The patch titled
Subject: ksm: convert to use common struct mm_slot
has been added to the -mm mm-unstable branch. Its filename is
ksm-convert-to-use-common-struct-mm_slot.patch
This patch will shortly appear at
https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/ksm-convert-to-use-common-struct-mm_slot.patch
This patch will later appear in the mm-unstable branch at
git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
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*** Remember to use Documentation/process/submit-checklist.rst when testing your code ***
The -mm tree is included into linux-next via the mm-everything
branch at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
and is updated there every 2-3 working days
------------------------------------------------------
From: Qi Zheng <zhengqi.arch@xxxxxxxxxxxxx>
Subject: ksm: convert to use common struct mm_slot
Date: Wed, 31 Aug 2022 11:19:51 +0800
Convert to use common struct mm_slot, no functional change.
Link: https://lkml.kernel.org/r/20220831031951.43152-8-zhengqi.arch@xxxxxxxxxxxxx
Signed-off-by: Qi Zheng <zhengqi.arch@xxxxxxxxxxxxx>
Cc: Johannes Weiner <hannes@xxxxxxxxxxx>
Cc: Matthew Wilcox <willy@xxxxxxxxxxxxx>
Cc: Mike Rapoport <rppt@xxxxxxxxxx>
Cc: Minchan Kim <minchan@xxxxxxxxxx>
Cc: Vlastimil Babka <vbabka@xxxxxxx>
Cc: Yang Shi <shy828301@xxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
mm/ksm.c | 132 ++++++++++++++++++++++-------------------------------
1 file changed, 56 insertions(+), 76 deletions(-)
--- a/mm/ksm.c~ksm-convert-to-use-common-struct-mm_slot
+++ a/mm/ksm.c
@@ -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,
@@ -409,36 +406,6 @@ static inline void free_stable_node(stru
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,
@@ -976,20 +943,22 @@ 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))
@@ -1006,14 +975,15 @@ static int unmerge_and_remove_all_rmap_i
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);
+ mm_slot_free(mm_slot_cache, mm_slot);
clear_bit(MMF_VM_MERGEABLE, &mm->flags);
mmdrop(mm);
} else
@@ -2234,7 +2204,7 @@ static struct ksm_rmap_item *get_next_rm
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->mm->ksm_rmap_items++;
rmap_item->address = addr;
rmap_item->rmap_list = *rmap_list;
@@ -2246,17 +2216,18 @@ static struct ksm_rmap_item *get_next_rm
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
@@ -2293,20 +2264,23 @@ static struct ksm_rmap_item *scan_get_ne
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);
@@ -2336,7 +2310,7 @@ next_mm:
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 =
@@ -2357,7 +2331,7 @@ next_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:
@@ -2366,8 +2340,9 @@ no_vmas:
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
@@ -2378,11 +2353,11 @@ no_vmas:
* 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);
+ mm_slot_free(mm_slot_cache, mm_slot);
clear_bit(MMF_VM_MERGEABLE, &mm->flags);
mmap_read_unlock(mm);
mmdrop(mm);
@@ -2399,8 +2374,8 @@ no_vmas:
}
/* 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++;
@@ -2428,7 +2403,7 @@ static void ksm_do_scan(unsigned int sca
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)
@@ -2518,17 +2493,20 @@ 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 = mm_slot_alloc(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);
+ mm_slot_insert(mm_slots_hash, mm, slot);
/*
* When KSM_RUN_MERGE (or KSM_RUN_STOP),
* insert just behind the scanning cursor, to let the area settle
@@ -2540,9 +2518,9 @@ 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);
@@ -2557,6 +2535,7 @@ 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;
/*
@@ -2569,21 +2548,22 @@ void __ksm_exit(struct mm_struct *mm)
*/
spin_lock(&ksm_mmlist_lock);
- mm_slot = get_mm_slot(mm);
+ slot = mm_slot_lookup(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);
+ mm_slot_free(mm_slot_cache, mm_slot);
clear_bit(MMF_VM_MERGEABLE, &mm->flags);
mmdrop(mm);
} else if (mm_slot) {
_
Patches currently in -mm which might be from zhengqi.arch@xxxxxxxxxxxxx are
mm-thp-remove-redundant-pgtable-check-in-set_huge_zero_page.patch
mm-introduce-common-struct-mm_slot.patch
mm-thp-convert-to-use-common-struct-mm_slot.patch
ksm-remove-redundant-declarations-in-ksmh.patch
ksm-add-the-ksm-prefix-to-the-names-of-the-ksm-private-structures.patch
ksm-convert-ksm_mm_slotmm_list-to-ksm_mm_slotmm_node.patch
ksm-convert-ksm_mm_slotlink-to-ksm_mm_slothash.patch
ksm-convert-to-use-common-struct-mm_slot.patch
