Commit 4ce36584 authored Jun 24, 2023 by Sergey Senozhatsky Committed by Andrew Morton Aug 18, 2023

zsmalloc: move migration destination zspage inuse check

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@chromium.org

Signed-off-by: Sergey Senozhatsky <senozhatsky@chromium.org>
Acked-by: Minchan Kim <minchan@kernel.org>
Cc: Alexey Romanov <avromanov@sberdevices.ru>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

parent df9cd3cb

mm/zsmalloc.c

+4 −4

Original line number	Diff line number	Diff line
		@@ -1620,10 +1620,6 @@ static void migrate_zspage(struct zs_pool pool, struct size_class class,
		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_pool pool, struct size_class class,
		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;