From e87b881489085b4832ad417da653739cbace49e7 Mon Sep 17 00:00:00 2001 From: Yosry Ahmed Date: Sat, 13 Apr 2024 02:24:06 +0000 Subject: mm: zswap: move more same-filled pages checks outside of zswap_store() Currently, zswap_store() checks zswap_same_filled_pages_enabled, kmaps the folio, then calls zswap_is_page_same_filled() to check the folio contents. Move this logic into zswap_is_page_same_filled() as well (and rename it to use 'folio' while we are at it). This makes zswap_store() cleaner, and makes following changes to that logic contained within the helper. While we are at it: - Rename the insert_entry label to store_entry to match xa_store(). - Add comment headers for same-filled functions and the main API functions (load, store, invalidate, swapon, swapoff). No functional change intended. Link: https://lkml.kernel.org/r/20240413022407.785696-4-yosryahmed@google.com Signed-off-by: Yosry Ahmed Reviewed-by: Nhat Pham Reviewed-by: Chengming Zhou Acked-by: Johannes Weiner Cc: "Maciej S. Szmigiero" Signed-off-by: Andrew Morton --- mm/zswap.c | 45 +++++++++++++++++++++++++-------------------- 1 file changed, 25 insertions(+), 20 deletions(-) diff --git a/mm/zswap.c b/mm/zswap.c index 1cbd3cf97eef..18fd70795f5b 100644 --- a/mm/zswap.c +++ b/mm/zswap.c @@ -1383,26 +1383,35 @@ resched: } while (zswap_total_pages() > thr); } -static int zswap_is_page_same_filled(void *ptr, unsigned long *value) +/********************************* +* same-filled functions +**********************************/ +static bool zswap_is_folio_same_filled(struct folio *folio, unsigned long *value) { unsigned long *page; unsigned long val; unsigned int pos, last_pos = PAGE_SIZE / sizeof(*page) - 1; + bool ret = false; - page = (unsigned long *)ptr; + if (!zswap_same_filled_pages_enabled) + return false; + + page = kmap_local_folio(folio, 0); val = page[0]; if (val != page[last_pos]) - return 0; + goto out; for (pos = 1; pos < last_pos; pos++) { if (val != page[pos]) - return 0; + goto out; } *value = val; - - return 1; + ret = true; +out: + kunmap_local(page); + return ret; } static void zswap_fill_page(void *ptr, unsigned long value) @@ -1413,6 +1422,9 @@ static void zswap_fill_page(void *ptr, unsigned long value) memset_l(page, value, PAGE_SIZE / sizeof(unsigned long)); } +/********************************* +* main API +**********************************/ bool zswap_store(struct folio *folio) { swp_entry_t swp = folio->swap; @@ -1421,6 +1433,7 @@ bool zswap_store(struct folio *folio) struct zswap_entry *entry, *old; struct obj_cgroup *objcg = NULL; struct mem_cgroup *memcg = NULL; + unsigned long value; VM_WARN_ON_ONCE(!folio_test_locked(folio)); VM_WARN_ON_ONCE(!folio_test_swapcache(folio)); @@ -1453,19 +1466,11 @@ bool zswap_store(struct folio *folio) goto reject; } - if (zswap_same_filled_pages_enabled) { - unsigned long value; - u8 *src; - - src = kmap_local_folio(folio, 0); - if (zswap_is_page_same_filled(src, &value)) { - kunmap_local(src); - entry->length = 0; - entry->value = value; - atomic_inc(&zswap_same_filled_pages); - goto insert_entry; - } - kunmap_local(src); + if (zswap_is_folio_same_filled(folio, &value)) { + entry->length = 0; + entry->value = value; + atomic_inc(&zswap_same_filled_pages); + goto store_entry; } if (!zswap_non_same_filled_pages_enabled) @@ -1488,7 +1493,7 @@ bool zswap_store(struct folio *folio) if (!zswap_compress(folio, entry)) goto put_pool; -insert_entry: +store_entry: entry->swpentry = swp; entry->objcg = objcg; -- cgit v1.2.3