From: Zhaoyang Huang <zhaoyang.huang@unisoc.com>
commit c8b979530f27 ("mm: alloc_pages_bulk_noprof: drop page_list
argument") drops alloc_pages_bulk_list. This commit would like to call back
it since it is proved to be helpful to the drivers which allocate a bulk of
pages(see patch of 2 in this series ).
I do notice that Matthew's comment of the time cost of iterating a list.
However, I also observed in our test that the extra page_array's allocation
could be more expensive than cpu iteration when direct reclaiming happens
when ram is low[1]. IMHO, could we leave the API here to have the users
choose between the array or list according to their scenarios.
[1]
android.hardwar-728 [002] ..... 334.573875: system_heap_do_allocate: Execution time: order 0 1 us
android.hardwar-728 [002] ..... 334.573879: system_heap_do_allocate: Execution time: order 0 2 us
android.hardwar-728 [002] ..... 334.574239: system_heap_do_allocate: Execution time: order 0 354 us
android.hardwar-728 [002] ..... 334.574247: system_heap_do_allocate: Execution time: order 0 4 us
android.hardwar-728 [002] ..... 334.574250: system_heap_do_allocate: Execution time: order 0 2 us
Signed-off-by: Zhaoyang Huang <zhaoyang.huang@unisoc.com>
---
include/linux/gfp.h | 9 +++++++--
mm/mempolicy.c | 14 +++++++-------
mm/page_alloc.c | 39 +++++++++++++++++++++++++++------------
3 files changed, 41 insertions(+), 21 deletions(-)
diff --git a/include/linux/gfp.h b/include/linux/gfp.h
index 5ebf26fcdcfa..f1540c9fcd87 100644
--- a/include/linux/gfp.h
+++ b/include/linux/gfp.h
@@ -231,6 +231,7 @@ struct folio *__folio_alloc_noprof(gfp_t gfp, unsigned int order, int preferred_
unsigned long alloc_pages_bulk_noprof(gfp_t gfp, int preferred_nid,
nodemask_t *nodemask, int nr_pages,
+ struct list_head *page_list,
struct page **page_array);
#define __alloc_pages_bulk(...) alloc_hooks(alloc_pages_bulk_noprof(__VA_ARGS__))
@@ -242,7 +243,11 @@ unsigned long alloc_pages_bulk_mempolicy_noprof(gfp_t gfp,
/* Bulk allocate order-0 pages */
#define alloc_pages_bulk(_gfp, _nr_pages, _page_array) \
- __alloc_pages_bulk(_gfp, numa_mem_id(), NULL, _nr_pages, _page_array)
+ __alloc_pages_bulk(_gfp, numa_mem_id(), NULL, _nr_pages, NULL, _page_array)
+
+#define alloc_pages_bulk_list(_gfp, _nr_pages, _list) \
+ __alloc_pages_bulk(_gfp, numa_mem_id(), NULL, _nr_pages, _list, NULL)
+
static inline unsigned long
alloc_pages_bulk_node_noprof(gfp_t gfp, int nid, unsigned long nr_pages,
@@ -251,7 +256,7 @@ alloc_pages_bulk_node_noprof(gfp_t gfp, int nid, unsigned long nr_pages,
if (nid == NUMA_NO_NODE)
nid = numa_mem_id();
- return alloc_pages_bulk_noprof(gfp, nid, NULL, nr_pages, page_array);
+ return alloc_pages_bulk_noprof(gfp, nid, NULL, nr_pages, NULL, page_array);
}
#define alloc_pages_bulk_node(...) \
diff --git a/mm/mempolicy.c b/mm/mempolicy.c
index eb83cff7db8c..26274302ee01 100644
--- a/mm/mempolicy.c
+++ b/mm/mempolicy.c
@@ -2537,13 +2537,13 @@ static unsigned long alloc_pages_bulk_interleave(gfp_t gfp,
if (delta) {
nr_allocated = alloc_pages_bulk_noprof(gfp,
interleave_nodes(pol), NULL,
- nr_pages_per_node + 1,
+ nr_pages_per_node + 1, NULL,
page_array);
delta--;
} else {
nr_allocated = alloc_pages_bulk_noprof(gfp,
interleave_nodes(pol), NULL,
- nr_pages_per_node, page_array);
+ nr_pages_per_node, NULL, page_array);
}
page_array += nr_allocated;
