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 <[email protected]>
---
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)
{
- 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 */
--
2.30.0
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 <[email protected]>
>> ---
>> 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 */
>
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 <[email protected]>
> ---
> 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.
> {
> - 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 */
on 8/19/2023 8:14 PM, Baolin Wang wrote:
>
>
> On 8/15/2023 8:04 PM, Kemeng Shi wrote:
>>
>>
>> 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 <[email protected]>
>>>> ---
>>>> 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
>
> They can all be called proactive compaction.
I have considered rename to is_proactive_compaction. But "proactive compaction"
in comments of compaction.c mostly implies to compaction triggerred from
/proc/sys/vm/compaction_proactiveness. So "proactive compaction" itself looks
ambiguous...
>
>>
>> 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.
>
> IMO, the is_via_compact_memory() function helps people better distinguish the compaction logic we have under direct compaction or kcompactd compaction, while proactive compaction does not concern itself with these details. But compaction_with_allocation_order() will make me just wonder why we should compare with -1. So I don't think this patch is worth it, but as you said above, we can add more comments to make it more clear.
>
Sure, no insistant on this.
Is it looks good to you just change comment of is_via_compact_memory to:
We need do compaction proactively with order == -1
order == -1 is expected for proactive compaction via:
1. via /proc/sys/vm/compact_memory
2. via /sys/devices/system/node/nodex/compact
3. /proc/sys/vm/compaction_proactiveness
>>>> {
>>>> - 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 */
>>>
>
>