@@ -42,6 +42,7 @@
#include <asm/tlbflush.h>
#include "internal.h"
+#include "mm_slot.h"
#ifdef CONFIG_NUMA
#define NUMA(x) (x)
@@ -113,16 +114,12 @@
/**
* struct ksm_mm_slot - ksm information per mm that is being scanned
- * @hash: link to the mm_slots hash list
- * @mm_node: link into the mm_slots list, rooted in ksm_mm_head
+ * @slot: hash lookup from mm to mm_slot
* @rmap_list: head for this mm_slot's singly-linked list of rmap_items
- * @mm: the mm that this information is valid for
*/
struct ksm_mm_slot {
- struct hlist_node hash;
- struct list_head mm_node;
+ struct mm_slot slot;
struct ksm_rmap_item *rmap_list;
- struct mm_struct *mm;
};
/**
@@ -231,7 +228,7 @@ static LIST_HEAD(migrate_nodes);
static DEFINE_HASHTABLE(mm_slots_hash, MM_SLOTS_HASH_BITS);
static struct ksm_mm_slot ksm_mm_head = {
- .mm_node = LIST_HEAD_INIT(ksm_mm_head.mm_node),
+ .slot.mm_node = LIST_HEAD_INIT(ksm_mm_head.slot.mm_node),
};
static struct ksm_scan ksm_scan = {
.mm_slot = &ksm_mm_head,
@@ -408,36 +405,6 @@ static inline void free_stable_node(struct ksm_stable_node *stable_node)
kmem_cache_free(stable_node_cache, stable_node);
}
-static inline struct ksm_mm_slot *alloc_mm_slot(void)
-{
- if (!mm_slot_cache) /* initialization failed */
- return NULL;
- return kmem_cache_zalloc(mm_slot_cache, GFP_KERNEL);
-}
-
-static inline void free_mm_slot(struct ksm_mm_slot *mm_slot)
-{
- kmem_cache_free(mm_slot_cache, mm_slot);
-}
-
-static struct ksm_mm_slot *get_mm_slot(struct mm_struct *mm)
-{
- struct ksm_mm_slot *slot;
-
- hash_for_each_possible(mm_slots_hash, slot, hash, (unsigned long)mm)
- if (slot->mm == mm)
- return slot;
-
- return NULL;
-}
-
-static void insert_to_mm_slots_hash(struct mm_struct *mm,
- struct ksm_mm_slot *mm_slot)
-{
- mm_slot->mm = mm;
- hash_add(mm_slots_hash, &mm_slot->hash, (unsigned long)mm);
-}
-
/*
* ksmd, and unmerge_and_remove_all_rmap_items(), must not touch an mm's
* page tables after it has passed through ksm_exit() - which, if necessary,
@@ -975,20 +942,22 @@ static int remove_all_stable_nodes(void)
static int unmerge_and_remove_all_rmap_items(void)
{
struct ksm_mm_slot *mm_slot;
+ struct mm_slot *slot;
struct mm_struct *mm;
struct vm_area_struct *vma;
int err = 0;
spin_lock(&ksm_mmlist_lock);
- ksm_scan.mm_slot = list_entry(ksm_mm_head.mm_node.next,
- struct ksm_mm_slot, mm_node);
+ slot = list_entry(ksm_mm_head.slot.mm_node.next,
+ struct mm_slot, mm_node);
+ ksm_scan.mm_slot = mm_slot_entry(slot, struct ksm_mm_slot, slot);
spin_unlock(&ksm_mmlist_lock);
for (mm_slot = ksm_scan.mm_slot; mm_slot != &ksm_mm_head;
mm_slot = ksm_scan.mm_slot) {
- VMA_ITERATOR(vmi, mm_slot->mm, 0);
+ VMA_ITERATOR(vmi, mm_slot->slot.mm, 0);
- mm = mm_slot->mm;
+ mm = mm_slot->slot.mm;
mmap_read_lock(mm);
for_each_vma(vmi, vma) {
if (ksm_test_exit(mm))
@@ -1005,14 +974,15 @@ static int unmerge_and_remove_all_rmap_items(void)
mmap_read_unlock(mm);
spin_lock(&ksm_mmlist_lock);
- ksm_scan.mm_slot = list_entry(mm_slot->mm_node.next,
- struct ksm_mm_slot, mm_node);
+ slot = list_entry(mm_slot->slot.mm_node.next,
+ struct mm_slot, mm_node);
+ ksm_scan.mm_slot = mm_slot_entry(slot, struct ksm_mm_slot, slot);
if (ksm_test_exit(mm)) {
- hash_del(&mm_slot->hash);
- list_del(&mm_slot->mm_node);
+ hash_del(&mm_slot->slot.hash);
+ list_del(&mm_slot->slot.mm_node);
spin_unlock(&ksm_mmlist_lock);
- free_mm_slot(mm_slot);
