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| author | Kemeng Shi <shikemeng@huaweicloud.com> | 2023-01-16 17:51:48 +0800 |
|---|---|---|
| committer | Jens Axboe <axboe@kernel.dk> | 2023-01-29 20:03:49 -0700 |
| commit | 1c970450a7fd8be0298758c4e2c631e4a739292d (patch) | |
| tree | f38eb1c1b6850b18ac13e0c30f40b532d2417dc2 | |
| parent | bebeb9e582e8040944b12942ccc56f4ebacaa9f8 (diff) | |
| download | linux-riscv-1c970450a7fd8be0298758c4e2c631e4a739292d.tar.gz linux-riscv-1c970450a7fd8be0298758c4e2c631e4a739292d.tar.bz2 linux-riscv-1c970450a7fd8be0298758c4e2c631e4a739292d.zip | |
block, bfq: initialize bfqq->decrease_time_jif correctly
Inject limit is updated or reset when time_is_before_eq_jiffies(
decrease_time_jif + several msecs) or think-time state changes.
decrease_time_jif is initialized to 0 and will be set to current jiffies
when inject limit is updated or reset. If the jiffies is slightly greater
than LONG_MAX, time_is_after_eq_jiffies(0) will keep for a long time, so as
time_is_after_eq_jiffies(decrease_time_jif + several msecs). If the
think-time state never chages, then the injection will not work as expected
for long time.
To be more specific:
Function bfq_update_inject_limit maybe triggered when jiffies pasts
decrease_time_jif + msecs_to_jiffies(10) in bfq_add_request by setting
bfqd->wait_dispatch to true.
Function bfq_reset_inject_limit are called in two conditions:
1. jiffies pasts bfqq->decrease_time_jif + msecs_to_jiffies(1000) in
function bfq_add_request.
2. jiffies pasts bfqq->decrease_time_jif + msecs_to_jiffies(100) or
bfq think-time state change from short to long.
Fix this by initializing bfqq->decrease_time_jif to current jiffies
to trigger service injection soon when service injection conditions
are met.
Signed-off-by: Kemeng Shi <shikemeng@huaweicloud.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Link: https://lore.kernel.org/r/20230116095153.3810101-4-shikemeng@huaweicloud.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
| -rw-r--r-- | block/bfq-iosched.c | 2 |
1 files changed, 2 insertions, 0 deletions
diff --git a/block/bfq-iosched.c b/block/bfq-iosched.c index f038b4d16d86..698c5918ad10 100644 --- a/block/bfq-iosched.c +++ b/block/bfq-iosched.c @@ -5654,6 +5654,8 @@ static void bfq_init_bfqq(struct bfq_data *bfqd, struct bfq_queue *bfqq, /* first request is almost certainly seeky */ bfqq->seek_history = 1; + + bfqq->decrease_time_jif = jiffies; } static struct bfq_queue **bfq_async_queue_prio(struct bfq_data *bfqd, |