Re: [PATCH 05/10] blk-mq: export some helpers we need to the scheduling framework

[Jens Axboe]

On Fri, Jan 13 2017, Christoph Hellwig wrote:
> Do we really need to make any of the blk-mq scheduling modular?

I think so - I want to be able to turn it on and off. And since we
already have a framework for this (see reply in other patch), I don't
see a reason NOT to do this.

-- 
Jens Axboe

Re: [PATCH 05/10] blk-mq: export some helpers we need to the scheduling framework

[Christoph Hellwig]

Do we really need to make any of the blk-mq scheduling modular?

Re: [PATCH 05/10] blk-mq: export some helpers we need to the scheduling framework

[Bart Van Assche]

On Wed, 2017-01-11 at 14:39 -0700, Jens Axboe wrote:
> [ ... ]

Reviewed-by: Bart Van Assche 

Re: [PATCH 05/10] blk-mq: export some helpers we need to the scheduling framework

[Johannes Thumshirn]

On Wed, Jan 11, 2017 at 02:39:58PM -0700, Jens Axboe wrote:
> Signed-off-by: Jens Axboe 
> ---

Looks good,
Reviewed-by: Johannes Thumshirn 

-- 
Johannes Thumshirn  Storage
jthumsh...@suse.de+49 911 74053 689
SUSE LINUX GmbH, Maxfeldstr. 5, 90409 Nürnberg
GF: Felix Imendörffer, Jane Smithard, Graham Norton
HRB 21284 (AG Nürnberg)
Key fingerprint = EC38 9CAB C2C4 F25D 8600 D0D0 0393 969D 2D76 0850

[PATCH 05/10] blk-mq: export some helpers we need to the scheduling framework

[Jens Axboe]

Signed-off-by: Jens Axboe 
---
 block/blk-mq.c | 39 +--
 block/blk-mq.h | 25 +
 2 files changed, 46 insertions(+), 18 deletions(-)

diff --git a/block/blk-mq.c b/block/blk-mq.c
index f49f6325b332..9fc521755e22 100644
--- a/block/blk-mq.c
+++ b/block/blk-mq.c
@@ -167,8 +167,8 @@ bool blk_mq_can_queue(struct blk_mq_hw_ctx *hctx)
 }
 EXPORT_SYMBOL(blk_mq_can_queue);
 
-static void blk_mq_rq_ctx_init(struct request_queue *q, struct blk_mq_ctx *ctx,
-  struct request *rq, unsigned int op)
+void blk_mq_rq_ctx_init(struct request_queue *q, struct blk_mq_ctx *ctx,
+   struct request *rq, unsigned int op)
 {
INIT_LIST_HEAD(&rq->queuelist);
/* csd/requeue_work/fifo_time is initialized before use */
@@ -213,9 +213,10 @@ static void blk_mq_rq_ctx_init(struct request_queue *q, 
struct blk_mq_ctx *ctx,
 
ctx->rq_dispatched[op_is_sync(op)]++;
 }
+EXPORT_SYMBOL_GPL(blk_mq_rq_ctx_init);
 
-static struct request *
-__blk_mq_alloc_request(struct blk_mq_alloc_data *data, unsigned int op)
+struct request *__blk_mq_alloc_request(struct blk_mq_alloc_data *data,
+  unsigned int op)
 {
struct request *rq;
unsigned int tag;
@@ -236,6 +237,7 @@ __blk_mq_alloc_request(struct blk_mq_alloc_data *data, 
unsigned int op)
 
return NULL;
 }
+EXPORT_SYMBOL_GPL(__blk_mq_alloc_request);
 
 struct request *blk_mq_alloc_request(struct request_queue *q, int rw,
unsigned int flags)
@@ -319,8 +321,8 @@ struct request *blk_mq_alloc_request_hctx(struct 
request_queue *q, int rw,
 }
 EXPORT_SYMBOL_GPL(blk_mq_alloc_request_hctx);
 