@@ -2593,7 +2593,7 @@ static unsigned long alloc_pages_bulk_weighted_interleave(gfp_t gfp,
if (weight && node_isset(node, nodes)) {
node_pages = min(rem_pages, weight);
nr_allocated = __alloc_pages_bulk(gfp, node, NULL, node_pages,
- page_array);
+ NULL, page_array);
page_array += nr_allocated;
total_allocated += nr_allocated;
/* if that's all the pages, no need to interleave */
@@ -2658,7 +2658,7 @@ static unsigned long alloc_pages_bulk_weighted_interleave(gfp_t gfp,
if (!node_pages)
break;
nr_allocated = __alloc_pages_bulk(gfp, node, NULL, node_pages,
- page_array);
+ NULL, page_array);
page_array += nr_allocated;
total_allocated += nr_allocated;
if (total_allocated == nr_pages)
@@ -2682,11 +2682,11 @@ static unsigned long alloc_pages_bulk_preferred_many(gfp_t gfp, int nid,
preferred_gfp &= ~(__GFP_DIRECT_RECLAIM | __GFP_NOFAIL);
nr_allocated = alloc_pages_bulk_noprof(preferred_gfp, nid, &pol->nodes,
- nr_pages, page_array);
+ nr_pages, NULL, page_array);
if (nr_allocated < nr_pages)
nr_allocated += alloc_pages_bulk_noprof(gfp, numa_node_id(), NULL,
- nr_pages - nr_allocated,
+ nr_pages - nr_allocated, NULL,
page_array + nr_allocated);
return nr_allocated;
}
@@ -2722,7 +2722,7 @@ unsigned long alloc_pages_bulk_mempolicy_noprof(gfp_t gfp,
nid = numa_node_id();
nodemask = policy_nodemask(gfp, pol, NO_INTERLEAVE_INDEX, &nid);
return alloc_pages_bulk_noprof(gfp, nid, nodemask,
- nr_pages, page_array);
+ nr_pages, NULL, page_array);
}
int vma_dup_policy(struct vm_area_struct *src, struct vm_area_struct *dst)
diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index d1d037f97c5f..a95bdd8cbf5b 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -4940,23 +4940,28 @@ static inline bool prepare_alloc_pages(gfp_t gfp_mask, unsigned int order,
}
/*
- * __alloc_pages_bulk - Allocate a number of order-0 pages to an array
+ * __alloc_pages_bulk - Allocate a number of order-0 pages to a list or array
* @gfp: GFP flags for the allocation
* @preferred_nid: The preferred NUMA node ID to allocate from
* @nodemask: Set of nodes to allocate from, may be NULL
- * @nr_pages: The number of pages desired in the array
- * @page_array: Array to store the pages
+ * @nr_pages: The number of pages desired on the list or array
+ * @page_list: Optional list to store the allocated pages
+ * @page_array: Optional array to store the pages
*
* This is a batched version of the page allocator that attempts to
- * allocate nr_pages quickly. Pages are added to the page_array.
+ * allocate nr_pages quickly. Pages are added to page_list if page_list
+ * is not NULL, otherwise it is assumed that the page_array is valid.
*
- * Note that only NULL elements are populated with pages and nr_pages
+ * For lists, nr_pages is the number of pages that should be allocated.
+ *
+ * For arrays, only NULL elements are populated with pages and nr_pages
* is the maximum number of pages that will be stored in the array.
*
- * Returns the number of pages in the array.
+ * Returns the number of pages on the list or array.
*/
unsigned long alloc_pages_bulk_noprof(gfp_t gfp, int preferred_nid,
nodemask_t *nodemask, int nr_pages,
+ struct list_head *page_list,
struct page **page_array)
{
struct page *page;
@@ -4974,7 +4979,7 @@ unsigned long alloc_pages_bulk_noprof(gfp_t gfp, int preferred_nid,
* Skip populated array elements to determine if any pages need
* to be allocated before disabling IRQs.
