2024-04-12 18:23:23

by Sidhartha Kumar

[permalink] [raw]
Subject: [PATCH v2 1/2] mm/hugetlb: convert dissolve_free_huge_pages() to folios

Allows us to rename dissolve_free_huge_pages() to
dissolve_free_hugetlb_folio(). Convert one caller to pass in a folio
directly and use page_folio() to convert the caller in mm/memory-failure.

Signed-off-by: Sidhartha Kumar <[email protected]>
Reviewed-by: Oscar Salvador <[email protected]>
---

v1 -> v2:
- Change additional comments which reference hugepages to
hugetlb folios per Miaohe Lin.
- introduce patch 2

include/linux/hugetlb.h | 4 ++--
mm/hugetlb.c | 17 ++++++++---------
mm/memory-failure.c | 8 ++++----
3 files changed, 14 insertions(+), 15 deletions(-)

diff --git a/include/linux/hugetlb.h b/include/linux/hugetlb.h
index 3f3e628802792..f4191b10345d6 100644
--- a/include/linux/hugetlb.h
+++ b/include/linux/hugetlb.h
@@ -861,7 +861,7 @@ static inline int hstate_index(struct hstate *h)
return h - hstates;
}

-extern int dissolve_free_huge_page(struct page *page);
+extern int dissolve_free_hugetlb_folio(struct folio *folio);
extern int dissolve_free_huge_pages(unsigned long start_pfn,
unsigned long end_pfn);

@@ -1148,7 +1148,7 @@ static inline int hstate_index(struct hstate *h)
return 0;
}

-static inline int dissolve_free_huge_page(struct page *page)
+static inline int dissolve_free_hugetlb_folio(struct folio *folio)
{
return 0;
}
diff --git a/mm/hugetlb.c b/mm/hugetlb.c
index 454900c84b303..f6dd5f597df16 100644
--- a/mm/hugetlb.c
+++ b/mm/hugetlb.c
@@ -2377,8 +2377,8 @@ static struct folio *remove_pool_hugetlb_folio(struct hstate *h,
}

/*
- * Dissolve a given free hugepage into free buddy pages. This function does
- * nothing for in-use hugepages and non-hugepages.
+ * Dissolve a given free hugetlb folio into free buddy pages. This function
+ * does nothing for in-use hugetlb folios and non-hugetlb folios.
* This function returns values like below:
*
* -ENOMEM: failed to allocate vmemmap pages to free the freed hugepages
@@ -2390,10 +2390,9 @@ static struct folio *remove_pool_hugetlb_folio(struct hstate *h,
* 0: successfully dissolved free hugepages or the page is not a
* hugepage (considered as already dissolved)
*/
-int dissolve_free_huge_page(struct page *page)
+int dissolve_free_hugetlb_folio(struct folio *folio)
{
int rc = -EBUSY;
- struct folio *folio = page_folio(page);

retry:
/* Not to disrupt normal path by vainly holding hugetlb_lock */
@@ -2470,13 +2469,13 @@ int dissolve_free_huge_page(struct page *page)
* make specified memory blocks removable from the system.
* Note that this will dissolve a free gigantic hugepage completely, if any
* part of it lies within the given range.
- * Also note that if dissolve_free_huge_page() returns with an error, all
- * free hugepages that were dissolved before that error are lost.
+ * Also note that if dissolve_free_hugetlb_folio() returns with an error, all
+ * free hugetlb folios that were dissolved before that error are lost.
*/
int dissolve_free_huge_pages(unsigned long start_pfn, unsigned long end_pfn)
{
unsigned long pfn;
- struct page *page;
+ struct folio *folio;
int rc = 0;
unsigned int order;
struct hstate *h;
@@ -2489,8 +2488,8 @@ int dissolve_free_huge_pages(unsigned long start_pfn, unsigned long end_pfn)
order = min(order, huge_page_order(h));

for (pfn = start_pfn; pfn < end_pfn; pfn += 1 << order) {
- page = pfn_to_page(pfn);
- rc = dissolve_free_huge_page(page);
+ folio = pfn_folio(pfn);
+ rc = dissolve_free_hugetlb_folio(folio);
if (rc)
break;
}
diff --git a/mm/memory-failure.c b/mm/memory-failure.c
index 88359a185c5f9..8cc91aa1a3f47 100644
--- a/mm/memory-failure.c
+++ b/mm/memory-failure.c
@@ -155,11 +155,11 @@ static int __page_handle_poison(struct page *page)