+ free_mm_slot(mm_slot_cache, mm_slot);
clear_bit(MMF_VM_MERGEABLE, &mm->flags);
mmdrop(mm);
} else
@@ -2233,7 +2203,7 @@ static struct ksm_rmap_item *get_next_rmap_item(struct ksm_mm_slot *mm_slot,
rmap_item = alloc_rmap_item();
if (rmap_item) {
/* It has already been zeroed */
- rmap_item->mm = mm_slot->mm;
+ rmap_item->mm = mm_slot->slot.mm;
rmap_item->address = addr;
rmap_item->rmap_list = *rmap_list;
*rmap_list = rmap_item;
@@ -2244,17 +2214,18 @@ static struct ksm_rmap_item *get_next_rmap_item(struct ksm_mm_slot *mm_slot,
static struct ksm_rmap_item *scan_get_next_rmap_item(struct page **page)
{
struct mm_struct *mm;
- struct ksm_mm_slot *slot;
+ struct ksm_mm_slot *mm_slot;
+ struct mm_slot *slot;
struct vm_area_struct *vma;
struct ksm_rmap_item *rmap_item;
struct vma_iterator vmi;
int nid;
- if (list_empty(&ksm_mm_head.mm_node))
+ if (list_empty(&ksm_mm_head.slot.mm_node))
return NULL;
- slot = ksm_scan.mm_slot;
- if (slot == &ksm_mm_head) {
+ mm_slot = ksm_scan.mm_slot;
+ if (mm_slot == &ksm_mm_head) {
/*
* A number of pages can hang around indefinitely on per-cpu
* pagevecs, raised page count preventing write_protect_page
@@ -2291,20 +2262,23 @@ static struct ksm_rmap_item *scan_get_next_rmap_item(struct page **page)
root_unstable_tree[nid] = RB_ROOT;
spin_lock(&ksm_mmlist_lock);
- slot = list_entry(slot->mm_node.next, struct ksm_mm_slot, mm_node);
- ksm_scan.mm_slot = slot;
+ slot = list_entry(mm_slot->slot.mm_node.next,
+ struct mm_slot, mm_node);
+ mm_slot = mm_slot_entry(slot, struct ksm_mm_slot, slot);
+ ksm_scan.mm_slot = mm_slot;
spin_unlock(&ksm_mmlist_lock);
/*
* Although we tested list_empty() above, a racing __ksm_exit
* of the last mm on the list may have removed it since then.
*/
- if (slot == &ksm_mm_head)
+ if (mm_slot == &ksm_mm_head)
return NULL;
next_mm:
ksm_scan.address = 0;
- ksm_scan.rmap_list = &slot->rmap_list;
+ ksm_scan.rmap_list = &mm_slot->rmap_list;
}
+ slot = &mm_slot->slot;
mm = slot->mm;
vma_iter_init(&vmi, mm, ksm_scan.address);
@@ -2334,7 +2308,7 @@ static struct ksm_rmap_item *scan_get_next_rmap_item(struct page **page)
if (PageAnon(*page)) {
flush_anon_page(vma, *page, ksm_scan.address);
flush_dcache_page(*page);
- rmap_item = get_next_rmap_item(slot,
+ rmap_item = get_next_rmap_item(mm_slot,
ksm_scan.rmap_list, ksm_scan.address);
if (rmap_item) {
ksm_scan.rmap_list =
@@ -2355,7 +2329,7 @@ static struct ksm_rmap_item *scan_get_next_rmap_item(struct page **page)
if (ksm_test_exit(mm)) {
no_vmas:
ksm_scan.address = 0;
- ksm_scan.rmap_list = &slot->rmap_list;
+ ksm_scan.rmap_list = &mm_slot->rmap_list;
}
/*
* Nuke all the rmap_items that are above this current rmap:
@@ -2364,8 +2338,9 @@ static struct ksm_rmap_item *scan_get_next_rmap_item(struct page **page)
remove_trailing_rmap_items(ksm_scan.rmap_list);
spin_lock(&ksm_mmlist_lock);
- ksm_scan.mm_slot = list_entry(slot->mm_node.next,
- struct ksm_mm_slot, mm_node);
+ slot = list_entry(mm_slot->slot.mm_node.next,
+ struct mm_slot, mm_node);
+ ksm_scan.mm_slot = mm_slot_entry(slot, struct ksm_mm_slot, slot);
if (ksm_scan.address == 0) {
/*
* We've completed a full scan of all vmas, holding mmap_lock
@@ -2376,11 +2351,11 @@ static struct ksm_rmap_item *scan_get_next_rmap_item(struct page **page)
* or when all VM_MERGEABLE areas have been unmapped (and
* mmap_lock then protects against race with MADV_MERGEABLE).