*/
- while (nr_populated < nr_pages && page_array[nr_populated])
+ while (page_array && nr_populated < nr_pages && page_array[nr_populated])
nr_populated++;
/* No pages requested? */
@@ -4982,7 +4987,7 @@ unsigned long alloc_pages_bulk_noprof(gfp_t gfp, int preferred_nid,
goto out;
/* Already populated array? */
- if (unlikely(nr_pages - nr_populated == 0))
+ if (unlikely(page_array && nr_pages - nr_populated == 0))
goto out;
/* Bulk allocator does not support memcg accounting. */
@@ -5064,7 +5069,7 @@ unsigned long alloc_pages_bulk_noprof(gfp_t gfp, int preferred_nid,
while (nr_populated < nr_pages) {
/* Skip existing pages */
- if (page_array[nr_populated]) {
+ if (page_array && page_array[nr_populated]) {
nr_populated++;
continue;
}
@@ -5083,7 +5088,11 @@ unsigned long alloc_pages_bulk_noprof(gfp_t gfp, int preferred_nid,
prep_new_page(page, 0, gfp, 0);
set_page_refcounted(page);
- page_array[nr_populated++] = page;
+ if (page_list)
+ list_add(&page->lru, page_list);
+ else
+ page_array[nr_populated] = page;
+ nr_populated++;
}
pcp_spin_unlock(pcp);
@@ -5100,8 +5109,14 @@ unsigned long alloc_pages_bulk_noprof(gfp_t gfp, int preferred_nid,
failed:
page = __alloc_pages_noprof(gfp, 0, preferred_nid, nodemask);
- if (page)
- page_array[nr_populated++] = page;
+ if (page) {
+ if (page_list)
+ list_add(&page->lru, page_list);
+ else
+ page_array[nr_populated] = page;
+ nr_populated++;
+ }
+
goto out;
}
EXPORT_SYMBOL_GPL(alloc_pages_bulk_noprof);
--
2.25.1On 14.10.25 10:32, zhaoyang.huang wrote:
> From: Zhaoyang Huang <zhaoyang.huang@unisoc.com>
Probably the subject should be "mm: reintroduce alloc_pages_bulk_list()"
>
> commit c8b979530f27 ("mm: alloc_pages_bulk_noprof: drop page_list
> argument") drops alloc_pages_bulk_list. This commit would like to call back
> it since it is proved to be helpful to the drivers which allocate a bulk of
> pages(see patch of 2 in this series ).
"Let's reintroduce it so we can us for bulk allocation in the context of
XXX next."
> I do notice that Matthew's comment of the time cost of iterating a list.
> However, I also observed in our test that the extra page_array's allocation
> could be more expensive than cpu iteration when direct reclaiming happens
> when ram is low[1]. IMHO, could we leave the API here to have the users
> choose between the array or list according to their scenarios.
I'd prefer if we avoid reintroducing this interface.
How many pages are you intending to allocate? Wouldn't a smaller array
on the stack be sufficient?
--
Cheers
David / dhildenb
On Wed, Oct 15, 2025 at 8:16 PM David Hildenbrand <david@redhat.com> wrote:
>
> On 14.10.25 10:32, zhaoyang.huang wrote:
> > From: Zhaoyang Huang <zhaoyang.huang@unisoc.com>
>
> Probably the subject should be "mm: reintroduce alloc_pages_bulk_list()"
ok
>
> >
> > commit c8b979530f27 ("mm: alloc_pages_bulk_noprof: drop page_list
> > argument") drops alloc_pages_bulk_list. This commit would like to call back
> > it since it is proved to be helpful to the drivers which allocate a bulk of
> > pages(see patch of 2 in this series ).
>
> "Let's reintroduce it so we can us for bulk allocation in the context of
> XXX next."
>
> > I do notice that Matthew's comment of the time cost of iterating a list.
> > However, I also observed in our test that the extra page_array's allocation
> > could be more expensive than cpu iteration when direct reclaiming happens
> > when ram is low[1]. IMHO, could we leave the API here to have the users
> > choose between the array or list according to their scenarios.
>
> I'd prefer if we avoid reintroducing this interface.
>
> How many pages are you intending to allocate? Wouldn't a smaller array
> on the stack be sufficient?
Actually, dma-buf is the main consumer in android which could occupy
half of the system RAM(mainly by multimedia which passes the memory
between GPU and display, camera driver, NPU driver etc). Dozens MB is
quite common or maybe more. This commit is proved to be helpful in the
scenario of camera APP cold start which allocate around 300MB memory
in an 6GB RAM ANDROID system
IMHO, page_list could be more efficient than page_array in memory
perspective which is an uncertain factor than iterating the list
>
>
> --
> Cheers
>
> David / dhildenb
>
On Tue, 14 Oct 2025 16:32:29 +0800
"zhaoyang.huang" <zhaoyang.huang@unisoc.com> wrote:
> From: Zhaoyang Huang <zhaoyang.huang@unisoc.com>
>
> commit c8b979530f27 ("mm: alloc_pages_bulk_noprof: drop page_list
> argument") drops alloc_pages_bulk_list. This commit would like to call back
> it since it is proved to be helpful to the drivers which allocate a bulk of
> pages(see patch of 2 in this series ).
> I do notice that Matthew's comment of the time cost of iterating a list.
> However, I also observed in our test that the extra page_array's allocation
> could be more expensive than cpu iteration when direct reclaiming happens
> when ram is low[1]. IMHO, could we leave the API here to have the users
> choose between the array or list according to their scenarios.
