From: Mel Gorman <mgorman@xxxxxxxxxxxxxxxxxxx> Subject: mm, compaction: rework compact_should_abort as compact_check_resched With incremental changes, compact_should_abort no longer makes any documented sense. Rename to compact_check_resched and update the associated comments. There is no benefit other than reducing redundant code and making the intent slightly clearer. It could potentially be merged with earlier patches but it just makes the review slightly harder. Link: http://lkml.kernel.org/r/20190118175136.31341-17-mgorman@xxxxxxxxxxxxxxxxxxx Signed-off-by: Mel Gorman <mgorman@xxxxxxxxxxxxxxxxxxx> Acked-by: Vlastimil Babka <vbabka@xxxxxxx> Cc: Andrea Arcangeli <aarcange@xxxxxxxxxx> Cc: Dan Carpenter <dan.carpenter@xxxxxxxxxx> Cc: David Rientjes <rientjes@xxxxxxxxxx> Cc: YueHaibing <yuehaibing@xxxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- mm/compaction.c | 61 +++++++++++++++++----------------------------- 1 file changed, 23 insertions(+), 38 deletions(-) --- a/mm/compaction.c~mm-compaction-rework-compact_should_abort-as-compact_check_resched +++ a/mm/compaction.c @@ -405,6 +405,21 @@ static bool compact_lock_irqsave(spinloc } /* + * Aside from avoiding lock contention, compaction also periodically checks + * need_resched() and records async compaction as contended if necessary. + */ +static inline void compact_check_resched(struct compact_control *cc) +{ + /* async compaction aborts if contended */ + if (need_resched()) { + if (cc->mode == MIGRATE_ASYNC) + cc->contended = true; + + cond_resched(); + } +} + +/* * Compaction requires the taking of some coarse locks that are potentially * very heavily contended. The lock should be periodically unlocked to avoid * having disabled IRQs for a long time, even when there is nobody waiting on @@ -432,33 +447,7 @@ static bool compact_unlock_should_abort( return true; } - if (need_resched()) { - if (cc->mode == MIGRATE_ASYNC) - cc->contended = true; - cond_resched(); - } - - return false; -} - -/* - * Aside from avoiding lock contention, compaction also periodically checks - * need_resched() and either schedules in sync compaction or aborts async - * compaction. This is similar to what compact_unlock_should_abort() does, but - * is used where no lock is concerned. - * - * Returns false when no scheduling was needed, or sync compaction scheduled. - * Returns true when async compaction should abort. - */ -static inline bool compact_should_abort(struct compact_control *cc) -{ - /* async compaction aborts if contended */ - if (need_resched()) { - if (cc->mode == MIGRATE_ASYNC) - cc->contended = true; - - cond_resched(); - } + compact_check_resched(cc); return false; } @@ -747,8 +736,7 @@ isolate_migratepages_block(struct compac return 0; } - if (compact_should_abort(cc)) - return 0; + compact_check_resched(cc); if (cc->direct_compaction && (cc->mode == MIGRATE_ASYNC)) { skip_on_failure = true; @@ -1379,12 +1367,10 @@ static void isolate_freepages(struct com isolate_start_pfn = block_start_pfn) { /* * This can iterate a massively long zone without finding any - * suitable migration targets, so periodically check if we need - * to schedule, or even abort async compaction. + * suitable migration targets, so periodically check resched. */ - if (!(block_start_pfn % (SWAP_CLUSTER_MAX * pageblock_nr_pages)) - && compact_should_abort(cc)) - break; + if (!(block_start_pfn % (SWAP_CLUSTER_MAX * pageblock_nr_pages))) + compact_check_resched(cc); page = pageblock_pfn_to_page(block_start_pfn, block_end_pfn, zone); @@ -1677,11 +1663,10 @@ static isolate_migrate_t isolate_migrate /* * This can potentially iterate a massively long zone with * many pageblocks unsuitable, so periodically check if we - * need to schedule, or even abort async compaction. + * need to schedule. */ - if (!(low_pfn % (SWAP_CLUSTER_MAX * pageblock_nr_pages)) - && compact_should_abort(cc)) - break; + if (!(low_pfn % (SWAP_CLUSTER_MAX * pageblock_nr_pages))) + compact_check_resched(cc); page = pageblock_pfn_to_page(block_start_pfn, block_end_pfn, zone); _
