From c98b33cb630d3590113b9d17dd34c5b5be0cd135 Mon Sep 17 00:00:00 2001 From: SeongJae Park Date: Fri, 5 Nov 2021 13:47:20 -0700 Subject: [PATCH] mm/damon/schemes: skip already charged targets and regions If DAMOS has stopped applying action in the middle of a group of memory regions due to its size quota, it starts the work again from the beginning of the address space in the next charge window. If there is a huge memory region at the beginning of the address space and it fulfills the scheme's target data access pattern always, the action will applied to only the region. This mitigates the case by skipping memory regions that charged in current charge window at the beginning of next charge window. Link: https://lkml.kernel.org/r/20211019150731.16699-4-sj@kernel.org Signed-off-by: SeongJae Park Cc: Amit Shah Cc: Benjamin Herrenschmidt Cc: David Hildenbrand Cc: David Rientjes Cc: David Woodhouse Cc: Greg Thelen Cc: Jonathan Cameron Cc: Jonathan Corbet Cc: Leonard Foerster Cc: Marco Elver Cc: Markus Boehme Cc: Shakeel Butt Cc: Shuah Khan Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- include/linux/damon.h | 5 +++++ mm/damon/core.c | 37 +++++++++++++++++++++++++++++++++++++ 2 files changed, 42 insertions(+) diff --git a/include/linux/damon.h b/include/linux/damon.h index 3a1ce9d9921c8..585d985768fd1 100644 --- a/include/linux/damon.h +++ b/include/linux/damon.h @@ -107,6 +107,8 @@ struct damos_quota { /* private: For charging the quota */ unsigned long charged_sz; unsigned long charged_from; + struct damon_target *charge_target_from; + unsigned long charge_addr_from; }; /** @@ -307,6 +309,9 @@ struct damon_ctx { #define damon_prev_region(r) \ (container_of(r->list.prev, struct damon_region, list)) +#define damon_last_region(t) \ + (list_last_entry(&t->regions_list, struct damon_region, list)) + #define damon_for_each_region(r, t) \ list_for_each_entry(r, &t->regions_list, list) diff --git a/mm/damon/core.c b/mm/damon/core.c index cce14a0d5c725..693b75bc34505 100644 --- a/mm/damon/core.c +++ b/mm/damon/core.c @@ -111,6 +111,8 @@ struct damos *damon_new_scheme( scheme->quota.reset_interval = quota->reset_interval; scheme->quota.charged_sz = 0; scheme->quota.charged_from = 0; + scheme->quota.charge_target_from = NULL; + scheme->quota.charge_addr_from = 0; return scheme; } @@ -553,6 +555,37 @@ static void damon_do_apply_schemes(struct damon_ctx *c, if (quota->sz && quota->charged_sz >= quota->sz) continue; + /* Skip previously charged regions */ + if (quota->charge_target_from) { + if (t != quota->charge_target_from) + continue; + if (r == damon_last_region(t)) { + quota->charge_target_from = NULL; + quota->charge_addr_from = 0; + continue; + } + if (quota->charge_addr_from && + r->ar.end <= quota->charge_addr_from) + continue; + + if (quota->charge_addr_from && r->ar.start < + quota->charge_addr_from) { + sz = ALIGN_DOWN(quota->charge_addr_from - + r->ar.start, DAMON_MIN_REGION); + if (!sz) { + if (r->ar.end - r->ar.start <= + DAMON_MIN_REGION) + continue; + sz = DAMON_MIN_REGION; + } + damon_split_region_at(c, t, r, sz); + r = damon_next_region(r); + sz = r->ar.end - r->ar.start; + } + quota->charge_target_from = NULL; + quota->charge_addr_from = 0; + } + /* Check the target regions condition */ if (sz < s->min_sz_region || s->max_sz_region < sz) continue; @@ -573,6 +606,10 @@ static void damon_do_apply_schemes(struct damon_ctx *c, } c->primitive.apply_scheme(c, t, r, s); quota->charged_sz += sz; + if (quota->sz && quota->charged_sz >= quota->sz) { + quota->charge_target_from = t; + quota->charge_addr_from = r->ar.end + 1; + } } if (s->action != DAMOS_STAT) r->age = 0; -- 2.39.5