[PATCH 1/4] mm/mempolicy: Use folio_alloc_mpol_noprof() in alloc_pages_noprof()

[PATCH 1/4] mm/mempolicy: Use folio_alloc_mpol_noprof() in alloc_pages_noprof()

[Aruna Ramakrishna]

Convert alloc_pages_noprof() to use folio_alloc_mpol_noprof() so that
alloc_pages_mpol(_noprof)() can be removed in a future commit.

Signed-off-by: Aruna Ramakrishna <aruna.ramakrishna@oracle.com>
---
 mm/mempolicy.c | 7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)

diff --git a/mm/mempolicy.c b/mm/mempolicy.c
index b3b5f376471f..2d367ef15d0f 100644
--- a/mm/mempolicy.c
+++ b/mm/mempolicy.c
@@ -2332,6 +2332,7 @@ EXPORT_SYMBOL(vma_alloc_folio_noprof);
 struct page *alloc_pages_noprof(gfp_t gfp, unsigned int order)
 {
 	struct mempolicy *pol = &default_policy;
+	struct folio *folio;
 
 	/*
 	 * No reference counting needed for current->mempolicy
@@ -2340,8 +2341,10 @@ struct page *alloc_pages_noprof(gfp_t gfp, unsigned int order)
 	if (!in_interrupt() && !(gfp & __GFP_THISNODE))
 		pol = get_task_policy(current);
 
-	return alloc_pages_mpol_noprof(gfp, order, pol, NO_INTERLEAVE_INDEX,
-				       numa_node_id());
+	folio = folio_alloc_mpol_noprof(gfp, order, pol, NO_INTERLEAVE_INDEX,
+			numa_node_id());
+
+	return &folio->page;
 }
 EXPORT_SYMBOL(alloc_pages_noprof);
 

base-commit: 2b820b576dfc4aa9b65f18b68f468cb5b38ece84
-- 
2.43.5

[PATCH 2/4] mm/mempolicy: Make alloc_pages_mpol_noprof() static

[Aruna Ramakrishna]

As a first step to removing/replacing alloc_pages_mpol()
and alloc_pages_mpol_noprof() with their folio equivalents,
make alloc_pages_mpol_noprof() static.

Signed-off-by: Aruna Ramakrishna <aruna.ramakrishna@oracle.com>
---
 include/linux/gfp.h | 7 -------
 mm/mempolicy.c      | 2 +-
 2 files changed, 1 insertion(+), 8 deletions(-)

diff --git a/include/linux/gfp.h b/include/linux/gfp.h
index f53f76e0b17e..f5ce91ccc954 100644
--- a/include/linux/gfp.h
+++ b/include/linux/gfp.h
@@ -300,8 +300,6 @@ static inline struct page *alloc_pages_node_noprof(int nid, gfp_t gfp_mask,
 
 #ifdef CONFIG_NUMA
 struct page *alloc_pages_noprof(gfp_t gfp, unsigned int order);
-struct page *alloc_pages_mpol_noprof(gfp_t gfp, unsigned int order,
-		struct mempolicy *mpol, pgoff_t ilx, int nid);
 struct folio *folio_alloc_noprof(gfp_t gfp, unsigned int order);
 struct folio *folio_alloc_mpol_noprof(gfp_t gfp, unsigned int order,
 		struct mempolicy *mpol, pgoff_t ilx, int nid);
@@ -312,11 +310,6 @@ static inline struct page *alloc_pages_noprof(gfp_t gfp_mask, unsigned int order
 {
 	return alloc_pages_node_noprof(numa_node_id(), gfp_mask, order);
 }
-static inline struct page *alloc_pages_mpol_noprof(gfp_t gfp, unsigned int order,
-		struct mempolicy *mpol, pgoff_t ilx, int nid)
-{
-	return alloc_pages_noprof(gfp, order);
-}
 static inline struct folio *folio_alloc_noprof(gfp_t gfp, unsigned int order)
 {
 	return __folio_alloc_node(gfp, order, numa_node_id());
diff --git a/mm/mempolicy.c b/mm/mempolicy.c
index 2d367ef15d0f..6132a230a3b9 100644
--- a/mm/mempolicy.c
+++ b/mm/mempolicy.c
@@ -2216,7 +2216,7 @@ static struct page *alloc_pages_preferred_many(gfp_t gfp, unsigned int order,
  *
  * Return: The page on success or NULL if allocation fails.
  */
-struct page *alloc_pages_mpol_noprof(gfp_t gfp, unsigned int order,
+static struct page *alloc_pages_mpol_noprof(gfp_t gfp, unsigned int order,
 		struct mempolicy *pol, pgoff_t ilx, int nid)
 {
 	nodemask_t *nodemask;
-- 
2.43.5

[PATCH 3/4] mm/mempolicy: Remove alloc_pages_mpol_noprof()

[Aruna Ramakrishna]

There are now no callers of either alloc_pages_mpol() or
alloc_pages_mpol_noprof(). Remove both functions, and fully
convert the body of folio_alloc_mpol_nprof() to use folios.