/*
* zone_pcp_disable() can't be used here. It will hold pcp_batch_high_lock and
- * dissolve_free_huge_page() might hold cpu_hotplug_lock via static_key_slow_dec()
+ * dissolve_free_hugetlb_folio() might hold cpu_hotplug_lock via static_key_slow_dec()
* when hugetlb vmemmap optimization is enabled. This will break current lock
* dependency chain and leads to deadlock.
*/
- ret = dissolve_free_huge_page(page);
+ ret = dissolve_free_hugetlb_folio(page_folio(page));
if (!ret) {
drain_all_pages(page_zone(page));
ret = take_page_off_buddy(page);
@@ -172,8 +172,8 @@ static bool page_handle_poison(struct page *page, bool hugepage_or_freepage, boo
{
if (hugepage_or_freepage) {
/*
- * Doing this check for free pages is also fine since dissolve_free_huge_page
- * returns 0 for non-hugetlb pages as well.
+ * Doing this check for free pages is also fine since
+ * dissolve_free_hugetlb_folio() returns 0 for non-hugetlb folios as well.
*/
if (__page_handle_poison(page) <= 0)
/*
--
2.44.0



2024-04-15 18:28:17

by Vishal Moola

[permalink] [raw]
Subject: Re: [PATCH v2 1/2] mm/hugetlb: convert dissolve_free_huge_pages() to folios

On Fri, Apr 12, 2024 at 11:21:38AM -0700, Sidhartha Kumar wrote:
> Allows us to rename dissolve_free_huge_pages() to
> dissolve_free_hugetlb_folio(). Convert one caller to pass in a folio
> directly and use page_folio() to convert the caller in mm/memory-failure.
>
> Signed-off-by: Sidhartha Kumar <[email protected]>
> Reviewed-by: Oscar Salvador <[email protected]>
> ---
>
> v1 -> v2:
> - Change additional comments which reference hugepages to
> hugetlb folios per Miaohe Lin.
> - introduce patch 2
>
> include/linux/hugetlb.h | 4 ++--
> mm/hugetlb.c | 17 ++++++++---------
> mm/memory-failure.c | 8 ++++----
> 3 files changed, 14 insertions(+), 15 deletions(-)
>
> diff --git a/include/linux/hugetlb.h b/include/linux/hugetlb.h
> index 3f3e628802792..f4191b10345d6 100644
> --- a/include/linux/hugetlb.h
> +++ b/include/linux/hugetlb.h
> @@ -861,7 +861,7 @@ static inline int hstate_index(struct hstate *h)
> return h - hstates;
> }
>
> -extern int dissolve_free_huge_page(struct page *page);
> +extern int dissolve_free_hugetlb_folio(struct folio *folio);

You could drop the extern here as we don't need it anymore. Aside from that
LGTM.

Reviewed-by: Vishal Moola (Oracle) <[email protected]>

2024-04-15 19:09:28

by Sidhartha Kumar

[permalink] [raw]
Subject: Re: [PATCH v2 1/2] mm/hugetlb: convert dissolve_free_huge_pages() to folios

On 4/15/24 11:28 AM, Vishal Moola wrote:
> On Fri, Apr 12, 2024 at 11:21:38AM -0700, Sidhartha Kumar wrote:
>> Allows us to rename dissolve_free_huge_pages() to
>> dissolve_free_hugetlb_folio(). Convert one caller to pass in a folio
>> directly and use page_folio() to convert the caller in mm/memory-failure.
>>
>> Signed-off-by: Sidhartha Kumar <[email protected]>
>> Reviewed-by: Oscar Salvador <[email protected]>
>> ---
>>
>> v1 -> v2:
>> - Change additional comments which reference hugepages to
>> hugetlb folios per Miaohe Lin.
>> - introduce patch 2
>>
>> include/linux/hugetlb.h | 4 ++--
>> mm/hugetlb.c | 17 ++++++++---------
>> mm/memory-failure.c | 8 ++++----
>> 3 files changed, 14 insertions(+), 15 deletions(-)
>>
>> diff --git a/include/linux/hugetlb.h b/include/linux/hugetlb.h
>> index 3f3e628802792..f4191b10345d6 100644
>> --- a/include/linux/hugetlb.h
>> +++ b/include/linux/hugetlb.h
>> @@ -861,7 +861,7 @@ static inline int hstate_index(struct hstate *h)
>> return h - hstates;
>> }
>>
>> -extern int dissolve_free_huge_page(struct page *page);
>> +extern int dissolve_free_hugetlb_folio(struct folio *folio);
>
> You could drop the extern here as we don't need it anymore. Aside from that
> LGTM.
>
> Reviewed-by: Vishal Moola (Oracle) <[email protected]>
>
Hi Andrew,

Could this diff be folded in this patch to remove the extern per Vishal.

