From f2297b5a8932594a45c99d3d01b0d53a16ea9753 Mon Sep 17 00:00:00 2001 From: Brian Behlendorf Date: Thu, 7 Aug 2014 16:23:04 -0700 Subject: [PATCH] Set spl_kmem_cache_slab_limit=16384 to default For small objects the Linux slab allocator should be used to make the most efficient use of the memory. However, large objects are not supported by the Linux slab and therefore the SPL implementation is preferred. A cutoff of 16K was determined to be optimal for architectures using 4K pages. Signed-off-by: Brian Behlendorf Signed-off-by: DHE Issue #356 Closes #379 --- module/spl/spl-kmem.c | 10 ++++++++++ 1 file changed, 10 insertions(+) diff --git a/module/spl/spl-kmem.c b/module/spl/spl-kmem.c index 0d1da43..0a9d775 100644 --- a/module/spl/spl-kmem.c +++ b/module/spl/spl-kmem.c @@ -81,7 +81,17 @@ unsigned int spl_kmem_cache_max_size = 32; module_param(spl_kmem_cache_max_size, uint, 0644); MODULE_PARM_DESC(spl_kmem_cache_max_size, "Maximum size of slab in MB"); +/* + * For small objects the Linux slab allocator should be used to make the most + * efficient use of the memory. However, large objects are not supported by + * the Linux slab and therefore the SPL implementation is preferred. A cutoff + * of 16K was determined to be optimal for architectures using 4K pages. + */ +#if PAGE_SIZE == 4096 +unsigned int spl_kmem_cache_slab_limit = 16384; +#else unsigned int spl_kmem_cache_slab_limit = 0; +#endif module_param(spl_kmem_cache_slab_limit, uint, 0644); MODULE_PARM_DESC(spl_kmem_cache_slab_limit, "Objects less than N bytes use the Linux slab"); -- 2.39.5