linux.git/block/kyber-iosched.c, branch v5.9.12

blk-mq: remove the bio argument to ->prepare_request

2020-05-29T16:23:24+00:00

None of the I/O schedulers actually needs it.

Signed-off-by: Christoph Hellwig 
Reviewed-by: Ming Lei 
Reviewed-by: Hannes Reinecke 
Reviewed-by: Johannes Thumshirn 
Reviewed-by: Bart Van Assche 
Reviewed-by: Daniel Wagner 
Signed-off-by: Jens Axboe

blk-mq: remove blk_mq_put_ctx()

2019-07-03T03:03:27+00:00

No code that occurs between blk_mq_get_ctx() and blk_mq_put_ctx() depends
on preemption being disabled for its correctness. Since removing the CPU
preemption calls does not measurably affect performance, simplify the
blk-mq code by removing the blk_mq_put_ctx() function and also by not
disabling preemption in blk_mq_get_ctx().

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

block: remove the bi_phys_segments field in struct bio

2019-06-20T16:29:22+00:00

We only need the number of segments in the blk-mq submission path.
Remove the field from struct bio, and return it from a variant of
blk_queue_split instead of that it can passed as an argument to
those functions that need the value.

This also means we stop recounting segments except for cloning
and partial segments.

To keep the number of arguments in this how path down remove
pointless struct request_queue arguments from any of the functions
that had it and grew a nr_segs argument.

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

block: switch all files cleared marked as GPLv2 to SPDX tags

2019-04-30T22:11:57+00:00

All these files have some form of the usual GPLv2 boilerplate.  Switch
them to use SPDX tags instead.

Reviewed-by: Chaitanya Kulkarni 
Signed-off-by: Christoph Hellwig 
Signed-off-by: Jens Axboe

kyber: use sbitmap add_wait_queue/list_del wait helpers

2018-12-20T19:17:21+00:00

sbq_wake_ptr() checks sbq->ws_active to know if it needs to loop
the wait indexes or not. This requires the use of the sbitmap
waitqueue wrappers, but kyber doesn't use those for its domain
token waitqueue handling.

Convert kyber to use the helpers. This fixes a hang with waiting
for domain tokens.

Fixes: 5d2ee7122c73 ("sbitmap: optimize wakeup check")
Tested-by: Ming Lei 
Reported-by: Ming Lei 
Reviewed-by: Omar Sandoval 
Signed-off-by: Jens Axboe

blk-mq: allow software queue to map to multiple hardware queues

2018-11-07T20:44:59+00:00

The mapping used to be dependent on just the CPU location, but
now it's a tuple of (type, cpu) instead. This is a prep patch
for allowing a single software queue to map to multiple hardware
queues. No functional changes in this patch.

This changes the software queue count to an unsigned short
to save a bit of space. We can still support 64K-1 CPUs,
which should be enough. Add a check to catch a wrap.

Reviewed-by: Hannes Reinecke 
Reviewed-by: Keith Busch 
Signed-off-by: Jens Axboe

block: get rid of MQ scheduler ops union

2018-11-07T20:42:32+00:00

This is a remnant of when we had ops for both SQ and MQ
schedulers. Now it's just MQ, so get rid of the union.

Reviewed-by: Omar Sandoval 
Signed-off-by: Jens Axboe

block: remove dead elevator code

2018-11-07T20:42:32+00:00

This removes a bunch of core and elevator related code. On the core
front, we remove anything related to queue running, draining,
initialization, plugging, and congestions. We also kill anything
related to request allocation, merging, retrieval, and completion.

Remove any checking for single queue IO schedulers, as they no
longer exist. This means we can also delete a bunch of code related
to request issue, adding, completion, etc - and all the SQ related
ops and helpers.

Also kill the load_default_modules(), as all that did was provide
for a way to load the default single queue elevator.

Tested-by: Ming Lei 
Reviewed-by: Omar Sandoval 
Signed-off-by: Jens Axboe

kyber: fix integer overflow of latency targets on 32-bit

2018-09-28T16:49:39+00:00

NSEC_PER_SEC has type long, so 5 * NSEC_PER_SEC is calculated as a long.
However, 5 seconds is 5,000,000,000 nanoseconds, which overflows a
32-bit long. Make sure all of the targets are calculated as 64-bit
values.

Fixes: 6e25cb01ea20 ("kyber: implement improved heuristics")
Reported-by: Stephen Rothwell 
Signed-off-by: Omar Sandoval 
Signed-off-by: Jens Axboe

kyber: add tracepoints

2018-09-27T23:34:59+00:00

When debugging Kyber, it's really useful to know what latencies we've
been having, how the domain depths have been adjusted, and if we've
actually been throttling. Add three tracepoints, kyber_latency,
kyber_adjust, and kyber_throttled, to record that.

Signed-off-by: Omar Sandoval 
Signed-off-by: Jens Axboe