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 @@ ...@@ -33,6 +33,7 @@
#include <linux/mmu_notifier.h> #include <linux/mmu_notifier.h>
#include <linux/swap.h> #include <linux/swap.h>
#include <linux/ksm.h> #include <linux/ksm.h>
#include <linux/hash.h>
#include <asm/tlbflush.h> #include <asm/tlbflush.h>
#include "internal.h" #include "internal.h"
...@@ -153,8 +154,9 @@ struct rmap_item { ...@@ -153,8 +154,9 @@ struct rmap_item {
static struct rb_root root_stable_tree = RB_ROOT; static struct rb_root root_stable_tree = RB_ROOT;
static struct rb_root root_unstable_tree = RB_ROOT; static struct rb_root root_unstable_tree = RB_ROOT;
#define MM_SLOTS_HASH_HEADS 1024 #define MM_SLOTS_HASH_SHIFT 10
static struct hlist_head *mm_slots_hash; #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 = { static struct mm_slot ksm_mm_head = {
.mm_list = LIST_HEAD_INIT(ksm_mm_head.mm_list), .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) ...@@ -269,28 +271,13 @@ static inline void free_mm_slot(struct mm_slot *mm_slot)
kmem_cache_free(mm_slot_cache, 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) static struct mm_slot *get_mm_slot(struct mm_struct *mm)
{ {
struct mm_slot *mm_slot; struct mm_slot *mm_slot;
struct hlist_head *bucket; struct hlist_head *bucket;
struct hlist_node *node; struct hlist_node *node;
bucket = &mm_slots_hash[((unsigned long)mm / sizeof(struct mm_struct)) bucket = &mm_slots_hash[hash_ptr(mm, MM_SLOTS_HASH_SHIFT)];
% MM_SLOTS_HASH_HEADS];
hlist_for_each_entry(mm_slot, node, bucket, link) { hlist_for_each_entry(mm_slot, node, bucket, link) {
if (mm == mm_slot->mm) if (mm == mm_slot->mm)
return mm_slot; return mm_slot;
...@@ -303,8 +290,7 @@ static void insert_to_mm_slots_hash(struct mm_struct *mm, ...@@ -303,8 +290,7 @@ static void insert_to_mm_slots_hash(struct mm_struct *mm,
{ {
struct hlist_head *bucket; struct hlist_head *bucket;
bucket = &mm_slots_hash[((unsigned long)mm / sizeof(struct mm_struct)) bucket = &mm_slots_hash[hash_ptr(mm, MM_SLOTS_HASH_SHIFT)];
% MM_SLOTS_HASH_HEADS];
mm_slot->mm = mm; mm_slot->mm = mm;
hlist_add_head(&mm_slot->link, bucket); hlist_add_head(&mm_slot->link, bucket);
} }
...@@ -1938,15 +1924,11 @@ static int __init ksm_init(void) ...@@ -1938,15 +1924,11 @@ static int __init ksm_init(void)
if (err) if (err)
goto out; goto out;
err = mm_slots_hash_init();
if (err)
goto out_free1;
ksm_thread = kthread_run(ksm_scan_thread, NULL, "ksmd"); ksm_thread = kthread_run(ksm_scan_thread, NULL, "ksmd");
if (IS_ERR(ksm_thread)) { if (IS_ERR(ksm_thread)) {
printk(KERN_ERR "ksm: creating kthread failed\n"); printk(KERN_ERR "ksm: creating kthread failed\n");
err = PTR_ERR(ksm_thread); err = PTR_ERR(ksm_thread);
goto out_free2; goto out_free;
} }
#ifdef CONFIG_SYSFS #ifdef CONFIG_SYSFS
...@@ -1954,7 +1936,7 @@ static int __init ksm_init(void) ...@@ -1954,7 +1936,7 @@ static int __init ksm_init(void)
if (err) { if (err) {
printk(KERN_ERR "ksm: register sysfs failed\n"); printk(KERN_ERR "ksm: register sysfs failed\n");
kthread_stop(ksm_thread); kthread_stop(ksm_thread);
goto out_free2; goto out_free;
} }
#else #else
ksm_run = KSM_RUN_MERGE; /* no way for user to start it */ ksm_run = KSM_RUN_MERGE; /* no way for user to start it */
...@@ -1970,9 +1952,7 @@ static int __init ksm_init(void) ...@@ -1970,9 +1952,7 @@ static int __init ksm_init(void)
#endif #endif
return 0; return 0;
out_free2: out_free:
mm_slots_hash_free();
out_free1:
ksm_slab_free(); ksm_slab_free();
out: out:
return err; return err;
......
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