Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) client-ip=2620:137:e000::1:20;
From:   Usama Arif <usama.arif@bytedance.com>
To:     linux-mm@kvack.org, muchun.song@linux.dev, mike.kravetz@oracle.com,
        rppt@kernel.org
Cc:     linux-kernel@vger.kernel.org, fam.zheng@bytedance.com,
        liangma@liangbit.com, simon.evans@bytedance.com,
        punit.agrawal@bytedance.com, Usama Arif <usama.arif@bytedance.com>
Subject: [v1 5/6] mm: move allocation of gigantic hstates to the start of mm_core_init
Date:   Thu, 27 Jul 2023 21:46:23 +0100
Message-Id: <20230727204624.1942372-6-usama.arif@bytedance.com>
In-Reply-To: <20230727204624.1942372-1-usama.arif@bytedance.com>
References: <20230727204624.1942372-1-usama.arif@bytedance.com>
MIME-Version: 1.0
Content-Transfer-Encoding: 8bit
Precedence: bulk

Whether the initialization of tail struct pages of a hugepage
happens or not will become dependent on the commandline
parameter hugetlb_free_vmemmap in the future. Hence,
hugetlb_hstate_alloc_pages needs to be after command line parameters
are parsed and the start of mm_core_init is a good point.

Signed-off-by: Usama Arif <usama.arif@bytedance.com>
---
 include/linux/hugetlb.h |  1 +
 mm/hugetlb.c            | 18 ++++++++++--------
 mm/mm_init.c            |  4 ++++
 3 files changed, 15 insertions(+), 8 deletions(-)

diff --git a/include/linux/hugetlb.h b/include/linux/hugetlb.h
index ca3c8e10f24a..2b20553deef3 100644
--- a/include/linux/hugetlb.h
+++ b/include/linux/hugetlb.h
@@ -1271,4 +1271,5 @@ hugetlb_walk(struct vm_area_struct *vma, unsigned long addr, unsigned long sz)
 	return huge_pte_offset(vma->vm_mm, addr, sz);
 }
 
+void __init hugetlb_hstate_alloc_gigantic_pages(void);
 #endif /* _LINUX_HUGETLB_H */
diff --git a/mm/hugetlb.c b/mm/hugetlb.c
index 58cf5978bee1..c1fcf2af591a 100644
--- a/mm/hugetlb.c
+++ b/mm/hugetlb.c
@@ -4418,14 +4418,6 @@ static int __init hugepages_setup(char *s)
 		}
 	}
 
-	/*
-	 * Global state is always initialized later in hugetlb_init.
-	 * But we need to allocate gigantic hstates here early to still
-	 * use the bootmem allocator.
-	 */
-	if (hugetlb_max_hstate && hstate_is_gigantic(parsed_hstate))
-		hugetlb_hstate_alloc_pages(parsed_hstate);
-
 	last_mhp = mhp;
 
 	return 1;
@@ -4437,6 +4429,16 @@ static int __init hugepages_setup(char *s)
 }
 __setup("hugepages=", hugepages_setup);
 
+void __init hugetlb_hstate_alloc_gigantic_pages(void)
+{
+	int i;
+
+	for (i = 0; i < HUGE_MAX_HSTATE; i++) {
+		if (hstate_is_gigantic(&hstates[i]))
+			hugetlb_hstate_alloc_pages(&hstates[i]);
+	}
+}
+
 /*
  * hugepagesz command line processing
  * A specific huge page size can only be specified once with hugepagesz.
diff --git a/mm/mm_init.c b/mm/mm_init.c
index a1963c3322af..5585c66c3c42 100644
--- a/mm/mm_init.c
+++ b/mm/mm_init.c
@@ -26,6 +26,7 @@
 #include <linux/pgtable.h>
 #include <linux/swap.h>
 #include <linux/cma.h>
+#include <linux/hugetlb.h>
 #include "internal.h"
 #include "slab.h"
 #include "shuffle.h"
@@ -2768,6 +2769,9 @@ static void __init mem_init_print_info(void)
  */
 void __init mm_core_init(void)
 {
+#ifdef CONFIG_HUGETLBFS
+	hugetlb_hstate_alloc_gigantic_pages();
+#endif
 	/* Initializations relying on SMP setup */
 	build_all_zonelists(NULL);
 	page_alloc_init_cpuhp();
-- 
2.25.1