Got some -EBUSY from zs_page_migrate that will make migration
slow (retry) or fail (zs_page_putback will schedule_work free_work,
but it cannot ensure the success).
And I didn't find anything that make zs_page_migrate cannot work with
a ZS_EMPTY zspage.
So make the patch to not check inuse if migrate_mode is not
MIGRATE_ASYNC.
Signed-off-by: Hui Zhu <zhu...@xiaomi.com>
---
mm/zsmalloc.c | 66 +++++++++++++++++++++++++++++++++--------------------------
1 file changed, 37 insertions(+), 29 deletions(-)
diff --git a/mm/zsmalloc.c b/mm/zsmalloc.c
index d41edd2..c298e5c 100644
--- a/mm/zsmalloc.c
+++ b/mm/zsmalloc.c
@@ -1982,6 +1982,7 @@ int zs_page_migrate(struct address_space *mapping, struct
page *newpage,
unsigned long old_obj, new_obj;
unsigned int obj_idx;
int ret = -EAGAIN;
+ int inuse;
VM_BUG_ON_PAGE(!PageMovable(page), page);
VM_BUG_ON_PAGE(!PageIsolated(page), page);
@@ -1996,21 +1997,24 @@ int zs_page_migrate(struct address_space *mapping,
struct page *newpage,
offset = get_first_obj_offset(page);
spin_lock(&class->lock);
- if (!get_zspage_inuse(zspage)) {
+ inuse = get_zspage_inuse(zspage);
+ if (mode == MIGRATE_ASYNC && !inuse) {
ret = -EBUSY;
goto unlock_class;
}
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 (!trypin_tag(handle))
- goto unpin_objects;
+ if (inuse) {
+ while (pos < PAGE_SIZE) {
+ head = obj_to_head(page, s_addr + pos);
+ if (head & OBJ_ALLOCATED_TAG) {
+ handle = head & ~OBJ_ALLOCATED_TAG;
+ if (!trypin_tag(handle))
+ goto unpin_objects;
+ }
+ pos += class->size;
}
- pos += class->size;
}
/*
@@ -2020,20 +2024,22 @@ int zs_page_migrate(struct address_space *mapping,
struct page *newpage,
memcpy(d_addr, s_addr, PAGE_SIZE);
kunmap_atomic(d_addr);
- 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 (!testpin_tag(handle))
- BUG();
-
- old_obj = handle_to_obj(handle);
- obj_to_location(old_obj, &dummy, &obj_idx);
- new_obj = (unsigned long)location_to_obj(newpage,
- obj_idx);
- new_obj |= BIT(HANDLE_PIN_BIT);
- record_obj(handle, new_obj);
+ if (inuse) {
+ 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 (!testpin_tag(handle))
+ BUG();
+
+ old_obj = handle_to_obj(handle);
+ obj_to_location(old_obj, &dummy, &obj_idx);
+ new_obj = (unsigned long)
+ location_to_obj(newpage, obj_idx);
+ new_obj |= BIT(HANDLE_PIN_BIT);
+ record_obj(handle, new_obj);
+ }
}
}
@@ -2055,14 +2061,16 @@ int zs_page_migrate(struct address_space *mapping,
struct page *newpage,
ret = MIGRATEPAGE_SUCCESS;
unpin_objects:
- for (addr = s_addr + offset; addr < s_addr + pos;
+ if (inuse) {
+ 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 (!testpin_tag(handle))
- BUG();
- unpin_tag(handle);
+ head = obj_to_head(page, addr);
+ if (head & OBJ_ALLOCATED_TAG) {
+ handle = head & ~OBJ_ALLOCATED_TAG;
+ if (!testpin_tag(handle))
+ BUG();
+ unpin_tag(handle);
+ }
}
}
kunmap_atomic(s_addr);
--
1.9.1
