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* [PATCH v2] memcg: page_alloc: skip bulk allocator for __GFP_ACCOUNT
@ 2021-10-14 15:16 Shakeel Butt
  2021-10-14 15:24 ` David Hildenbrand
                   ` (4 more replies)
  0 siblings, 5 replies; 6+ messages in thread
From: Shakeel Butt @ 2021-10-14 15:16 UTC (permalink / raw)
  To: Johannes Weiner, Michal Hocko, Mel Gorman
  Cc: Uladzislau Rezki, Vasily Averin, Roman Gushchin, Matthew Wilcox,
	Andrew Morton, cgroups, linux-mm, linux-kernel, Shakeel Butt

The commit 5c1f4e690eec ("mm/vmalloc: switch to bulk allocator in
__vmalloc_area_node()") switched to bulk page allocator for order 0
allocation backing vmalloc. However bulk page allocator does not support
__GFP_ACCOUNT allocations and there are several users of
kvmalloc(__GFP_ACCOUNT).

For now make __GFP_ACCOUNT allocations bypass bulk page allocator. In
future if there is workload that can be significantly improved with the
bulk page allocator with __GFP_ACCCOUNT support, we can revisit the
decision.

Fixes: 5c1f4e690eec ("mm/vmalloc: switch to bulk allocator in __vmalloc_area_node()")
Signed-off-by: Shakeel Butt <shakeelb@google.com>
---
Changes since v1:
- do fallback allocation instead of failure, suggested by Michal Hocko.
- Added memcg_kmem_enabled() check, corrected by Vasily Averin

 mm/page_alloc.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index 668edb16446a..9ca871dc8602 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -5230,6 +5230,10 @@ unsigned long __alloc_pages_bulk(gfp_t gfp, int preferred_nid,
 	if (unlikely(page_array && nr_pages - nr_populated == 0))
 		goto out;
 
+	/* Bulk allocator does not support memcg accounting. */
+	if (memcg_kmem_enabled() && (gfp & __GFP_ACCOUNT))
+		goto failed;
+
 	/* Use the single page allocator for one page. */
 	if (nr_pages - nr_populated == 1)
 		goto failed;
-- 
2.33.0.882.g93a45727a2-goog


^ permalink raw reply related	[flat|nested] 6+ messages in thread

* Re: [PATCH v2] memcg: page_alloc: skip bulk allocator for __GFP_ACCOUNT
  2021-10-14 15:16 [PATCH v2] memcg: page_alloc: skip bulk allocator for __GFP_ACCOUNT Shakeel Butt
@ 2021-10-14 15:24 ` David Hildenbrand
  2021-10-14 15:32 ` Michal Hocko
                   ` (3 subsequent siblings)
  4 siblings, 0 replies; 6+ messages in thread
From: David Hildenbrand @ 2021-10-14 15:24 UTC (permalink / raw)
  To: Shakeel Butt, Johannes Weiner, Michal Hocko, Mel Gorman
  Cc: Uladzislau Rezki, Vasily Averin, Roman Gushchin, Matthew Wilcox,
	Andrew Morton, cgroups, linux-mm, linux-kernel

On 14.10.21 17:16, Shakeel Butt wrote:
> The commit 5c1f4e690eec ("mm/vmalloc: switch to bulk allocator in
> __vmalloc_area_node()") switched to bulk page allocator for order 0
> allocation backing vmalloc. However bulk page allocator does not support
> __GFP_ACCOUNT allocations and there are several users of
> kvmalloc(__GFP_ACCOUNT).
> 
> For now make __GFP_ACCOUNT allocations bypass bulk page allocator. In
> future if there is workload that can be significantly improved with the
> bulk page allocator with __GFP_ACCCOUNT support, we can revisit the
> decision.
> 
> Fixes: 5c1f4e690eec ("mm/vmalloc: switch to bulk allocator in __vmalloc_area_node()")
> Signed-off-by: Shakeel Butt <shakeelb@google.com>
> ---
> Changes since v1:
> - do fallback allocation instead of failure, suggested by Michal Hocko.
> - Added memcg_kmem_enabled() check, corrected by Vasily Averin
> 
>  mm/page_alloc.c | 4 ++++
>  1 file changed, 4 insertions(+)
> 
> diff --git a/mm/page_alloc.c b/mm/page_alloc.c
> index 668edb16446a..9ca871dc8602 100644
> --- a/mm/page_alloc.c
> +++ b/mm/page_alloc.c
> @@ -5230,6 +5230,10 @@ unsigned long __alloc_pages_bulk(gfp_t gfp, int preferred_nid,
>  	if (unlikely(page_array && nr_pages - nr_populated == 0))
>  		goto out;
>  
> +	/* Bulk allocator does not support memcg accounting. */
> +	if (memcg_kmem_enabled() && (gfp & __GFP_ACCOUNT))
> +		goto failed;
> +
>  	/* Use the single page allocator for one page. */
>  	if (nr_pages - nr_populated == 1)
>  		goto failed;
> 

