Commit 5f0985bb authored by Jianyu Zhan's avatar Jianyu Zhan Committed by Pekka Enberg
Browse files

mm/slab.c: cleanup outdated comments and unify variables naming



As time goes, the code changes a lot, and this leads to that
some old-days comments scatter around , which instead of faciliating
understanding, but make more confusion. So this patch cleans up them.

Also, this patch unifies some variables naming.
Acked-by: default avatarChristoph Lameter <cl@linux.com>
Signed-off-by: default avatarJianyu Zhan <nasa4836@gmail.com>
Signed-off-by: default avatarPekka Enberg <penberg@kernel.org>
parent 24f870d8
......@@ -288,8 +288,8 @@ static void kmem_cache_node_init(struct kmem_cache_node *parent)
* OTOH the cpuarrays can contain lots of objects,
* which could lock up otherwise freeable slabs.
*/
#define REAPTIMEOUT_CPUC (2*HZ)
#define REAPTIMEOUT_LIST3 (4*HZ)
#define REAPTIMEOUT_AC (2*HZ)
#define REAPTIMEOUT_NODE (4*HZ)
#if STATS
#define STATS_INC_ACTIVE(x) ((x)->num_active++)
......@@ -1084,7 +1084,7 @@ static int init_cache_node_node(int node)
list_for_each_entry(cachep, &slab_caches, list) {
/*
* Set up the size64 kmemlist for cpu before we can
* Set up the kmem_cache_node for cpu before we can
* begin anything. Make sure some other cpu on this
* node has not already allocated this
*/
......@@ -1093,12 +1093,12 @@ static int init_cache_node_node(int node)
if (!n)
return -ENOMEM;
kmem_cache_node_init(n);
n->next_reap = jiffies + REAPTIMEOUT_LIST3 +
((unsigned long)cachep) % REAPTIMEOUT_LIST3;
n->next_reap = jiffies + REAPTIMEOUT_NODE +
((unsigned long)cachep) % REAPTIMEOUT_NODE;
/*
* The l3s don't come and go as CPUs come and
* go. slab_mutex is sufficient
* The kmem_cache_nodes don't come and go as CPUs
* come and go. slab_mutex is sufficient
* protection here.
*/
cachep->node[node] = n;
......@@ -1423,8 +1423,8 @@ static void __init set_up_node(struct kmem_cache *cachep, int index)
for_each_online_node(node) {
cachep->node[node] = &init_kmem_cache_node[index + node];
cachep->node[node]->next_reap = jiffies +
REAPTIMEOUT_LIST3 +
((unsigned long)cachep) % REAPTIMEOUT_LIST3;
REAPTIMEOUT_NODE +
((unsigned long)cachep) % REAPTIMEOUT_NODE;
}
}
......@@ -2124,8 +2124,8 @@ static int __init_refok setup_cpu_cache(struct kmem_cache *cachep, gfp_t gfp)
}
}
cachep->node[numa_mem_id()]->next_reap =
jiffies + REAPTIMEOUT_LIST3 +
((unsigned long)cachep) % REAPTIMEOUT_LIST3;
jiffies + REAPTIMEOUT_NODE +
((unsigned long)cachep) % REAPTIMEOUT_NODE;
cpu_cache_get(cachep)->avail = 0;
cpu_cache_get(cachep)->limit = BOOT_CPUCACHE_ENTRIES;
......@@ -2327,10 +2327,10 @@ __kmem_cache_create (struct kmem_cache *cachep, unsigned long flags)
if (flags & CFLGS_OFF_SLAB) {
cachep->freelist_cache = kmalloc_slab(freelist_size, 0u);
/*
* This is a possibility for one of the malloc_sizes caches.
* This is a possibility for one of the kmalloc_{dma,}_caches.
* But since we go off slab only for object size greater than
* PAGE_SIZE/8, and malloc_sizes gets created in ascending order,
* this should not happen at all.
* PAGE_SIZE/8, and kmalloc_{dma,}_caches get created
* in ascending order,this should not happen at all.
* But leave a BUG_ON for some lucky dude.
*/
BUG_ON(ZERO_OR_NULL_PTR(cachep->freelist_cache));
......@@ -2538,14 +2538,17 @@ int __kmem_cache_shutdown(struct kmem_cache *cachep)
/*
* Get the memory for a slab management obj.
* For a slab cache when the slab descriptor is off-slab, slab descriptors
