From: Alex Shi <alex.shi@xxxxxxxxxxxxxxxxx> Subject: mm/compaction: correct the comments of compact_defer_shift There is no compact_defer_limit. It should be compact_defer_shift in use. and add compact_order_failed explanation. Link: http://lkml.kernel.org/r/3bd60e1b-a74e-050d-ade4-6e8f54e00b92@xxxxxxxxxxxxxxxxx Signed-off-by: Alex Shi <alex.shi@xxxxxxxxxxxxxxxxx> Reviewed-by: Alexander Duyck <alexander.h.duyck@xxxxxxxxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- include/linux/mmzone.h | 1 + mm/compaction.c | 2 +- 2 files changed, 2 insertions(+), 1 deletion(-) --- a/include/linux/mmzone.h~mm-compaction-correct-the-comments-of-compact_defer_shift +++ a/include/linux/mmzone.h @@ -536,6 +536,7 @@ struct zone { * On compaction failure, 1<<compact_defer_shift compactions * are skipped before trying again. The number attempted since * last failure is tracked with compact_considered. + * compact_order_failed is the minimum compaction failed order. */ unsigned int compact_considered; unsigned int compact_defer_shift; --- a/mm/compaction.c~mm-compaction-correct-the-comments-of-compact_defer_shift +++ a/mm/compaction.c @@ -154,7 +154,7 @@ EXPORT_SYMBOL(__ClearPageMovable); /* * Compaction is deferred when compaction fails to result in a page - * allocation success. 1 << compact_defer_limit compactions are skipped up + * allocation success. 1 << compact_defer_shift, compactions are skipped up * to a limit of 1 << COMPACT_MAX_DEFER_SHIFT */ void defer_compaction(struct zone *zone, int order) _