*/
- hash_del(&slot->hash);
- list_del(&slot->mm_node);
+ hash_del(&mm_slot->slot.hash);
+ list_del(&mm_slot->slot.mm_node);
spin_unlock(&ksm_mmlist_lock);
- free_mm_slot(slot);
+ free_mm_slot(mm_slot_cache, mm_slot);
clear_bit(MMF_VM_MERGEABLE, &mm->flags);
mmap_read_unlock(mm);
mmdrop(mm);
@@ -2397,8 +2372,8 @@ static struct ksm_rmap_item *scan_get_next_rmap_item(struct page **page)
}
/* Repeat until we've completed scanning the whole list */
- slot = ksm_scan.mm_slot;
- if (slot != &ksm_mm_head)
+ mm_slot = ksm_scan.mm_slot;
+ if (mm_slot != &ksm_mm_head)
goto next_mm;
ksm_scan.seqnr++;
@@ -2426,7 +2401,7 @@ static void ksm_do_scan(unsigned int scan_npages)
static int ksmd_should_run(void)
{
- return (ksm_run & KSM_RUN_MERGE) && !list_empty(&ksm_mm_head.mm_node);
+ return (ksm_run & KSM_RUN_MERGE) && !list_empty(&ksm_mm_head.slot.mm_node);
}
static int ksm_scan_thread(void *nothing)
@@ -2516,17 +2491,20 @@ EXPORT_SYMBOL_GPL(ksm_madvise);
int __ksm_enter(struct mm_struct *mm)
{
struct ksm_mm_slot *mm_slot;
+ struct mm_slot *slot;
int needs_wakeup;
- mm_slot = alloc_mm_slot();
+ mm_slot = alloc_mm_slot(mm_slot_cache);
if (!mm_slot)
return -ENOMEM;
+ slot = &mm_slot->slot;
+
/* Check ksm_run too? Would need tighter locking */
- needs_wakeup = list_empty(&ksm_mm_head.mm_node);
+ needs_wakeup = list_empty(&ksm_mm_head.slot.mm_node);
spin_lock(&ksm_mmlist_lock);
- insert_to_mm_slots_hash(mm, mm_slot);
+ insert_to_mm_slots_hash(mm_slots_hash, mm, slot);
/*
* When KSM_RUN_MERGE (or KSM_RUN_STOP),
* insert just behind the scanning cursor, to let the area settle
@@ -2538,9 +2516,9 @@ int __ksm_enter(struct mm_struct *mm)
* missed: then we might as well insert at the end of the list.
*/
if (ksm_run & KSM_RUN_UNMERGE)
- list_add_tail(&mm_slot->mm_node, &ksm_mm_head.mm_node);
+ list_add_tail(&slot->mm_node, &ksm_mm_head.slot.mm_node);
else
- list_add_tail(&mm_slot->mm_node, &ksm_scan.mm_slot->mm_node);
+ list_add_tail(&slot->mm_node, &ksm_scan.mm_slot->slot.mm_node);
spin_unlock(&ksm_mmlist_lock);
set_bit(MMF_VM_MERGEABLE, &mm->flags);
@@ -2555,6 +2533,7 @@ int __ksm_enter(struct mm_struct *mm)
void __ksm_exit(struct mm_struct *mm)
{
struct ksm_mm_slot *mm_slot;
+ struct mm_slot *slot;
int easy_to_free = 0;
/*
@@ -2567,21 +2546,22 @@ void __ksm_exit(struct mm_struct *mm)
*/
spin_lock(&ksm_mmlist_lock);
- mm_slot = get_mm_slot(mm);
+ slot = get_mm_slot(mm_slots_hash, mm);
+ mm_slot = mm_slot_entry(slot, struct ksm_mm_slot, slot);
if (mm_slot && ksm_scan.mm_slot != mm_slot) {
if (!mm_slot->rmap_list) {
- hash_del(&mm_slot->hash);
- list_del(&mm_slot->mm_node);
+ hash_del(&slot->hash);
+ list_del(&slot->mm_node);
easy_to_free = 1;
} else {
- list_move(&mm_slot->mm_node,
- &ksm_scan.mm_slot->mm_node);
+ list_move(&slot->mm_node,
+ &ksm_scan.mm_slot->slot.mm_node);
}
}
spin_unlock(&ksm_mmlist_lock);
if (easy_to_free) {
- free_mm_slot(mm_slot);
+ free_mm_slot(mm_slot_cache, mm_slot);
clear_bit(MMF_VM_MERGEABLE, &mm->flags);
mmdrop(mm);
} else if (mm_slot) {
Convert to use common struct mm_slot, no functional change. Signed-off-by: Qi Zheng <zhengqi.arch@bytedance.com> --- mm/ksm.c | 132 +++++++++++++++++++++++-------------------------------- 1 file changed, 56 insertions(+), 76 deletions(-)