kernel.git/mm/slab.h, branch linux-3.18.y

mm/slab: use percpu allocator for cpu cache

2014-10-10T02:25:51Z

Because of chicken and egg problem, initialization of SLAB is really complicated. We need to allocate cpu cache through SLAB to make the kmem_cache work, but before initialization of kmem_cache, allocation through SLAB is impossible. On the other hand, SLUB does initialization in a more simple way. It uses percpu allocator to allocate cpu cache so there is no chicken and egg problem. So, this patch try to use percpu allocator in SLAB. This simplifies the initialization step in SLAB so that we could maintain SLAB code more easily. In my testing there is no performance difference. This implementation relies on percpu allocator. Because percpu allocator uses vmalloc address space, vmalloc address space could be exhausted by this change on many cpu system with *32 bit* kernel. This implementation can cover 1024 cpus in worst case by following calculation. Worst: 1024 cpus * 4 bytes for pointer * 300 kmem_caches * 120 objects per cpu_cache = 140 MB Normal: 1024 cpus * 4 bytes for pointer * 150 kmem_caches(slab merge) * 80 objects per cpu_cache = 46 MB Signed-off-by: Joonsoo Kim Acked-by: Christoph Lameter Cc: Pekka Enberg Cc: David Rientjes Cc: Jeremiah Mahler Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

mm/slab: support slab merge

2014-10-10T02:25:51Z

Slab merge is good feature to reduce fragmentation. If new creating slab have similar size and property with exsitent slab, this feature reuse it rather than creating new one. As a result, objects are packed into fewer slabs so that fragmentation is reduced. Below is result of my testing. * After boot, sleep 20; cat /proc/meminfo | grep Slab Slab: 25136 kB Slab: 24364 kB We can save 3% memory used by slab. For supporting this feature in SLAB, we need to implement SLAB specific kmem_cache_flag() and __kmem_cache_alias(), because SLUB implements some SLUB specific processing related to debug flag and object size change on these functions. Signed-off-by: Joonsoo Kim Cc: Christoph Lameter Cc: Pekka Enberg Cc: David Rientjes Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

mm/slab_common: commonize slab merge logic

2014-10-10T02:25:51Z

Slab merge is good feature to reduce fragmentation. Now, it is only applied to SLUB, but, it would be good to apply it to SLAB. This patch is preparation step to apply slab merge to SLAB by commonizing slab merge logic. Signed-off-by: Joonsoo Kim Cc: Randy Dunlap Cc: Christoph Lameter Cc: Pekka Enberg Cc: David Rientjes Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

slab: fix for_each_kmem_cache_node()

2014-10-10T02:25:51Z

Fix a bug (discovered with kmemcheck) in for_each_kmem_cache_node(). The for loop reads the array "node" before verifying that the index is within the range. This results in kmemcheck warning. Signed-off-by: Mikulas Patocka Reviewed-by: Pekka Enberg Acked-by: Christoph Lameter Cc: David Rientjes Cc: Joonsoo Kim Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

mm/slab_common: move kmem_cache definition to internal header

2014-10-10T02:25:50Z

We don't need to keep kmem_cache definition in include/linux/slab.h if we don't need to inline kmem_cache_size(). According to my code inspection, this function is only called at lc_create() in lib/lru_cache.c which may be called at initialization phase of something, so we don't need to inline it. Therfore, move it to slab_common.c and move kmem_cache definition to internal header. After this change, we can change kmem_cache definition easily without full kernel build. For instance, we can turn on/off CONFIG_SLUB_STATS without full kernel build. [akpm@linux-foundation.org: export kmem_cache_size() to modules] [rdunlap@infradead.org: add header files to fix kmemcheck.c build errors] Signed-off-by: Joonsoo Kim Acked-by: Christoph Lameter Cc: Pekka Enberg Cc: David Rientjes Cc: Zhang Yanfei Signed-off-by: Randy Dunlap Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

slab: convert last use of FUNCTION to func

2014-08-07T01:01:15Z

Just about all of these have been converted to __func__, so convert the last use. Signed-off-by: Joe Perches Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

slab: introduce alien_cache

2014-08-07T01:01:14Z

Currently, we use array_cache for alien_cache. Although they are mostly similar, there is one difference, that is, need for spinlock. We don't need spinlock for array_cache itself, but to use array_cache for alien_cache, array_cache structure should have spinlock. This is needless overhead, so removing it would be better. This patch prepare it by introducing alien_cache and using it. In the following patch, we remove spinlock in array_cache. Signed-off-by: Joonsoo Kim Acked-by: Christoph Lameter Cc: Pekka Enberg Cc: David Rientjes Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

mm: slab.h: wrap the whole file with guarding macro

2014-08-07T01:01:14Z

Guarding section: #ifndef MM_SLAB_H #define MM_SLAB_H ... #endif currently doesn't cover the whole mm/slab.h. It seems like it was done unintentionally. Wrap the whole file by moving closing #endif to the end of it. Signed-off-by: Andrey Ryabinin Acked-by: Christoph Lameter Acked-by: David Rientjes Reviewed-by: Vladimir Davydov Cc: Pekka Enberg Cc: Joonsoo Kim Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

slab common: add functions for kmem_cache_node access

2014-08-07T01:01:13Z

The patchset provides two new functions in mm/slab.h and modifies SLAB and SLUB to use these. The kmem_cache_node structure is shared between both allocators and the use of common accessors will allow us to move more code into slab_common.c in the future. This patch (of 3): These functions allow to eliminate repeatedly used code in both SLAB and SLUB and also allow for the insertion of debugging code that may be needed in the development process. Signed-off-by: Christoph Lameter Cc: Pekka Enberg Acked-by: David Rientjes Acked-by: Joonsoo Kim Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

memcg, slab: merge memcg_{bind,release}_pages to memcg_{un}charge_slab

2014-06-04T23:54:01Z

Currently we have two pairs of kmemcg-related functions that are called on slab alloc/free. The first is memcg_{bind,release}_pages that count the total number of pages allocated on a kmem cache. The second is memcg_{un}charge_slab that {un}charge slab pages to kmemcg resource counter. Let's just merge them to keep the code clean. Signed-off-by: Vladimir Davydov Acked-by: Johannes Weiner Cc: Michal Hocko Cc: Glauber Costa Cc: Pekka Enberg Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

kernel.git/mm/slab.h, branch linux-3.18.y

mm/slab: use percpu allocator for cpu cache

mm/slab: support slab merge

mm/slab_common: commonize slab merge logic

slab: fix for_each_kmem_cache_node()

mm/slab_common: move kmem_cache definition to internal header

slab: convert last use of __FUNCTION__ to __func__

slab: introduce alien_cache

mm: slab.h: wrap the whole file with guarding macro

slab common: add functions for kmem_cache_node access

memcg, slab: merge memcg_{bind,release}_pages to memcg_{un}charge_slab

slab: convert last use of FUNCTION to func