linux-toradex.git/include/linux/blkdev.h, branch v4.13-rc4

block: remove the queue_bounce_pfn helper

2017-06-27T18:13:45+00:00

Only used inside the bounce code, and opencoding it makes it more obvious
what is going on.

Signed-off-by: Christoph Hellwig 
Signed-off-by: Jens Axboe

block: move bounce declarations to block/blk.h

2017-06-27T18:13:45+00:00

Signed-off-by: Christoph Hellwig 
Signed-off-by: Jens Axboe

blk-mq: expose write hints through debugfs

2017-06-27T18:05:31+00:00

Useful to verify that things are working the way they should.
Reading the file will return number of kb written with each
write hint. Writing the file will reset the statistics. No care
is taken to ensure that we don't race on updates.

Drivers will write to q->write_hints[] if they handle a given
write hint.

Reviewed-by: Andreas Dilger 
Reviewed-by: Martin K. Petersen 
Reviewed-by: Christoph Hellwig 
Signed-off-by: Jens Axboe

block: add support for write hints in a bio

2017-06-27T18:05:27+00:00

No functional changes in this patch, we just use up some holes
in the bio and request structures to define a write hint that
we psas down the stack.

Ensure that we don't merge requests that have different life time
hints assigned to them, and that we inherit the write hint when
cloning a bio.

Reviewed-by: Martin K. Petersen 
Reviewed-by: Christoph Hellwig 
Signed-off-by: Jens Axboe

Merge commit '8e8320c9315c' into for-4.13/block

2017-06-23T03:55:24+00:00

Pull in the fix for shared tags, as it conflicts with the pending
changes in for-4.13/block. We already pulled in v4.12-rc5 to solve
other conflicts or get fixes that went into 4.12, so not a lot
of changes in this merge.

Signed-off-by: Jens Axboe

blk-mq: fix performance regression with shared tags

2017-06-21T16:17:49+00:00

If we have shared tags enabled, then every IO completion will trigger
a full loop of every queue belonging to a tag set, and every hardware
queue for each of those queues, even if nothing needs to be done.
This causes a massive performance regression if you have a lot of
shared devices.

Instead of doing this huge full scan on every IO, add an atomic
counter to the main queue that tracks how many hardware queues have
been marked as needing a restart. With that, we can avoid looking for
restartable queues, if we don't have to.

Max reports that this restores performance. Before this patch, 4K
IOPS was limited to 22-23K IOPS. With the patch, we are running at
950-970K IOPS.

Fixes: 6d8c6c0f97ad ("blk-mq: Restart a single queue if tag sets are shared")
Reported-by: Max Gurtovoy 
Tested-by: Max Gurtovoy 
Reviewed-by: Bart Van Assche 
Tested-by: Bart Van Assche 
Signed-off-by: Jens Axboe

block: Add a comment above queue_lockdep_assert_held()

2017-06-21T01:27:14+00:00

Add a comment above the queue_lockdep_assert_held() macro that
explains the purpose of the q->queue_lock test.

Signed-off-by: Bart Van Assche 
Reviewed-by: Christoph Hellwig 
Cc: Hannes Reinecke 
Cc: Omar Sandoval 
Cc: Ming Lei 
Signed-off-by: Jens Axboe

block: Introduce request_queue.initialize_rq_fn()

2017-06-21T01:27:14+00:00

Several block drivers need to initialize the driver-private request
data after having called blk_get_request() and before .prep_rq_fn()
is called, e.g. when submitting a REQ_OP_SCSI_* request. Avoid that
that initialization code has to be repeated after every
blk_get_request() call by adding new callback functions to struct
request_queue and to struct blk_mq_ops.

Signed-off-by: Bart Van Assche 
Cc: Christoph Hellwig 
Cc: Hannes Reinecke 
Cc: Omar Sandoval 
Signed-off-by: Jens Axboe

block: Make request operation type argument declarations consistent

2017-06-21T01:27:14+00:00

Instead of declaring the second argument of blk_*_get_request()
as int and passing it to functions that expect an unsigned int,
declare that second argument as unsigned int. Also because of
consistency, rename that second argument from 'rw' into 'op'.
This patch does not change any functionality.

Signed-off-by: Bart Van Assche 
Reviewed-by: Christoph Hellwig 
Cc: Hannes Reinecke 
Cc: Omar Sandoval 
Cc: Ming Lei 
Signed-off-by: Jens Axboe

block: stop using bio_data() in blk_write_same_mergeable

2017-06-21T01:21:48+00:00

While the Write Same page currently always is in low-level it is just
as easy and safer to just compare the page and offset directly.

Signed-off-by: Christoph Hellwig 
Reviewed-by: Martin K. Petersen 
Signed-off-by: Jens Axboe