think that it will make much overhead difference, so ok to omit
for now if more trouble than it's worth to implement.
Thanks,
John
