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authorSeongJae Park <sj@kernel.org>2021-11-05 13:47:23 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2021-11-06 13:30:45 -0700
commit1cd2430300594a230dba9178ac9e286d868d9da2 (patch)
tree1896f6ebfc67d13b3733ba66910f68dd78dd2f9a /mm/damon
parent50585192bc2ef9309d32dabdbb5e735679f4f128 (diff)
downloadlinux-1cd2430300594a230dba9178ac9e286d868d9da2.tar.bz2
mm/damon/schemes: implement time quota
The size quota feature of DAMOS is useful for IO resource-critical systems, but not so intuitive for CPU time-critical systems. Systems using zram or zswap-like swap device would be examples. To provide another intuitive ways for such systems, this implements time-based quota for DAMON-based Operation Schemes. If the quota is set, DAMOS tries to use only up to the user-defined quota of CPU time within a given time window. Link: https://lkml.kernel.org/r/20211019150731.16699-5-sj@kernel.org Signed-off-by: SeongJae Park <sj@kernel.org> Cc: Amit Shah <amit@kernel.org> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: David Hildenbrand <david@redhat.com> Cc: David Rientjes <rientjes@google.com> Cc: David Woodhouse <dwmw@amazon.com> Cc: Greg Thelen <gthelen@google.com> Cc: Jonathan Cameron <Jonathan.Cameron@huawei.com> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Leonard Foerster <foersleo@amazon.de> Cc: Marco Elver <elver@google.com> Cc: Markus Boehme <markubo@amazon.de> Cc: Shakeel Butt <shakeelb@google.com> Cc: Shuah Khan <shuah@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'mm/damon')
-rw-r--r--mm/damon/core.c45
1 files changed, 40 insertions, 5 deletions
diff --git a/mm/damon/core.c b/mm/damon/core.c
index 693b75bc3450..d1da4bef96ed 100644
--- a/mm/damon/core.c
+++ b/mm/damon/core.c
@@ -107,8 +107,12 @@ struct damos *damon_new_scheme(
scheme->stat_sz = 0;
INIT_LIST_HEAD(&scheme->list);
+ scheme->quota.ms = quota->ms;
scheme->quota.sz = quota->sz;
scheme->quota.reset_interval = quota->reset_interval;
+ scheme->quota.total_charged_sz = 0;
+ scheme->quota.total_charged_ns = 0;
+ scheme->quota.esz = 0;
scheme->quota.charged_sz = 0;
scheme->quota.charged_from = 0;
scheme->quota.charge_target_from = NULL;
@@ -550,9 +554,10 @@ static void damon_do_apply_schemes(struct damon_ctx *c,
damon_for_each_scheme(s, c) {
struct damos_quota *quota = &s->quota;
unsigned long sz = r->ar.end - r->ar.start;
+ struct timespec64 begin, end;
/* Check the quota */
- if (quota->sz && quota->charged_sz >= quota->sz)
+ if (quota->esz && quota->charged_sz >= quota->esz)
continue;
/* Skip previously charged regions */
@@ -597,16 +602,21 @@ static void damon_do_apply_schemes(struct damon_ctx *c,
/* Apply the scheme */
if (c->primitive.apply_scheme) {
- if (quota->sz && quota->charged_sz + sz > quota->sz) {
- sz = ALIGN_DOWN(quota->sz - quota->charged_sz,
+ if (quota->esz &&
+ quota->charged_sz + sz > quota->esz) {
+ sz = ALIGN_DOWN(quota->esz - quota->charged_sz,
DAMON_MIN_REGION);
if (!sz)
goto update_stat;
damon_split_region_at(c, t, r, sz);
}
+ ktime_get_coarse_ts64(&begin);
c->primitive.apply_scheme(c, t, r, s);
+ ktime_get_coarse_ts64(&end);
+ quota->total_charged_ns += timespec64_to_ns(&end) -
+ timespec64_to_ns(&begin);
quota->charged_sz += sz;
- if (quota->sz && quota->charged_sz >= quota->sz) {
+ if (quota->esz && quota->charged_sz >= quota->esz) {
quota->charge_target_from = t;
quota->charge_addr_from = r->ar.end + 1;
}
@@ -620,6 +630,29 @@ update_stat:
}
}
+/* Shouldn't be called if quota->ms and quota->sz are zero */
+static void damos_set_effective_quota(struct damos_quota *quota)
+{
+ unsigned long throughput;
+ unsigned long esz;
+
+ if (!quota->ms) {
+ quota->esz = quota->sz;
+ return;
+ }
+
+ if (quota->total_charged_ns)
+ throughput = quota->total_charged_sz * 1000000 /
+ quota->total_charged_ns;
+ else
+ throughput = PAGE_SIZE * 1024;
+ esz = throughput * quota->ms;
+
+ if (quota->sz && quota->sz < esz)
+ esz = quota->sz;
+ quota->esz = esz;
+}
+
static void kdamond_apply_schemes(struct damon_ctx *c)
{
struct damon_target *t;
@@ -629,15 +662,17 @@ static void kdamond_apply_schemes(struct damon_ctx *c)
damon_for_each_scheme(s, c) {
struct damos_quota *quota = &s->quota;
- if (!quota->sz)
+ if (!quota->ms && !quota->sz)
continue;
/* New charge window starts */
if (time_after_eq(jiffies, quota->charged_from +
msecs_to_jiffies(
quota->reset_interval))) {
+ quota->total_charged_sz += quota->charged_sz;
quota->charged_from = jiffies;
quota->charged_sz = 0;
+ damos_set_effective_quota(quota);
}
}