[BUG] Page allocation failures with newest kernels
From: Mel Gorman <hidden>
Date: 2016-06-02 13:52:37
Also in:
linux-mm, lkml
On Thu, Jun 02, 2016 at 07:48:38AM +0200, Marcin Wojtas wrote:
quoted hunk ↗ jump to hunk
Hi Will, I think I found a right trace. Following one-liner fixes the issue beginning from v4.2-rc1 up to v4.4 included:--- a/mm/page_alloc.c +++ b/mm/page_alloc.c@@ -294,7 +294,7 @@ static inline boolearly_page_uninitialised(unsigned long pfn) static inline bool early_page_nid_uninitialised(unsigned long pfn, int nid) { - return false; + return true; }
How does that make a difference in v4.4 since commit 974a786e63c96a2401a78ddba926f34c128474f1 removed the only early_page_nid_uninitialised() ? It further doesn't make sense if deferred memory initialisation is not enabled as the pages will always be initialised.
From what I understood, now order-0 allocation keep no reserve at all.
Watermarks should still be preserved. zone_watermark_ok is still there. What might change is the size of reserves for high-order atomic allocations only. Fragmentation shouldn't be a factor. I'm missing some major part of the picture. -- Mel Gorman SUSE Labs