From 8922e16cf6269e668123acb1ae1fdc62b7a3a4fc Mon Sep 17 00:00:00 2001 From: Tejun Heo Date: Thu, 20 Oct 2005 16:23:44 +0200 Subject: [PATCH] 01/05 Implement generic dispatch queue Implements generic dispatch queue which can replace all dispatch queues implemented by each iosched. This reduces code duplication, eases enforcing semantics over dispatch queue, and simplifies specific ioscheds. Signed-off-by: Tejun Heo Signed-off-by: Jens Axboe --- include/linux/blkdev.h | 17 +++++++++++------ 1 file changed, 11 insertions(+), 6 deletions(-) (limited to 'include/linux/blkdev.h') diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h index efdc9b5bc05c..2c7b9154927a 100644 --- a/include/linux/blkdev.h +++ b/include/linux/blkdev.h @@ -203,6 +203,7 @@ struct request { enum rq_flag_bits { __REQ_RW, /* not set, read. set, write */ __REQ_FAILFAST, /* no low level driver retries */ + __REQ_SORTED, /* elevator knows about this request */ __REQ_SOFTBARRIER, /* may not be passed by ioscheduler */ __REQ_HARDBARRIER, /* may not be passed by drive either */ __REQ_CMD, /* is a regular fs rw request */ @@ -235,6 +236,7 @@ enum rq_flag_bits { #define REQ_RW (1 << __REQ_RW) #define REQ_FAILFAST (1 << __REQ_FAILFAST) +#define REQ_SORTED (1 << __REQ_SORTED) #define REQ_SOFTBARRIER (1 << __REQ_SOFTBARRIER) #define REQ_HARDBARRIER (1 << __REQ_HARDBARRIER) #define REQ_CMD (1 << __REQ_CMD) @@ -332,6 +334,13 @@ struct request_queue prepare_flush_fn *prepare_flush_fn; end_flush_fn *end_flush_fn; + /* + * Dispatch queue sorting + */ + sector_t last_sector; + struct request *boundary_rq; + unsigned int max_back_kb; + /* * Auto-unplugging state */ @@ -454,6 +463,7 @@ enum { #define blk_pm_request(rq) \ ((rq)->flags & (REQ_PM_SUSPEND | REQ_PM_RESUME)) +#define blk_sorted_rq(rq) ((rq)->flags & REQ_SORTED) #define blk_barrier_rq(rq) ((rq)->flags & REQ_HARDBARRIER) #define blk_barrier_preflush(rq) ((rq)->flags & REQ_BAR_PREFLUSH) #define blk_barrier_postflush(rq) ((rq)->flags & REQ_BAR_POSTFLUSH) @@ -611,12 +621,7 @@ extern void end_request(struct request *req, int uptodate); static inline void blkdev_dequeue_request(struct request *req) { - BUG_ON(list_empty(&req->queuelist)); - - list_del_init(&req->queuelist); - - if (req->rl) - elv_remove_request(req->q, req); + elv_dequeue_request(req->q, req); } /* -- cgit v1.2.3 From 1b47f531e244e339b648dfff071c086f936e49e1 Mon Sep 17 00:00:00 2001 From: Jens Axboe Date: Thu, 20 Oct 2005 16:37:00 +0200 Subject: [PATCH] generic dispatch fixes - Split elv_dispatch_insert() into two functions - Rename rq_last_sector() to rq_end_sector() Signed-off-by: Jens Axboe --- include/linux/blkdev.h | 13 ++++++++++++- 1 file changed, 12 insertions(+), 1 deletion(-) (limited to 'include/linux/blkdev.h') diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h index 2c7b9154927a..a2e496f285a4 100644 --- a/include/linux/blkdev.h +++ b/include/linux/blkdev.h @@ -337,7 +337,7 @@ struct request_queue /* * Dispatch queue sorting */ - sector_t last_sector; + sector_t end_sector; struct request *boundary_rq; unsigned int max_back_kb; @@ -624,6 +624,17 @@ static inline void blkdev_dequeue_request(struct request *req) elv_dequeue_request(req->q, req); } +/* + * This should be in elevator.h, but that requires pulling in rq and q + */ +static inline void elv_dispatch_add_tail(struct request_queue *q, + struct request *rq) +{ + q->end_sector = rq_end_sector(rq); + q->boundary_rq = rq; + list_add_tail(&rq->queuelist, &q->queue_head); +} + /* * Access functions for manipulating queue properties */ -- cgit v1.2.3 From 06b86245c052963029bfd9020ca1f08ceb66f85a Mon Sep 17 00:00:00 2001 From: Tejun Heo Date: Thu, 20 Oct 2005 16:46:23 +0200 Subject: [PATCH] 03/05 move last_merge handlin into generic elevator code Currently, both generic elevator code and specific ioscheds participate in the management and usage of last_merge. This and the following patches move last_merge handling into generic elevator code. Signed-off-by: Tejun Heo Signed-off-by: Jens Axboe --- include/linux/blkdev.h | 3 +++ 1 file changed, 3 insertions(+) (limited to 'include/linux/blkdev.h') diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h index a2e496f285a4..bd55b1df8997 100644 --- a/include/linux/blkdev.h +++ b/include/linux/blkdev.h @@ -630,6 +630,9 @@ static inline void blkdev_dequeue_request(struct request *req) static inline void elv_dispatch_add_tail(struct request_queue *q, struct request *rq) { + if (q->last_merge == rq) + q->last_merge = NULL; + q->end_sector = rq_end_sector(rq); q->boundary_rq = rq; list_add_tail(&rq->queuelist, &q->queue_head); -- cgit v1.2.3 From cb19833dccb32f97cacbfff834b53523915f13f6 Mon Sep 17 00:00:00 2001 From: Tejun Heo Date: Mon, 24 Oct 2005 08:35:58 +0200 Subject: [BLOCK] kill generic max_back_kb handling This patch kills max_back_kb handling from elv_dispatch_sort() and kills max_back_kb field from struct request_queue. Signed-off-by: Tejun Heo Signed-off-by: Jens Axboe --- include/linux/blkdev.h | 1 - 1 file changed, 1 deletion(-) (limited to 'include/linux/blkdev.h') diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h index bd55b1df8997..159dbcd2eb59 100644 --- a/include/linux/blkdev.h +++ b/include/linux/blkdev.h @@ -339,7 +339,6 @@ struct request_queue */ sector_t end_sector; struct request *boundary_rq; - unsigned int max_back_kb; /* * Auto-unplugging state -- cgit v1.2.3 From cb98fc8bb9c141009e2bda99c0db39d387e142cf Mon Sep 17 00:00:00 2001 From: Tejun Heo Date: Fri, 28 Oct 2005 08:29:39 +0200 Subject: [BLOCK] Reimplement elevator switch This patch reimplements elevator switch. This patch assumes generic dispatch queue patchset is applied. * Each request is tagged with REQ_ELVPRIV flag if it has its elevator private data set. * Requests which doesn't have REQ_ELVPRIV flag set never enter iosched. They are always directly back inserted to dispatch queue. Of course, elevator_put_req_fn is called only for requests which have its REQ_ELVPRIV set. * Request queue maintains the current number of requests which have its elevator data set (elevator_set_req_fn called) in q->rq->elvpriv. * If a request queue has QUEUE_FLAG_BYPASS set, elevator private data is not allocated for new requests. To switch to another iosched, we set QUEUE_FLAG_BYPASS and wait until elvpriv goes to zero; then, we attach the new iosched and clears QUEUE_FLAG_BYPASS. New implementation is much simpler and main code paths are less cluttered, IMHO. Signed-off-by: Tejun Heo Signed-off-by: Jens Axboe --- include/linux/blkdev.h | 10 ++++------ 1 file changed, 4 insertions(+), 6 deletions(-) (limited to 'include/linux/blkdev.h') diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h index 159dbcd2eb59..6186d5e2110f 100644 --- a/include/linux/blkdev.h +++ b/include/linux/blkdev.h @@ -107,9 +107,9 @@ typedef void (rq_end_io_fn)(struct request *); struct request_list { int count[2]; int starved[2]; + int elvpriv; mempool_t *rq_pool; wait_queue_head_t wait[2]; - wait_queue_head_t drain; }; #define BLK_MAX_CDB 16 @@ -211,6 +211,7 @@ enum rq_flag_bits { __REQ_STARTED, /* drive already may have started this one */ __REQ_DONTPREP, /* don't call prep for this one */ __REQ_QUEUED, /* uses queueing */ + __REQ_ELVPRIV, /* elevator private data attached */ /* * for ATA/ATAPI devices */ @@ -244,6 +245,7 @@ enum rq_flag_bits { #define REQ_STARTED (1 << __REQ_STARTED) #define REQ_DONTPREP (1 << __REQ_DONTPREP) #define REQ_QUEUED (1 << __REQ_QUEUED) +#define REQ_ELVPRIV (1 << __REQ_ELVPRIV) #define REQ_PC (1 << __REQ_PC) #define REQ_BLOCK_PC (1 << __REQ_BLOCK_PC) #define REQ_SENSE (1 << __REQ_SENSE) @@ -413,8 +415,6 @@ struct request_queue unsigned int sg_reserved_size; int node; - struct list_head drain_list; - /* * reserved for flush operations */ @@ -442,7 +442,7 @@ enum { #define QUEUE_FLAG_DEAD 5 /* queue being torn down */ #define QUEUE_FLAG_REENTER 6 /* Re-entrancy avoidance */ #define QUEUE_FLAG_PLUGGED 7 /* queue is plugged */ -#define QUEUE_FLAG_DRAIN 8 /* draining queue for sched switch */ +#define QUEUE_FLAG_BYPASS 8 /* don't use elevator, just do FIFO */ #define QUEUE_FLAG_FLUSH 9 /* doing barrier flush sequence */ #define blk_queue_plugged(q) test_bit(QUEUE_FLAG_PLUGGED, &(q)->queue_flags) @@ -668,8 +668,6 @@ extern void blk_dump_rq_flags(struct request *, char *); extern void generic_unplug_device(request_queue_t *); extern void __generic_unplug_device(request_queue_t *); extern long nr_blockdev_pages(void); -extern void blk_wait_queue_drained(request_queue_t *, int); -extern void blk_finish_queue_drain(request_queue_t *); int blk_get_queue(request_queue_t *); request_queue_t *blk_alloc_queue(int gfp_mask); -- cgit v1.2.3 From 64521d1a3ba7cc7fe4ab5640da83d88144f05340 Mon Sep 17 00:00:00 2001 From: Jens Axboe Date: Fri, 28 Oct 2005 08:30:39 +0200 Subject: [BLOCK] elevator switch fixes/cleanup - 100msec sleep is a little excessive, lots of requests can complete in that timeframe. Use 10msec instead. - Rename QUEUE_FLAG_BYPASS to QUEUE_FLAG_ELVSWITCH to indicate what is going on. Signed-off-by: Jens Axboe --- include/linux/blkdev.