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blk-throttle: use calculate_io/bytes_allowed() for throtl_trim_slice() 

There are no functional changes, just make the code cleaner.

Signed-off-by: Yu Kuai <yukuai3@huawei.com>
Acked-by: Tejun Heo <tj@kernel.org>
Link: https://lore.kernel.org/r/20230816012708.1193747-4-yukuai1@huaweicloud.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
This commit is contained in:
Yu Kuai 2023-08-16 09:27:07 +08:00 committed by Jens Axboe
parent bb8d5587bd
commit e8368b57c0
1 changed files with 56 additions and 60 deletions
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116
block/blk-throttle.c
View File

@ -697,66 +697,6 @@ static bool throtl_slice_used(struct throtl_grp *tg, bool rw)
return true;
}
/* Trim the used slices and adjust slice start accordingly */
static inline void throtl_trim_slice(struct throtl_grp *tg, bool rw)
{
unsigned long nr_slices, time_elapsed, io_trim;
u64 bytes_trim, tmp;
BUG_ON(time_before(tg->slice_end[rw], tg->slice_start[rw]));
/*
* If bps are unlimited (-1), then time slice don't get
* renewed. Don't try to trim the slice if slice is used. A new
* slice will start when appropriate.
*/
if (throtl_slice_used(tg, rw))
return;
/*
* A bio has been dispatched. Also adjust slice_end. It might happen
* that initially cgroup limit was very low resulting in high
* slice_end, but later limit was bumped up and bio was dispatched
* sooner, then we need to reduce slice_end. A high bogus slice_end
* is bad because it does not allow new slice to start.
*/
throtl_set_slice_end(tg, rw, jiffies + tg->td->throtl_slice);
time_elapsed = jiffies - tg->slice_start[rw];
nr_slices = time_elapsed / tg->td->throtl_slice;
if (!nr_slices)
return;
tmp = tg_bps_limit(tg, rw) * tg->td->throtl_slice * nr_slices;
do_div(tmp, HZ);
bytes_trim = tmp;
io_trim = (tg_iops_limit(tg, rw) * tg->td->throtl_slice * nr_slices) /
HZ;
if (!bytes_trim && !io_trim)
return;
if (tg->bytes_disp[rw] >= bytes_trim)
tg->bytes_disp[rw] -= bytes_trim;
else
tg->bytes_disp[rw] = 0;
if (tg->io_disp[rw] >= io_trim)
tg->io_disp[rw] -= io_trim;
else
tg->io_disp[rw] = 0;
tg->slice_start[rw] += nr_slices * tg->td->throtl_slice;
throtl_log(&tg->service_queue,
"[%c] trim slice nr=%lu bytes=%llu io=%lu start=%lu end=%lu jiffies=%lu",
rw == READ ? 'R' : 'W', nr_slices, bytes_trim, io_trim,
tg->slice_start[rw], tg->slice_end[rw], jiffies);
}
static unsigned int calculate_io_allowed(u32 iops_limit,
unsigned long jiffy_elapsed)
{
@ -786,6 +726,62 @@ static u64 calculate_bytes_allowed(u64 bps_limit, unsigned long jiffy_elapsed)
return mul_u64_u64_div_u64(bps_limit, (u64)jiffy_elapsed, (u64)HZ);
}
/* Trim the used slices and adjust slice start accordingly */
static inline void throtl_trim_slice(struct throtl_grp *tg, bool rw)
{
unsigned long time_elapsed, io_trim;
u64 bytes_trim;
BUG_ON(time_before(tg->slice_end[rw], tg->slice_start[rw]));
/*
* If bps are unlimited (-1), then time slice don't get
* renewed. Don't try to trim the slice if slice is used. A new
* slice will start when appropriate.
*/
if (throtl_slice_used(tg, rw))
return;
/*
* A bio has been dispatched. Also adjust slice_end. It might happen
* that initially cgroup limit was very low resulting in high
* slice_end, but later limit was bumped up and bio was dispatched
* sooner, then we need to reduce slice_end. A high bogus slice_end
* is bad because it does not allow new slice to start.
*/
throtl_set_slice_end(tg, rw, jiffies + tg->td->throtl_slice);
time_elapsed = rounddown(jiffies - tg->slice_start[rw],
tg->td->throtl_slice);
if (!time_elapsed)
return;
bytes_trim = calculate_bytes_allowed(tg_bps_limit(tg, rw),
time_elapsed);
io_trim = calculate_io_allowed(tg_iops_limit(tg, rw), time_elapsed);
if (!bytes_trim && !io_trim)
return;
if (tg->bytes_disp[rw] >= bytes_trim)
tg->bytes_disp[rw] -= bytes_trim;
else
tg->bytes_disp[rw] = 0;
if (tg->io_disp[rw] >= io_trim)
tg->io_disp[rw] -= io_trim;
else
tg->io_disp[rw] = 0;
tg->slice_start[rw] += time_elapsed;
throtl_log(&tg->service_queue,
"[%c] trim slice nr=%lu bytes=%llu io=%lu start=%lu end=%lu jiffies=%lu",
rw == READ ? 'R' : 'W', time_elapsed / tg->td->throtl_slice,
bytes_trim, io_trim, tg->slice_start[rw], tg->slice_end[rw],
jiffies);
}
static void __tg_update_carryover(struct throtl_grp *tg, bool rw)
{
unsigned long jiffy_elapsed = jiffies - tg->slice_start[rw];