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author | Linus Torvalds <torvalds@linux-foundation.org> | 2013-11-14 07:08:14 +0400 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2013-11-14 07:08:14 +0400 |
commit | 0910c0bdf7c291a41bc21e40a97389c9d4c1960d (patch) | |
tree | 177c4cb22ece78b18f64f548ae82b9a15edbb99c /block/blk-mq.h | |
parent | 2821fe6b00a1e902fd399bb4b7e40bc3041f4d44 (diff) | |
parent | e37459b8e2c7db6735e39e019e448b76e5e77647 (diff) | |
download | linux-0910c0bdf7c291a41bc21e40a97389c9d4c1960d.tar.xz |
Merge branch 'for-3.13/core' of git://git.kernel.dk/linux-block
Pull block IO core updates from Jens Axboe:
"This is the pull request for the core changes in the block layer for
3.13. It contains:
- The new blk-mq request interface.
This is a new and more scalable queueing model that marries the
best part of the request based interface we currently have (which
is fully featured, but scales poorly) and the bio based "interface"
which the new drivers for high IOPS devices end up using because
it's much faster than the request based one.
The bio interface has no block layer support, since it taps into
the stack much earlier. This means that drivers end up having to
implement a lot of functionality on their own, like tagging,
timeout handling, requeue, etc. The blk-mq interface provides all
these. Some drivers even provide a switch to select bio or rq and
has code to handle both, since things like merging only works in
the rq model and hence is faster for some workloads. This is a
huge mess. Conversion of these drivers nets us a substantial code
reduction. Initial results on converting SCSI to this model even
shows an 8x improvement on single queue devices. So while the
model was intended to work on the newer multiqueue devices, it has
substantial improvements for "classic" hardware as well. This code
has gone through extensive testing and development, it's now ready
to go. A pull request is coming to convert virtio-blk to this
model will be will be coming as well, with more drivers scheduled
for 3.14 conversion.
- Two blktrace fixes from Jan and Chen Gang.
- A plug merge fix from Alireza Haghdoost.
- Conversion of __get_cpu_var() from Christoph Lameter.
- Fix for sector_div() with 64-bit divider from Geert Uytterhoeven.
- A fix for a race between request completion and the timeout
handling from Jeff Moyer. This is what caused the merge conflict
with blk-mq/core, in case you are looking at that.
- A dm stacking fix from Mike Snitzer.
- A code consolidation fix and duplicated code removal from Kent
Overstreet.
- A handful of block bug fixes from Mikulas Patocka, fixing a loop
crash and memory corruption on blk cg.
- Elevator switch bug fix from Tomoki Sekiyama.
A heads-up that I had to rebase this branch. Initially the immutable
bio_vecs had been queued up for inclusion, but a week later, it became
clear that it wasn't fully cooked yet. So the decision was made to
pull this out and postpone it until 3.14. It was a straight forward
rebase, just pruning out the immutable series and the later fixes of
problems with it. The rest of the patches applied directly and no
further changes were made"
* 'for-3.13/core' of git://git.kernel.dk/linux-block: (31 commits)
block: replace IS_ERR and PTR_ERR with PTR_ERR_OR_ZERO
block: replace IS_ERR and PTR_ERR with PTR_ERR_OR_ZERO
block: Do not call sector_div() with a 64-bit divisor
kernel: trace: blktrace: remove redundent memcpy() in compat_blk_trace_setup()
block: Consolidate duplicated bio_trim() implementations
block: Use rw_copy_check_uvector()
block: Enable sysfs nomerge control for I/O requests in the plug list
block: properly stack underlying max_segment_size to DM device
elevator: acquire q->sysfs_lock in elevator_change()
elevator: Fix a race in elevator switching and md device initialization
block: Replace __get_cpu_var uses
bdi: test bdi_init failure
block: fix a probe argument to blk_register_region
loop: fix crash if blk_alloc_queue fails
blk-core: Fix memory corruption if blkcg_init_queue fails
block: fix race between request completion and timeout handling
blktrace: Send BLK_TN_PROCESS events to all running traces
blk-mq: don't disallow request merges for req->special being set
blk-mq: mq plug list breakage
blk-mq: fix for flush deadlock
...
Diffstat (limited to 'block/blk-mq.h')
-rw-r--r-- | block/blk-mq.h | 52 |
1 files changed, 52 insertions, 0 deletions
diff --git a/block/blk-mq.h b/block/blk-mq.h new file mode 100644 index 000000000000..52bf1f96a2c2 --- /dev/null +++ b/block/blk-mq.h @@ -0,0 +1,52 @@ +#ifndef INT_BLK_MQ_H +#define INT_BLK_MQ_H + +struct blk_mq_ctx { + struct { + spinlock_t lock; + struct list_head rq_list; + } ____cacheline_aligned_in_smp; + + unsigned int cpu; + unsigned int index_hw; + unsigned int ipi_redirect; + + /* incremented at dispatch time */ + unsigned long rq_dispatched[2]; + unsigned long rq_merged; + + /* incremented at completion time */ + unsigned long ____cacheline_aligned_in_smp rq_completed[2]; + + struct request_queue *queue; + struct kobject kobj; +}; + +void __blk_mq_end_io(struct request *rq, int error); +void blk_mq_complete_request(struct request *rq, int error); +void blk_mq_run_request(struct request *rq, bool run_queue, bool async); +void blk_mq_run_hw_queue(struct blk_mq_hw_ctx *hctx, bool async); +void blk_mq_init_flush(struct request_queue *q); + +/* + * CPU hotplug helpers + */ +struct blk_mq_cpu_notifier; +void blk_mq_init_cpu_notifier(struct blk_mq_cpu_notifier *notifier, + void (*fn)(void *, unsigned long, unsigned int), + void *data); +void blk_mq_register_cpu_notifier(struct blk_mq_cpu_notifier *notifier); +void blk_mq_unregister_cpu_notifier(struct blk_mq_cpu_notifier *notifier); +void blk_mq_cpu_init(void); +DECLARE_PER_CPU(struct llist_head, ipi_lists); + +/* + * CPU -> queue mappings + */ +struct blk_mq_reg; +extern unsigned int *blk_mq_make_queue_map(struct blk_mq_reg *reg); +extern int blk_mq_update_queue_map(unsigned int *map, unsigned int nr_queues); + +void blk_mq_add_timer(struct request *rq); + +#endif |