The patch titled
Subject: zsmalloc: introduce obj_allocated
has been added to the -mm tree. Its filename is
zsmalloc-introduce-obj_allocated.patch
This patch should soon appear at
https://ozlabs.org/~akpm/mmots/broken-out/zsmalloc-introduce-obj_allocated.patch
and later at
https://ozlabs.org/~akpm/mmotm/broken-out/zsmalloc-introduce-obj_allocated.patch
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*** Remember to use Documentation/process/submit-checklist.rst when testing your code ***
The -mm tree is included into linux-next and is updated
there every 3-4 working days
------------------------------------------------------
From: Minchan Kim <minchan@xxxxxxxxxx>
Subject: zsmalloc: introduce obj_allocated
The usage pattern for obj_to_head is to check whether the zpage is
allocated or not. Thus, introduce obj_allocated.
Link: https://lkml.kernel.org/r/20211115185909.3949505-5-minchan@xxxxxxxxxx
Signed-off-by: Minchan Kim <minchan@xxxxxxxxxx>
Cc: Mike Galbraith <umgwanakikbuti@xxxxxxxxx>
Cc: Peter Zijlstra (Intel) <peterz@xxxxxxxxxxxxx>
Cc: Sebastian Andrzej Siewior <bigeasy@xxxxxxxxxxxxx>
Cc: Sergey Senozhatsky <senozhatsky@xxxxxxxxxxxx>
Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
mm/zsmalloc.c | 33 ++++++++++++++++-----------------
1 file changed, 16 insertions(+), 17 deletions(-)
--- a/mm/zsmalloc.c~zsmalloc-introduce-obj_allocated
+++ a/mm/zsmalloc.c
@@ -877,13 +877,21 @@ static unsigned long handle_to_obj(unsig
return *(unsigned long *)handle;
}
-static unsigned long obj_to_head(struct page *page, void *obj)
+static bool obj_allocated(struct page *page, void *obj, unsigned long *phandle)
{
+ unsigned long handle;
+
if (unlikely(PageHugeObject(page))) {
VM_BUG_ON_PAGE(!is_first_page(page), page);
- return page->index;
+ handle = page->index;
} else
- return *(unsigned long *)obj;
+ handle = *(unsigned long *)obj;
+
+ if (!(handle & OBJ_ALLOCATED_TAG))
+ return false;
+
+ *phandle = handle & ~OBJ_ALLOCATED_TAG;
+ return true;
}
static inline int testpin_tag(unsigned long handle)
@@ -1606,7 +1614,6 @@ static void zs_object_copy(struct size_c
static unsigned long find_alloced_obj(struct size_class *class,
struct page *page, int *obj_idx)
{
- unsigned long head;
int offset = 0;
int index = *obj_idx;
unsigned long handle = 0;
@@ -1616,9 +1623,7 @@ static unsigned long find_alloced_obj(st
offset += class->size * index;
while (offset < PAGE_SIZE) {
- head = obj_to_head(page, addr + offset);
- if (head & OBJ_ALLOCATED_TAG) {
- handle = head & ~OBJ_ALLOCATED_TAG;
+ if (obj_allocated(page, addr + offset, &handle)) {
if (trypin_tag(handle))
break;
handle = 0;
@@ -1928,7 +1933,7 @@ static int zs_page_migrate(struct addres
struct page *dummy;
void *s_addr, *d_addr, *addr;
int offset, pos;
- unsigned long handle, head;
+ unsigned long handle;
unsigned long old_obj, new_obj;
unsigned int obj_idx;
int ret = -EAGAIN;
@@ -1964,9 +1969,7 @@ static int zs_page_migrate(struct addres
pos = offset;
s_addr = kmap_atomic(page);
while (pos < PAGE_SIZE) {
- head = obj_to_head(page, s_addr + pos);
- if (head & OBJ_ALLOCATED_TAG) {
- handle = head & ~OBJ_ALLOCATED_TAG;
+ if (obj_allocated(page, s_addr + pos, &handle)) {
if (!trypin_tag(handle))
goto unpin_objects;
}
@@ -1982,9 +1985,7 @@ static int zs_page_migrate(struct addres
for (addr = s_addr + offset; addr < s_addr + pos;
addr += class->size) {
- head = obj_to_head(page, addr);
- if (head & OBJ_ALLOCATED_TAG) {
- handle = head & ~OBJ_ALLOCATED_TAG;
+ if (obj_allocated(page, addr, &handle)) {
BUG_ON(!testpin_tag(handle));
old_obj = handle_to_obj(handle);
@@ -2029,9 +2030,7 @@ static int zs_page_migrate(struct addres
unpin_objects:
for (addr = s_addr + offset; addr < s_addr + pos;
addr += class->size) {
- head = obj_to_head(page, addr);
- if (head & OBJ_ALLOCATED_TAG) {
- handle = head & ~OBJ_ALLOCATED_TAG;
+ if (obj_allocated(page, addr, &handle)) {
BUG_ON(!testpin_tag(handle));
unpin_tag(handle);
}
_
Patches currently in -mm which might be from minchan@xxxxxxxxxx are
zsmalloc-introduce-some-helper-functions.patch
zsmalloc-rename-zs_stat_type-to-class_stat_type.patch
zsmalloc-decouple-class-actions-from-zspage-works.patch
zsmalloc-introduce-obj_allocated.patch
zsmalloc-move-huge-compressed-obj-from-page-to-zspage.patch
zsmalloc-remove-zspage-isolation-for-migration.patch
locking-rwlocks-introduce-write_lock_nested.patch
zsmalloc-replace-per-zpage-lock-with-pool-migrate_lock.patch