OK, so this is more or less a revert of commit c8b979530f27 ("mm:
alloc_pages_bulk_noprof: drop page_list argument")...
I cannot comment on the performance gains, but I dislike the fact that
the patch re-introduces alloc_pages_bulk_noprof() as a function with two
signatures (either page_list is used, or page_array is used).
If we can agree that allocations onto a linked list are useful, then I
suggest to split the existing function so that the common bits end up
in helper functions, called by both variants (one function using a
list, one using an array).
Petr T
> [1]
> android.hardwar-728 [002] ..... 334.573875: system_heap_do_allocate: Execution time: order 0 1 us
> android.hardwar-728 [002] ..... 334.573879: system_heap_do_allocate: Execution time: order 0 2 us
> android.hardwar-728 [002] ..... 334.574239: system_heap_do_allocate: Execution time: order 0 354 us
> android.hardwar-728 [002] ..... 334.574247: system_heap_do_allocate: Execution time: order 0 4 us
> android.hardwar-728 [002] ..... 334.574250: system_heap_do_allocate: Execution time: order 0 2 us
>
> Signed-off-by: Zhaoyang Huang <zhaoyang.huang@unisoc.com>
> ---
> include/linux/gfp.h | 9 +++++++--
> mm/mempolicy.c | 14 +++++++-------
> mm/page_alloc.c | 39 +++++++++++++++++++++++++++------------
> 3 files changed, 41 insertions(+), 21 deletions(-)
>
> diff --git a/include/linux/gfp.h b/include/linux/gfp.h
> index 5ebf26fcdcfa..f1540c9fcd87 100644
> --- a/include/linux/gfp.h
> +++ b/include/linux/gfp.h
> @@ -231,6 +231,7 @@ struct folio *__folio_alloc_noprof(gfp_t gfp, unsigned int order, int preferred_
>
> unsigned long alloc_pages_bulk_noprof(gfp_t gfp, int preferred_nid,
> nodemask_t *nodemask, int nr_pages,
> + struct list_head *page_list,
> struct page **page_array);
> #define __alloc_pages_bulk(...) alloc_hooks(alloc_pages_bulk_noprof(__VA_ARGS__))
>
> @@ -242,7 +243,11 @@ unsigned long alloc_pages_bulk_mempolicy_noprof(gfp_t gfp,
>
> /* Bulk allocate order-0 pages */
> #define alloc_pages_bulk(_gfp, _nr_pages, _page_array) \
> - __alloc_pages_bulk(_gfp, numa_mem_id(), NULL, _nr_pages, _page_array)
> + __alloc_pages_bulk(_gfp, numa_mem_id(), NULL, _nr_pages, NULL, _page_array)
> +
> +#define alloc_pages_bulk_list(_gfp, _nr_pages, _list) \
> + __alloc_pages_bulk(_gfp, numa_mem_id(), NULL, _nr_pages, _list, NULL)
> +
>
> static inline unsigned long
> alloc_pages_bulk_node_noprof(gfp_t gfp, int nid, unsigned long nr_pages,
> @@ -251,7 +256,7 @@ alloc_pages_bulk_node_noprof(gfp_t gfp, int nid, unsigned long nr_pages,
> if (nid == NUMA_NO_NODE)
> nid = numa_mem_id();
>
> - return alloc_pages_bulk_noprof(gfp, nid, NULL, nr_pages, page_array);
> + return alloc_pages_bulk_noprof(gfp, nid, NULL, nr_pages, NULL, page_array);
> }
>
> #define alloc_pages_bulk_node(...) \
> diff --git a/mm/mempolicy.c b/mm/mempolicy.c
> index eb83cff7db8c..26274302ee01 100644
> --- a/mm/mempolicy.c
> +++ b/mm/mempolicy.c
> @@ -2537,13 +2537,13 @@ static unsigned long alloc_pages_bulk_interleave(gfp_t gfp,
> if (delta) {
> nr_allocated = alloc_pages_bulk_noprof(gfp,
> interleave_nodes(pol), NULL,
> - nr_pages_per_node + 1,
> + nr_pages_per_node + 1, NULL,
> page_array);
> delta--;
> } else {
> nr_allocated = alloc_pages_bulk_noprof(gfp,
> interleave_nodes(pol), NULL,
> - nr_pages_per_node, page_array);
> + nr_pages_per_node, NULL, page_array);
> }
>
> page_array += nr_allocated;
> @@ -2593,7 +2593,7 @@ static unsigned long alloc_pages_bulk_weighted_interleave(gfp_t gfp,
