From 76e961157e078bc5d3cd2df08317e00b00a829eb Mon Sep 17 00:00:00 2001
From: "Ritesh Harjani (IBM)" <ritesh.list@gmail.com>
Date: Sat, 11 Jan 2025 16:36:55 +0530
Subject: [PATCH] mm/hugetlb: fix hugepage allocation for interleaved memory
 nodes

gather_bootmem_prealloc() assumes the start nid as 0 and size as
num_node_state(N_MEMORY).  That means in case if memory attached numa
nodes are interleaved, then gather_bootmem_prealloc_parallel() will fail
to scan few of these nodes.

Since memory attached numa nodes can be interleaved in any fashion, hence
ensure that the current code checks for all numa node ids
(.size = nr_node_ids). Let's still keep max_threads as N_MEMORY, so that
it can distributes all nr_node_ids among the these many no. threads.

e.g. qemu cmdline
========================
numa_cmd="-numa node,nodeid=1,memdev=mem1,cpus=2-3 -numa node,nodeid=0,cpus=0-1 -numa dist,src=0,dst=1,val=20"
mem_cmd="-object memory-backend-ram,id=mem1,size=16G"

w/o this patch for cmdline (default_hugepagesz=1GB hugepagesz=1GB hugepages=2):
==========================
~ # cat /proc/meminfo  |grep -i huge
AnonHugePages:         0 kB
ShmemHugePages:        0 kB
FileHugePages:         0 kB
HugePages_Total:       0
HugePages_Free:        0
HugePages_Rsvd:        0
HugePages_Surp:        0
Hugepagesize:    1048576 kB
Hugetlb:               0 kB

with this patch for cmdline (default_hugepagesz=1GB hugepagesz=1GB hugepages=2):
===========================
~ # cat /proc/meminfo |grep -i huge
AnonHugePages:         0 kB
ShmemHugePages:        0 kB
FileHugePages:         0 kB
HugePages_Total:       2
HugePages_Free:        2
HugePages_Rsvd:        0
HugePages_Surp:        0
Hugepagesize:    1048576 kB
Hugetlb:         2097152 kB

Link: https://lkml.kernel.org/r/f8d8dad3a5471d284f54185f65d575a6aaab692b.1736592534.git.ritesh.list@gmail.com
Fixes: b78b27d02930 ("hugetlb: parallelize 1G hugetlb initialization")
Signed-off-by: Ritesh Harjani (IBM) <ritesh.list@gmail.com>
Reported-by: Pavithra Prakash <pavrampu@linux.ibm.com>
Suggested-by: Muchun Song <muchun.song@linux.dev>
Tested-by: Sourabh Jain <sourabhjain@linux.ibm.com>
Reviewed-by: Luiz Capitulino <luizcap@redhat.com>
Acked-by: David Rientjes <rientjes@google.com>
Cc: Donet Tom <donettom@linux.ibm.com>
Cc: Gang Li <gang.li@linux.dev>
Cc: Daniel Jordan <daniel.m.jordan@oracle.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---
 mm/hugetlb.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/mm/hugetlb.c b/mm/hugetlb.c
index 3b25b69aa94f1..65068671e460a 100644
--- a/mm/hugetlb.c
+++ b/mm/hugetlb.c
@@ -3309,7 +3309,7 @@ static void __init gather_bootmem_prealloc(void)
 		.thread_fn	= gather_bootmem_prealloc_parallel,
 		.fn_arg		= NULL,
 		.start		= 0,
-		.size		= num_node_state(N_MEMORY),
+		.size		= nr_node_ids,
 		.align		= 1,
 		.min_chunk	= 1,
 		.max_threads	= num_node_state(N_MEMORY),
-- 
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