Update Linux to v5.4.148
Sourced from [1]
[1] https://cdn.kernel.org/pub/linux/kernel/v5.x/linux-5.4.148.tar.gz
Change-Id: Ib3d26c5ba9b022e2e03533005c4fed4d7c30b61b
Signed-off-by: Olivier Deprez <olivier.deprez@arm.com>
diff --git a/mm/compaction.c b/mm/compaction.c
index 672d3c7..d686887 100644
--- a/mm/compaction.c
+++ b/mm/compaction.c
@@ -1276,7 +1276,7 @@
{
unsigned int limit = min(1U, freelist_scan_limit(cc) >> 1);
unsigned int nr_scanned = 0;
- unsigned long low_pfn, min_pfn, high_pfn = 0, highest = 0;
+ unsigned long low_pfn, min_pfn, highest = 0;
unsigned long nr_isolated = 0;
unsigned long distance;
struct page *page = NULL;
@@ -1321,6 +1321,7 @@
struct page *freepage;
unsigned long flags;
unsigned int order_scanned = 0;
+ unsigned long high_pfn = 0;
if (!area->nr_free)
continue;
@@ -1629,6 +1630,7 @@
unsigned long pfn = cc->migrate_pfn;
unsigned long high_pfn;
int order;
+ bool found_block = false;
/* Skip hints are relied on to avoid repeats on the fast search */
if (cc->ignore_skip_hint)
@@ -1671,7 +1673,7 @@
high_pfn = pageblock_start_pfn(cc->migrate_pfn + distance);
for (order = cc->order - 1;
- order >= PAGE_ALLOC_COSTLY_ORDER && pfn == cc->migrate_pfn && nr_scanned < limit;
+ order >= PAGE_ALLOC_COSTLY_ORDER && !found_block && nr_scanned < limit;
order--) {
struct free_area *area = &cc->zone->free_area[order];
struct list_head *freelist;
@@ -1686,7 +1688,11 @@
list_for_each_entry(freepage, freelist, lru) {
unsigned long free_pfn;
- nr_scanned++;
+ if (nr_scanned++ >= limit) {
+ move_freelist_tail(freelist, freepage);
+ break;
+ }
+
free_pfn = page_to_pfn(freepage);
if (free_pfn < high_pfn) {
/*
@@ -1695,12 +1701,8 @@
* the list assumes an entry is deleted, not
* reordered.
*/
- if (get_pageblock_skip(freepage)) {
- if (list_is_last(freelist, &freepage->lru))
- break;
-
+ if (get_pageblock_skip(freepage))
continue;
- }
/* Reorder to so a future search skips recent pages */
move_freelist_tail(freelist, freepage);
@@ -1708,15 +1710,10 @@
update_fast_start_pfn(cc, free_pfn);
pfn = pageblock_start_pfn(free_pfn);
cc->fast_search_fail = 0;
+ found_block = true;
set_pageblock_skip(freepage);
break;
}
-
- if (nr_scanned >= limit) {
- cc->fast_search_fail++;
- move_freelist_tail(freelist, freepage);
- break;
- }
}
spin_unlock_irqrestore(&cc->zone->lock, flags);
}
@@ -1727,9 +1724,10 @@
* If fast scanning failed then use a cached entry for a page block
* that had free pages as the basis for starting a linear scan.
*/
- if (pfn == cc->migrate_pfn)
+ if (!found_block) {
+ cc->fast_search_fail++;
pfn = reinit_migrate_pfn(cc);
-
+ }
return pfn;
}
@@ -2310,16 +2308,26 @@
.page = NULL,
};
- if (capture)
- current->capture_control = &capc;
+ /*
+ * Make sure the structs are really initialized before we expose the
+ * capture control, in case we are interrupted and the interrupt handler
+ * frees a page.
+ */
+ barrier();
+ WRITE_ONCE(current->capture_control, &capc);
ret = compact_zone(&cc, &capc);
VM_BUG_ON(!list_empty(&cc.freepages));
VM_BUG_ON(!list_empty(&cc.migratepages));
- *capture = capc.page;
- current->capture_control = NULL;
+ /*
+ * Make sure we hide capture control first before we read the captured
+ * page pointer, otherwise an interrupt could free and capture a page
+ * and we would leak it.
+ */
+ WRITE_ONCE(current->capture_control, NULL);
+ *capture = READ_ONCE(capc.page);
return ret;
}
@@ -2333,6 +2341,7 @@
* @alloc_flags: The allocation flags of the current allocation
* @ac: The context of current allocation
* @prio: Determines how hard direct compaction should try to succeed
+ * @capture: Pointer to free page created by compaction will be stored here
*
* This is the main entry point for direct page compaction.
*/