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authorJianyu Zhan <nasa4836@gmail.com>2014-03-30 05:02:20 -0400
committerPekka Enberg <penberg@kernel.org>2014-04-01 06:49:25 -0400
commit5f0985bb1123b48bbfc632006bdbe76d3dfea76b (patch)
tree5661241bdd61b933a43db4d9567ae784979d45ff /mm
parent24f870d8f0adcd38639f2f66e37aa7591a3fc408 (diff)
mm/slab.c: cleanup outdated comments and unify variables naming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: Christoph Lameter <cl@linux.com> Signed-off-by: Jianyu Zhan <nasa4836@gmail.com> Signed-off-by: Pekka Enberg <penberg@kernel.org>
Diffstat (limited to 'mm')
-rw-r--r--mm/slab.c66
1 files changed, 32 insertions, 34 deletions
diff --git a/mm/slab.c b/mm/slab.c
index 8347d803a23f..8dd8e0875e4c 100644
--- a/mm/slab.c
+++ b/mm/slab.c
@@ -288,8 +288,8 @@ static void kmem_cache_node_init(struct kmem_cache_node *parent)
288 * OTOH the cpuarrays can contain lots of objects, 288 * OTOH the cpuarrays can contain lots of objects,
289 * which could lock up otherwise freeable slabs. 289 * which could lock up otherwise freeable slabs.
290 */ 290 */
291#define REAPTIMEOUT_CPUC (2*HZ) 291#define REAPTIMEOUT_AC (2*HZ)
292#define REAPTIMEOUT_LIST3 (4*HZ) 292#define REAPTIMEOUT_NODE (4*HZ)
293 293
294#if STATS 294#if STATS
295#define STATS_INC_ACTIVE(x) ((x)->num_active++) 295#define STATS_INC_ACTIVE(x) ((x)->num_active++)
@@ -1084,7 +1084,7 @@ static int init_cache_node_node(int node)
1084 1084
1085 list_for_each_entry(cachep, &slab_caches, list) { 1085 list_for_each_entry(cachep, &slab_caches, list) {
1086 /* 1086 /*
1087 * Set up the size64 kmemlist for cpu before we can 1087 * Set up the kmem_cache_node for cpu before we can
1088 * begin anything. Make sure some other cpu on this 1088 * begin anything. Make sure some other cpu on this
1089 * node has not already allocated this 1089 * node has not already allocated this
1090 */ 1090 */
@@ -1093,12 +1093,12 @@ static int init_cache_node_node(int node)
1093 if (!n) 1093 if (!n)
1094 return -ENOMEM; 1094 return -ENOMEM;
1095 kmem_cache_node_init(n); 1095 kmem_cache_node_init(n);
1096 n->next_reap = jiffies + REAPTIMEOUT_LIST3 + 1096 n->next_reap = jiffies + REAPTIMEOUT_NODE +
1097 ((unsigned long)cachep) % REAPTIMEOUT_LIST3; 1097 ((unsigned long)cachep) % REAPTIMEOUT_NODE;
1098 1098
1099 /* 1099 /*
1100 * The l3s don't come and go as CPUs come and 1100 * The kmem_cache_nodes don't come and go as CPUs
1101 * go. slab_mutex is sufficient 1101 * come and go. slab_mutex is sufficient
1102 * protection here. 1102 * protection here.