* always come from malloc_sizes caches. The slab descriptor cannot
* come from the same cache which is getting created because,
* when we are searching for an appropriate cache for these
* descriptors in kmem_cache_create, we search through the malloc_sizes array.
* If we are creating a malloc_sizes cache here it would not be visible to
* kmem_find_general_cachep till the initialization is complete.
* Hence we cannot have freelist_cache same as the original cache.
*
* For a slab cache when the slab descriptor is off-slab, the
* slab descriptor can't come from the same cache which is being created,
* Because if it is the case, that means we defer the creation of
* the kmalloc_{dma,}_cache of size sizeof(slab descriptor) to this point.
* And we eventually call down to __kmem_cache_create(), which
* in turn looks up in the kmalloc_{dma,}_caches for the disired-size one.
* This is a "chicken-and-egg" problem.
*
* So the off-slab slab descriptor shall come from the kmalloc_{dma,}_caches,
* which are all initialized during kmem_cache_init().
*/
static void *alloc_slabmgmt(struct kmem_cache *cachep,
struct page *page, int colour_off,
......@@ -3353,7 +3356,7 @@ slab_alloc(struct kmem_cache *cachep, gfp_t flags, unsigned long caller)
}
/*
* Caller needs to acquire correct kmem_list's list_lock
* Caller needs to acquire correct kmem_cache_node's list_lock
*/
static void free_block(struct kmem_cache *cachep, void **objpp, int nr_objects,
int node)
......@@ -3607,11 +3610,6 @@ static __always_inline void *__do_kmalloc(size_t size, gfp_t flags,
struct kmem_cache *cachep;
void *ret;
/* If you want to save a few bytes .text space: replace
* __ with kmem_.
* Then kmalloc uses the uninlined functions instead of the inline
* functions.
*/
cachep = kmalloc_slab(size, flags);
if (unlikely(ZERO_OR_NULL_PTR(cachep)))
return cachep;
......@@ -3703,7 +3701,7 @@ EXPORT_SYMBOL(kfree);
/*
* This initializes kmem_cache_node or resizes various caches for all nodes.
*/
static int alloc_kmemlist(struct kmem_cache *cachep, gfp_t gfp)
static int alloc_kmem_cache_node(struct kmem_cache *cachep, gfp_t gfp)
{
int node;
struct kmem_cache_node *n;
......@@ -3759,8 +3757,8 @@ static int alloc_kmemlist(struct kmem_cache *cachep, gfp_t gfp)
}
kmem_cache_node_init(n);
n->next_reap = jiffies + REAPTIMEOUT_LIST3 +
((unsigned long)cachep) % REAPTIMEOUT_LIST3;
n->next_reap = jiffies + REAPTIMEOUT_NODE +
((unsigned long)cachep) % REAPTIMEOUT_NODE;
n->shared = new_shared;
n->alien = new_alien;
n->free_limit = (1 + nr_cpus_node(node)) *
......@@ -3846,7 +3844,7 @@ static int __do_tune_cpucache(struct kmem_cache *cachep, int limit,
kfree(ccold);
}
kfree(new);
return alloc_kmemlist(cachep, gfp);
return alloc_kmem_cache_node(cachep, gfp);
}
static int do_tune_cpucache(struct kmem_cache *cachep, int limit,
......@@ -4015,7 +4013,7 @@ static void cache_reap(struct work_struct *w)
if (time_after(n->next_reap, jiffies))
goto next;
n->next_reap = jiffies + REAPTIMEOUT_LIST3;
n->next_reap = jiffies + REAPTIMEOUT_NODE;
drain_array(searchp, n, n->shared, 0, node);
......@@ -4036,7 +4034,7 @@ next:
next_reap_node();
out:
/* Set up the next iteration */
schedule_delayed_work(work, round_jiffies_relative(REAPTIMEOUT_CPUC));
schedule_delayed_work(work, round_jiffies_relative(REAPTIMEOUT_AC));
}
#ifdef CONFIG_SLABINFO
......
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