LGTM

Acked-by: David Hildenbrand <david@redhat.com>

-- 
Thanks,

David / dhildenb


^ permalink raw reply	[flat|nested] 6+ messages in thread

* Re: [PATCH v2] memcg: page_alloc: skip bulk allocator for __GFP_ACCOUNT
  2021-10-14 15:16 [PATCH v2] memcg: page_alloc: skip bulk allocator for __GFP_ACCOUNT Shakeel Butt
  2021-10-14 15:24 ` David Hildenbrand
@ 2021-10-14 15:32 ` Michal Hocko
  2021-10-14 16:13 ` Roman Gushchin
                   ` (2 subsequent siblings)
  4 siblings, 0 replies; 6+ messages in thread
From: Michal Hocko @ 2021-10-14 15:32 UTC (permalink / raw)
  To: Shakeel Butt
  Cc: Johannes Weiner, Mel Gorman, Uladzislau Rezki, Vasily Averin,
	Roman Gushchin, Matthew Wilcox, Andrew Morton, cgroups, linux-mm,
	linux-kernel

On Thu 14-10-21 08:16:07, Shakeel Butt wrote:
> The commit 5c1f4e690eec ("mm/vmalloc: switch to bulk allocator in
> __vmalloc_area_node()") switched to bulk page allocator for order 0
> allocation backing vmalloc. However bulk page allocator does not support
> __GFP_ACCOUNT allocations and there are several users of
> kvmalloc(__GFP_ACCOUNT).
> 
> For now make __GFP_ACCOUNT allocations bypass bulk page allocator. In

I would go with
For now make __GFP_ACCOUNT allocations bypass the fast path of the bulk
allocator and make it fallback to the regular page allocator as if the
former failed.

> future if there is workload that can be significantly improved with the
> bulk page allocator with __GFP_ACCCOUNT support, we can revisit the
> decision.
> 
> Fixes: 5c1f4e690eec ("mm/vmalloc: switch to bulk allocator in __vmalloc_area_node()")
> Signed-off-by: Shakeel Butt <shakeelb@google.com>

Acked-by: Michal Hocko <mhocko@suse.com>
Thanks!

> ---
> Changes since v1:
> - do fallback allocation instead of failure, suggested by Michal Hocko.
> - Added memcg_kmem_enabled() check, corrected by Vasily Averin
> 
>  mm/page_alloc.c | 4 ++++
>  1 file changed, 4 insertions(+)
> 
> diff --git a/mm/page_alloc.c b/mm/page_alloc.c
> index 668edb16446a..9ca871dc8602 100644
> --- a/mm/page_alloc.c
> +++ b/mm/page_alloc.c
> @@ -5230,6 +5230,10 @@ unsigned long __alloc_pages_bulk(gfp_t gfp, int preferred_nid,
>  	if (unlikely(page_array && nr_pages - nr_populated == 0))
>  		goto out;
>  
> +	/* Bulk allocator does not support memcg accounting. */
> +	if (memcg_kmem_enabled() && (gfp & __GFP_ACCOUNT))
> +		goto failed;
> +
>  	/* Use the single page allocator for one page. */
>  	if (nr_pages - nr_populated == 1)
>  		goto failed;
> -- 
> 2.33.0.882.g93a45727a2-goog

