mm/slab.c: cleanup outdated comments and unify variables naming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>
This commit is contained in:
Jianyu Zhan
Pekka Enberg
parent
24f870d8f0
commit
5f0985bb11
66
mm/slab.c
66
mm/slab.c
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@ -288,8 +288,8 @@ static void kmem_cache_node_init(struct kmem_cache_node *parent)
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* OTOH the cpuarrays can contain lots of objects,
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* which could lock up otherwise freeable slabs.
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*/
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#define REAPTIMEOUT_CPUC (2*HZ)
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#define REAPTIMEOUT_LIST3 (4*HZ)
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#define REAPTIMEOUT_AC (2*HZ)
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#define REAPTIMEOUT_NODE (4*HZ)
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#if STATS
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#define STATS_INC_ACTIVE(x) ((x)->num_active++)
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@ -1084,7 +1084,7 @@ static int init_cache_node_node(int node)
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list_for_each_entry(cachep, &slab_caches, list) {
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/*
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* Set up the size64 kmemlist for cpu before we can
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* Set up the kmem_cache_node for cpu before we can
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* begin anything. Make sure some other cpu on this
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* node has not already allocated this
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*/
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@ -1093,12 +1093,12 @@ static int init_cache_node_node(int node)
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if (!n)
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return -ENOMEM;
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kmem_cache_node_init(n);
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n->next_reap = jiffies + REAPTIMEOUT_LIST3 +
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((unsigned long)cachep) % REAPTIMEOUT_LIST3;
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n->next_reap = jiffies + REAPTIMEOUT_NODE +
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((unsigned long)cachep) % REAPTIMEOUT_NODE;
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/*
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* The l3s don't come and go as CPUs come and
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* go. slab_mutex is sufficient
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* The kmem_cache_nodes don't come and go as CPUs
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* come and go. slab_mutex is sufficient
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* protection here.
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*/
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cachep->node[node] = n;
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@ -1423,8 +1423,8 @@ static void __init set_up_node(struct kmem_cache *cachep, int index)
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for_each_online_node(node) {
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cachep->node[node] = &init_kmem_cache_node[index + node];
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cachep->node[node]->next_reap = jiffies +
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REAPTIMEOUT_LIST3 +
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((unsigned long)cachep) % REAPTIMEOUT_LIST3;
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REAPTIMEOUT_NODE +
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((unsigned long)cachep) % REAPTIMEOUT_NODE;
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}
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}
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@ -2124,8 +2124,8 @@ static int __init_refok setup_cpu_cache(struct kmem_cache *cachep, gfp_t gfp)
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}
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}
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cachep->node[numa_mem_id()]->next_reap =
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jiffies + REAPTIMEOUT_LIST3 +
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((unsigned long)cachep) % REAPTIMEOUT_LIST3;
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jiffies + REAPTIMEOUT_NODE +
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((unsigned long)cachep) % REAPTIMEOUT_NODE;
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cpu_cache_get(cachep)->avail = 0;
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cpu_cache_get(cachep)->limit = BOOT_CPUCACHE_ENTRIES;
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@ -2327,10 +2327,10 @@ __kmem_cache_create (struct kmem_cache *cachep, unsigned long flags)
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if (flags & CFLGS_OFF_SLAB) {
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cachep->freelist_cache = kmalloc_slab(freelist_size, 0u);
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/*
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* This is a possibility for one of the malloc_sizes caches.
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* This is a possibility for one of the kmalloc_{dma,}_caches.
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* But since we go off slab only for object size greater than
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* PAGE_SIZE/8, and malloc_sizes gets created in ascending order,
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* this should not happen at all.
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* PAGE_SIZE/8, and kmalloc_{dma,}_caches get created
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* in ascending order,this should not happen at all.
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* But leave a BUG_ON for some lucky dude.
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*/
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BUG_ON(ZERO_OR_NULL_PTR(cachep->freelist_cache));
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@ -2538,14 +2538,17 @@ int __kmem_cache_shutdown(struct kmem_cache *cachep)
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/*
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* Get the memory for a slab management obj.
