[RFC PATCH 15/16] hugetlb: cma: move cma reserve function to cma.c.

From: Zi Yan
Date: Wed Sep 02 2020 - 14:08:15 EST


From: Zi Yan <ziy@xxxxxxxxxx>

It will be used by other allocations, like 1GB THP allocation in the
upcoming commit.

Signed-off-by: Zi Yan <ziy@xxxxxxxxxx>
---
.../admin-guide/kernel-parameters.txt | 2 +-
arch/arm64/mm/hugetlbpage.c | 2 +-
arch/powerpc/mm/hugetlbpage.c | 2 +-
arch/x86/kernel/setup.c | 8 +-
include/linux/cma.h | 15 ++++
include/linux/hugetlb.h | 12 ---
mm/cma.c | 88 +++++++++++++++++++
mm/hugetlb.c | 88 ++-----------------
8 files changed, 118 insertions(+), 99 deletions(-)

diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt
index 68fee5e034ca..600668ee0ac7 100644
--- a/Documentation/admin-guide/kernel-parameters.txt
+++ b/Documentation/admin-guide/kernel-parameters.txt
@@ -1507,7 +1507,7 @@
hpet_mmap= [X86, HPET_MMAP] Allow userspace to mmap HPET
registers. Default set by CONFIG_HPET_MMAP_DEFAULT.

- hugetlb_cma= [HW] The size of a cma area used for allocation
+ hugepage_cma= [HW] The size of a cma area used for allocation
of gigantic hugepages.
Format: nn[KMGTPE]

diff --git a/arch/arm64/mm/hugetlbpage.c b/arch/arm64/mm/hugetlbpage.c
index 55ecf6de9ff7..8a3ad7eaae49 100644
--- a/arch/arm64/mm/hugetlbpage.c
+++ b/arch/arm64/mm/hugetlbpage.c
@@ -52,7 +52,7 @@ void __init arm64_hugetlb_cma_reserve(void)
* breaking this assumption.
*/
WARN_ON(order <= MAX_ORDER);
- hugetlb_cma_reserve(order);
+ hugepage_cma_reserve(order);
}
#endif /* CONFIG_CMA */

diff --git a/arch/powerpc/mm/hugetlbpage.c b/arch/powerpc/mm/hugetlbpage.c
index 26292544630f..d608e58cb69b 100644
--- a/arch/powerpc/mm/hugetlbpage.c
+++ b/arch/powerpc/mm/hugetlbpage.c
@@ -699,6 +699,6 @@ void __init gigantic_hugetlb_cma_reserve(void)

if (order) {
VM_WARN_ON(order < MAX_ORDER);
- hugetlb_cma_reserve(order);
+ hugepage_cma_reserve(order);
}
}
diff --git a/arch/x86/kernel/setup.c b/arch/x86/kernel/setup.c
index 52e83ba607b3..93c8fbdff972 100644
--- a/arch/x86/kernel/setup.c
+++ b/arch/x86/kernel/setup.c
@@ -16,7 +16,7 @@
#include <linux/pci.h>
#include <linux/root_dev.h>
#include <linux/sfi.h>
-#include <linux/hugetlb.h>
+#include <linux/cma.h>
#include <linux/tboot.h>
#include <linux/usb/xhci-dbgp.h>

@@ -640,7 +640,7 @@ static void __init trim_snb_memory(void)
* already been reserved.
*/
memblock_reserve(0, 1<<20);
-
+
for (i = 0; i < ARRAY_SIZE(bad_pages); i++) {
if (memblock_reserve(bad_pages[i], PAGE_SIZE))
printk(KERN_WARNING "failed to reserve 0x%08lx\n",
@@ -732,7 +732,7 @@ static void __init trim_low_memory_range(void)
{
memblock_reserve(0, ALIGN(reserve_low, PAGE_SIZE));
}
-
+
/*
* Dump out kernel offset information on panic.
*/
@@ -1142,7 +1142,7 @@ void __init setup_arch(char **cmdline_p)
dma_contiguous_reserve(max_pfn_mapped << PAGE_SHIFT);

if (boot_cpu_has(X86_FEATURE_GBPAGES))
- hugetlb_cma_reserve(PUD_SHIFT - PAGE_SHIFT);
+ hugepage_cma_reserve(PUD_SHIFT - PAGE_SHIFT);

