[v9,6/8] hugetlb_cgroup: support noreserve mappings
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Message ID 20191217231615.164161-6-almasrymina@google.com
State New
Headers show
Series
  • [v9,1/8] hugetlb_cgroup: Add hugetlb_cgroup reservation counter
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Commit Message

Mina Almasry Dec. 17, 2019, 11:16 p.m. UTC
Support MAP_NORESERVE accounting as part of the new counter.

For each hugepage allocation, at allocation time we check if there is
a reservation for this allocation or not. If there is a reservation for
this allocation, then this allocation was charged at reservation time,
and we don't re-account it. If there is no reserevation for this
allocation, we charge the appropriate hugetlb_cgroup.

The hugetlb_cgroup to uncharge for this allocation is stored in
page[3].private. We use new APIs added in an earlier patch to set this
pointer.

Signed-off-by: Mina Almasry <almasrymina@google.com>

---
 mm/hugetlb.c | 26 +++++++++++++++++++++++++-
 1 file changed, 25 insertions(+), 1 deletion(-)

--
2.24.1.735.g03f4e72817-goog

Comments

David Rientjes Jan. 14, 2020, 12:48 a.m. UTC | #1
On Tue, 17 Dec 2019, Mina Almasry wrote:

> diff --git a/mm/hugetlb.c b/mm/hugetlb.c
> index 39eb2fa53a420..3e94f5c2d7cd4 100644
> --- a/mm/hugetlb.c
> +++ b/mm/hugetlb.c
> @@ -1367,6 +1367,9 @@ void free_huge_page(struct page *page)
>  	clear_page_huge_active(page);
>  	hugetlb_cgroup_uncharge_page(hstate_index(h), pages_per_huge_page(h),
>  				     page, false);
> +	hugetlb_cgroup_uncharge_page(hstate_index(h), pages_per_huge_page(h),
> +				     page, true);
> +
>  	if (restore_reserve)
>  		h->resv_huge_pages++;
> 
> @@ -2189,10 +2192,19 @@ struct page *alloc_huge_page(struct vm_area_struct *vma,
>  			gbl_chg = 1;
>  	}
> 
> +	/* If this allocation is not consuming a reservation, charge it now.
> +	 */
> +	if (map_chg || avoid_reserve || !vma_resv_map(vma)) {

These conditions are checked three times in this function, maybe better 
set a bool on the stack and use it throughout the function to guarantee it 
remains consistent?

bool deferred_reserve = !vma_resv_map(vma) || map_chg || avoid_reserve;

> +		ret = hugetlb_cgroup_charge_cgroup(idx, pages_per_huge_page(h),
> +						   &h_cg, true);
> +		if (ret)
> +			goto out_subpool_put;
> +	}
> +
>  	ret = hugetlb_cgroup_charge_cgroup(idx, pages_per_huge_page(h), &h_cg,
>  					   false);
>  	if (ret)
> -		goto out_subpool_put;
> +		goto out_uncharge_cgroup_reservation;
> 
>  	spin_lock(&hugetlb_lock);
>  	/*
> @@ -2216,6 +2228,14 @@ struct page *alloc_huge_page(struct vm_area_struct *vma,
>  	}
>  	hugetlb_cgroup_commit_charge(idx, pages_per_huge_page(h), h_cg, page,
>  				     false);
> +	/* If allocation is not consuming a reservation, also store the
> +	 * hugetlb_cgroup pointer on the page.
> +	 */
> +	if (!vma_resv_map(vma) || map_chg || avoid_reserve) {
> +		hugetlb_cgroup_commit_charge(idx, pages_per_huge_page(h), h_cg,
> +					     page, true);
> +	}
> +
>  	spin_unlock(&hugetlb_lock);
> 
>  	set_page_private(page, (unsigned long)spool);
> @@ -2241,6 +2261,10 @@ struct page *alloc_huge_page(struct vm_area_struct *vma,
>  out_uncharge_cgroup:
>  	hugetlb_cgroup_uncharge_cgroup(idx, pages_per_huge_page(h), h_cg,
>  				       false);
> +out_uncharge_cgroup_reservation:
> +	if (map_chg || avoid_reserve || !vma_resv_map(vma))
> +		hugetlb_cgroup_uncharge_cgroup(idx, pages_per_huge_page(h),
> +					       h_cg, true);
>  out_subpool_put:
>  	if (map_chg || avoid_reserve)
>  		hugepage_subpool_put_pages(spool, 1);
> --
> 2.24.1.735.g03f4e72817-goog
>

Patch
diff mbox series

diff --git a/mm/hugetlb.c b/mm/hugetlb.c
index 39eb2fa53a420..3e94f5c2d7cd4 100644
--- a/mm/hugetlb.c
+++ b/mm/hugetlb.c
@@ -1367,6 +1367,9 @@  void free_huge_page(struct page *page)
 	clear_page_huge_active(page);
 	hugetlb_cgroup_uncharge_page(hstate_index(h), pages_per_huge_page(h),
 				     page, false);
+	hugetlb_cgroup_uncharge_page(hstate_index(h), pages_per_huge_page(h),
+				     page, true);
+
 	if (restore_reserve)
 		h->resv_huge_pages++;

@@ -2189,10 +2192,19 @@  struct page *alloc_huge_page(struct vm_area_struct *vma,
 			gbl_chg = 1;
 	}

+	/* If this allocation is not consuming a reservation, charge it now.
+	 */
+	if (map_chg || avoid_reserve || !vma_resv_map(vma)) {
+		ret = hugetlb_cgroup_charge_cgroup(idx, pages_per_huge_page(h),
+						   &h_cg, true);
+		if (ret)
+			goto out_subpool_put;
+	}
+
 	ret = hugetlb_cgroup_charge_cgroup(idx, pages_per_huge_page(h), &h_cg,
 					   false);
 	if (ret)
-		goto out_subpool_put;
+		goto out_uncharge_cgroup_reservation;

 	spin_lock(&hugetlb_lock);
 	/*
@@ -2216,6 +2228,14 @@  struct page *alloc_huge_page(struct vm_area_struct *vma,
 	}
 	hugetlb_cgroup_commit_charge(idx, pages_per_huge_page(h), h_cg, page,
 				     false);
+	/* If allocation is not consuming a reservation, also store the
+	 * hugetlb_cgroup pointer on the page.
+	 */
+	if (!vma_resv_map(vma) || map_chg || avoid_reserve) {
+		hugetlb_cgroup_commit_charge(idx, pages_per_huge_page(h), h_cg,
+					     page, true);
+	}
+
 	spin_unlock(&hugetlb_lock);

 	set_page_private(page, (unsigned long)spool);
@@ -2241,6 +2261,10 @@  struct page *alloc_huge_page(struct vm_area_struct *vma,
 out_uncharge_cgroup:
 	hugetlb_cgroup_uncharge_cgroup(idx, pages_per_huge_page(h), h_cg,
 				       false);
+out_uncharge_cgroup_reservation:
+	if (map_chg || avoid_reserve || !vma_resv_map(vma))
+		hugetlb_cgroup_uncharge_cgroup(idx, pages_per_huge_page(h),
+					       h_cg, true);
 out_subpool_put:
 	if (map_chg || avoid_reserve)
 		hugepage_subpool_put_pages(spool, 1);