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authorYosry Ahmed <yosryahmed@google.com>2023-06-07 19:51:43 +0000
committerAndrew Morton <akpm@linux-foundation.org>2023-06-19 16:19:05 -0700
commitb9c91c43412f2e07a5287dfe7027acdd8fb0b1ef (patch)
tree1dfa30c07b46c1c9e048c89eaf66ba58c18daa1a /mm/frontswap.c
parent32b6a4a1745a46918f748f6fb7641e588fbec6f2 (diff)
mm: zswap: support exclusive loads
Commit 71024cb4a0bf ("frontswap: remove frontswap_tmem_exclusive_gets") removed support for exclusive loads from frontswap as it was not used. Bring back exclusive loads support to frontswap by adding an "exclusive" output parameter to frontswap_ops->load. On the zswap side, add a module parameter to enable/disable exclusive loads, and a config option to control the boot default value. Refactor zswap entry invalidation in zswap_frontswap_invalidate_page() into zswap_invalidate_entry() to reuse it in zswap_frontswap_load() if exclusive loads are enabled. With exclusive loads, we avoid having two copies of the same page in memory (compressed & uncompressed) after faulting it in from zswap. On the other hand, if the page is to be reclaimed again without being dirtied, it will be re-compressed. Compression is not usually slow, and a page that was just faulted in is less likely to be reclaimed again soon. Link: https://lkml.kernel.org/r/20230607195143.1473802-1-yosryahmed@google.com Signed-off-by: Yosry Ahmed <yosryahmed@google.com> Suggested-by: Yu Zhao <yuzhao@google.com> Acked-by: Johannes Weiner <hannes@cmpxchg.org> Cc: Dan Streetman <ddstreet@ieee.org> Cc: Domenico Cerasuolo <cerasuolodomenico@gmail.com> Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Cc: Nhat Pham <nphamcs@gmail.com> Cc: Seth Jennings <sjenning@redhat.com> Cc: Vitaly Wool <vitaly.wool@konsulko.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Diffstat (limited to 'mm/frontswap.c')
-rw-r--r--mm/frontswap.c10
1 files changed, 8 insertions, 2 deletions
diff --git a/mm/frontswap.c b/mm/frontswap.c
index 279e55b4ed87..2fb5df3384b8 100644
--- a/mm/frontswap.c
+++ b/mm/frontswap.c
@@ -206,6 +206,7 @@ int __frontswap_load(struct page *page)
int type = swp_type(entry);
struct swap_info_struct *sis = swap_info[type];
pgoff_t offset = swp_offset(entry);
+ bool exclusive = false;
VM_BUG_ON(!frontswap_ops);
VM_BUG_ON(!PageLocked(page));
@@ -215,9 +216,14 @@ int __frontswap_load(struct page *page)
return -1;
/* Try loading from each implementation, until one succeeds. */
- ret = frontswap_ops->load(type, offset, page);
- if (ret == 0)
+ ret = frontswap_ops->load(type, offset, page, &exclusive);
+ if (ret == 0) {
inc_frontswap_loads();
+ if (exclusive) {
+ SetPageDirty(page);
+ __frontswap_clear(sis, offset);
+ }
+ }
return ret;
}