* list of requested migratetype, possibly along with other pages from the same
* block, depending on fragmentation avoidance heuristics. Returns true if
* fallback was found so that __rmqueue_smallest() can grab it.
+ *
+ * The use of signed ints for order and current_order is a deliberate
+ * deviation from the rest of this file, to make the for loop
+ * condition simpler.
*/
static inline bool
-__rmqueue_fallback(struct zone *zone, unsigned int order, int start_migratetype)
+__rmqueue_fallback(struct zone *zone, int order, int start_migratetype)
{
struct free_area *area;
- unsigned int current_order;
+ int current_order;
struct page *page;
int fallback_mt;
bool can_steal;
* approximates finding the pageblock with the most free pages, which
* would be too costly to do exactly.
*/
- for (current_order = MAX_ORDER-1;
- current_order >= order && current_order <= MAX_ORDER-1;
+ for (current_order = MAX_ORDER - 1; current_order >= order;
--current_order) {
area = &(zone->free_area[current_order]);
fallback_mt = find_suitable_fallback(area, current_order,
/* The OOM killer will not help higher order allocs */
if (order > PAGE_ALLOC_COSTLY_ORDER)
goto out;
+ /*
+ * We have already exhausted all our reclaim opportunities without any
+ * success so it is time to admit defeat. We will skip the OOM killer
+ * because it is very likely that the caller has a more reasonable
+ * fallback than shooting a random task.
+ */
+ if (gfp_mask & __GFP_RETRY_MAYFAIL)
+ goto out;
/* The OOM killer does not needlessly kill tasks for lowmem */
if (ac->high_zoneidx < ZONE_NORMAL)
goto out;
}
/*
- * !costly requests are much more important than __GFP_REPEAT
+ * !costly requests are much more important than __GFP_RETRY_MAYFAIL
* costly ones because they are de facto nofail and invoke OOM
* killer to move on while costly can fail and users are ready
* to cope with that. 1/4 retries is rather arbitrary but we
/*
* Do not retry costly high order allocations unless they are
- * __GFP_REPEAT
+ * __GFP_RETRY_MAYFAIL
*/
- if (costly_order && !(gfp_mask & __GFP_REPEAT))
+ if (costly_order && !(gfp_mask & __GFP_RETRY_MAYFAIL))
goto nopage;
if (should_reclaim_retry(gfp_mask, order, ac, alloc_flags,
#endif
/* we have to stop all cpus to guarantee there is no user
of zonelist */
- stop_machine(__build_all_zonelists, pgdat, NULL);
+ stop_machine_cpuslocked(__build_all_zonelists, pgdat, NULL);
/* cpuset refresh routine should be here */
}
vm_total_pages = nr_free_pagecache_pages();