> if (weight && node_isset(node, nodes)) {
> node_pages = min(rem_pages, weight);
> nr_allocated = __alloc_pages_bulk(gfp, node, NULL, node_pages,
> - page_array);
> + NULL, page_array);
> page_array += nr_allocated;
> total_allocated += nr_allocated;
> /* if that's all the pages, no need to interleave */
> @@ -2658,7 +2658,7 @@ static unsigned long alloc_pages_bulk_weighted_interleave(gfp_t gfp,
> if (!node_pages)
> break;
> nr_allocated = __alloc_pages_bulk(gfp, node, NULL, node_pages,
> - page_array);
> + NULL, page_array);
> page_array += nr_allocated;
> total_allocated += nr_allocated;
> if (total_allocated == nr_pages)
> @@ -2682,11 +2682,11 @@ static unsigned long alloc_pages_bulk_preferred_many(gfp_t gfp, int nid,
> preferred_gfp &= ~(__GFP_DIRECT_RECLAIM | __GFP_NOFAIL);
>
> nr_allocated = alloc_pages_bulk_noprof(preferred_gfp, nid, &pol->nodes,
> - nr_pages, page_array);
> + nr_pages, NULL, page_array);
>
> if (nr_allocated < nr_pages)
> nr_allocated += alloc_pages_bulk_noprof(gfp, numa_node_id(), NULL,
> - nr_pages - nr_allocated,
> + nr_pages - nr_allocated, NULL,
> page_array + nr_allocated);
> return nr_allocated;
> }
> @@ -2722,7 +2722,7 @@ unsigned long alloc_pages_bulk_mempolicy_noprof(gfp_t gfp,
> nid = numa_node_id();
> nodemask = policy_nodemask(gfp, pol, NO_INTERLEAVE_INDEX, &nid);
> return alloc_pages_bulk_noprof(gfp, nid, nodemask,
> - nr_pages, page_array);
> + nr_pages, NULL, page_array);
> }
>
> int vma_dup_policy(struct vm_area_struct *src, struct vm_area_struct *dst)
> diff --git a/mm/page_alloc.c b/mm/page_alloc.c
> index d1d037f97c5f..a95bdd8cbf5b 100644
> --- a/mm/page_alloc.c
> +++ b/mm/page_alloc.c
> @@ -4940,23 +4940,28 @@ static inline bool prepare_alloc_pages(gfp_t gfp_mask, unsigned int order,
> }
>
> /*
> - * __alloc_pages_bulk - Allocate a number of order-0 pages to an array
> + * __alloc_pages_bulk - Allocate a number of order-0 pages to a list or array
> * @gfp: GFP flags for the allocation
> * @preferred_nid: The preferred NUMA node ID to allocate from
> * @nodemask: Set of nodes to allocate from, may be NULL
> - * @nr_pages: The number of pages desired in the array
> - * @page_array: Array to store the pages
> + * @nr_pages: The number of pages desired on the list or array
> + * @page_list: Optional list to store the allocated pages
> + * @page_array: Optional array to store the pages
> *
> * This is a batched version of the page allocator that attempts to
> - * allocate nr_pages quickly. Pages are added to the page_array.
> + * allocate nr_pages quickly. Pages are added to page_list if page_list
> + * is not NULL, otherwise it is assumed that the page_array is valid.
> *
> - * Note that only NULL elements are populated with pages and nr_pages
> + * For lists, nr_pages is the number of pages that should be allocated.
> + *
> + * For arrays, only NULL elements are populated with pages and nr_pages
> * is the maximum number of pages that will be stored in the array.
> *
> - * Returns the number of pages in the array.
> + * Returns the number of pages on the list or array.
> */
> unsigned long alloc_pages_bulk_noprof(gfp_t gfp, int preferred_nid,
> nodemask_t *nodemask, int nr_pages,
> + struct list_head *page_list,
> struct page **page_array)
> {
> struct page *page;
> @@ -4974,7 +4979,7 @@ unsigned long alloc_pages_bulk_noprof(gfp_t gfp, int preferred_nid,
> * Skip populated array elements to determine if any pages need
> * to be allocated before disabling IRQs.
