github-mirror/linux
1
0
Fork 0
mirror of https://github.com/torvalds/linux.git synced 2026-07-27 17:47:41 +02:00
Code Issues Actions Packages Projects Releases Wiki Activity Graph

mm/damon/core: introduce damon_region->probe_hits

Browse Source 
Add an array for the per-region per-probe positive samples count.  For
simple and efficient implementation, add a limit to the number of data
probes and set the array to support only the limited number of counters.

Link: https://lore.kernel.org/20260518234119.97569-6-sj@kernel.org
Signed-off-by: SeongJae Park <sj@kernel.org>
Cc: David Hildenbrand <david@kernel.org>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Liam R. Howlett <liam@infradead.org>
Cc: Lorenzo Stoakes <ljs@kernel.org>
Cc: "Masami Hiramatsu (Google)" <mhiramat@kernel.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: Shuah Khan <shuah@kernel.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Vlastimil Babka <vbabka@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
This commit is contained in:
SeongJae Park 2026-05-18 16:40:53 -07:00 committed by Andrew Morton
parent d0de4b29c7
commit 57c6332f25
2 changed files with 14 additions and 0 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

4
include/linux/damon.h
View File

@ -17,6 +17,8 @@
/* Minimal region size. Every damon_region is aligned by this. */
#define DAMON_MIN_REGION_SZ PAGE_SIZE
/* Maximum number of monitoring probes. */
#define DAMON_MAX_PROBES (4)
/* Max priority score for DAMON-based operation schemes */
#define DAMOS_MAX_SCORE (99)
@ -47,6 +49,7 @@ struct damon_size_range {
* @nr_accesses: Access frequency of this region.
* @nr_accesses_bp: @nr_accesses in basis point (0.01%) that updated for
* each sampling interval.
* @probe_hits: Number of probe-positive region samples.
* @list: List head for siblings.
* @age: Age of this region.
*
@ -75,6 +78,7 @@ struct damon_region {
unsigned long sampling_addr;
unsigned int nr_accesses;
unsigned int nr_accesses_bp;
unsigned char probe_hits[DAMON_MAX_PROBES];
struct list_head list;
unsigned int age;

10
mm/damon/core.c
View File

@ -229,6 +229,7 @@ static void damon_verify_new_region(unsigned long start, unsigned long end)
struct damon_region *damon_new_region(unsigned long start, unsigned long end)
{
struct damon_region *region;
int i;
damon_verify_new_region(start, end);
region = kmem_cache_alloc(damon_region_cache, GFP_KERNEL);
@ -239,6 +240,8 @@ struct damon_region *damon_new_region(unsigned long start, unsigned long end)
region->ar.end = end;
region->nr_accesses = 0;
region->nr_accesses_bp = 0;
for (i = 0; i < DAMON_MAX_PROBES; i++)
region->probe_hits[i] = 0;
INIT_LIST_HEAD(&region->list);
region->age = 0;
@ -2980,12 +2983,17 @@ static void damon_merge_two_regions(struct damon_target *t,
struct damon_region *l, struct damon_region *r)
{
unsigned long sz_l = damon_sz_region(l), sz_r = damon_sz_region(r);
int i;
l->nr_accesses = (l->nr_accesses * sz_l + r->nr_accesses * sz_r) /
(sz_l + sz_r);
l->nr_accesses_bp = l->nr_accesses * 10000;
l->age = (l->age * sz_l + r->age * sz_r) / (sz_l + sz_r);
l->ar.end = r->ar.end;
/* todo: do this for only installed probes */
for (i = 0; i < DAMON_MAX_PROBES; i++)
l->probe_hits[i] = (l->probe_hits[i] * sz_l + r->probe_hits[i]
* sz_r) / (sz_l + sz_r);
damon_verify_merge_two_regions(l, r);
damon_destroy_region(r, t);
}
@ -3108,6 +3116,8 @@ static void damon_split_region_at(struct damon_target *t,
new->last_nr_accesses = r->last_nr_accesses;
new->nr_accesses_bp = r->nr_accesses_bp;
new->nr_accesses = r->nr_accesses;
/* todo: do this for only installed probes */
memcpy(new->probe_hits, r->probe_hits, sizeof(r->probe_hits));
damon_insert_region(new, r, damon_next_region(r), t);
}