Messages in this thread Patch in this message | | | Date | Thu, 25 Apr 2024 01:58:53 +0800 | Subject | Re: [PATCH 1/2] mm: add per-order mTHP split counters | From | Bang Li <> |
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Hey, sorry for making noise, there was something wrong with the format of the last email.
On 2024/4/25 1:12, Bang Li wrote: > Hey Lance, > > On 2024/4/24 21:51, Lance Yang wrote: > >> At present, the split counters in THP statistics no longer include >> PTE-mapped mTHP. Therefore, this commit introduces per-order mTHP split >> counters to monitor the frequency of mTHP splits. This will assist >> developers in better analyzing and optimizing system performance. >> >> /sys/kernel/mm/transparent_hugepage/hugepages-<size>/stats >> split_page >> split_page_failed >> deferred_split_page >> >> Signed-off-by: Lance Yang <ioworker0@gmail.com> >> --- >> include/linux/huge_mm.h | 3 +++ >> mm/huge_memory.c | 14 ++++++++++++-- >> 2 files changed, 15 insertions(+), 2 deletions(-) >> >> diff --git a/include/linux/huge_mm.h b/include/linux/huge_mm.h >> index 56c7ea73090b..7b9c6590e1f7 100644 >> --- a/include/linux/huge_mm.h >> +++ b/include/linux/huge_mm.h >> @@ -272,6 +272,9 @@ enum mthp_stat_item { >> MTHP_STAT_ANON_FAULT_FALLBACK_CHARGE, >> MTHP_STAT_ANON_SWPOUT, >> MTHP_STAT_ANON_SWPOUT_FALLBACK, >> + MTHP_STAT_SPLIT_PAGE, >> + MTHP_STAT_SPLIT_PAGE_FAILED, >> + MTHP_STAT_DEFERRED_SPLIT_PAGE, >> __MTHP_STAT_COUNT >> }; >> diff --git a/mm/huge_memory.c b/mm/huge_memory.c >> index 055df5aac7c3..52db888e47a6 100644 >> --- a/mm/huge_memory.c >> +++ b/mm/huge_memory.c >> @@ -557,6 +557,9 @@ DEFINE_MTHP_STAT_ATTR(anon_fault_fallback, >> MTHP_STAT_ANON_FAULT_FALLBACK); >> DEFINE_MTHP_STAT_ATTR(anon_fault_fallback_charge, >> MTHP_STAT_ANON_FAULT_FALLBACK_CHARGE); >> DEFINE_MTHP_STAT_ATTR(anon_swpout, MTHP_STAT_ANON_SWPOUT); >> DEFINE_MTHP_STAT_ATTR(anon_swpout_fallback, >> MTHP_STAT_ANON_SWPOUT_FALLBACK); >> +DEFINE_MTHP_STAT_ATTR(split_page, MTHP_STAT_SPLIT_PAGE); >> +DEFINE_MTHP_STAT_ATTR(split_page_failed, MTHP_STAT_SPLIT_PAGE_FAILED); >> +DEFINE_MTHP_STAT_ATTR(deferred_split_page, >> MTHP_STAT_DEFERRED_SPLIT_PAGE); >> static struct attribute *stats_attrs[] = { >> &anon_fault_alloc_attr.attr, >> @@ -564,6 +567,9 @@ static struct attribute *stats_attrs[] = { >> &anon_fault_fallback_charge_attr.attr, >> &anon_swpout_attr.attr, >> &anon_swpout_fallback_attr.attr, >> + &split_page_attr.attr, >> + &split_page_failed_attr.attr, >> + &deferred_split_page_attr.attr, >> NULL, >> }; >> @@ -3083,7 +3089,7 @@ int split_huge_page_to_list_to_order(struct >> page *page, struct list_head *list, >> XA_STATE_ORDER(xas, &folio->mapping->i_pages, folio->index, >> new_order); >> struct anon_vma *anon_vma = NULL; >> struct address_space *mapping = NULL; >> - bool is_thp = folio_test_pmd_mappable(folio); >> + int order = folio_order(folio); >> int extra_pins, ret; >> pgoff_t end; >> bool is_hzp; >> @@ -3262,8 +3268,10 @@ int split_huge_page_to_list_to_order(struct >> page *page, struct list_head *list, >> i_mmap_unlock_read(mapping); >> out: >> xas_destroy(&xas); >> - if (is_thp) >> + if (order >= HPAGE_PMD_ORDER) >> count_vm_event(!ret ? THP_SPLIT_PAGE : THP_SPLIT_PAGE_FAILED); >> + count_mthp_stat(order, !ret ? MTHP_STAT_SPLIT_PAGE : >> + MTHP_STAT_SPLIT_PAGE_FAILED); >> return ret; >> } >> @@ -3327,6 +3335,8 @@ void deferred_split_folio(struct folio *folio) >> if (list_empty(&folio->_deferred_list)) { >> if (folio_test_pmd_mappable(folio)) >> count_vm_event(THP_DEFERRED_SPLIT_PAGE); >> + count_mthp_stat(folio_order(folio), >> + MTHP_STAT_DEFERRED_SPLIT_PAGE); >> list_add_tail(&folio->_deferred_list, &ds_queue->split_queue); >> ds_queue->split_queue_len++; >> #ifdef CONFIG_MEMCG > > My opinion can be ignored :). Would it be better to modify the > deferred_split_folio > function as follows? I'm not sure. > > diff --git a/mm/huge_memory.c b/mm/huge_memory.c index > 055df5aac7c3..e8562e8630b1 100644 --- a/mm/huge_memory.c +++ > b/mm/huge_memory.c @@ -3299,12 +3299,13 @@ void > deferred_split_folio(struct folio *folio) struct mem_cgroup *memcg = > folio_memcg(folio); #endif unsigned long flags; + int order = > folio_order(folio); /* * Order 1 folios have no space for a deferred > list, but we also * won't waste much memory by not adding them to the > deferred list. */ - if (folio_order(folio) <= 1) + if (order <= 1) > return; /* @@ -3325,8 +3326,9 @@ void deferred_split_folio(struct > folio *folio) spin_lock_irqsave(&ds_queue->split_queue_lock, flags); > if (list_empty(&folio->_deferred_list)) { - if > (folio_test_pmd_mappable(folio)) + if (order >= HPAGE_PMD_ORDER) > count_vm_event(THP_DEFERRED_SPLIT_PAGE); + count_mthp_stat(order, > MTHP_STAT_DEFERRED_SPLIT_PAGE); list_add_tail(&folio->_deferred_list, > &ds_queue->split_queue); ds_queue->split_queue_len++; #ifdef > CONFIG_MEMCG thanks, > bang >
My opinion can be ignored :). Would it be better to modify the deferred_split_folio function as follows? I'm not sure.
diff --git a/mm/huge_memory.c b/mm/huge_memory.c index 055df5aac7c3..e8562e8630b1 100644 --- a/mm/huge_memory.c +++ b/mm/huge_memory.c @@ -3299,12 +3299,13 @@ void deferred_split_folio(struct folio *folio) struct mem_cgroup *memcg = folio_memcg(folio); #endif unsigned long flags; + int order = folio_order(folio);
/* * Order 1 folios have no space for a deferred list, but we also * won't waste much memory by not adding them to the deferred list. */ - if (folio_order(folio) <= 1) + if (order <= 1) return;
/* @@ -3325,8 +3326,9 @@ void deferred_split_folio(struct folio *folio)
spin_lock_irqsave(&ds_queue->split_queue_lock, flags); if (list_empty(&folio->_deferred_list)) { - if (folio_test_pmd_mappable(folio)) + if (order >= HPAGE_PMD_ORDER) count_vm_event(THP_DEFERRED_SPLIT_PAGE); + count_mthp_stat(order, MTHP_STAT_DEFERRED_SPLIT_PAGE); list_add_tail(&folio->_deferred_list, &ds_queue->split_queue); ds_queue->split_queue_len++; #ifdef CONFIG_MEMCG thanks, bang
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