From: David Rientjes <rientjes@xxxxxxxxxx> Subject: mm, compaction: kcompactd should not ignore pageblock skip Kcompactd is needlessly ignoring pageblock skip information. It is doing MIGRATE_SYNC_LIGHT compaction, which is no more powerful than MIGRATE_SYNC compaction. If compaction recently failed to isolate memory from a set of pageblocks, there is nothing to indicate that kcompactd will be able to do so, or that it is beneficial from attempting to isolate memory. Use the pageblock skip hint to avoid rescanning pageblocks needlessly until that information is reset. Link: http://lkml.kernel.org/r/alpine.DEB.2.10.1708151638550.106658@xxxxxxxxxxxxxxxxxxxxxxxxx Signed-off-by: David Rientjes <rientjes@xxxxxxxxxx> Cc: Vlastimil Babka <vbabka@xxxxxxx> Cc: Mel Gorman <mgorman@xxxxxxxxxxxxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- mm/compaction.c | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-) diff -puN mm/compaction.c~mm-compaction-kcompactd-should-not-ignore-pageblock-skip mm/compaction.c --- a/mm/compaction.c~mm-compaction-kcompactd-should-not-ignore-pageblock-skip +++ a/mm/compaction.c @@ -1928,9 +1928,8 @@ static void kcompactd_do_work(pg_data_t .total_free_scanned = 0, .classzone_idx = pgdat->kcompactd_classzone_idx, .mode = MIGRATE_SYNC_LIGHT, - .ignore_skip_hint = true, + .ignore_skip_hint = false, .gfp_mask = GFP_KERNEL, - }; trace_mm_compaction_kcompactd_wake(pgdat->node_id, cc.order, cc.classzone_idx); _ -- To unsubscribe from this list: send the line "unsubscribe mm-commits" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