Signed-off-by: Aruna Ramakrishna <aruna.ramakrishna@oracle.com>
---
 include/linux/gfp.h |  1 -
 mm/mempolicy.c      | 42 ++++++++++++++++++++----------------------
 2 files changed, 20 insertions(+), 23 deletions(-)

diff --git a/include/linux/gfp.h b/include/linux/gfp.h
index f5ce91ccc954..58f23f15a71a 100644
--- a/include/linux/gfp.h
+++ b/include/linux/gfp.h
@@ -324,7 +324,6 @@ static inline struct folio *folio_alloc_mpol_noprof(gfp_t gfp, unsigned int orde
 #endif
 
 #define alloc_pages(...)			alloc_hooks(alloc_pages_noprof(__VA_ARGS__))
-#define alloc_pages_mpol(...)			alloc_hooks(alloc_pages_mpol_noprof(__VA_ARGS__))
 #define folio_alloc(...)			alloc_hooks(folio_alloc_noprof(__VA_ARGS__))
 #define folio_alloc_mpol(...)			alloc_hooks(folio_alloc_mpol_noprof(__VA_ARGS__))
 #define vma_alloc_folio(...)			alloc_hooks(vma_alloc_folio_noprof(__VA_ARGS__))
diff --git a/mm/mempolicy.c b/mm/mempolicy.c
index 6132a230a3b9..9be32c3bfff2 100644
--- a/mm/mempolicy.c
+++ b/mm/mempolicy.c
@@ -2207,25 +2207,28 @@ static struct page *alloc_pages_preferred_many(gfp_t gfp, unsigned int order,
 }
 
 /**
- * alloc_pages_mpol - Allocate pages according to NUMA mempolicy.
+ * folio_alloc_mpol_noprof - Allocate pages according to NUMA mempolicy.
  * @gfp: GFP flags.
- * @order: Order of the page allocation.
+ * @order: Order of the folio allocation.
  * @pol: Pointer to the NUMA mempolicy.
  * @ilx: Index for interleave mempolicy (also distinguishes alloc_pages()).
  * @nid: Preferred node (usually numa_node_id() but @mpol may override it).
  *
- * Return: The page on success or NULL if allocation fails.
+ * Return: The folio on success or NULL if allocation fails.
  */
-static struct page *alloc_pages_mpol_noprof(gfp_t gfp, unsigned int order,
+struct folio *folio_alloc_mpol_noprof(gfp_t gfp, unsigned int order,
 		struct mempolicy *pol, pgoff_t ilx, int nid)
 {
 	nodemask_t *nodemask;
-	struct page *page;
+	struct folio *folio;
 
+	gfp |= __GFP_COMP;
 	nodemask = policy_nodemask(gfp, pol, ilx, &nid);
 
 	if (pol->mode == MPOL_PREFERRED_MANY)
-		return alloc_pages_preferred_many(gfp, order, nid, nodemask);
+		return page_rmappable_folio(
+				alloc_pages_preferred_many(gfp, order,
+					nid, nodemask));
 
 	if (IS_ENABLED(CONFIG_TRANSPARENT_HUGEPAGE) &&
 	    /* filter "hugepage" allocation, unless from alloc_pages() */
@@ -2247,10 +2250,12 @@ static struct page *alloc_pages_mpol_noprof(gfp_t gfp, unsigned int order,
 			 * First, try to allocate THP only on local node, but
 			 * don't reclaim unnecessarily, just compact.
 			 */
-			page = __alloc_pages_node_noprof(nid,
-				gfp | __GFP_THISNODE | __GFP_NORETRY, order);
-			if (page || !(gfp & __GFP_DIRECT_RECLAIM))
-				return page;
+			folio = __folio_alloc_node_noprof(
+					gfp | __GFP_THISNODE | __GFP_NORETRY,
+					order, nid);
+
+			if (folio || !(gfp & __GFP_DIRECT_RECLAIM))
+				return folio;
 			/*
 			 * If hugepage allocations are configured to always
 			 * synchronous compact or the vma has been madvised
@@ -2260,26 +2265,19 @@ static struct page *alloc_pages_mpol_noprof(gfp_t gfp, unsigned int order,
 		}
 	}
 
