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authorPavel Tatashin <pasha.tatashin@oracle.com>2017-11-15 17:38:41 -0800
committerLinus Torvalds <torvalds@linux-foundation.org>2017-11-15 18:21:07 -0800
commitd135e5750205a21a212a19dbb05aeb339e2cbea7 (patch)
treecc96e583458549e9a9385b6e3a8557cf0eddca4f /mm
parent400e22499dd92613821374c8c6c88c7225359980 (diff)
download96b-common-d135e5750205a21a212a19dbb05aeb339e2cbea7.tar.gz
mm/page_alloc.c: broken deferred calculation
In reset_deferred_meminit() we determine number of pages that must not be deferred. We initialize pages for at least 2G of memory, but also pages for reserved memory in this node. The reserved memory is determined in this function: memblock_reserved_memory_within(), which operates over physical addresses, and returns size in bytes. However, reset_deferred_meminit() assumes that that this function operates with pfns, and returns page count. The result is that in the best case machine boots slower than expected due to initializing more pages than needed in single thread, and in the worst case panics because fewer than needed pages are initialized early. Link: http://lkml.kernel.org/r/20171021011707.15191-1-pasha.tatashin@oracle.com Fixes: 864b9a393dcb ("mm: consider memblock reservations for deferred memory initialization sizing") Signed-off-by: Pavel Tatashin <pasha.tatashin@oracle.com> Acked-by: Michal Hocko <mhocko@suse.com> Cc: Mel Gorman <mgorman@techsingularity.net> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'mm')
-rw-r--r--mm/page_alloc.c27
1 files changed, 18 insertions, 9 deletions
diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index bd1a686e40fe..8f2b9ad2e23f 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -291,28 +291,37 @@ EXPORT_SYMBOL(nr_online_nodes);
int page_group_by_mobility_disabled __read_mostly;
#ifdef CONFIG_DEFERRED_STRUCT_PAGE_INIT
+
+/*
+ * Determine how many pages need to be initialized durig early boot
+ * (non-deferred initialization).
+ * The value of first_deferred_pfn will be set later, once non-deferred pages
+ * are initialized, but for now set it ULONG_MAX.
+ */
static inline void reset_deferred_meminit(pg_data_t *pgdat)
{
- unsigned long max_initialise;
- unsigned long reserved_lowmem;
+ phys_addr_t start_addr, end_addr;
+ unsigned long max_pgcnt;
+ unsigned long reserved;
/*
* Initialise at least 2G of a node but also take into account that
* two large system hashes that can take up 1GB for 0.25TB/node.
*/
- max_initialise = max(2UL << (30 - PAGE_SHIFT),
- (pgdat->node_spanned_pages >> 8));
+ max_pgcnt = max(2UL << (30 - PAGE_SHIFT),
+ (pgdat->node_spanned_pages >> 8));
/*
* Compensate the all the memblock reservations (e.g. crash kernel)
* from the initial estimation to make sure we will initialize enough
* memory to boot.
*/
- reserved_lowmem = memblock_reserved_memory_within(pgdat->node_start_pfn,
- pgdat->node_start_pfn + max_initialise);
- max_initialise += reserved_lowmem;
+ start_addr = PFN_PHYS(pgdat->node_start_pfn);
+ end_addr = PFN_PHYS(pgdat->node_start_pfn + max_pgcnt);
+ reserved = memblock_reserved_memory_within(start_addr, end_addr);
+ max_pgcnt += PHYS_PFN(reserved);
- pgdat->static_init_size = min(max_initialise, pgdat->node_spanned_pages);
+ pgdat->static_init_pgcnt = min(max_pgcnt, pgdat->node_spanned_pages);
pgdat->first_deferred_pfn = ULONG_MAX;
}
@@ -339,7 +348,7 @@ static inline bool update_defer_init(pg_data_t *pgdat,
if (zone_end < pgdat_end_pfn(pgdat))
return true;
(*nr_initialised)++;
- if ((*nr_initialised > pgdat->static_init_size) &&
+ if ((*nr_initialised > pgdat->static_init_pgcnt) &&
(pfn & (PAGES_PER_SECTION - 1)) == 0) {
pgdat->first_deferred_pfn = pfn;
return false;