01 May, 2019
1 commit
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Various block layer files do not have any licensing information at all.
Add SPDX tags for the default kernel GPLv2 license to those.Reviewed-by: Chaitanya Kulkarni
Signed-off-by: Christoph Hellwig
Signed-off-by: Jens Axboe
18 Dec, 2018
1 commit
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The blk-iolatency controller measures the time from rq_qos_throttle() to
rq_qos_done_bio() and attributes this time to the first bio that needs
to create the request. This means if a bio is plug-mergeable or
bio-mergeable, it gets to bypass the blk-iolatency controller.The recent series [1], to tag all bios w/ blkgs undermined how iolatency
was determining which bios it was charging and should process in
rq_qos_done_bio(). Because all bios are being tagged, this caused the
atomic_t for the struct rq_wait inflight count to underflow and result
in a stall.This patch adds a new flag BIO_TRACKED to let controllers know that a
bio is going through the rq_qos path. blk-iolatency now checks if this
flag is set to see if it should process the bio in rq_qos_done_bio().Overloading BLK_QUEUE_ENTERED works, but makes the flag rules confusing.
BIO_THROTTLED was another candidate, but the flag is set for all bios
that have gone through blk-throttle code. Overloading a flag comes with
the burden of making sure that when either implementation changes, a
change in setting rules for one doesn't cause a bug in the other. So
here, we unfortunately opt for adding a new flag.[1] https://lore.kernel.org/lkml/20181205171039.73066-1-dennis@kernel.org/
Fixes: 5cdf2e3fea5e ("blkcg: associate blkg when associating a device")
Signed-off-by: Dennis Zhou
Cc: Josef Bacik
Signed-off-by: Jens Axboe
17 Dec, 2018
1 commit
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blk-mq-debugfs has been proved as very helpful for debug some
tough issues, such as IO hang.We have seen blk-wbt related IO hang several times, even inside
Red Hat BZ, there is such report not sovled yet, so this patch
adds support debugfs on rq_qos.Cc: Bart Van Assche
Cc: Omar Sandoval
Cc: Christoph Hellwig
Cc: Josef Bacik
Signed-off-by: Ming Lei
Signed-off-by: Jens Axboe
08 Dec, 2018
1 commit
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Originally when I split out the common code from blk-wbt into rq_qos I
left the wbt_wait() where it was and simply copied and modified it
slightly to work for io-latency. However they are both basically the
same thing, and as time has gone on wbt_wait() has ended up much smarter
and kinder than it was when I copied it into io-latency, which means
io-latency has lost out on these improvements.Since they are the same thing essentially except for a few minor things,
create rq_qos_wait() that replicates what wbt_wait() currently does with
callbacks that can be passed in for the snowflakes to do their own thing
as appropriate.Signed-off-by: Josef Bacik
Signed-off-by: Jens Axboe
16 Nov, 2018
2 commits
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Put the short code in the fast path, where we don't have any
functions attached to the queue. This minimizes the impact on
the hot path in the core code.Cc: Josef Bacik
Reviewed-by: Christoph Hellwig
Signed-off-by: Jens Axboe -
Unused now that the legacy request path is gone.
Reviewed-by: Hannes Reinecke
Signed-off-by: Christoph Hellwig
Signed-off-by: Jens Axboe
23 Jul, 2018
1 commit
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With the change to use UINT_MAX I broke the depth check as any value of
inflight (ie 0) would be less than (int)UINT_MAX. Fix this by changing
everything to unsigned int to match the depth.Signed-off-by: Josef Bacik
Signed-off-by: Jens Axboe
09 Jul, 2018
3 commits
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wbt cares only about request completion time, but controllers may need
information that is on the bio itself, so add a done_bio callback for
rq-qos so things like blk-iolatency can use it to have the bio when it
completes.Signed-off-by: Josef Bacik
Signed-off-by: Jens Axboe -
We don't really need to save this stuff in the core block code, we can
just pass the bio back into the helpers later on to derive the same
flags and update the rq->wbt_flags appropriately.Signed-off-by: Josef Bacik
Signed-off-by: Jens Axboe -
blkcg-qos is going to do essentially what wbt does, only on a cgroup
basis. Break out the common code that will be shared between blkcg-qos
and wbt into blk-rq-qos.* so they can both utilize the same
infrastructure.Signed-off-by: Josef Bacik
Signed-off-by: Jens Axboe