> */
> - while (nr_populated < nr_pages && page_array[nr_populated])
> + while (page_array && nr_populated < nr_pages && page_array[nr_populated])
> nr_populated++;
>
> /* No pages requested? */
> @@ -4982,7 +4987,7 @@ unsigned long alloc_pages_bulk_noprof(gfp_t gfp, int preferred_nid,
> goto out;
>
> /* Already populated array? */
> - if (unlikely(nr_pages - nr_populated == 0))
> + if (unlikely(page_array && nr_pages - nr_populated == 0))
> goto out;
>
> /* Bulk allocator does not support memcg accounting. */
> @@ -5064,7 +5069,7 @@ unsigned long alloc_pages_bulk_noprof(gfp_t gfp, int preferred_nid,
> while (nr_populated < nr_pages) {
>
> /* Skip existing pages */
> - if (page_array[nr_populated]) {
> + if (page_array && page_array[nr_populated]) {
> nr_populated++;
> continue;
> }
> @@ -5083,7 +5088,11 @@ unsigned long alloc_pages_bulk_noprof(gfp_t gfp, int preferred_nid,
>
> prep_new_page(page, 0, gfp, 0);
> set_page_refcounted(page);
> - page_array[nr_populated++] = page;
> + if (page_list)
> + list_add(&page->lru, page_list);
> + else
> + page_array[nr_populated] = page;
> + nr_populated++;
> }
>
> pcp_spin_unlock(pcp);
> @@ -5100,8 +5109,14 @@ unsigned long alloc_pages_bulk_noprof(gfp_t gfp, int preferred_nid,
>
> failed:
> page = __alloc_pages_noprof(gfp, 0, preferred_nid, nodemask);
> - if (page)
> - page_array[nr_populated++] = page;
> + if (page) {
> + if (page_list)
> + list_add(&page->lru, page_list);
> + else
> + page_array[nr_populated] = page;
> + nr_populated++;
> + }
> +
> goto out;
> }
> EXPORT_SYMBOL_GPL(alloc_pages_bulk_noprof);
On Tue, Oct 14, 2025 at 5:41 PM Petr Tesarik <ptesarik@suse.com> wrote:
>
> On Tue, 14 Oct 2025 16:32:29 +0800
> "zhaoyang.huang" <zhaoyang.huang@unisoc.com> wrote:
>
> > From: Zhaoyang Huang <zhaoyang.huang@unisoc.com>
> >
> > commit c8b979530f27 ("mm: alloc_pages_bulk_noprof: drop page_list
> > argument") drops alloc_pages_bulk_list. This commit would like to call back
> > it since it is proved to be helpful to the drivers which allocate a bulk of
> > pages(see patch of 2 in this series ).
> > I do notice that Matthew's comment of the time cost of iterating a list.
> > However, I also observed in our test that the extra page_array's allocation
> > could be more expensive than cpu iteration when direct reclaiming happens
> > when ram is low[1]. IMHO, could we leave the API here to have the users
> > choose between the array or list according to their scenarios.
>
> OK, so this is more or less a revert of commit c8b979530f27 ("mm:
> alloc_pages_bulk_noprof: drop page_list argument")...
>
> I cannot comment on the performance gains, but I dislike the fact that
> the patch re-introduces alloc_pages_bulk_noprof() as a function with two
> signatures (either page_list is used, or page_array is used).
>
> If we can agree that allocations onto a linked list are useful, then I
> suggest to split the existing function so that the common bits end up
> in helper functions, called by both variants (one function using a
> list, one using an array).
Yes. That is also what I wanted to do in the beginning. I will
implement if dma-buf would like to take the change
>
> Petr T
>
> > [1]
> > android.hardwar-728 [002] ..... 334.573875: system_heap_do_allocate: Execution time: order 0 1 us
> > android.hardwar-728 [002] ..... 334.573879: system_heap_do_allocate: Execution time: order 0 2 us
> > android.hardwar-728 [002] ..... 334.574239: system_heap_do_allocate: Execution time: order 0 354 us
> > android.hardwar-728 [002] ..... 334.574247: system_heap_do_allocate: Execution time: order 0 4 us
> > android.hardwar-728 [002] ..... 334.574250: system_heap_do_allocate: Execution time: order 0 2 us
> >
> > Signed-off-by: Zhaoyang Huang <zhaoyang.huang@unisoc.com>
> > ---
> > include/linux/gfp.h | 9 +++++++--
> > mm/mempolicy.c | 14 +++++++-------
