Commit d9f8984c authored by Lai Jiangshan's avatar Lai Jiangshan Committed by Linus Torvalds

ksm: cleanup for mm_slots_hash

Use compile-allocated memory instead of dynamic allocated memory for
mm_slots_hash.

Use hash_ptr() instead divisions for bucket calculation.
Signed-off-by: default avatarLai Jiangshan <laijs@cn.fujitsu.com>
Signed-off-by: default avatarIzik Eidus <ieidus@redhat.com>
Cc: Avi Kivity <avi@redhat.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent e31f3698
......@@ -33,6 +33,7 @@
#include <linux/mmu_notifier.h>
#include <linux/swap.h>
#include <linux/ksm.h>
#include <linux/hash.h>
#include <asm/tlbflush.h>
#include "internal.h"
......@@ -153,8 +154,9 @@ struct rmap_item {
static struct rb_root root_stable_tree = RB_ROOT;
static struct rb_root root_unstable_tree = RB_ROOT;
#define MM_SLOTS_HASH_HEADS 1024
static struct hlist_head *mm_slots_hash;
#define MM_SLOTS_HASH_SHIFT 10
#define MM_SLOTS_HASH_HEADS (1 << MM_SLOTS_HASH_SHIFT)
static struct hlist_head mm_slots_hash[MM_SLOTS_HASH_HEADS];
static struct mm_slot ksm_mm_head = {
.mm_list = LIST_HEAD_INIT(ksm_mm_head.mm_list),
......@@ -269,28 +271,13 @@ static inline void free_mm_slot(struct mm_slot *mm_slot)
kmem_cache_free(mm_slot_cache, mm_slot);
}
static int __init mm_slots_hash_init(void)
{
mm_slots_hash = kzalloc(MM_SLOTS_HASH_HEADS * sizeof(struct hlist_head),
GFP_KERNEL);
if (!mm_slots_hash)
return -ENOMEM;
return 0;
}
static void __init mm_slots_hash_free(void)
{
kfree(mm_slots_hash);
}
static struct mm_slot *get_mm_slot(struct mm_struct *mm)
{
struct mm_slot *mm_slot;
struct hlist_head *bucket;
struct hlist_node *node;
bucket = &mm_slots_hash[((unsigned long)mm / sizeof(struct mm_struct))
% MM_SLOTS_HASH_HEADS];
bucket = &mm_slots_hash[hash_ptr(mm, MM_SLOTS_HASH_SHIFT)];
hlist_for_each_entry(mm_slot, node, bucket, link) {
if (mm == mm_slot->mm)
return mm_slot;
......@@ -303,8 +290,7 @@ static void insert_to_mm_slots_hash(struct mm_struct *mm,
{
struct hlist_head *bucket;
bucket = &mm_slots_hash[((unsigned long)mm / sizeof(struct mm_struct))
% MM_SLOTS_HASH_HEADS];
bucket = &mm_slots_hash[hash_ptr(mm, MM_SLOTS_HASH_SHIFT)];
mm_slot->mm = mm;
hlist_add_head(&mm_slot->link, bucket);
}
......@@ -1938,15 +1924,11 @@ static int __init ksm_init(void)
if (err)
goto out;
err = mm_slots_hash_init();
if (err)
goto out_free1;
ksm_thread = kthread_run(ksm_scan_thread, NULL, "ksmd");
if (IS_ERR(ksm_thread)) {
printk(KERN_ERR "ksm: creating kthread failed\n");
err = PTR_ERR(ksm_thread);
goto out_free2;
goto out_free;
}
#ifdef CONFIG_SYSFS
......@@ -1954,7 +1936,7 @@ static int __init ksm_init(void)
if (err) {
printk(KERN_ERR "ksm: register sysfs failed\n");
kthread_stop(ksm_thread);
goto out_free2;
goto out_free;
}
#else
ksm_run = KSM_RUN_MERGE; /* no way for user to start it */
......@@ -1970,9 +1952,7 @@ static int __init ksm_init(void)
#endif
return 0;
out_free2:
mm_slots_hash_free();
out_free1:
out_free:
ksm_slab_free();
out:
return err;
......
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