From 90ce872c22b248724d1c87232410e3b38536e107 Mon Sep 17 00:00:00 2001 From: Vlastimil Babka Date: Mon, 21 Nov 2022 11:44:54 +0100 Subject: [PATCH] mm, slub: lower the default slub_max_order with CONFIG_SLUB_TINY With CONFIG_SLUB_TINY we want to minimize memory overhead. By lowering the default slub_max_order we can make slab allocations use smaller pages. However depending on object sizes, order-0 might not be the best due to increased fragmentation. When testing on a 8MB RAM k210 system by Damien Le Moal [1], slub_max_order=1 had the best results, so use that as the default for CONFIG_SLUB_TINY. [1] https://lore.kernel.org/all/6a1883c4-4c3f-545a-90e8-2cd805bcf4ae@opensource.wdc.com/ Signed-off-by: Vlastimil Babka Acked-by: Roman Gushchin Reviewed-by: Hyeonggon Yoo <42.hyeyoo@gmail.com> Acked-by: Mike Rapoport Reviewed-by: Christoph Lameter --- mm/slub.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/mm/slub.c b/mm/slub.c index 19b6cf74bdfc..f4c7f4e3751f 100644 --- a/mm/slub.c +++ b/mm/slub.c @@ -3888,7 +3888,8 @@ EXPORT_SYMBOL(kmem_cache_alloc_bulk); * take the list_lock. */ static unsigned int slub_min_order; -static unsigned int slub_max_order = PAGE_ALLOC_COSTLY_ORDER; +static unsigned int slub_max_order = + IS_ENABLED(CONFIG_SLUB_TINY) ? 1 : PAGE_ALLOC_COSTLY_ORDER; static unsigned int slub_min_objects; /*