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: Lai Jiangshan <laijs@cn.fujitsu.com>
Signed-off-by: Izik Eidus <ieidus@redhat.com>
Cc: Avi Kivity <avi@redhat.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/mm/ksm.c b/mm/ksm.c
index 9f2acc9..e2ae004 100644
--- a/mm/ksm.c
+++ b/mm/ksm.c
@@ -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 @@
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 @@
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 @@
{
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 @@
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 @@
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 @@
#endif
return 0;
-out_free2:
- mm_slots_hash_free();
-out_free1:
+out_free:
ksm_slab_free();
out:
return err;