on 8/15/2023 4:58 PM, Baolin Wang wrote:
>
>
> On 8/5/2023 7:07 PM, Kemeng Shi wrote:
>> We have order = -1 via proactive compaction, the is_via_compact_memory is
>> not proper name anymore.
>> As cc->order informs the compaction to satisfy a allocation with that
>> order, so rename it to compaction_with_allocation_order.
>>
>> Signed-off-by: Kemeng Shi <shikemeng@xxxxxxxxxxxxxxx>
>> ---
>> mm/compaction.c | 11 +++++------
>> 1 file changed, 5 insertions(+), 6 deletions(-)
>>
>> diff --git a/mm/compaction.c b/mm/compaction.c
>> index d8416d3dd445..b5a699ed526b 100644
>> --- a/mm/compaction.c
>> +++ b/mm/compaction.c
>> @@ -2055,12 +2055,11 @@ static isolate_migrate_t isolate_migratepages(struct compact_control *cc)
>> }
>> /*
>> - * order == -1 is expected when compacting via
>> - * /proc/sys/vm/compact_memory
>> + * compact to satisfy allocation with target order
>> */
>> -static inline bool is_via_compact_memory(int order)
>> +static inline bool compaction_with_allocation_order(int order)
>
> I know naming is hard, but this name is not good enough that can show the compaction mode. But the original one could.
>
Yes, I agree with this, but name and comment of is_via_compact_memory may
mislead reader that order == -1 is equivalent to compaction from
/proc/sys/vm/compact_memory.
Actually, we have several approaches to trigger compaction with order == -1:
1. via /proc/sys/vm/compact_memory
2. via /sys/devices/system/node/nodex/compact
3. via proactive compact
Instead of indicate compaction is tirggerred by compact_memocy or anything,
order == -1 implies if compaction is triggerrred to meet allocation with high
order and we will stop compaction if allocation with target order will success.
>> {
>> - return order == -1;
>> + return order != -1;
>> }
>> /*
>> @@ -2200,7 +2199,7 @@ static enum compact_result __compact_finished(struct compact_control *cc)
>> goto out;
>> }
>> - if (is_via_compact_memory(cc->order))
>> + if (!compaction_with_allocation_order(cc->order))
>> return COMPACT_CONTINUE;
>> /*
>> @@ -2390,7 +2389,7 @@ compact_zone(struct compact_control *cc, struct capture_control *capc)
>> cc->migratetype = gfp_migratetype(cc->gfp_mask);
>> - if (!is_via_compact_memory(cc->order)) {
>> + if (compaction_with_allocation_order(cc->order)) {
>> unsigned long watermark;
>> /* Allocation can already succeed, nothing to do */
>