/*
* Reserve memory for crash kernel after SRAT is parsed so that it
diff --git a/include/linux/cma.h b/include/linux/cma.h
index 6ff79fefd01f..abcf7ab712f9 100644
--- a/include/linux/cma.h
+++ b/include/linux/cma.h
@@ -47,4 +47,19 @@ extern struct page *cma_alloc(struct cma *cma, size_t count, unsigned int align,
extern bool cma_release(struct cma *cma, const struct page *pages, unsigned int count);

extern int cma_for_each_area(int (*it)(struct cma *cma, void *data), void *data);
+
+extern void cma_reserve(int min_order, unsigned long requested_size,
+ const char *name, struct cma *cma_struct[N_MEMORY]);
+#if defined(CONFIG_TRANSPARENT_HUGEPAGE) || defined(CONFIG_HUGETLBFS)
+extern void __init hugepage_cma_reserve(int order);
+extern void __init hugepage_cma_check(void);
+#else
+static inline void __init hugepage_cma_check(void)
+{
+}
+static inline void __init hugepage_cma_reserve(int order)
+{
+}
+#endif
+
#endif
diff --git a/include/linux/hugetlb.h b/include/linux/hugetlb.h
index d5cc5f802dd4..087d13a1dc24 100644
--- a/include/linux/hugetlb.h
+++ b/include/linux/hugetlb.h
@@ -935,16 +935,4 @@ static inline spinlock_t *huge_pte_lock(struct hstate *h,
return ptl;
}

-#if defined(CONFIG_HUGETLB_PAGE) && defined(CONFIG_CMA)
-extern void __init hugetlb_cma_reserve(int order);
-extern void __init hugetlb_cma_check(void);
-#else
-static inline __init void hugetlb_cma_reserve(int order)
-{
-}
-static inline __init void hugetlb_cma_check(void)
-{
-}
-#endif
-
#endif /* _LINUX_HUGETLB_H */
diff --git a/mm/cma.c b/mm/cma.c
index 7f415d7cda9f..aa3a17d8a191 100644
--- a/mm/cma.c
+++ b/mm/cma.c
@@ -37,6 +37,10 @@
#include "cma.h"

struct cma cma_areas[MAX_CMA_AREAS];
+#if defined(CONFIG_TRANSPARENT_HUGEPAGE) || defined(CONFIG_HUGETLBFS)
+struct cma *hugepage_cma[MAX_NUMNODES];
+#endif
+unsigned long hugepage_cma_size __initdata;
unsigned cma_area_count;
static DEFINE_MUTEX(cma_mutex);

@@ -541,3 +545,87 @@ int cma_for_each_area(int (*it)(struct cma *cma, void *data), void *data)