-static void __blk_mq_free_request(struct blk_mq_hw_ctx *hctx,
- struct blk_mq_ctx *ctx, struct request *rq)
+void __blk_mq_free_request(struct blk_mq_hw_ctx *hctx, struct blk_mq_ctx *ctx,
+  struct request *rq)
 {
const int tag = rq->tag;
struct request_queue *q = rq->q;
@@ -802,7 +804,7 @@ static bool flush_busy_ctx(struct sbitmap *sb, unsigned int 
bitnr, void *data)
  * Process software queues that have been marked busy, splicing them
  * to the for-dispatch
  */
-static void flush_busy_ctxs(struct blk_mq_hw_ctx *hctx, struct list_head *list)
+void blk_mq_flush_busy_ctxs(struct blk_mq_hw_ctx *hctx, struct list_head *list)
 {
struct flush_busy_ctx_data data = {
.hctx = hctx,
@@ -811,6 +813,7 @@ static void flush_busy_ctxs(struct blk_mq_hw_ctx *hctx, 
struct list_head *list)
 
sbitmap_for_each_set(&hctx->ctx_map, flush_busy_ctx, &data);
 }
+EXPORT_SYMBOL_GPL(blk_mq_flush_busy_ctxs);
 
 static inline unsigned int queued_to_index(unsigned int queued)
 {
@@ -921,7 +924,7 @@ static void blk_mq_process_rq_list(struct blk_mq_hw_ctx 
*hctx)
/*
 * Touch any software queue that has pending entries.
 */
-   flush_busy_ctxs(hctx, &rq_list);
+   blk_mq_flush_busy_ctxs(hctx, &rq_list);
 
/*
 * If we have previous entries on our dispatch list, grab them
@@ -1135,8 +1138,8 @@ static inline void __blk_mq_insert_req_list(struct 
blk_mq_hw_ctx *hctx,
list_add_tail(&rq->queuelist, &ctx->rq_list);
 }
 
-static void __blk_mq_insert_request(struct blk_mq_hw_ctx *hctx,
-   struct request *rq, bool at_head)
+void __blk_mq_insert_request(struct blk_mq_hw_ctx *hctx, struct request *rq,
+bool at_head)
 {
struct blk_mq_ctx *ctx = rq->mq_ctx;
 
@@ -1550,8 +1553,8 @@ static blk_qc_t blk_sq_make_request(struct request_queue 
*q, struct bio *bio)
return cookie;
 }
 
-static void blk_mq_free_rq_map(struct blk_mq_tag_set *set,
-   struct blk_mq_tags *tags, unsigned int hctx_idx)
+void blk_mq_free_rq_map(struct blk_mq_tag_set *set, struct blk_mq_tags *tags,
+   unsigned int hctx_idx)
 {
struct page *page;
 
@@ -1588,8 +1591,8 @@ static size_t order_to_size(unsigned int order)
return (size_t)PAGE_SIZE << order;
 }
 
-static struct blk_mq_tags *blk_mq_init_rq_map(struct blk_mq_tag_set *set,
-   unsigned int hctx_idx)
+struct blk_mq_tags *blk_mq_init_rq_map(struct blk_mq_tag_set *set,
+  unsigned int hctx_idx)
 {
struct blk_mq_tags *tags;
unsigned int i, j, entries_per_page, max_order = 4;
@@ -2279,10 +2282,10 @@ static int blk_mq_queue_reinit_dead(unsigned int cpu)
  * Now CPU1 is just onlined and a request is inserted into ctx1->rq_list
  * and set bit0 in pending bitmap as ctx1->index_hw is still zero.
  *
- * And then while running hw queue, flush_busy_ctxs() finds bit0 is set in
- * pending bitmap and tries to retrieve requests in hctx->ctxs[0]->rq_list.
- * But htx->ctxs[0] is a pointer to ctx0, so the request in ctx1->rq_list
- * is ignored.
+ * And then while running hw queue, blk_mq_flush_busy_ctx