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authorSeongJae Park <sj@kernel.org>2021-11-05 23:46:32 +0300
committerLinus Torvalds <torvalds@linux-foundation.org>2021-11-06 23:30:44 +0300
commit2f0b548c9f03a78f4ce6ab48986e3108028936a6 (patch)
tree43f04253ff4968d09ffa7ddfacf825e3e38c2480 /mm/damon/core.c
parentaf122dd8f3c0099349bc98ff69f0d90efd8b149f (diff)
downloadlinux-2f0b548c9f03a78f4ce6ab48986e3108028936a6.tar.xz
mm/damon/schemes: implement statistics feature
To tune the DAMON-based operation schemes, knowing how many and how large regions are affected by each of the schemes will be helful. Those stats could be used for not only the tuning, but also monitoring of the working set size and the number of regions, if the scheme does not change the program behavior too much. For the reason, this implements the statistics for the schemes. The total number and size of the regions that each scheme is applied are exported to users via '->stat_count' and '->stat_sz' of 'struct damos'. Admins can also check the number by reading 'schemes' debugfs file. The last two integers now represents the stats. To allow collecting the stats without changing the program behavior, this also adds new scheme action, 'DAMOS_STAT'. Note that 'DAMOS_STAT' is not only making no memory operation actions, but also does not reset the age of regions. Link: https://lkml.kernel.org/r/20211001125604.29660-6-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 Rienjes <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/core.c')
-rw-r--r--mm/damon/core.c7
1 files changed, 6 insertions, 1 deletions
diff --git a/mm/damon/core.c b/mm/damon/core.c
index 0ed97b21cbb6..2f6785737902 100644
--- a/mm/damon/core.c
+++ b/mm/damon/core.c
@@ -103,6 +103,8 @@ struct damos *damon_new_scheme(
scheme->min_age_region = min_age_region;
scheme->max_age_region = max_age_region;
scheme->action = action;
+ scheme->stat_count = 0;
+ scheme->stat_sz = 0;
INIT_LIST_HEAD(&scheme->list);
return scheme;
@@ -544,9 +546,12 @@ static void damon_do_apply_schemes(struct damon_ctx *c,
continue;
if (r->age < s->min_age_region || s->max_age_region < r->age)
continue;
+ s->stat_count++;
+ s->stat_sz += sz;
if (c->primitive.apply_scheme)
c->primitive.apply_scheme(c, t, r, s);
- r->age = 0;
+ if (s->action != DAMOS_STAT)
+ r->age = 0;
}
}