linux-kernel - Re: [PATCH v4 11/12] khugepaged: add per-order mTHP khugepaged stats

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [day] [month] [year] [list]

Message-ID: <30180bde-d813-40dd-83f4-0cc04daf6df6@linux.alibaba.com>
Date: Thu, 24 Apr 2025 15:58:31 +0800
From: Baolin Wang <baolin.wang@...ux.alibaba.com>
To: Nico Pache <npache@...hat.com>, linux-mm@...ck.org,
 linux-doc@...r.kernel.org, linux-kernel@...r.kernel.org,
 linux-trace-kernel@...r.kernel.org
Cc: akpm@...ux-foundation.org, corbet@....net, rostedt@...dmis.org,
 mhiramat@...nel.org, mathieu.desnoyers@...icios.com, david@...hat.com,
 baohua@...nel.org, ryan.roberts@....com, willy@...radead.org,
 peterx@...hat.com, ziy@...dia.com, wangkefeng.wang@...wei.com,
 usamaarif642@...il.com, sunnanyong@...wei.com, vishal.moola@...il.com,
 thomas.hellstrom@...ux.intel.com, yang@...amperecomputing.com,
 kirill.shutemov@...ux.intel.com, aarcange@...hat.com, raquini@...hat.com,
 dev.jain@....com, anshuman.khandual@....com, catalin.marinas@....com,
 tiwai@...e.de, will@...nel.org, dave.hansen@...ux.intel.com, jack@...e.cz,
 cl@...two.org, jglisse@...gle.com, surenb@...gle.com, zokeefe@...gle.com,
 hannes@...xchg.org, rientjes@...gle.com, mhocko@...e.com,
 rdunlap@...radead.org
Subject: Re: [PATCH v4 11/12] khugepaged: add per-order mTHP khugepaged stats



On 2025/4/17 08:02, Nico Pache wrote:
> With mTHP support inplace, let add the per-order mTHP stats for
> exceeding NONE, SWAP, and SHARED.
> 
> Signed-off-by: Nico Pache <npache@...hat.com>
> ---
>   include/linux/huge_mm.h |  3 +++
>   mm/huge_memory.c        |  7 +++++++
>   mm/khugepaged.c         | 16 +++++++++++++---
>   3 files changed, 23 insertions(+), 3 deletions(-)
> 
> diff --git a/include/linux/huge_mm.h b/include/linux/huge_mm.h
> index 55b242335420..782d3a7854b4 100644
> --- a/include/linux/huge_mm.h
> +++ b/include/linux/huge_mm.h
> @@ -139,6 +139,9 @@ enum mthp_stat_item {
>   	MTHP_STAT_SPLIT_DEFERRED,
>   	MTHP_STAT_NR_ANON,
>   	MTHP_STAT_NR_ANON_PARTIALLY_MAPPED,
> +	MTHP_STAT_COLLAPSE_EXCEED_SWAP,
> +	MTHP_STAT_COLLAPSE_EXCEED_NONE,
> +	MTHP_STAT_COLLAPSE_EXCEED_SHARED,
>   	__MTHP_STAT_COUNT
>   };
>   
> diff --git a/mm/huge_memory.c b/mm/huge_memory.c
> index 7798c9284533..de4704af0022 100644
> --- a/mm/huge_memory.c
> +++ b/mm/huge_memory.c
> @@ -633,6 +633,10 @@ DEFINE_MTHP_STAT_ATTR(split_failed, MTHP_STAT_SPLIT_FAILED);
>   DEFINE_MTHP_STAT_ATTR(split_deferred, MTHP_STAT_SPLIT_DEFERRED);
>   DEFINE_MTHP_STAT_ATTR(nr_anon, MTHP_STAT_NR_ANON);
>   DEFINE_MTHP_STAT_ATTR(nr_anon_partially_mapped, MTHP_STAT_NR_ANON_PARTIALLY_MAPPED);
> +DEFINE_MTHP_STAT_ATTR(collapse_exceed_swap_pte, MTHP_STAT_COLLAPSE_EXCEED_SWAP);
> +DEFINE_MTHP_STAT_ATTR(collapse_exceed_none_pte, MTHP_STAT_COLLAPSE_EXCEED_NONE);
> +DEFINE_MTHP_STAT_ATTR(collapse_exceed_shared_pte, MTHP_STAT_COLLAPSE_EXCEED_SHARED);
> +
>   
>   static struct attribute *anon_stats_attrs[] = {
>   	&anon_fault_alloc_attr.attr,
> @@ -649,6 +653,9 @@ static struct attribute *anon_stats_attrs[] = {
>   	&split_deferred_attr.attr,
>   	&nr_anon_attr.attr,
>   	&nr_anon_partially_mapped_attr.attr,
> +	&collapse_exceed_swap_pte_attr.attr,
> +	&collapse_exceed_none_pte_attr.attr,
> +	&collapse_exceed_shared_pte_attr.attr,
>   	NULL,
>   };
>   
> diff --git a/mm/khugepaged.c b/mm/khugepaged.c
> index 67da0950b833..38643a681ba5 100644
> --- a/mm/khugepaged.c
> +++ b/mm/khugepaged.c
> @@ -604,7 +604,10 @@ static int __collapse_huge_page_isolate(struct vm_area_struct *vma,
>   				continue;
>   			} else {
>   				result = SCAN_EXCEED_NONE_PTE;
> -				count_vm_event(THP_SCAN_EXCEED_NONE_PTE);
> +				if (order == HPAGE_PMD_ORDER)
> +					count_vm_event(THP_SCAN_EXCEED_NONE_PTE);
> +				else
> +					count_mthp_stat(order, MTHP_STAT_COLLAPSE_EXCEED_NONE);
>   				goto out;
>   			}
>   		}
> @@ -633,8 +636,14 @@ static int __collapse_huge_page_isolate(struct vm_area_struct *vma,
>   		/* See khugepaged_scan_pmd(). */
>   		if (folio_maybe_mapped_shared(folio)) {
>   			++shared;
> -			if (order != HPAGE_PMD_ORDER || (cc->is_khugepaged &&
> -			    shared > khugepaged_max_ptes_shared)) {
> +			if (order != HPAGE_PMD_ORDER) {
> +				result = SCAN_EXCEED_SHARED_PTE;
> +				count_mthp_stat(order, MTHP_STAT_COLLAPSE_EXCEED_SHARED);
> +				goto out;
> +			}
> +
> +			if (cc->is_khugepaged &&
> +				shared > khugepaged_max_ptes_shared) {
>   				result = SCAN_EXCEED_SHARED_PTE;
>   				count_vm_event(THP_SCAN_EXCEED_SHARED_PTE);
>   				goto out;
> @@ -1060,6 +1069,7 @@ static int __collapse_huge_page_swapin(struct mm_struct *mm,
>   
>   		/* Dont swapin for mTHP collapse */
>   		if (order != HPAGE_PMD_ORDER) {
> +			count_mthp_stat(order, MTHP_STAT_COLLAPSE_EXCEED_SHARED);

Should be MTHP_STAT_COLLAPSE_EXCEED_SWAP?

>   			result = SCAN_EXCEED_SWAP_PTE;
>   			goto out;
>   		}