-	page = __alloc_pages_noprof(gfp, order, nid, nodemask);
+	folio = __folio_alloc_noprof(gfp, order, nid, nodemask);
 
-	if (unlikely(pol->mode == MPOL_INTERLEAVE) && page) {
+	if (unlikely(pol->mode == MPOL_INTERLEAVE) && folio) {
 		/* skip NUMA_INTERLEAVE_HIT update if numa stats is disabled */
 		if (static_branch_likely(&vm_numa_stat_key) &&
-		    page_to_nid(page) == nid) {
+		    folio_nid(folio) == nid) {
 			preempt_disable();
-			__count_numa_event(page_zone(page), NUMA_INTERLEAVE_HIT);
+			__count_numa_event(folio_zone(folio), NUMA_INTERLEAVE_HIT);
 			preempt_enable();
 		}
 	}
 
-	return page;
-}
-
-struct folio *folio_alloc_mpol_noprof(gfp_t gfp, unsigned int order,
-		struct mempolicy *pol, pgoff_t ilx, int nid)
-{
-	return page_rmappable_folio(alloc_pages_mpol_noprof(gfp | __GFP_COMP,
-							order, pol, ilx, nid));
+	return folio;
 }
 
 /**
-- 
2.43.5

[PATCH 4/4] mm/mempolicy: Convert alloc_pages_preferred_many() to return a folio

[Aruna Ramakrishna]

There is only one caller of alloc_pages_preferred_many(), which
already expects a folio. Rename the function and convert the body
of alloc_pages_preferred_many() to work with folios too.

Signed-off-by: Aruna Ramakrishna <aruna.ramakrishna@oracle.com>
---
 mm/mempolicy.c | 18 ++++++++----------
 1 file changed, 8 insertions(+), 10 deletions(-)

diff --git a/mm/mempolicy.c b/mm/mempolicy.c
index 9be32c3bfff2..33074ffd59fe 100644
--- a/mm/mempolicy.c
+++ b/mm/mempolicy.c
@@ -2185,10 +2185,10 @@ bool mempolicy_in_oom_domain(struct task_struct *tsk,
 	return ret;
 }
 
-static struct page *alloc_pages_preferred_many(gfp_t gfp, unsigned int order,
-						int nid, nodemask_t *nodemask)
+static struct folio *folio_alloc_preferred_many(gfp_t gfp, unsigned int order,
+		int nid, nodemask_t *nodemask)
 {
-	struct page *page;
+	struct folio *folio;
 	gfp_t preferred_gfp;
 
 	/*
@@ -2199,11 +2199,11 @@ static struct page *alloc_pages_preferred_many(gfp_t gfp, unsigned int order,
 	 */
 	preferred_gfp = gfp | __GFP_NOWARN;
 	preferred_gfp &= ~(__GFP_DIRECT_RECLAIM | __GFP_NOFAIL);
-	page = __alloc_pages_noprof(preferred_gfp, order, nid, nodemask);
-	if (!page)
-		page = __alloc_pages_noprof(gfp, order, nid, NULL);
+	folio = __folio_alloc_noprof(preferred_gfp, order, nid, nodemask);
+	if (!folio)
+		folio = __folio_alloc_noprof(gfp, order, nid, NULL);
 
-	return page;
+	return folio;
 }
 
 /**
@@ -2226,9 +2226,7 @@ struct folio *folio_alloc_mpol_noprof(gfp_t gfp, unsigned int order,
 	nodemask = policy_nodemask(gfp, pol, ilx, &nid);
 
 	if (pol->mode == MPOL_PREFERRED_MANY)
-		return page_rmappable_folio(
-				alloc_pages_preferred_many(gfp, order,
-					nid, nodemask));
+		return folio_alloc_preferred_many(gfp, order, nid, nodemask);
 
 	if (IS_ENABLED(CONFIG_TRANSPARENT_HUGEPAGE) &&
 	    /* filter "hugepage" allocation, unless from alloc_pages() */
-- 
2.43.5

Re: [PATCH 1/4] mm/mempolicy: Use folio_alloc_mpol_noprof() in alloc_pages_noprof()

[Kefeng Wang]