1103 */ 1103 */
1104 cachep->node[node] = n; 1104 cachep->node[node] = n;
@@ -1423,8 +1423,8 @@ static void __init set_up_node(struct kmem_cache *cachep, int index)
1423 for_each_online_node(node) { 1423 for_each_online_node(node) {
1424 cachep->node[node] = &init_kmem_cache_node[index + node]; 1424 cachep->node[node] = &init_kmem_cache_node[index + node];
1425 cachep->node[node]->next_reap = jiffies + 1425 cachep->node[node]->next_reap = jiffies +
1426 REAPTIMEOUT_LIST3 + 1426 REAPTIMEOUT_NODE +
1427 ((unsigned long)cachep) % REAPTIMEOUT_LIST3; 1427 ((unsigned long)cachep) % REAPTIMEOUT_NODE;
1428 } 1428 }
1429} 1429}
1430 1430
@@ -2124,8 +2124,8 @@ static int __init_refok setup_cpu_cache(struct kmem_cache *cachep, gfp_t gfp)
2124 } 2124 }
2125 } 2125 }
2126 cachep->node[numa_mem_id()]->next_reap = 2126 cachep->node[numa_mem_id()]->next_reap =
2127 jiffies + REAPTIMEOUT_LIST3 + 2127 jiffies + REAPTIMEOUT_NODE +
2128 ((unsigned long)cachep) % REAPTIMEOUT_LIST3; 2128 ((unsigned long)cachep) % REAPTIMEOUT_NODE;
2129 2129
2130 cpu_cache_get(cachep)->avail = 0; 2130 cpu_cache_get(cachep)->avail = 0;
2131 cpu_cache_get(cachep)->limit = BOOT_CPUCACHE_ENTRIES; 2131 cpu_cache_get(cachep)->limit = BOOT_CPUCACHE_ENTRIES;
@@ -2327,10 +2327,10 @@ __kmem_cache_create (struct kmem_cache *cachep, unsigned long flags)
2327 if (flags & CFLGS_OFF_SLAB) { 2327 if (flags & CFLGS_OFF_SLAB) {
2328 cachep->freelist_cache = kmalloc_slab(freelist_size, 0u); 2328 cachep->freelist_cache = kmalloc_slab(freelist_size, 0u);
2329 /* 2329 /*
2330 * This is a possibility for one of the malloc_sizes caches. 2330 * This is a possibility for one of the kmalloc_{dma,}_caches.
2331 * But since we go off slab only for object size greater than 2331 * But since we go off slab only for object size greater than
2332 * PAGE_SIZE/8, and malloc_sizes gets created in ascending order, 2332 * PAGE_SIZE/8, and kmalloc_{dma,}_caches get created
2333 * this should not happen at all. 2333 * in ascending order,this should not happen at all.
2334 * But leave a BUG_ON for some lucky dude. 2334 * But leave a BUG_ON for some lucky dude.
2335 */ 2335 */
2336 BUG_ON(ZERO_OR_NULL_PTR(cachep->freelist_cache)); 2336 BUG_ON(ZERO_OR_NULL_PTR(cachep->freelist_cache));
@@ -2538,14 +2538,17 @@ int __kmem_cache_shutdown(struct kmem_cache *cachep)
2538 2538
2539/* 2539/*
2540 * Get the memory for a slab management obj. 2540 * Get the memory for a slab management obj.
2541 * For a slab cache when the slab descriptor is off-slab, slab descriptors 2541 *
2542 * always come from malloc_sizes caches. The slab descriptor cannot 2542 * For a slab cache when the slab descriptor is off-slab, the
2543 * come from the same cache which is getting created because, 2543 * slab descriptor can't come from the same cache which is being created,
2544 * when we are searching for an appropriate cache for these 2544 * Because if it is the case, that means we defer the creation of
2545 * descriptors in kmem_cache_create, we search through the malloc_sizes array. 2545 * the kmalloc_{dma,}_cache of size sizeof(slab descriptor) to this point.
2546 * If we are creating a malloc_sizes cache here it would not be visible to 2546 * And we eventually call down to __kmem_cache_create(), which
2547 * kmem_find_general_cachep till the initialization is complete. 2547 * in turn looks up in the kmalloc_{dma,}_caches for the disired-size one.
2548 * Hence we cannot have freelist_cache same as the original cache. 2548 * This is a "chicken-and-egg" problem.
2549 *
2550 * So the off-slab slab descriptor shall come from the kmalloc_{dma,}_caches,
2551 * which are all initialized during kmem_cache_init().
2549 */ 2552 */
2550static void *alloc_slabmgmt(struct kmem_cache *cachep, 2553static void *alloc_slabmgmt(struct kmem_cache *cachep,
2551 struct page *page, int colour_off, 2554 struct page *page, int colour_off,
@@ -3353,7 +3356,7 @@ slab_alloc(struct kmem_cache *cachep, gfp_t flags, unsigned long caller)
3353} 3356}
3354 3357
3355/* 3358/*
3356 * Caller needs to acquire correct kmem_list's list_lock 3359 * Caller needs to acquire correct kmem_cache_node's list_lock
3357 */ 3360 */
3358static void free_block(struct kmem_cache *cachep, void **objpp, int nr_objects, 3361static void free_block(struct kmem_cache *cachep, void **objpp, int nr_objects,
3359 int node) 3362 int node)
@@ -3607,11 +3610,6 @@ static __always_inline void *__do_kmalloc(size_t size, gfp_t flags,
3607 struct kmem_cache *cachep; 3610 struct kmem_cache *cachep;
3608 void *ret; 3611 void *ret;
3609 3612
3610 /* If you want to save a few bytes .text space: replace
3611 * __ with kmem_.
