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authorKemeng Shi <shikemeng@huaweicloud.com>2023-01-16 12:51:48 +0300
committerJens Axboe <axboe@kernel.dk>2023-01-30 06:03:49 +0300
commit1c970450a7fd8be0298758c4e2c631e4a739292d (patch)
treef38eb1c1b6850b18ac13e0c30f40b532d2417dc2
parentbebeb9e582e8040944b12942ccc56f4ebacaa9f8 (diff)
downloadlinux-1c970450a7fd8be0298758c4e2c631e4a739292d.tar.xz
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.c2
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,