On 2024/8/6 0:31, Aruna Ramakrishna wrote:
> Convert alloc_pages_noprof() to use folio_alloc_mpol_noprof() so that
> alloc_pages_mpol(_noprof)() can be removed in a future commit.
> 
> Signed-off-by: Aruna Ramakrishna <aruna.ramakrishna@oracle.com>
> ---
>   mm/mempolicy.c | 7 +++++--
>   1 file changed, 5 insertions(+), 2 deletions(-)
> 
> diff --git a/mm/mempolicy.c b/mm/mempolicy.c
> index b3b5f376471f..2d367ef15d0f 100644
> --- a/mm/mempolicy.c
> +++ b/mm/mempolicy.c
> @@ -2332,6 +2332,7 @@ EXPORT_SYMBOL(vma_alloc_folio_noprof);
>   struct page *alloc_pages_noprof(gfp_t gfp, unsigned int order)
>   {
>   	struct mempolicy *pol = &default_policy;
> +	struct folio *folio;
>   
>   	/*
>   	 * No reference counting needed for current->mempolicy
> @@ -2340,8 +2341,10 @@ struct page *alloc_pages_noprof(gfp_t gfp, unsigned int order)
>   	if (!in_interrupt() && !(gfp & __GFP_THISNODE))
>   		pol = get_task_policy(current);
>   
> -	return alloc_pages_mpol_noprof(gfp, order, pol, NO_INTERLEAVE_INDEX,
> -				       numa_node_id());
> +	folio = folio_alloc_mpol_noprof(gfp, order, pol, NO_INTERLEAVE_INDEX,
> +			numa_node_id());

We have __GFP_COMP in folio_alloc_mpol_noprof and set large_rmappable
for large folio, not sure that there is some issue for alloc_pages()
callers.


> +
> +	return &folio->page;
>   }
>   EXPORT_SYMBOL(alloc_pages_noprof);
>   
> 
> base-commit: 2b820b576dfc4aa9b65f18b68f468cb5b38ece84

Re: [PATCH 1/4] mm/mempolicy: Use folio_alloc_mpol_noprof() in alloc_pages_noprof()

[Aruna Ramakrishna]

> On Aug 6, 2024, at 1:05 AM, Kefeng Wang <wangkefeng.wang@huawei.com> wrote:
> 
> 
> 
> On 2024/8/6 0:31, Aruna Ramakrishna wrote:
>> Convert alloc_pages_noprof() to use folio_alloc_mpol_noprof() so that
>> alloc_pages_mpol(_noprof)() can be removed in a future commit.
>> Signed-off-by: Aruna Ramakrishna <aruna.ramakrishna@oracle.com>
>> ---
>>  mm/mempolicy.c | 7 +++++--
>>  1 file changed, 5 insertions(+), 2 deletions(-)
>> diff --git a/mm/mempolicy.c b/mm/mempolicy.c
>> index b3b5f376471f..2d367ef15d0f 100644
>> --- a/mm/mempolicy.c
>> +++ b/mm/mempolicy.c
>> @@ -2332,6 +2332,7 @@ EXPORT_SYMBOL(vma_alloc_folio_noprof);
>>  struct page *alloc_pages_noprof(gfp_t gfp, unsigned int order)
>>  {
>>   struct mempolicy *pol = &default_policy;
>> + struct folio *folio;
>>     /*
>>    * No reference counting needed for current->mempolicy
>> @@ -2340,8 +2341,10 @@ struct page *alloc_pages_noprof(gfp_t gfp, unsigned int order)
>>   if (!in_interrupt() && !(gfp & __GFP_THISNODE))
>>   pol = get_task_policy(current);
>>  - return alloc_pages_mpol_noprof(gfp, order, pol, NO_INTERLEAVE_INDEX,
>> -        numa_node_id());
>> + folio = folio_alloc_mpol_noprof(gfp, order, pol, NO_INTERLEAVE_INDEX,
>> + numa_node_id());
> 
> We have __GFP_COMP in folio_alloc_mpol_noprof and set large_rmappable
> for large folio, not sure that there is some issue for alloc_pages()
> callers.
> 

Hi Kefeng,

You’re right, this will force all callers of alloc_pages() to use __GFP_COMP which,
at this point, seems risky to do. I was trying to find a way to separate out the compound
page users from the non-, but it makes things too complicated. I do not think it is possible
to convert alloc_pages_noprof() to folios at this point, without addressing that first.

Thank you for catching that.

Thanks,
Aruna