> > mm/page_alloc.c | 39 +++++++++++++++++++++++++++------------
> > 3 files changed, 41 insertions(+), 21 deletions(-)
> >
> > diff --git a/include/linux/gfp.h b/include/linux/gfp.h
> > index 5ebf26fcdcfa..f1540c9fcd87 100644
> > --- a/include/linux/gfp.h
> > +++ b/include/linux/gfp.h
> > @@ -231,6 +231,7 @@ struct folio *__folio_alloc_noprof(gfp_t gfp, unsigned int order, int preferred_
> >
> > unsigned long alloc_pages_bulk_noprof(gfp_t gfp, int preferred_nid,
> > nodemask_t *nodemask, int nr_pages,
> > + struct list_head *page_list,
> > struct page **page_array);
> > #define __alloc_pages_bulk(...) alloc_hooks(alloc_pages_bulk_noprof(__VA_ARGS__))
> >
> > @@ -242,7 +243,11 @@ unsigned long alloc_pages_bulk_mempolicy_noprof(gfp_t gfp,
> >
> > /* Bulk allocate order-0 pages */
> > #define alloc_pages_bulk(_gfp, _nr_pages, _page_array) \
> > - __alloc_pages_bulk(_gfp, numa_mem_id(), NULL, _nr_pages, _page_array)
> > + __alloc_pages_bulk(_gfp, numa_mem_id(), NULL, _nr_pages, NULL, _page_array)
> > +
> > +#define alloc_pages_bulk_list(_gfp, _nr_pages, _list) \
> > + __alloc_pages_bulk(_gfp, numa_mem_id(), NULL, _nr_pages, _list, NULL)
> > +
> >
> > static inline unsigned long
> > alloc_pages_bulk_node_noprof(gfp_t gfp, int nid, unsigned long nr_pages,
> > @@ -251,7 +256,7 @@ alloc_pages_bulk_node_noprof(gfp_t gfp, int nid, unsigned long nr_pages,
> > if (nid == NUMA_NO_NODE)
> > nid = numa_mem_id();
> >
> > - return alloc_pages_bulk_noprof(gfp, nid, NULL, nr_pages, page_array);
> > + return alloc_pages_bulk_noprof(gfp, nid, NULL, nr_pages, NULL, page_array);
> > }
> >
> > #define alloc_pages_bulk_node(...) \
> > diff --git a/mm/mempolicy.c b/mm/mempolicy.c
> > index eb83cff7db8c..26274302ee01 100644
> > --- a/mm/mempolicy.c
> > +++ b/mm/mempolicy.c
> > @@ -2537,13 +2537,13 @@ static unsigned long alloc_pages_bulk_interleave(gfp_t gfp,
> > if (delta) {
> > nr_allocated = alloc_pages_bulk_noprof(gfp,
> > interleave_nodes(pol), NULL,
> > - nr_pages_per_node + 1,
> > + nr_pages_per_node + 1, NULL,
> > page_array);
> > delta--;
> > } else {
> > nr_allocated = alloc_pages_bulk_noprof(gfp,
> > interleave_nodes(pol), NULL,
> > - nr_pages_per_node, page_array);
> > + nr_pages_per_node, NULL, page_array);
> > }
> >
> > page_array += nr_allocated;
> > @@ -2593,7 +2593,7 @@ static unsigned long alloc_pages_bulk_weighted_interleave(gfp_t gfp,
> > if (weight && node_isset(node, nodes)) {
> > node_pages = min(rem_pages, weight);
> > nr_allocated = __alloc_pages_bulk(gfp, node, NULL, node_pages,
> > - page_array);
> > + NULL, page_array);
> > page_array += nr_allocated;
> > total_allocated += nr_allocated;
> > /* if that's all the pages, no need to interleave */
> > @@ -2658,7 +2658,7 @@ static unsigned long alloc_pages_bulk_weighted_interleave(gfp_t gfp,
> > if (!node_pages)
> > break;
> > nr_allocated = __alloc_pages_bulk(gfp, node, NULL, node_pages,
> > - page_array);
> > + NULL, page_array);
> > page_array += nr_allocated;
> > total_allocated += nr_allocated;
> > if (total_allocated == nr_pages)
> > @@ -2682,11 +2682,11 @@ static unsigned long alloc_pages_bulk_preferred_many(gfp_t gfp, int nid,
> > preferred_gfp &= ~(__GFP_DIRECT_RECLAIM | __GFP_NOFAIL);
> >
> > nr_allocated = alloc_pages_bulk_noprof(preferred_gfp, nid, &pol->nodes,
> > - nr_pages, page_array);
> > + nr_pages, NULL, page_array);
> >
> > if (nr_allocated < nr_pages)
> > nr_allocated += alloc_pages_bulk_noprof(gfp, numa_node_id(), NULL,
> > - nr_pages - nr_allocated,
> > + nr_pages - nr_allocated, NULL,
> > page_array + nr_allocated);
> > return nr_allocated;
> > }
> > @@ -2722,7 +2722,7 @@ unsigned long alloc_pages_bulk_mempolicy_noprof(gfp_t gfp,
> > nid = numa_node_id();
> > nodemask = policy_nodemask(gfp, pol, NO_INTERLEAVE_INDEX, &nid);
> > return alloc_pages_bulk_noprof(gfp, nid, nodemask,
> > - nr_pages, page_array);
> > + nr_pages, NULL, page_array);
