[PATCHv2 2/7] zsmalloc: re-shuffle zs_pool members
From: Sergey Senozhatsky
Date: Wed Jan 29 2025 - 23:45:29 EST
There is no need in having ->name at offset 0, it's never user and is
being followed but a very large RO (after init) array of size classes,
so each time we need to lock pool->migrate_lock (which happens relatively
often) we need to jump over that RO region. Swap ->migrate_lock and ->name.
Move ->pages_allocated is modified relatively often, move it up
right after RO size_classes arrays.
We modify ->compaction_in_progress and ->stats only from compaction
(defragmentation), which can run only on one CPU at a time and,
depending on the case, may or may not be common. Move both to down.
Signed-off-by: Sergey Senozhatsky <senozhatsky@xxxxxxxxxxxx>
---
mm/zsmalloc.c | 20 +++++++++++---------
1 file changed, 11 insertions(+), 9 deletions(-)
diff --git a/mm/zsmalloc.c b/mm/zsmalloc.c
index 8972b4b56cd3..2280ea17796b 100644
--- a/mm/zsmalloc.c
+++ b/mm/zsmalloc.c
@@ -204,18 +204,15 @@ struct link_free {
};
struct zs_pool {
- const char *name;
+ /* protect page/zspage migration */
+ rwlock_t migrate_lock;
struct size_class *size_class[ZS_SIZE_CLASSES];
- struct kmem_cache *handle_cachep;
- struct kmem_cache *zspage_cachep;
atomic_long_t pages_allocated;
- struct zs_pool_stats stats;
-
- /* Compact classes */
- struct shrinker *shrinker;
+ struct kmem_cache *handle_cachep;
+ struct kmem_cache *zspage_cachep;
#ifdef CONFIG_ZSMALLOC_STAT
struct dentry *stat_dentry;
@@ -223,9 +220,14 @@ struct zs_pool {
#ifdef CONFIG_COMPACTION
struct work_struct free_work;
#endif
- /* protect page/zspage migration */
- rwlock_t migrate_lock;
+ const char *name;
+
+ /* Compact classes */
+ struct shrinker *shrinker;
+ /* Permit only once compaction at a time */
atomic_t compaction_in_progress;
+ /* compaction stats */
+ struct zs_pool_stats stats;
};
static void pool_write_unlock(struct zs_pool *pool)
--
2.48.1.262.g85cc9f2d1e-goog