Messages in this thread | | | Date | Thu, 24 Aug 2023 10:20:03 +0800 | Subject | Re: [PATCH 6/9] mm/compaction: rename is_via_compact_memory to compaction_with_allocation_order | From | Baolin Wang <> |
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On 8/22/2023 9:51 AM, Kemeng Shi wrote: > > > 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 <shikemeng@huaweicloud.com> >>>>> --- >>>>> 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
Look good to me. Thanks.
> >>>>> { >>>>> - 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 */ >>>> >> >>
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