Messages in this thread | | | Subject | Re: [PATCH 3/3] mm/compaction: add an is_via_compact_memory helper function | From | Vlastimil Babka <> | Date | Wed, 23 Sep 2015 18:42:53 +0200 |
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On 09/16/2015 02:00 PM, Yaowei Bai wrote: > Introduce is_via_compact_memory helper function indicating compacting > via /proc/sys/vm/compact_memory to improve readability.
Note that it can also be through single node, i.e. /sys/devices/system/node/node0/compact
is_manual_compaction() would perhaps be better name
> To catch this situation in __compaction_suitable, use order as parameter > directly instead of using struct compact_control.
That can be fixed as well. Remove the test from __compaction_suitable(), and in compact_zone(), do something like: ret = is_manual_compaction() ? COMPACT_CONTINUE : compaction_suitable()
I think it's better since it's more explicit, but I understand others might feel differently.
> This patch has no functional changes. > > Signed-off-by: Yaowei Bai <bywxiaobai@163.com> > --- > mm/compaction.c | 26 ++++++++++++++------------ > 1 file changed, 14 insertions(+), 12 deletions(-) > > diff --git a/mm/compaction.c b/mm/compaction.c > index c5c627a..a8e6593 100644 > --- a/mm/compaction.c > +++ b/mm/compaction.c > @@ -1197,6 +1197,15 @@ static isolate_migrate_t isolate_migratepages(struct zone *zone, > return cc->nr_migratepages ? ISOLATE_SUCCESS : ISOLATE_NONE; > } > > +/* > + * order == -1 is expected when compacting via > + * /proc/sys/vm/compact_memory > + */ > +static inline bool is_via_compact_memory(int order) > +{ > + return order == -1; > +} > + > static int __compact_finished(struct zone *zone, struct compact_control *cc, > const int migratetype) > { > @@ -1223,11 +1232,7 @@ static int __compact_finished(struct zone *zone, struct compact_control *cc, > return COMPACT_COMPLETE; > } > > - /* > - * order == -1 is expected when compacting via > - * /proc/sys/vm/compact_memory > - */ > - if (cc->order == -1) > + if (is_via_compact_memory(cc->order)) > return COMPACT_CONTINUE; > > /* Compaction run is not finished if the watermark is not met */ > @@ -1290,11 +1295,7 @@ static unsigned long __compaction_suitable(struct zone *zone, int order, > int fragindex; > unsigned long watermark; > > - /* > - * order == -1 is expected when compacting via > - * /proc/sys/vm/compact_memory > - */ > - if (order == -1) > + if (is_via_compact_memory(order)) > return COMPACT_CONTINUE; > > watermark = low_wmark_pages(zone); > @@ -1658,10 +1659,11 @@ static void __compact_pgdat(pg_data_t *pgdat, struct compact_control *cc) > * this makes sure we compact the whole zone regardless of > * cached scanner positions. > */ > - if (cc->order == -1) > + if (is_via_compact_memory(cc->order)) > __reset_isolation_suitable(zone); > > - if (cc->order == -1 || !compaction_deferred(zone, cc->order)) > + if (is_via_compact_memory(cc->order) || > + !compaction_deferred(zone, cc->order)) > compact_zone(zone, cc); > > if (cc->order > 0) { >
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