Messages in this thread | | | Date | Thu, 24 Aug 2023 10:25:04 +0800 | Subject | Re: [PATCH 7/9] mm/compaction: factor out code to test if we should run compaction for target order | From | Baolin Wang <> |
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On 8/22/2023 9:57 AM, Kemeng Shi wrote: > > > on 8/19/2023 8:27 PM, Baolin Wang wrote: >> >> >> On 8/15/2023 8:10 PM, Kemeng Shi wrote: >>> >>> >>> on 8/15/2023 4:53 PM, Baolin Wang wrote: >>>> >>>> >>>> On 8/5/2023 7:07 PM, Kemeng Shi wrote: >>>>> We always do zone_watermark_ok check and compaction_suitable check >>>>> together to test if compaction for target order should be runned. >>>>> Factor these code out for preparation to remove repeat code. >>>>> >>>>> Signed-off-by: Kemeng Shi <shikemeng@huaweicloud.com> >>>>> --- >>>>> mm/compaction.c | 42 +++++++++++++++++++++++++++++------------- >>>>> 1 file changed, 29 insertions(+), 13 deletions(-) >>>>> >>>>> diff --git a/mm/compaction.c b/mm/compaction.c >>>>> index b5a699ed526b..26787ebb0297 100644 >>>>> --- a/mm/compaction.c >>>>> +++ b/mm/compaction.c >>>>> @@ -2365,6 +2365,30 @@ bool compaction_zonelist_suitable(struct alloc_context *ac, int order, >>>>> return false; >>>>> } >>>>> +/* >>>>> + * Should we do compaction for target allocation order. >>>>> + * Return COMPACT_SUCCESS if allocation for target order can be already >>>>> + * satisfied >>>>> + * Return COMPACT_SKIPPED if compaction for target order is likely to fail >>>>> + * Return COMPACT_CONTINUE if compaction for target order should be runned >>>>> + */ >>>>> +static inline enum compact_result >>>>> +compaction_suit_allocation_order(struct zone *zone, unsigned int order, >>>>> + int highest_zoneidx, unsigned int alloc_flags) >>>>> +{ >>>>> + unsigned long watermark; >>>>> + >>>>> + watermark = wmark_pages(zone, alloc_flags & ALLOC_WMARK_MASK); >>>> >>>> IIUC, the watermark used in patch 8 and patch 9 is different, right? Have you measured the impact of modifying this watermark? >>>> >>> Actually, there is no functional change intended. Consider wmark_pages with >>> alloc_flags = 0 is equivalent to min_wmark_pages, patch 8 and patch 9 still >>> use original watermark. >> >> Can you use ALLOC_WMARK_MIN macro to make it more clear? > Sorry, I can't quite follow this. The watermark should differ with different > alloc_flags instead of WMARK_MIN hard-coded. > Patch 8 and patch 9 use watermark with WMARK_MIN as they get alloc_flags = 0.
I mean you can pass 'alloc_flags=ALLOC_WMARK_MIN' instead of a magic number 0 when calling compaction_suit_allocation_order() in patch 8 and patch 9.
>> And I think patch 8 and patch 9 should be squashed into patch 7 to convert all at once. > Sure, i could do this in next version. >> >>>>> + if (zone_watermark_ok(zone, order, watermark, highest_zoneidx, >>>>> + alloc_flags)) >>>>> + return COMPACT_SUCCESS; >>>>> + >>>>> + if (!compaction_suitable(zone, order, highest_zoneidx)) >>>>> + return COMPACT_SKIPPED; >>>>> + >>>>> + return COMPACT_CONTINUE; >>>>> +} >>>>> + >>>>> static enum compact_result >>>>> compact_zone(struct compact_control *cc, struct capture_control *capc) >>>>> { >>>>> @@ -2390,19 +2414,11 @@ compact_zone(struct compact_control *cc, struct capture_control *capc) >>>>> cc->migratetype = gfp_migratetype(cc->gfp_mask); >>>>> if (compaction_with_allocation_order(cc->order)) { >>>>> - unsigned long watermark; >>>>> - >>>>> - /* Allocation can already succeed, nothing to do */ >>>>> - watermark = wmark_pages(cc->zone, >>>>> - cc->alloc_flags & ALLOC_WMARK_MASK); >>>>> - if (zone_watermark_ok(cc->zone, cc->order, watermark, >>>>> - cc->highest_zoneidx, cc->alloc_flags)) >>>>> - return COMPACT_SUCCESS; >>>>> - >>>>> - /* Compaction is likely to fail */ >>>>> - if (!compaction_suitable(cc->zone, cc->order, >>>>> - cc->highest_zoneidx)) >>>>> - return COMPACT_SKIPPED; >>>>> + ret = compaction_suit_allocation_order(cc->zone, cc->order, >>>>> + cc->highest_zoneidx, >>>>> + cc->alloc_flags); >>>>> + if (ret != COMPACT_CONTINUE) >>>>> + return ret; >>>>> } >>>>> /* >>>> >>>> >> >>
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