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'include/linux/blkdev.h') diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h index 6186d5e2110f..7d9d14d6d8f9 100644 --- a/include/linux/blkdev.h +++ b/include/linux/blkdev.h @@ -442,7 +442,7 @@ enum { #define QUEUE_FLAG_DEAD 5 /* queue being torn down */ #define QUEUE_FLAG_REENTER 6 /* Re-entrancy avoidance */ #define QUEUE_FLAG_PLUGGED 7 /* queue is plugged */ -#define QUEUE_FLAG_BYPASS 8 /* don't use elevator, just do FIFO */ +#define QUEUE_FLAG_ELVSWITCH 8 /* don't use elevator, just do FIFO */ #define QUEUE_FLAG_FLUSH 9 /* doing barrier flush sequence */ #define blk_queue_plugged(q) test_bit(QUEUE_FLAG_PLUGGED, &(q)->queue_flags) -- cgit v1.2.3 From 8267e268e0914ac9371d07f711fcf20cc572993c Mon Sep 17 00:00:00 2001 From: Al Viro Date: Fri, 21 Oct 2005 03:20:53 -0400 Subject: [PATCH] gfp_t: block layer core Signed-off-by: Al Viro Signed-off-by: Linus Torvalds --- include/linux/blkdev.h | 14 +++++++------- 1 file changed, 7 insertions(+), 7 deletions(-) (limited to 'include/linux/blkdev.h') diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h index efdc9b5bc05c..1afbdb2d752c 100644 --- a/include/linux/blkdev.h +++ b/include/linux/blkdev.h @@ -96,8 +96,8 @@ struct io_context { void put_io_context(struct io_context *ioc); void exit_io_context(void); -struct io_context *current_io_context(int gfp_flags); -struct io_context *get_io_context(int gfp_flags); +struct io_context *current_io_context(gfp_t gfp_flags); +struct io_context *get_io_context(gfp_t gfp_flags); void copy_io_context(struct io_context **pdst, struct io_context **psrc); void swap_io_context(struct io_context **ioc1, struct io_context **ioc2); @@ -354,7 +354,7 @@ struct request_queue * queue needs bounce pages for pages above this limit */ unsigned long bounce_pfn; - unsigned int bounce_gfp; + gfp_t bounce_gfp; /* * various queue flags, see QUEUE_* below @@ -550,7 +550,7 @@ extern void generic_make_request(struct bio *bio); extern void blk_put_request(struct request *); extern void blk_end_sync_rq(struct request *rq); extern void blk_attempt_remerge(request_queue_t *, struct request *); -extern struct request *blk_get_request(request_queue_t *, int, int); +extern struct request *blk_get_request(request_queue_t *, int, gfp_t); extern void blk_insert_request(request_queue_t *, struct request *, int, void *); extern void blk_requeue_request(request_queue_t *, struct request *); extern void blk_plug_device(request_queue_t *); @@ -565,7 +565,7 @@ extern void blk_run_queue(request_queue_t *); extern void blk_queue_activity_fn(request_queue_t *, activity_fn *, void *); extern int blk_rq_map_user(request_queue_t *, struct request *, void __user *, unsigned int); extern int blk_rq_unmap_user(struct bio *, unsigned int); -extern int blk_rq_map_kern(request_queue_t *, struct request *, void *, unsigned int, unsigned int); +extern int blk_rq_map_kern(request_queue_t *, struct request *, void *, unsigned int, gfp_t); extern int blk_rq_map_user_iov(request_queue_t *, struct request *, struct sg_iovec *, int); extern int blk_execute_rq(request_queue_t *, struct gendisk *, struct request *, int); @@ -654,8 +654,8 @@ extern void blk_wait_queue_drained(request_queue_t *, int); extern void blk_finish_queue_drain(request_queue_t *); int blk_get_queue(request_queue_t *); -request_queue_t *blk_alloc_queue(int gfp_mask); -request_queue_t *blk_alloc_queue_node(int,int); +request_queue_t *blk_alloc_queue(gfp_t); +request_queue_t *blk_alloc_queue_node(gfp_t, int); #define blk_put_queue(q) blk_cleanup_queue((q)) /* -- cgit v1.2.3