> > }
> >
> > int vma_dup_policy(struct vm_area_struct *src, struct vm_area_struct *dst)
> > diff --git a/mm/page_alloc.c b/mm/page_alloc.c
> > index d1d037f97c5f..a95bdd8cbf5b 100644
> > --- a/mm/page_alloc.c
> > +++ b/mm/page_alloc.c
> > @@ -4940,23 +4940,28 @@ static inline bool prepare_alloc_pages(gfp_t gfp_mask, unsigned int order,
> > }
> >
> > /*
> > - * __alloc_pages_bulk - Allocate a number of order-0 pages to an array
> > + * __alloc_pages_bulk - Allocate a number of order-0 pages to a list or array
> > * @gfp: GFP flags for the allocation
> > * @preferred_nid: The preferred NUMA node ID to allocate from
> > * @nodemask: Set of nodes to allocate from, may be NULL
> > - * @nr_pages: The number of pages desired in the array
> > - * @page_array: Array to store the pages
> > + * @nr_pages: The number of pages desired on the list or array
> > + * @page_list: Optional list to store the allocated pages
> > + * @page_array: Optional array to store the pages
> > *
> > * This is a batched version of the page allocator that attempts to
> > - * allocate nr_pages quickly. Pages are added to the page_array.
> > + * allocate nr_pages quickly. Pages are added to page_list if page_list
> > + * is not NULL, otherwise it is assumed that the page_array is valid.
> > *
> > - * Note that only NULL elements are populated with pages and nr_pages
> > + * For lists, nr_pages is the number of pages that should be allocated.
> > + *
> > + * For arrays, only NULL elements are populated with pages and nr_pages
> > * is the maximum number of pages that will be stored in the array.
> > *
> > - * Returns the number of pages in the array.
> > + * Returns the number of pages on the list or array.
> > */
> > unsigned long alloc_pages_bulk_noprof(gfp_t gfp, int preferred_nid,
> > nodemask_t *nodemask, int nr_pages,
> > + struct list_head *page_list,
> > struct page **page_array)
> > {
> > struct page *page;
> > @@ -4974,7 +4979,7 @@ unsigned long alloc_pages_bulk_noprof(gfp_t gfp, int preferred_nid,
> > * Skip populated array elements to determine if any pages need
> > * to be allocated before disabling IRQs.
> > */
> > - while (nr_populated < nr_pages && page_array[nr_populated])
> > + while (page_array && nr_populated < nr_pages && page_array[nr_populated])
> > nr_populated++;
> >
> > /* No pages requested? */
> > @@ -4982,7 +4987,7 @@ unsigned long alloc_pages_bulk_noprof(gfp_t gfp, int preferred_nid,
> > goto out;
> >
> > /* Already populated array? */
> > - if (unlikely(nr_pages - nr_populated == 0))
> > + if (unlikely(page_array && nr_pages - nr_populated == 0))
> > goto out;
> >
> > /* Bulk allocator does not support memcg accounting. */
> > @@ -5064,7 +5069,7 @@ unsigned long alloc_pages_bulk_noprof(gfp_t gfp, int preferred_nid,
> > while (nr_populated < nr_pages) {
> >
> > /* Skip existing pages */
> > - if (page_array[nr_populated]) {
> > + if (page_array && page_array[nr_populated]) {
> > nr_populated++;
> > continue;
> > }
> > @@ -5083,7 +5088,11 @@ unsigned long alloc_pages_bulk_noprof(gfp_t gfp, int preferred_nid,
> >
> > prep_new_page(page, 0, gfp, 0);
> > set_page_refcounted(page);
> > - page_array[nr_populated++] = page;
> > + if (page_list)
> > + list_add(&page->lru, page_list);
> > + else
> > + page_array[nr_populated] = page;
> > + nr_populated++;
> > }
> >
> > pcp_spin_unlock(pcp);
> > @@ -5100,8 +5109,14 @@ unsigned long alloc_pages_bulk_noprof(gfp_t gfp, int preferred_nid,
> >
> > failed:
> > page = __alloc_pages_noprof(gfp, 0, preferred_nid, nodemask);
> > - if (page)
> > - page_array[nr_populated++] = page;
> > + if (page) {
> > + if (page_list)
> > + list_add(&page->lru, page_list);
> > + else
> > + page_array[nr_populated] = page;
> > + nr_populated++;
> > + }
> > +
> > goto out;
> > }
> > EXPORT_SYMBOL_GPL(alloc_pages_bulk_noprof);
>
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