return true;
}
+static unsigned int calculate_io_allowed(u32 iops_limit,
+ unsigned long jiffy_elapsed)
+{
+ unsigned int io_allowed;
+ u64 tmp;
+
+ /*
+ * jiffy_elapsed should not be a big value as minimum iops can be
+ * 1 then at max jiffy elapsed should be equivalent of 1 second as we
+ * will allow dispatch after 1 second and after that slice should
+ * have been trimmed.
+ */
+
+ tmp = (u64)iops_limit * jiffy_elapsed;
+ do_div(tmp, HZ);
+
+ if (tmp > UINT_MAX)
+ io_allowed = UINT_MAX;
+ else
+ io_allowed = tmp;
+
+ return io_allowed;
+}
+
+static u64 calculate_bytes_allowed(u64 bps_limit, unsigned long jiffy_elapsed)
+{
+ /*
+ * Can result be wider than 64 bits?
+ * We check against 62, not 64, due to ilog2 truncation.
+ */
+ if (ilog2(bps_limit) + ilog2(jiffy_elapsed) - ilog2(HZ) > 62)
+ return U64_MAX;
+ 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 nr_slices, time_elapsed, io_trim;
- u64 bytes_trim, tmp;
+ unsigned long time_elapsed;
+ long long bytes_trim;
+ int io_trim;
BUG_ON(time_before(tg->slice_end[rw], tg->slice_start[rw]));
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)
+ time_elapsed = rounddown(jiffies - tg->slice_start[rw],
+ tg->td->throtl_slice);
+ if (!time_elapsed)
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)
+ bytes_trim = calculate_bytes_allowed(tg_bps_limit(tg, rw),
+ time_elapsed) +
+ tg->carryover_bytes[rw];
+ io_trim = calculate_io_allowed(tg_iops_limit(tg, rw), time_elapsed) +
+ tg->carryover_ios[rw];
+ if (bytes_trim <= 0 && io_trim <= 0)
return;
- if (tg->bytes_disp[rw] >= bytes_trim)
+ tg->carryover_bytes[rw] = 0;
+ if ((long long)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->carryover_ios[rw] = 0;
+ if ((int)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;
+ 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', 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)
-{
- unsigned int io_allowed;
- u64 tmp;
-
- /*
- * jiffy_elapsed should not be a big value as minimum iops can be
- * 1 then at max jiffy elapsed should be equivalent of 1 second as we
- * will allow dispatch after 1 second and after that slice should
- * have been trimmed.
- */
-
- tmp = (u64)iops_limit * jiffy_elapsed;
- do_div(tmp, HZ);
-
- if (tmp > UINT_MAX)
- io_allowed = UINT_MAX;
- else
- io_allowed = tmp;
-
- return io_allowed;
-}
-
-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);
+ "[%c] trim slice nr=%lu bytes=%lld io=%d 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)
__tg_update_carryover(tg, WRITE);
/* see comments in struct throtl_grp for meaning of these fields. */
- throtl_log(&tg->service_queue, "%s: %llu %llu %u %u\n", __func__,
+ throtl_log(&tg->service_queue, "%s: %lld %lld %d %d\n", __func__,
tg->carryover_bytes[READ], tg->carryover_bytes[WRITE],
tg->carryover_ios[READ], tg->carryover_ios[WRITE]);
}
u32 iops_limit)
{
bool rw = bio_data_dir(bio);
- unsigned int io_allowed;
+ int io_allowed;
unsigned long jiffy_elapsed, jiffy_wait, jiffy_elapsed_rnd;
if (iops_limit == UINT_MAX) {
jiffy_elapsed_rnd = roundup(jiffy_elapsed + 1, tg->td->throtl_slice);
io_allowed = calculate_io_allowed(iops_limit, jiffy_elapsed_rnd) +
tg->carryover_ios[rw];
- if (tg->io_disp[rw] + 1 <= io_allowed) {
+ if (io_allowed > 0 && tg->io_disp[rw] + 1 <= io_allowed)
return 0;
- }
/* Calc approx time to dispatch */
jiffy_wait = jiffy_elapsed_rnd - jiffy_elapsed;
u64 bps_limit)
{
bool rw = bio_data_dir(bio);
- u64 bytes_allowed, extra_bytes;
+ long long bytes_allowed;
+ u64 extra_bytes;
unsigned long jiffy_elapsed, jiffy_wait, jiffy_elapsed_rnd;
unsigned int bio_size = throtl_bio_data_size(bio);
jiffy_elapsed_rnd = roundup(jiffy_elapsed_rnd, tg->td->throtl_slice);
bytes_allowed = calculate_bytes_allowed(bps_limit, jiffy_elapsed_rnd) +
tg->carryover_bytes[rw];
- if (tg->bytes_disp[rw] + bio_size <= bytes_allowed) {
+ if (bytes_allowed > 0 && tg->bytes_disp[rw] + bio_size <= bytes_allowed)
return 0;
- }
/* Calc approx time to dispatch */
extra_bytes = tg->bytes_disp[rw] + bio_size - bytes_allowed;
tg_bps_limit(tg, READ), tg_bps_limit(tg, WRITE),
tg_iops_limit(tg, READ), tg_iops_limit(tg, WRITE));
+ rcu_read_lock();
/*
* Update has_rules[] flags for the updated tg's subtree. A tg is
* considered to have rules if either the tg itself or any of its
this_tg->latency_target = max(this_tg->latency_target,
parent_tg->latency_target);
}
+ rcu_read_unlock();
/*
* We're already holding queue_lock and know @tg is valid. Let's
projects / platform / kernel / linux-rpi.git / blobdiff