Mike,

On Wed, Jul 21, 2021 at 01:49:15PM -0700, Mike Kravetz wrote:

On 7/12/21 1:09 AM, Feng Tang wrote:

quoted

From: Ben Widawsky <redacted>

Implement the missing huge page allocation functionality while obeying
the preferred node semantics. This is similar to the implementation
for general page allocation, as it uses a fallback mechanism to try
multiple preferred nodes first, and then all other nodes.

[Thanks to 0day bot for caching the missing #ifdef CONFIG_NUMA issue]

Link: https://lore.kernel.org/r/20200630212517.308045-12-ben.widawsky@intel.com (local)
Suggested-by: Michal Hocko <mhocko@suse.com>
Signed-off-by: Ben Widawsky <redacted>
Co-developed-by: Feng Tang <redacted>
Signed-off-by: Feng Tang <redacted>
---
 mm/hugetlb.c   | 25 +++++++++++++++++++++++++
 mm/mempolicy.c |  3 ++-
 2 files changed, 27 insertions(+), 1 deletion(-)

diff --git a/mm/hugetlb.c b/mm/hugetlb.c
index 924553aa8f78..3e84508c1b8c 100644
--- a/mm/hugetlb.c
+++ b/mm/hugetlb.c

@@ -1164,7 +1164,18 @@ static struct page *dequeue_huge_page_vma(struct hstate *h,
 
 	gfp_mask = htlb_alloc_mask(h);
 	nid = huge_node(vma, address, gfp_mask, &mpol, &nodemask);
+#ifdef CONFIG_NUMA
+	if (mpol->mode == MPOL_PREFERRED_MANY) {
+		page = dequeue_huge_page_nodemask(h, gfp_mask, nid, nodemask);
+		if (page)
+			goto check_reserve;
+		/* Fallback to all nodes */
+		nodemask = NULL;
+	}
+#endif
 	page = dequeue_huge_page_nodemask(h, gfp_mask, nid, nodemask);
+
+check_reserve:
 	if (page && !avoid_reserve && vma_has_reserves(vma, chg)) {
 		SetHPageRestoreReserve(page);
 		h->resv_huge_pages--;

@@ -2095,6 +2106,20 @@ struct page *alloc_buddy_huge_page_with_mpol(struct hstate *h,
 	nodemask_t *nodemask;
 
 	nid = huge_node(vma, addr, gfp_mask, &mpol, &nodemask);
+#ifdef CONFIG_NUMA
+	if (mpol->mode == MPOL_PREFERRED_MANY) {
+		gfp_t gfp = (gfp_mask | __GFP_NOWARN) & ~__GFP_DIRECT_RECLAIM;

I believe __GFP_NOWARN will be added later in alloc_buddy_huge_page, so
no need to add here?

Thanks for the suggestion, will remove it. 

quoted

+
+		page = alloc_surplus_huge_page(h, gfp, nid, nodemask);
+		if (page) {
+			mpol_cond_put(mpol);
+			return page;
+		}
+
+		/* Fallback to all nodes */
+		nodemask = NULL;
+	}
+#endif
 	page = alloc_surplus_huge_page(h, gfp_mask, nid, nodemask);
 	mpol_cond_put(mpol);
 

diff --git a/mm/mempolicy.c b/mm/mempolicy.c
index 9dce67fc9bb6..93f8789758a7 100644
--- a/mm/mempolicy.c
+++ b/mm/mempolicy.c

@@ -2054,7 +2054,8 @@ int huge_node(struct vm_area_struct *vma, unsigned long addr, gfp_t gfp_flags,
 					huge_page_shift(hstate_vma(vma)));
 	} else {
 		nid = policy_node(gfp_flags, *mpol, numa_node_id());
-		if ((*mpol)->mode == MPOL_BIND)
+		if ((*mpol)->mode == MPOL_BIND ||
+		    (*mpol)->mode == MPOL_PREFERRED_MANY)
 			*nodemask = &(*mpol)->nodes;
 	}
 	return nid;

Other than the one nit above,

Reviewed-by: Mike Kravetz <redacted>

Thanks!



Andrew,

I have to ask for your help again to fold this to the 4/6 patch, thanks!

- Feng

---------------------------8<--------------------------------------------

From de1cd29d8da96856a6d754a30a4c7585d87b8348 Mon Sep 17 00:00:00 2001
From: Feng Tang <redacted>
Date: Thu, 22 Jul 2021 16:00:49 +0800
Subject: [PATCH] mm/hugetlb: remove the unneeded __GFP_NOWARN flag setting

As the alloc_buddy_huge_page() will set it anyway.

Suggested-by: Mike Kravetz <redacted>
Signed-off-by: Feng Tang <redacted>
---
 mm/hugetlb.c | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/mm/hugetlb.c b/mm/hugetlb.c
index 528947d..a96e283 100644
--- a/mm/hugetlb.c
+++ b/mm/hugetlb.c

@@ -2162,9 +2162,9 @@ struct page *alloc_buddy_huge_page_with_mpol(struct hstate *h,
 	nid = huge_node(vma, addr, gfp_mask, &mpol, &nodemask);
 #ifdef CONFIG_NUMA
 	if (mpol->mode == MPOL_PREFERRED_MANY) {
-		gfp_t gfp = (gfp_mask | __GFP_NOWARN) & ~__GFP_DIRECT_RECLAIM;
-
-		page = alloc_surplus_huge_page(h, gfp, nid, nodemask, false);
+		page = alloc_surplus_huge_page(h,
+					gfp_mask & ~__GFP_DIRECT_RECLAIM,
+					nid, nodemask, false);
 		if (page) {
 			mpol_cond_put(mpol);
 			return page;

-- 
2.7.4