167 lines
4.8 KiB
Diff
167 lines
4.8 KiB
Diff
From: Peter Zijlstra <peterz@infradead.org>
|
|
Date: Mon, 28 May 2018 15:24:21 +0200
|
|
Subject: [PATCH 2/4] Split IRQ-off and zone->lock while freeing pages from PCP
|
|
list #2
|
|
Origin: https://www.kernel.org/pub/linux/kernel/projects/rt/4.19/older/patches-4.19.1-rt3.tar.xz
|
|
|
|
Split the IRQ-off section while accessing the PCP list from zone->lock
|
|
while freeing pages.
|
|
Introcude isolate_pcp_pages() which separates the pages from the PCP
|
|
list onto a temporary list and then free the temporary list via
|
|
free_pcppages_bulk().
|
|
|
|
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
|
|
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
|
|
---
|
|
mm/page_alloc.c | 60 ++++++++++++++++++++++++++++++++++++++++++++++----------
|
|
1 file changed, 50 insertions(+), 10 deletions(-)
|
|
|
|
--- a/mm/page_alloc.c
|
|
+++ b/mm/page_alloc.c
|
|
@@ -1077,8 +1077,8 @@ static inline void prefetch_buddy(struct
|
|
* And clear the zone's pages_scanned counter, to hold off the "all pages are
|
|
* pinned" detection logic.
|
|
*/
|
|
-static void free_pcppages_bulk(struct zone *zone, int count,
|
|
- struct list_head *head)
|
|
+static void free_pcppages_bulk(struct zone *zone, struct list_head *head,
|
|
+ bool zone_retry)
|
|
{
|
|
bool isolated_pageblocks;
|
|
struct page *page, *tmp;
|
|
@@ -1093,12 +1093,27 @@ static void free_pcppages_bulk(struct zo
|
|
*/
|
|
list_for_each_entry_safe(page, tmp, head, lru) {
|
|
int mt = get_pcppage_migratetype(page);
|
|
+
|
|
+ if (page_zone(page) != zone) {
|
|
+ /*
|
|
+ * free_unref_page_list() sorts pages by zone. If we end
|
|
+ * up with pages from a different NUMA nodes belonging
|
|
+ * to the same ZONE index then we need to redo with the
|
|
+ * correct ZONE pointer. Skip the page for now, redo it
|
|
+ * on the next iteration.
|
|
+ */
|
|
+ WARN_ON_ONCE(zone_retry == false);
|
|
+ if (zone_retry)
|
|
+ continue;
|
|
+ }
|
|
+
|
|
/* MIGRATE_ISOLATE page should not go to pcplists */
|
|
VM_BUG_ON_PAGE(is_migrate_isolate(mt), page);
|
|
/* Pageblock could have been isolated meanwhile */
|
|
if (unlikely(isolated_pageblocks))
|
|
mt = get_pageblock_migratetype(page);
|
|
|
|
+ list_del(&page->lru);
|
|
__free_one_page(page, page_to_pfn(page), zone, 0, mt);
|
|
trace_mm_page_pcpu_drain(page, 0, mt);
|
|
}
|
|
@@ -2533,7 +2548,7 @@ void drain_zone_pages(struct zone *zone,
|
|
local_irq_restore(flags);
|
|
|
|
if (to_drain > 0)
|
|
- free_pcppages_bulk(zone, to_drain, &dst);
|
|
+ free_pcppages_bulk(zone, &dst, false);
|
|
}
|
|
#endif
|
|
|
|
@@ -2563,7 +2578,7 @@ static void drain_pages_zone(unsigned in
|
|
local_irq_restore(flags);
|
|
|
|
if (count)
|
|
- free_pcppages_bulk(zone, count, &dst);
|
|
+ free_pcppages_bulk(zone, &dst, false);
|
|
}
|
|
|
|
/*
|
|
@@ -2756,7 +2771,8 @@ static bool free_unref_page_prepare(stru
|
|
return true;
|
|
}
|
|
|
|
-static void free_unref_page_commit(struct page *page, unsigned long pfn)
|
|
+static void free_unref_page_commit(struct page *page, unsigned long pfn,
|
|
+ struct list_head *dst)
|
|
{
|
|
struct zone *zone = page_zone(page);
|
|
struct per_cpu_pages *pcp;
|
|
@@ -2785,10 +2801,8 @@ static void free_unref_page_commit(struc
|
|
pcp->count++;
|
|
if (pcp->count >= pcp->high) {
|
|
unsigned long batch = READ_ONCE(pcp->batch);
|
|
- LIST_HEAD(dst);
|
|
|
|
- isolate_pcp_pages(batch, pcp, &dst);
|
|
- free_pcppages_bulk(zone, batch, &dst);
|
|
+ isolate_pcp_pages(batch, pcp, dst);
|
|
}
|
|
}
|
|
|
|
@@ -2799,13 +2813,17 @@ void free_unref_page(struct page *page)
|
|
{
|
|
unsigned long flags;
|
|
unsigned long pfn = page_to_pfn(page);
|
|
+ struct zone *zone = page_zone(page);
|
|
+ LIST_HEAD(dst);
|
|
|
|
if (!free_unref_page_prepare(page, pfn))
|
|
return;
|
|
|
|
local_irq_save(flags);
|
|
- free_unref_page_commit(page, pfn);
|
|
+ free_unref_page_commit(page, pfn, &dst);
|
|
local_irq_restore(flags);
|
|
+ if (!list_empty(&dst))
|
|
+ free_pcppages_bulk(zone, &dst, false);
|
|
}
|
|
|
|
/*
|
|
@@ -2816,6 +2834,11 @@ void free_unref_page_list(struct list_he
|
|
struct page *page, *next;
|
|
unsigned long flags, pfn;
|
|
int batch_count = 0;
|
|
+ struct list_head dsts[__MAX_NR_ZONES];
|
|
+ int i;
|
|
+
|
|
+ for (i = 0; i < __MAX_NR_ZONES; i++)
|
|
+ INIT_LIST_HEAD(&dsts[i]);
|
|
|
|
/* Prepare pages for freeing */
|
|
list_for_each_entry_safe(page, next, list, lru) {
|
|
@@ -2828,10 +2851,12 @@ void free_unref_page_list(struct list_he
|
|
local_irq_save(flags);
|
|
list_for_each_entry_safe(page, next, list, lru) {
|
|
unsigned long pfn = page_private(page);
|
|
+ enum zone_type type;
|
|
|
|
set_page_private(page, 0);
|
|
trace_mm_page_free_batched(page);
|
|
- free_unref_page_commit(page, pfn);
|
|
+ type = page_zonenum(page);
|
|
+ free_unref_page_commit(page, pfn, &dsts[type]);
|
|
|
|
/*
|
|
* Guard against excessive IRQ disabled times when we get
|
|
@@ -2844,6 +2869,21 @@ void free_unref_page_list(struct list_he
|
|
}
|
|
}
|
|
local_irq_restore(flags);
|
|
+
|
|
+ for (i = 0; i < __MAX_NR_ZONES; ) {
|
|
+ struct page *page;
|
|
+ struct zone *zone;
|
|
+
|
|
+ if (list_empty(&dsts[i])) {
|
|
+ i++;
|
|
+ continue;
|
|
+ }
|
|
+
|
|
+ page = list_first_entry(&dsts[i], struct page, lru);
|
|
+ zone = page_zone(page);
|
|
+
|
|
+ free_pcppages_bulk(zone, &dsts[i], true);
|
|
+ }
|
|
}
|
|
|
|
/*
|