| From: Nhat Pham <nphamcs@gmail.com> |
| Subject: zswap: change zswap's default allocator to zsmalloc |
| Date: Fri, 8 Sep 2023 16:51:15 -0700 |
| |
| Out of zswap's 3 allocators, zsmalloc is the clear superior in terms of |
| memory utilization, both in theory and as observed in practice, with its |
| high storage density and low internal fragmentation. zsmalloc is also |
| more actively developed and maintained, since it is the allocator of |
| choice for zswap for many users, as well as the only allocator for zram. |
| |
| A historical objection to the selection of zsmalloc as the default |
| allocator for zswap is its lack of writeback capability. However, this |
| has changed, with the zsmalloc writeback patchset, and the subsequent |
| zswap LRU refactor. With this, there is not a lot of good reasons to keep |
| zbud, an otherwise inferior allocator, as the default instead of zswap. |
| |
| This patch changes the default allocator to zsmalloc. The only exception |
| is on settings without MMU, in which case zbud will remain as the default. |
| |
| Link: https://lkml.kernel.org/r/20230908235115.2943486-1-nphamcs@gmail.com |
| Signed-off-by: Nhat Pham <nphamcs@gmail.com> |
| Acked-by: Johannes Weiner <hannes@cmpxchg.org> |
| Acked-by: Yosry Ahmed <yosryahmed@google.com> |
| Cc: Dan Streetman <ddstreet@ieee.org> |
| Cc: Domenico Cerasuolo <cerasuolodomenico@gmail.com> |
| Cc: Seth Jennings <sjenning@redhat.com> |
| Cc: Vitaly Wool <vitaly.wool@konsulko.com> |
| Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
| --- |
| |
| mm/Kconfig | 1 + |
| 1 file changed, 1 insertion(+) |
| |
| --- a/mm/Kconfig~zswap-change-zswaps-default-allocator-to-zsmalloc |
| +++ a/mm/Kconfig |
| @@ -130,6 +130,7 @@ config ZSWAP_COMPRESSOR_DEFAULT |
| choice |
| prompt "Default allocator" |
| depends on ZSWAP |
| + default ZSWAP_ZPOOL_DEFAULT_ZSMALLOC if MMU |
| default ZSWAP_ZPOOL_DEFAULT_ZBUD |
| help |
| Selects the default allocator for the compressed cache for |
| _ |