Thanks,
Sid

diff --git a/include/linux/hugetlb.h b/include/linux/hugetlb.h
index f4191b10345d6..4cd7895590b6c 100644
--- a/include/linux/hugetlb.h
+++ b/include/linux/hugetlb.h
@@ -862,7 +862,7 @@ static inline int hstate_index(struct hstate *h)
}

extern int dissolve_free_hugetlb_folio(struct folio *folio);
-extern int dissolve_free_huge_pages(unsigned long start_pfn,
+int dissolve_free_huge_pages(unsigned long start_pfn,
unsigned long end_pfn);

#ifdef CONFIG_MEMORY_FAILURE

2024-04-15 19:14:40

by Sidhartha Kumar

[permalink] [raw]
Subject: Re: [PATCH v2 1/2] mm/hugetlb: convert dissolve_free_huge_pages() to folios

On 4/15/24 12:06 PM, Sidhartha Kumar wrote:
> On 4/15/24 11:28 AM, Vishal Moola wrote:
>> On Fri, Apr 12, 2024 at 11:21:38AM -0700, Sidhartha Kumar wrote:
>>> Allows us to rename dissolve_free_huge_pages() to
>>> dissolve_free_hugetlb_folio(). Convert one caller to pass in a folio
>>> directly and use page_folio() to convert the caller in mm/memory-failure.
>>>
>>> Signed-off-by: Sidhartha Kumar <[email protected]>
>>> Reviewed-by: Oscar Salvador <[email protected]>
>>> ---
>>>
>>> v1 -> v2:
>>>     - Change additional comments which reference hugepages to
>>>       hugetlb folios per Miaohe Lin.
>>>     - introduce patch 2
>>>
>>>   include/linux/hugetlb.h |  4 ++--
>>>   mm/hugetlb.c            | 17 ++++++++---------
>>>   mm/memory-failure.c     |  8 ++++----
>>>   3 files changed, 14 insertions(+), 15 deletions(-)
>>>
>>> diff --git a/include/linux/hugetlb.h b/include/linux/hugetlb.h
>>> index 3f3e628802792..f4191b10345d6 100644
>>> --- a/include/linux/hugetlb.h
>>> +++ b/include/linux/hugetlb.h
>>> @@ -861,7 +861,7 @@ static inline int hstate_index(struct hstate *h)
>>>       return h - hstates;
>>>   }
>>> -extern int dissolve_free_huge_page(struct page *page);
>>> +extern int dissolve_free_hugetlb_folio(struct folio *folio);
>>
>> You could drop the extern here as we don't need it anymore. Aside from that
>> LGTM.
>>
>> Reviewed-by: Vishal Moola (Oracle) <[email protected]>
>>
> Hi Andrew,
>
> Could this diff be folded in this patch to remove the extern per Vishal.
>
> Thanks,
> Sid
>
> diff --git a/include/linux/hugetlb.h b/include/linux/hugetlb.h
> index f4191b10345d6..4cd7895590b6c 100644
> --- a/include/linux/hugetlb.h
> +++ b/include/linux/hugetlb.h
> @@ -862,7 +862,7 @@ static inline int hstate_index(struct hstate *h)
>  }
>
>  extern int dissolve_free_hugetlb_folio(struct folio *folio);
> -extern int dissolve_free_huge_pages(unsigned long start_pfn,
> +int dissolve_free_huge_pages(unsigned long start_pfn,
>                                     unsigned long end_pfn);
>
>  #ifdef CONFIG_MEMORY_FAILURE
>

Sorry, that diff is wrong, it should be:

diff --git a/include/linux/hugetlb.h b/include/linux/hugetlb.h
index f4191b10345d6..8968e8a3a205d 100644
--- a/include/linux/hugetlb.h
+++ b/include/linux/hugetlb.h
@@ -861,7 +861,7 @@ static inline int hstate_index(struct hstate *h)
return h - hstates;
}

-extern int dissolve_free_hugetlb_folio(struct folio *folio);
+int dissolve_free_hugetlb_folio(struct folio *folio);
extern int dissolve_free_huge_pages(unsigned long start_pfn,
unsigned long end_pfn);