On 12/2/18 8:46 AM, Christoph Hellwig wrote:
Having another indirect all in the fast path doesn't really help
in our post-spectre world. Also having too many queue type is just
going to create confusion, so I'd rather manage them centrally.
Note that the queue type naming and ordering changes a bit - the
first index now is the default queue for everything not explicitly
marked, the optional ones are read and poll queues.
Signed-off-by: Christoph Hellwig <hch@xxxxxx>
---
block/blk-mq-sysfs.c | 9 +++++-
block/blk-mq.h | 21 +++++++------
drivers/nvme/host/pci.c | 68 +++++++++++++++--------------------------
include/linux/blk-mq.h | 15 ++++-----
4 files changed, 51 insertions(+), 62 deletions(-)
diff --git a/block/blk-mq-sysfs.c b/block/blk-mq-sysfs.c
index 6efef1f679f0..9c2df137256a 100644
--- a/block/blk-mq-sysfs.c
+++ b/block/blk-mq-sysfs.c
@@ -173,9 +173,16 @@ static ssize_t blk_mq_hw_sysfs_cpus_show(struct blk_mq_hw_ctx *hctx, char *page)
return ret;
}
+static const char *const hctx_types[] = {
+ [HCTX_TYPE_DEFAULT] = "default",
+ [HCTX_TYPE_READ] = "read",
+ [HCTX_TYPE_POLL] = "poll",
+};
+
static ssize_t blk_mq_hw_sysfs_type_show(struct blk_mq_hw_ctx *hctx, char *page)
{
- return sprintf(page, "%u\n", hctx->type);
+ BUILD_BUG_ON(ARRAY_SIZE(hctx_types) != HCTX_MAX_TYPES);
+ return sprintf(page, "%s\n", hctx_types[hctx->type]);
}
static struct attribute *default_ctx_attrs[] = {
diff --git a/block/blk-mq.h b/block/blk-mq.h
index 7291e5379358..a664ea44ffd4 100644
--- a/block/blk-mq.h
+++ b/block/blk-mq.h
@@ -81,16 +81,14 @@ extern int blk_mq_hw_queue_to_node(struct blk_mq_queue_map *qmap, unsigned int);
/*
* blk_mq_map_queue_type() - map (hctx_type,cpu) to hardware queue
* @q: request queue
- * @hctx_type: the hctx type index
+ * @type: the hctx type index
* @cpu: CPU
*/
static inline struct blk_mq_hw_ctx *blk_mq_map_queue_type(struct request_queue *q,
- unsigned int hctx_type,
+ enum hctx_type type,
unsigned int cpu)
{
- struct blk_mq_tag_set *set = q->tag_set;
-
- return q->queue_hw_ctx[set->map[hctx_type].mq_map[cpu]];
+ return q->queue_hw_ctx[q->tag_set->map[type].mq_map[cpu]];
}
/*
@@ -103,12 +101,17 @@ static inline struct blk_mq_hw_ctx *blk_mq_map_queue(struct request_queue *q,
unsigned int flags,
unsigned int cpu)
{
- int hctx_type = 0;
+ enum hctx_type type = HCTX_TYPE_DEFAULT;
+
+ if (q->tag_set->nr_maps > HCTX_TYPE_POLL &&
+ ((flags & REQ_HIPRI) && test_bit(QUEUE_FLAG_POLL, &q->queue_flags)))
+ type = HCTX_TYPE_POLL;
- if (q->mq_ops->rq_flags_to_type)
- hctx_type = q->mq_ops->rq_flags_to_type(q, flags);
+ else if (q->tag_set->nr_maps > HCTX_TYPE_READ &&
+ ((flags & REQ_OP_MASK) == REQ_OP_READ))
+ type = HCTX_TYPE_READ;
Nit, there seems to be an extra newline that can be omitted here before
the else if statement (if I'm reading this correctly)...
Otherwise looks good,
Reviewed-by: Sagi Grimberg <sagi@xxxxxxxxxxx>