-- 
Michal Hocko
SUSE Labs

^ permalink raw reply	[flat|nested] 6+ messages in thread

* Re: [PATCH v2] memcg: page_alloc: skip bulk allocator for __GFP_ACCOUNT
  2021-10-14 15:16 [PATCH v2] memcg: page_alloc: skip bulk allocator for __GFP_ACCOUNT Shakeel Butt
  2021-10-14 15:24 ` David Hildenbrand
  2021-10-14 15:32 ` Michal Hocko
@ 2021-10-14 16:13 ` Roman Gushchin
  2021-10-14 17:53 ` Johannes Weiner
  2021-10-15 12:19 ` Vasily Averin
  4 siblings, 0 replies; 6+ messages in thread
From: Roman Gushchin @ 2021-10-14 16:13 UTC (permalink / raw)
  To: Shakeel Butt
  Cc: Johannes Weiner, Michal Hocko, Mel Gorman, Uladzislau Rezki,
	Vasily Averin, Matthew Wilcox, Andrew Morton, cgroups, linux-mm,
	linux-kernel

On Thu, Oct 14, 2021 at 08:16:07AM -0700, Shakeel Butt wrote:
> The commit 5c1f4e690eec ("mm/vmalloc: switch to bulk allocator in
> __vmalloc_area_node()") switched to bulk page allocator for order 0
> allocation backing vmalloc. However bulk page allocator does not support
> __GFP_ACCOUNT allocations and there are several users of
> kvmalloc(__GFP_ACCOUNT).
> 
> For now make __GFP_ACCOUNT allocations bypass bulk page allocator. In
> future if there is workload that can be significantly improved with the
> bulk page allocator with __GFP_ACCCOUNT support, we can revisit the
> decision.
> 
> Fixes: 5c1f4e690eec ("mm/vmalloc: switch to bulk allocator in __vmalloc_area_node()")
> Signed-off-by: Shakeel Butt <shakeelb@google.com>
> ---
> Changes since v1:
> - do fallback allocation instead of failure, suggested by Michal Hocko.

Acked-by: Roman Gushchin <guro@fb.com>

This looks indeed better! Thanks!

> 
>  mm/page_alloc.c | 4 ++++
>  1 file changed, 4 insertions(+)
> 
> diff --git a/mm/page_alloc.c b/mm/page_alloc.c
> index 668edb16446a..9ca871dc8602 100644
> --- a/mm/page_alloc.c
> +++ b/mm/page_alloc.c
> @@ -5230,6 +5230,10 @@ unsigned long __alloc_pages_bulk(gfp_t gfp, int preferred_nid,
>  	if (unlikely(page_array && nr_pages - nr_populated == 0))
>  		goto out;
>  
> +	/* Bulk allocator does not support memcg accounting. */
> +	if (memcg_kmem_enabled() && (gfp & __GFP_ACCOUNT))
> +		goto failed;
> +
>  	/* Use the single page allocator for one page. */
>  	if (nr_pages - nr_populated == 1)
>  		goto failed;
> -- 
> 2.33.0.882.g93a45727a2-goog
> 

^ permalink raw reply	[flat|nested] 6+ messages in thread

* Re: [PATCH v2] memcg: page_alloc: skip bulk allocator for __GFP_ACCOUNT
  2021-10-14 15:16 [PATCH v2] memcg: page_alloc: skip bulk allocator for __GFP_ACCOUNT Shakeel Butt
                   ` (2 preceding siblings ...)
  2021-10-14 16:13 ` Roman Gushchin
@ 2021-10-14 17:53 ` Johannes Weiner
  2021-10-15 12:19 ` Vasily Averin
  4 siblings, 0 replies; 6+ messages in thread
From: Johannes Weiner @ 2021-10-14 17:53 UTC (permalink / raw)
  To: Shakeel Butt
  Cc: Michal Hocko, Mel Gorman, Uladzislau Rezki, Vasily Averin,
	Roman Gushchin, Matthew Wilcox, Andrew Morton, cgroups, linux-mm,
	linux-kernel

