68e3e92620
This reverts commit 5ceb9ce6fe.
That commit seems to be the cause of the mm compation list corruption
issues that Dave Jones reported. The locking (or rather, absense
there-of) is dubious, as is the use of the 'page' variable once it has
been found to be outside the pageblock range.
So revert it for now, we can re-visit this for 3.6. If we even need to:
as Minchan Kim says, "The patch wasn't a bug fix and even test workload
was very theoretical".
Reported-and-tested-by: Dave Jones <davej@redhat.com>
Acked-by: Hugh Dickins <hughd@google.com>
Acked-by: KOSAKI Motohiro <kosaki.motohiro@gmail.com>
Acked-by: Minchan Kim <minchan@kernel.org>
Cc: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>
Cc: Kyungmin Park <kyungmin.park@samsung.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
110 lines
3.2 KiB
C
110 lines
3.2 KiB
C
#ifndef _LINUX_COMPACTION_H
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#define _LINUX_COMPACTION_H
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/* Return values for compact_zone() and try_to_compact_pages() */
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/* compaction didn't start as it was not possible or direct reclaim was more suitable */
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#define COMPACT_SKIPPED 0
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/* compaction should continue to another pageblock */
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#define COMPACT_CONTINUE 1
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/* direct compaction partially compacted a zone and there are suitable pages */
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#define COMPACT_PARTIAL 2
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/* The full zone was compacted */
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#define COMPACT_COMPLETE 3
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#ifdef CONFIG_COMPACTION
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extern int sysctl_compact_memory;
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extern int sysctl_compaction_handler(struct ctl_table *table, int write,
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void __user *buffer, size_t *length, loff_t *ppos);
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extern int sysctl_extfrag_threshold;
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extern int sysctl_extfrag_handler(struct ctl_table *table, int write,
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void __user *buffer, size_t *length, loff_t *ppos);
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extern int fragmentation_index(struct zone *zone, unsigned int order);
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extern unsigned long try_to_compact_pages(struct zonelist *zonelist,
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int order, gfp_t gfp_mask, nodemask_t *mask,
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bool sync);
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extern int compact_pgdat(pg_data_t *pgdat, int order);
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extern unsigned long compaction_suitable(struct zone *zone, int order);
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/* Do not skip compaction more than 64 times */
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#define COMPACT_MAX_DEFER_SHIFT 6
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/*
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* Compaction is deferred when compaction fails to result in a page
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* allocation success. 1 << compact_defer_limit compactions are skipped up
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* to a limit of 1 << COMPACT_MAX_DEFER_SHIFT
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*/
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static inline void defer_compaction(struct zone *zone, int order)
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{
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zone->compact_considered = 0;
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zone->compact_defer_shift++;
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if (order < zone->compact_order_failed)
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zone->compact_order_failed = order;
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if (zone->compact_defer_shift > COMPACT_MAX_DEFER_SHIFT)
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zone->compact_defer_shift = COMPACT_MAX_DEFER_SHIFT;
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}
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/* Returns true if compaction should be skipped this time */
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static inline bool compaction_deferred(struct zone *zone, int order)
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{
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unsigned long defer_limit = 1UL << zone->compact_defer_shift;
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if (order < zone->compact_order_failed)
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return false;
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/* Avoid possible overflow */
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if (++zone->compact_considered > defer_limit)
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zone->compact_considered = defer_limit;
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return zone->compact_considered < (1UL << zone->compact_defer_shift);
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}
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#else
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static inline unsigned long try_to_compact_pages(struct zonelist *zonelist,
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int order, gfp_t gfp_mask, nodemask_t *nodemask,
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bool sync)
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{
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return COMPACT_CONTINUE;
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}
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static inline int compact_pgdat(pg_data_t *pgdat, int order)
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{
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return COMPACT_CONTINUE;
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}
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static inline unsigned long compaction_suitable(struct zone *zone, int order)
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{
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return COMPACT_SKIPPED;
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}
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static inline void defer_compaction(struct zone *zone, int order)
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{
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}
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static inline bool compaction_deferred(struct zone *zone, int order)
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{
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return 1;
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}
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#endif /* CONFIG_COMPACTION */
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#if defined(CONFIG_COMPACTION) && defined(CONFIG_SYSFS) && defined(CONFIG_NUMA)
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extern int compaction_register_node(struct node *node);
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extern void compaction_unregister_node(struct node *node);
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#else
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static inline int compaction_register_node(struct node *node)
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{
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return 0;
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}
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static inline void compaction_unregister_node(struct node *node)
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{
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}
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#endif /* CONFIG_COMPACTION && CONFIG_SYSFS && CONFIG_NUMA */
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#endif /* _LINUX_COMPACTION_H */
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