The patch titled Subject: zsmalloc: move migration destination zspage inuse check has been added to the -mm mm-unstable branch. Its filename is zsmalloc-move-migration-destination-zspage-inuse-check.patch This patch will shortly appear at https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/zsmalloc-move-migration-destination-zspage-inuse-check.patch This patch will later appear in the mm-unstable branch at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm Before you just go and hit "reply", please: a) Consider who else should be cc'ed b) Prefer to cc a suitable mailing list as well c) Ideally: find the original patch on the mailing list and do a reply-to-all to that, adding suitable additional cc's *** Remember to use Documentation/process/submit-checklist.rst when testing your code *** The -mm tree is included into linux-next via the mm-everything branch at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm and is updated there every 2-3 working days ------------------------------------------------------ From: Sergey Senozhatsky <senozhatsky@xxxxxxxxxxxx> Subject: zsmalloc: move migration destination zspage inuse check Date: Sat, 24 Jun 2023 14:12:15 +0900 Destination zspage fullness check need to be done after zs_object_copy() because that's where source and destination zspages fullness change. Checking destination zspage fullness before zs_object_copy() may cause migration to loop through source zspage sub-pages scanning for allocate objects just to find out at the end that the destination zspage is full. Link: https://lkml.kernel.org/r/20230624053120.643409-3-senozhatsky@xxxxxxxxxxxx Signed-off-by: Sergey Senozhatsky <senozhatsky@xxxxxxxxxxxx> Acked-by: Minchan Kim <minchan@xxxxxxxxxx> Cc: Alexey Romanov <avromanov@xxxxxxxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- mm/zsmalloc.c | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-) --- a/mm/zsmalloc.c~zsmalloc-move-migration-destination-zspage-inuse-check +++ a/mm/zsmalloc.c @@ -1620,10 +1620,6 @@ static void migrate_zspage(struct zs_poo continue; } - /* Stop if there is no more space */ - if (zspage_full(class, get_zspage(d_page))) - break; - used_obj = handle_to_obj(handle); free_obj = obj_malloc(pool, get_zspage(d_page), handle); zs_object_copy(class, free_obj, used_obj); @@ -1631,6 +1627,10 @@ static void migrate_zspage(struct zs_poo record_obj(handle, free_obj); obj_free(class->size, used_obj); + /* Stop if there is no more space */ + if (zspage_full(class, get_zspage(d_page))) + break; + /* Stop if there are no more objects to migrate */ if (zspage_empty(get_zspage(s_page))) break; _ Patches currently in -mm which might be from senozhatsky@xxxxxxxxxxxx are zsmalloc-do-not-scan-for-allocated-objects-in-empty-zspage.patch zsmalloc-move-migration-destination-zspage-inuse-check.patch