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* For a slab cache when the slab descriptor is off-slab, slab descriptors
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* always come from malloc_sizes caches. The slab descriptor cannot
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* come from the same cache which is getting created because,
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* when we are searching for an appropriate cache for these
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* descriptors in kmem_cache_create, we search through the malloc_sizes array.
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* If we are creating a malloc_sizes cache here it would not be visible to
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* kmem_find_general_cachep till the initialization is complete.
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* Hence we cannot have freelist_cache same as the original cache.
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*
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* For a slab cache when the slab descriptor is off-slab, the
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* slab descriptor can't come from the same cache which is being created,
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* Because if it is the case, that means we defer the creation of
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* the kmalloc_{dma,}_cache of size sizeof(slab descriptor) to this point.
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* And we eventually call down to __kmem_cache_create(), which
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* in turn looks up in the kmalloc_{dma,}_caches for the disired-size one.
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* This is a "chicken-and-egg" problem.
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*
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* So the off-slab slab descriptor shall come from the kmalloc_{dma,}_caches,
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* which are all initialized during kmem_cache_init().
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*/
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static void *alloc_slabmgmt(struct kmem_cache *cachep,
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struct page *page, int colour_off,
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@ -3353,7 +3356,7 @@ slab_alloc(struct kmem_cache *cachep, gfp_t flags, unsigned long caller)
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}
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/*
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* Caller needs to acquire correct kmem_list's list_lock
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* Caller needs to acquire correct kmem_cache_node's list_lock
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*/
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static void free_block(struct kmem_cache *cachep, void **objpp, int nr_objects,
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int node)
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@ -3607,11 +3610,6 @@ static __always_inline void *__do_kmalloc(size_t size, gfp_t flags,
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struct kmem_cache *cachep;
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void *ret;
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/* If you want to save a few bytes .text space: replace
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* __ with kmem_.
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* Then kmalloc uses the uninlined functions instead of the inline
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* functions.
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*/
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cachep = kmalloc_slab(size, flags);
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if (unlikely(ZERO_OR_NULL_PTR(cachep)))
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return cachep;
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@ -3703,7 +3701,7 @@ EXPORT_SYMBOL(kfree);
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/*
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* This initializes kmem_cache_node or resizes various caches for all nodes.
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*/
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static int alloc_kmemlist(struct kmem_cache *cachep, gfp_t gfp)
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static int alloc_kmem_cache_node(struct kmem_cache *cachep, gfp_t gfp)
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{
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int node;
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struct kmem_cache_node *n;
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@ -3759,8 +3757,8 @@ static int alloc_kmemlist(struct kmem_cache *cachep, gfp_t gfp)
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}
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kmem_cache_node_init(n);
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n->next_reap = jiffies + REAPTIMEOUT_LIST3 +
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((unsigned long)cachep) % REAPTIMEOUT_LIST3;
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n->next_reap = jiffies + REAPTIMEOUT_NODE +
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((unsigned long)cachep) % REAPTIMEOUT_NODE;
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n->shared = new_shared;
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n->alien = new_alien;
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n->free_limit = (1 + nr_cpus_node(node)) *
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@ -3846,7 +3844,7 @@ static int __do_tune_cpucache(struct kmem_cache *cachep, int limit,
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kfree(ccold);
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}
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kfree(new);
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return alloc_kmemlist(cachep, gfp);
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return alloc_kmem_cache_node(cachep, gfp);
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}
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static int do_tune_cpucache(struct kmem_cache *cachep, int limit,
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@ -4015,7 +4013,7 @@ static void cache_reap(struct work_struct *w)
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if (time_after(n->next_reap, jiffies))
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goto next;
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n->next_reap = jiffies + REAPTIMEOUT_LIST3;
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n->next_reap = jiffies + REAPTIMEOUT_NODE;
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drain_array(searchp, n, n->shared, 0, node);
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@ -4036,7 +4034,7 @@ next:
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next_reap_node();
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out:
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/* Set up the next iteration */
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schedule_delayed_work(work, round_jiffies_relative(REAPTIMEOUT_CPUC));
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schedule_delayed_work(work, round_jiffies_relative(REAPTIMEOUT_AC));
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}
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#ifdef CONFIG_SLABINFO
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