mm/damon/paddr: introduce DAMOS_MIGRATE_HOT action for promotion

This patch introduces DAMOS_MIGRATE_HOT action, which is similar to
DAMOS_MIGRATE_COLD, but proritizes hot pages.

It migrates pages inside the given region to the 'target_nid' NUMA node
in the sysfs.

Here is one of the example usage of this 'migrate_hot' action.

  $ cd /sys/kernel/mm/damon/admin/kdamonds/<N>
  $ cat contexts/<N>/schemes/<N>/action
  migrate_hot
  $ echo 0 > contexts/<N>/schemes/<N>/target_nid
  $ echo commit > state
  $ numactl -p 2 ./hot_cold 500M 600M &
  $ numastat -c -p hot_cold

  Per-node process memory usage (in MBs)
  PID             Node 0 Node 1 Node 2 Total
  --------------  ------ ------ ------ -----
  701 (hot_cold)     501      0    601  1101

Link: https://lkml.kernel.org/r/20240614030010.751-7-honggyu.kim@sk.com
Signed-off-by: Hyeongtak Ji <hyeongtak.ji@sk.com>
Signed-off-by: Honggyu Kim <honggyu.kim@sk.com>
Signed-off-by: SeongJae Park <sj@kernel.org>
Cc: Gregory Price <gregory.price@memverge.com>
Cc: Hyeonggon Yoo <42.hyeyoo@gmail.com>
Cc: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Rakie Kim <rakie.kim@sk.com>
Cc: Steven Rostedt (Google) <rostedt@goodmis.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

diff --git a/include/linux/damon.h b/include/linux/damon.h
index 56714b6eb0d789e046fef587eaa80aa3cf150a96..3d62d98d6359102c65377a1edcea4b96b86fe7e8 100644 (file)
--- a/include/linux/damon.h
+++ b/include/linux/damon.h
@@ -105,6 +105,7 @@ struct damon_target {
  * @DAMOS_NOHUGEPAGE:  Call ``madvise()`` for the region with MADV_NOHUGEPAGE.
  * @DAMOS_LRU_PRIO:    Prioritize the region on its LRU lists.
  * @DAMOS_LRU_DEPRIO:  Deprioritize the region on its LRU lists.
+ * @DAMOS_MIGRATE_HOT:  Migrate the regions prioritizing warmer regions.
  * @DAMOS_MIGRATE_COLD:        Migrate the regions prioritizing colder regions.
  * @DAMOS_STAT:                Do nothing but count the stat.
  * @NR_DAMOS_ACTIONS:  Total number of DAMOS actions
@@ -123,6 +124,7 @@ enum damos_action {
        DAMOS_NOHUGEPAGE,
        DAMOS_LRU_PRIO,
        DAMOS_LRU_DEPRIO,
+       DAMOS_MIGRATE_HOT,
        DAMOS_MIGRATE_COLD,
        DAMOS_STAT,             /* Do nothing but only record the stat */
        NR_DAMOS_ACTIONS,

diff --git a/mm/damon/paddr.c b/mm/damon/paddr.c
index 882ae54af8291d44299403255792ae7c744cc6a8..af6aac388a431fc1858b417f8b188cb67d41abcf 100644 (file)
--- a/mm/damon/paddr.c
+++ b/mm/damon/paddr.c
@@ -486,6 +486,7 @@ static unsigned long damon_pa_apply_scheme(struct damon_ctx *ctx,
                return damon_pa_mark_accessed(r, scheme);
        case DAMOS_LRU_DEPRIO:
                return damon_pa_deactivate_pages(r, scheme);
+       case DAMOS_MIGRATE_HOT:
        case DAMOS_MIGRATE_COLD:
                return damon_pa_migrate(r, scheme);
        case DAMOS_STAT:
@@ -508,6 +509,8 @@ static int damon_pa_scheme_score(struct damon_ctx *context,
                return damon_hot_score(context, r, scheme);
        case DAMOS_LRU_DEPRIO:
                return damon_cold_score(context, r, scheme);
+       case DAMOS_MIGRATE_HOT:
+               return damon_hot_score(context, r, scheme);
        case DAMOS_MIGRATE_COLD:
                return damon_cold_score(context, r, scheme);
        default:

diff --git a/mm/damon/sysfs-schemes.c b/mm/damon/sysfs-schemes.c
index 880015d5b5ead22d89e655bdd687b057b5675cbf..66fccfa776d7580aae7c943a4cbff1b4eab17a4f 100644 (file)
--- a/mm/damon/sysfs-schemes.c
+++ b/mm/damon/sysfs-schemes.c
@@ -1458,6 +1458,7 @@ static const char * const damon_sysfs_damos_action_strs[] = {
        "nohugepage",
        "lru_prio",
        "lru_deprio",
+       "migrate_hot",
        "migrate_cold",
        "stat",
 };