On Mon, 2016-08-29 at 17:44 -0700, Aruna Ramakrishna wrote:
> This patch optimizes 'cat /proc/slabinfo' by maintaining a counter for
> total number of allocated slabs per node, per cache.
[]
> We tested this after
> growing the dentry cache to 70GB, and the performance improved from 2s to
> 5ms.
Seems sensible, thanks.
One completely trivial note:
> diff --git a/mm/slab.c b/mm/slab.c
[]
> @@ -1394,24 +1395,27 @@ slab_out_of_memory(struct kmem_cache *cachep, gfp_t
> gfpflags, int nodeid)
> for_each_kmem_cache_node(cachep, node, n) {
> unsigned long active_objs = 0, num_objs = 0, free_objects = 0;
> unsigned long active_slabs = 0, num_slabs = 0;
> + unsigned long num_slabs_partial = 0, num_slabs_free = 0;
> + unsigned long num_slabs_full;
[]
> + num_slabs_full = num_slabs -
> + (num_slabs_partial + num_slabs_free);
vs
> @@ -4111,6 +4119,8 @@ void get_slabinfo(struct kmem_cache *cachep, struct
> slabinfo *sinfo)
> unsigned long num_objs;
> unsigned long active_slabs = 0;
> unsigned long num_slabs, free_objects = 0, shared_avail = 0;
> + unsigned long num_slabs_partial = 0, num_slabs_free = 0;
> + unsigned long num_slabs_full = 0;
[]
> + num_slabs_full = num_slabs - (num_slabs_partial + num_slabs_free);
It seems odd to have different initialization styles
for num_slabs_full. It seems the second one doesn't
need to be initialized.
It'd also be nicer I think if the two declarations
blocks had more similar layouts.
Maybe in a follow-on patch. Or not. Your choice.
