On Sat, Mar 15, 2025 at 09:28:16PM -0700, Hugh Dickins wrote: > [PATCH] mm: compaction: push watermark into compaction_suitable() callers fix > > Stop oops on out-of-range highest_zoneidx: compaction_suitable() pass > args to __compaction_suitable() in the order which it is expecting. > > Signed-off-by: Hugh Dickins <hughd@xxxxxxxxxx> > --- > mm/compaction.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/mm/compaction.c b/mm/compaction.c > index 4a2ccb82d0b2..b5c9e8fd39f1 100644 > --- a/mm/compaction.c > +++ b/mm/compaction.c > @@ -2433,7 +2433,7 @@ bool compaction_suitable(struct zone *zone, int order, unsigned long watermark, > enum compact_result compact_result; > bool suitable; > > - suitable = __compaction_suitable(zone, order, highest_zoneidx, watermark, > + suitable = __compaction_suitable(zone, order, watermark, highest_zoneidx, > zone_page_state(zone, NR_FREE_PAGES)); Ouch, thanks for the fix Hugh. This obviously didn't crash for me, but I re-ran the benchmarks with your fix in my test environment. This affects the direct compaction path, and I indeed see a minor uptick in direct compaction, with a larger reduction in daemon work. Compact daemon scanned migrate 2455570.93 ( +0.00%) 1770142.33 ( -27.91%) Compact daemon scanned free 2429309.20 ( +0.00%) 1604744.00 ( -33.94%) Compact direct scanned migrate 40136.60 ( +0.00%) 58326.67 ( +45.32%) Compact direct scanned free 22127.13 ( +0.00%) 52216.93 ( +135.98%) Compact total migrate scanned 2495707.53 ( +0.00%) 1828469.00 ( -26.74%) Compact total free scanned 2451436.33 ( +0.00%) 1656960.93 ( -32.41%) It doesn't change the overall A/B picture between baseline and the series, so I'm comfortable keeping the current changelog results.
