diff options
| author | Paolo Valente <paolo.valente@linaro.org> | 2021-01-25 20:02:43 +0100 |
|---|---|---|
| committer | Jens Axboe <axboe@kernel.dk> | 2021-01-25 14:18:29 -0700 |
| commit | eb2fd80f9d2c515a901599362e83bc3356fc5e97 (patch) | |
| tree | dffa32379b2d24d28f0ba317b69cb8fbbfe3282d /block/bfq-iosched.h | |
| parent | 3a905c37c3510ea6d7cfcdfd0f272ba731286560 (diff) | |
block, bfq: replace mechanism for evaluating I/O intensity
Some BFQ mechanisms make their decisions on a bfq_queue basing also on
whether the bfq_queue is I/O bound. In this respect, the current logic
for evaluating whether a bfq_queue is I/O bound is rather rough. This
commits replaces this logic with a more effective one.
The new logic measures the percentage of time during which a bfq_queue
is active, and marks the bfq_queue as I/O bound if the latter if this
percentage is above a fixed threshold.
Tested-by: Jan Kara <jack@suse.cz>
Signed-off-by: Paolo Valente <paolo.valente@linaro.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Diffstat (limited to 'block/bfq-iosched.h')
| -rw-r--r-- | block/bfq-iosched.h | 16 |
1 files changed, 8 insertions, 8 deletions
diff --git a/block/bfq-iosched.h b/block/bfq-iosched.h index 703895224562..c913b06016b3 100644 --- a/block/bfq-iosched.h +++ b/block/bfq-iosched.h @@ -291,6 +291,11 @@ struct bfq_queue { /* associated @bfq_ttime struct */ struct bfq_ttime ttime; + /* when bfqq started to do I/O within the last observation window */ + u64 io_start_time; + /* how long bfqq has remained empty during the last observ. window */ + u64 tot_idle_time; + /* bit vector: a 1 for each seeky requests in history */ u32 seek_history; @@ -407,6 +412,9 @@ struct bfq_io_cq { */ bool saved_IO_bound; + u64 saved_io_start_time; + u64 saved_tot_idle_time; + /* * Same purpose as the previous fields for the value of the * field keeping the queue's belonging to a large burst @@ -642,14 +650,6 @@ struct bfq_data { unsigned int bfq_timeout; /* - * Number of consecutive requests that must be issued within - * the idle time slice to set again idling to a queue which - * was marked as non-I/O-bound (see the definition of the - * IO_bound flag for further details). - */ - unsigned int bfq_requests_within_timer; - - /* * Force device idling whenever needed to provide accurate * service guarantees, without caring about throughput * issues. CAVEAT: this may even increase latencies, in case |