mm: zswap: refactor limit checking from zswap_store()

Refactor limit and acceptance threshold checking outside of zswap_store().
This code will be moved around in a following patch, so it would be
cleaner to move a function call around.

Link: https://lkml.kernel.org/r/20240413022407.785696-3-yosryahmed@google.com
Signed-off-by: Yosry Ahmed <yosryahmed@google.com>
Reviewed-by: Nhat Pham <nphamcs@gmail.com>
Cc: Chengming Zhou <chengming.zhou@linux.dev>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: "Maciej S. Szmigiero" <mail@maciej.szmigiero.name>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

diff --git a/mm/zswap.c b/mm/zswap.c
index d753ad9d45918b291f7afafd2fe2deda2f9486df..1cbd3cf97eeff99407147c334dec37b340c41f87 100644 (file)
--- a/mm/zswap.c
+++ b/mm/zswap.c
@@ -517,6 +517,21 @@ unsigned long zswap_total_pages(void)
        return total;
 }
 
+static bool zswap_check_limits(void)
+{
+       unsigned long cur_pages = zswap_total_pages();
+       unsigned long max_pages = zswap_max_pages();
+
+       if (cur_pages >= max_pages) {
+               zswap_pool_limit_hit++;
+               zswap_pool_reached_full = true;
+       } else if (zswap_pool_reached_full &&
+                  cur_pages <= zswap_accept_thr_pages()) {
+                       zswap_pool_reached_full = false;
+       }
+       return zswap_pool_reached_full;
+}
+
 /*********************************
 * param callbacks
 **********************************/
@@ -1406,7 +1421,6 @@ bool zswap_store(struct folio *folio)
        struct zswap_entry *entry, *old;
        struct obj_cgroup *objcg = NULL;
        struct mem_cgroup *memcg = NULL;
-       unsigned long max_pages, cur_pages;
 
        VM_WARN_ON_ONCE(!folio_test_locked(folio));
        VM_WARN_ON_ONCE(!folio_test_swapcache(folio));
@@ -1429,22 +1443,8 @@ bool zswap_store(struct folio *folio)
                mem_cgroup_put(memcg);
        }
 
-       /* Check global limits */
-       cur_pages = zswap_total_pages();
-       max_pages = zswap_max_pages();
-
-       if (cur_pages >= max_pages) {
-               zswap_pool_limit_hit++;
-               zswap_pool_reached_full = true;
+       if (zswap_check_limits())
                goto reject;
-       }
-
-       if (zswap_pool_reached_full) {
-               if (cur_pages > zswap_accept_thr_pages())
-                       goto reject;
-               else
-                       zswap_pool_reached_full = false;
-       }
 
        /* allocate entry */
        entry = zswap_entry_cache_alloc(GFP_KERNEL, folio_nid(folio));