On Thu, Oct 14, 2021 at 08:16:07AM -0700, Shakeel Butt wrote:
> The commit 5c1f4e690eec ("mm/vmalloc: switch to bulk allocator in
> __vmalloc_area_node()") switched to bulk page allocator for order 0
> allocation backing vmalloc. However bulk page allocator does not support
> __GFP_ACCOUNT allocations and there are several users of
> kvmalloc(__GFP_ACCOUNT).
> 
> For now make __GFP_ACCOUNT allocations bypass bulk page allocator. In
> future if there is workload that can be significantly improved with the
> bulk page allocator with __GFP_ACCCOUNT support, we can revisit the
> decision.
> 
> Fixes: 5c1f4e690eec ("mm/vmalloc: switch to bulk allocator in __vmalloc_area_node()")
> Signed-off-by: Shakeel Butt <shakeelb@google.com>

Acked-by: Johannes Weiner <hannes@cmpxchg.org>

^ permalink raw reply	[flat|nested] 6+ messages in thread

* Re: [PATCH v2] memcg: page_alloc: skip bulk allocator for __GFP_ACCOUNT
  2021-10-14 15:16 [PATCH v2] memcg: page_alloc: skip bulk allocator for __GFP_ACCOUNT Shakeel Butt
                   ` (3 preceding siblings ...)
  2021-10-14 17:53 ` Johannes Weiner
@ 2021-10-15 12:19 ` Vasily Averin
  4 siblings, 0 replies; 6+ messages in thread
From: Vasily Averin @ 2021-10-15 12:19 UTC (permalink / raw)
  To: Shakeel Butt, Johannes Weiner, Michal Hocko, Mel Gorman
  Cc: Uladzislau Rezki, Roman Gushchin, Matthew Wilcox, Andrew Morton,
	cgroups, linux-mm, linux-kernel

On 14.10.2021 18:16, Shakeel Butt wrote:
> The commit 5c1f4e690eec ("mm/vmalloc: switch to bulk allocator in
> __vmalloc_area_node()") switched to bulk page allocator for order 0
> allocation backing vmalloc. However bulk page allocator does not support
> __GFP_ACCOUNT allocations and there are several users of
> kvmalloc(__GFP_ACCOUNT).
> 
> For now make __GFP_ACCOUNT allocations bypass bulk page allocator. In
> future if there is workload that can be significantly improved with the
> bulk page allocator with __GFP_ACCCOUNT support, we can revisit the
> decision.
> 
> Fixes: 5c1f4e690eec ("mm/vmalloc: switch to bulk allocator in __vmalloc_area_node()")
> Signed-off-by: Shakeel Butt <shakeelb@google.com>

Reported-and-tested-by: Vasily Averin <vvs@virtuozzo.com>

> ---
> Changes since v1:
> - do fallback allocation instead of failure, suggested by Michal Hocko.
> - Added memcg_kmem_enabled() check, corrected by Vasily Averin
> 
>  mm/page_alloc.c | 4 ++++
>  1 file changed, 4 insertions(+)
> 
> diff --git a/mm/page_alloc.c b/mm/page_alloc.c
> index 668edb16446a..9ca871dc8602 100644
> --- a/mm/page_alloc.c
> +++ b/mm/page_alloc.c
> @@ -5230,6 +5230,10 @@ unsigned long __alloc_pages_bulk(gfp_t gfp, int preferred_nid,
>  	if (unlikely(page_array && nr_pages - nr_populated == 0))
>  		goto out;
>  
> +	/* Bulk allocator does not support memcg accounting. */
> +	if (memcg_kmem_enabled() && (gfp & __GFP_ACCOUNT))
> +		goto failed;
> +
>  	/* Use the single page allocator for one page. */
>  	if (nr_pages - nr_populated == 1)
>  		goto failed;
> 


^ permalink raw reply	[flat|nested] 6+ messages in thread

end of thread, other threads:[~2021-10-15 12:19 UTC | newest]

Thread overview: 6+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2021-10-14 15:16 [PATCH v2] memcg: page_alloc: skip bulk allocator for __GFP_ACCOUNT Shakeel Butt
2021-10-14 15:24 ` David Hildenbrand
2021-10-14 15:32 ` Michal Hocko
2021-10-14 16:13 ` Roman Gushchin
2021-10-14 17:53 ` Johannes Weiner
2021-10-15 12:19 ` Vasily Averin

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