3612 * Then kmalloc uses the uninlined functions instead of the inline
3613 * functions.
3614 */
3615 cachep = kmalloc_slab(size, flags); 3613 cachep = kmalloc_slab(size, flags);
3616 if (unlikely(ZERO_OR_NULL_PTR(cachep))) 3614 if (unlikely(ZERO_OR_NULL_PTR(cachep)))
3617 return cachep; 3615 return cachep;
@@ -3703,7 +3701,7 @@ EXPORT_SYMBOL(kfree);
3703/* 3701/*
3704 * This initializes kmem_cache_node or resizes various caches for all nodes. 3702 * This initializes kmem_cache_node or resizes various caches for all nodes.
3705 */ 3703 */
3706static int alloc_kmemlist(struct kmem_cache *cachep, gfp_t gfp) 3704static int alloc_kmem_cache_node(struct kmem_cache *cachep, gfp_t gfp)
3707{ 3705{
3708 int node; 3706 int node;
3709 struct kmem_cache_node *n; 3707 struct kmem_cache_node *n;
@@ -3759,8 +3757,8 @@ static int alloc_kmemlist(struct kmem_cache *cachep, gfp_t gfp)
3759 } 3757 }
3760 3758
3761 kmem_cache_node_init(n); 3759 kmem_cache_node_init(n);
3762 n->next_reap = jiffies + REAPTIMEOUT_LIST3 + 3760 n->next_reap = jiffies + REAPTIMEOUT_NODE +
3763 ((unsigned long)cachep) % REAPTIMEOUT_LIST3; 3761 ((unsigned long)cachep) % REAPTIMEOUT_NODE;
3764 n->shared = new_shared; 3762 n->shared = new_shared;
3765 n->alien = new_alien; 3763 n->alien = new_alien;
3766 n->free_limit = (1 + nr_cpus_node(node)) * 3764 n->free_limit = (1 + nr_cpus_node(node)) *
@@ -3846,7 +3844,7 @@ static int __do_tune_cpucache(struct kmem_cache *cachep, int limit,
3846 kfree(ccold); 3844 kfree(ccold);
3847 } 3845 }
3848 kfree(new); 3846 kfree(new);
3849 return alloc_kmemlist(cachep, gfp); 3847 return alloc_kmem_cache_node(cachep, gfp);
3850} 3848}
3851 3849
3852static int do_tune_cpucache(struct kmem_cache *cachep, int limit, 3850static int do_tune_cpucache(struct kmem_cache *cachep, int limit,
@@ -4015,7 +4013,7 @@ static void cache_reap(struct work_struct *w)
4015 if (time_after(n->next_reap, jiffies)) 4013 if (time_after(n->next_reap, jiffies))
4016 goto next; 4014 goto next;
4017 4015
4018 n->next_reap = jiffies + REAPTIMEOUT_LIST3; 4016 n->next_reap = jiffies + REAPTIMEOUT_NODE;
4019 4017
4020 drain_array(searchp, n, n->shared, 0, node); 4018 drain_array(searchp, n, n->shared, 0, node);
4021 4019
@@ -4036,7 +4034,7 @@ next:
4036 next_reap_node(); 4034 next_reap_node();
4037out: 4035out:
4038 /* Set up the next iteration */ 4036 /* Set up the next iteration */
4039 schedule_delayed_work(work, round_jiffies_relative(REAPTIMEOUT_CPUC)); 4037 schedule_delayed_work(work, round_jiffies_relative(REAPTIMEOUT_AC));
4040} 4038}
4041 4039
4042#ifdef CONFIG_SLABINFO 4040#ifdef CONFIG_SLABINFO
generated by cgit v1.2.2 (git 2.25.0) at 2025-03-28 21:28:43 -0400