diff options
| -rw-r--r-- | Documentation/kernel-parameters.txt | 6 | ||||
| -rw-r--r-- | mm/slab.c | 20 |
2 files changed, 23 insertions, 3 deletions
diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt index a0c5c5f4fce..b21093eabef 100644 --- a/Documentation/kernel-parameters.txt +++ b/Documentation/kernel-parameters.txt @@ -2362,6 +2362,12 @@ bytes respectively. Such letter suffixes can also be entirely omitted. slram= [HW,MTD] + slab_max_order= [MM, SLAB] + Determines the maximum allowed order for slabs. + A high setting may cause OOMs due to memory + fragmentation. Defaults to 1 for systems with + more than 32MB of RAM, 0 otherwise. + slub_debug[=options[,slabs]] [MM, SLUB] Enabling slub_debug allows one to determine the culprit if slab objects become corrupted. Enabling diff --git a/mm/slab.c b/mm/slab.c index 1a482e8402c..b0414d12fd0 100644 --- a/mm/slab.c +++ b/mm/slab.c @@ -479,11 +479,13 @@ EXPORT_SYMBOL(slab_buffer_size); #endif /* - * Do not go above this order unless 0 objects fit into the slab. + * Do not go above this order unless 0 objects fit into the slab or + * overridden on the command line. */ #define SLAB_MAX_ORDER_HI 1 #define SLAB_MAX_ORDER_LO 0 static int slab_max_order = SLAB_MAX_ORDER_LO; +static bool slab_max_order_set __initdata; /* * Functions for storing/retrieving the cachep and or slab from the page @@ -851,6 +853,17 @@ static int __init noaliencache_setup(char *s) } __setup("noaliencache", noaliencache_setup); +static int __init slab_max_order_setup(char *str) +{ + get_option(&str, &slab_max_order); + slab_max_order = slab_max_order < 0 ? 0 : + min(slab_max_order, MAX_ORDER - 1); + slab_max_order_set = true; + + return 1; +} +__setup("slab_max_order=", slab_max_order_setup); + #ifdef CONFIG_NUMA /* * Special reaping functions for NUMA systems called from cache_reap(). @@ -1499,9 +1512,10 @@ void __init kmem_cache_init(void) /* * Fragmentation resistance on low memory - only use bigger - * page orders on machines with more than 32MB of memory. + * page orders on machines with more than 32MB of memory if + * not overridden on the command line. */ - if (totalram_pages > (32 << 20) >> PAGE_SHIFT) + if (!slab_max_order_set && totalram_pages > (32 << 20) >> PAGE_SHIFT) slab_max_order = SLAB_MAX_ORDER_HI; /* Bootstrap is tricky, because several objects are allocated |