[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]
Message-Id: <1430231830-7702-10-git-send-email-mgorman@suse.de>
Date: Tue, 28 Apr 2015 15:37:06 +0100
From: Mel Gorman <mgorman@...e.de>
To: Andrew Morton <akpm@...ux-foundation.org>
Cc: Nathan Zimmer <nzimmer@....com>,
Dave Hansen <dave.hansen@...el.com>,
Waiman Long <waiman.long@...com>,
Scott Norton <scott.norton@...com>,
Daniel J Blueman <daniel@...ascale.com>,
Linux-MM <linux-mm@...ck.org>,
LKML <linux-kernel@...r.kernel.org>, Mel Gorman <mgorman@...e.de>
Subject: [PATCH 09/13] mm: meminit: Minimise number of pfn->page lookups during initialisation
Deferred struct page initialisation is using pfn_to_page() on every PFN
unnecessarily. This patch minimises the number of lookups and scheduler
checks.
Signed-off-by: Mel Gorman <mgorman@...e.de>
---
mm/page_alloc.c | 29 ++++++++++++++++++++++++-----
1 file changed, 24 insertions(+), 5 deletions(-)
diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index 96f2c2dc8ca6..6e366fd654e1 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -1092,6 +1092,7 @@ void __defermem_init deferred_init_memmap(int nid)
for_each_mem_pfn_range(i, nid, &walk_start, &walk_end, NULL) {
unsigned long pfn, end_pfn;
+ struct page *page = NULL;
end_pfn = min(walk_end, zone_end_pfn(zone));
pfn = first_init_pfn;
@@ -1101,13 +1102,32 @@ void __defermem_init deferred_init_memmap(int nid)
pfn = zone->zone_start_pfn;
for (; pfn < end_pfn; pfn++) {
- struct page *page;
-
- if (!pfn_valid(pfn))
+ if (!pfn_valid_within(pfn))
continue;
- if (!meminit_pfn_in_nid(pfn, nid, &nid_init_state))
+ /*
+ * Ensure pfn_valid is checked every
+ * MAX_ORDER_NR_PAGES for memory holes
+ */
+ if ((pfn & (MAX_ORDER_NR_PAGES - 1)) == 0) {
+ if (!pfn_valid(pfn)) {
+ page = NULL;
+ continue;
+ }
+ }
+
+ if (!meminit_pfn_in_nid(pfn, nid, &nid_init_state)) {
+ page = NULL;
continue;
+ }
+
+ /* Minimise pfn page lookups and scheduler checks */
+ if (page && (pfn & (MAX_ORDER_NR_PAGES - 1)) != 0) {
+ page++;
+ } else {
+ page = pfn_to_page(pfn);
+ cond_resched();
+ }
if (page->flags) {
VM_BUG_ON(page_zone(page) != zone);
@@ -1117,7 +1137,6 @@ void __defermem_init deferred_init_memmap(int nid)
__init_single_page(page, pfn, zid, nid);
__free_pages_boot_core(page, pfn, 0);
nr_pages++;
- cond_resched();
}
first_init_pfn = max(end_pfn, first_init_pfn);
}
--
2.3.5
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
Powered by blists - more mailing lists