return 0;
}
+
+#if defined(CONFIG_TRANSPARENT_HUGEPAGE) || defined(CONFIG_HUGETLBFS)
+/*
+ * cma_reserve() - reserve CMA for gigantic pages on nodes with memory
+ *
+ * must be called after free_area_init() that updates N_MEMORY via node_set_state().
+ * cma_reserve() scans over N_MEMORY nodemask and hence expects the platforms
+ * to have initialized N_MEMORY state.
+ */
+void __init cma_reserve(int min_order, unsigned long requested_size, const char *name,
+ struct cma *cma_struct[MAX_NUMNODES])
+{
+ unsigned long size, reserved, per_node;
+ int nid;
+
+ if (!requested_size)
+ return;
+
+ if (requested_size < (PAGE_SIZE << min_order)) {
+ pr_warn("%s_cma: cma area should be at least %lu MiB\n",
+ name, (PAGE_SIZE << min_order) / SZ_1M);
+ return;
+ }
+
+ /*
+ * If 3 GB area is requested on a machine with 4 numa nodes,
+ * let's allocate 1 GB on first three nodes and ignore the last one.
+ */
+ per_node = DIV_ROUND_UP(requested_size, nr_online_nodes);
+ pr_info("%s_cma: reserve %lu MiB, up to %lu MiB per node\n",
+ name, requested_size / SZ_1M, per_node / SZ_1M);
+
+ reserved = 0;
+ for_each_node_state(nid, N_ONLINE) {
+ int res;
+ char node_name[20];
+
+ size = min(per_node, requested_size - reserved);
+ size = round_up(size, PAGE_SIZE << min_order);
+
+ snprintf(node_name, 20, "%s%d", name, nid);
+ res = cma_declare_contiguous_nid(0, size, 0,
+ PAGE_SIZE << min_order,
+ 0, false, node_name,
+ &cma_struct[nid], nid);
+ if (res) {
+ pr_warn("%s_cma: reservation failed: err %d, node %d",
+ name, res, nid);
+ continue;
+ }
+
+ reserved += size;
+ pr_info("%s_cma: reserved %lu MiB on node %d\n",
+ name, size / SZ_1M, nid);
+
+ if (reserved >= requested_size)
+ break;
+ }
+}
+
+static bool hugepage_cma_reserve_called __initdata;
+
+static int __init cmdline_parse_hugepage_cma(char *p)
+{
+ hugepage_cma_size = memparse(p, &p);
+ return 0;
+}
+
+early_param("hugepage_cma", cmdline_parse_hugepage_cma);
+
+void __init hugepage_cma_reserve(int order)
+{
+ hugepage_cma_reserve_called = true;
+ cma_reserve(order, hugepage_cma_size, "hugepage", hugepage_cma);
+}
+
+void __init hugepage_cma_check(void)
+{
+ if (!hugepage_cma_size || hugepage_cma_reserve_called)
+ return;
+
+ pr_warn("hugepage_cma: the option isn't supported by current arch\n");
+}
+#endif
diff --git a/mm/hugetlb.c b/mm/hugetlb.c
index d5357778b026..6685cad879d0 100644
--- a/mm/hugetlb.c
+++ b/mm/hugetlb.c
@@ -48,9 +48,9 @@ unsigned int default_hstate_idx;
struct hstate hstates[HUGE_MAX_HSTATE];

#ifdef CONFIG_CMA
-static struct cma *hugetlb_cma[MAX_NUMNODES];
+extern struct cma *hugepage_cma[MAX_NUMNODES];
#endif
-static unsigned long hugetlb_cma_size __initdata;
+extern unsigned long hugepage_cma_size __initdata;

/*
* Minimum page order among possible hugepage sizes, set to a proper value
@@ -1218,7 +1218,7 @@ static void free_gigantic_page(struct page *page, unsigned int order)
* cma_release() returns false.
*/
#ifdef CONFIG_CMA
- if (cma_release(hugetlb_cma[page_to_nid(page)], page, 1 << order))
+ if (cma_release(hugepage_cma[page_to_nid(page)], page, 1 << order))
return;
#endif

@@ -1237,10 +1237,10 @@ static struct page *alloc_gigantic_page(struct hstate *h, gfp_t gfp_mask,
int node;

for_each_node_mask(node, *nodemask) {
- if (!hugetlb_cma[node])
+ if (!hugepage_cma[node])
continue;

- page = cma_alloc(hugetlb_cma[node], nr_pages,
+ page = cma_alloc(hugepage_cma[node], nr_pages,
huge_page_order(h), true);
if (page)
return page;
@@ -2532,8 +2532,8 @@ static void __init hugetlb_hstate_alloc_pages(struct hstate *h)

for (i = 0; i < h->max_huge_pages; ++i) {
if (hstate_is_gigantic(h)) {
- if (hugetlb_cma_size) {
- pr_warn_once("HugeTLB: hugetlb_cma is enabled, skip boot time allocation\n");
+ if (hugepage_cma_size) {
+ pr_warn_once("HugeTLB: hugepage_cma is enabled, skip boot time allocation\n");
break;
}
if (!alloc_bootmem_huge_page(h))
@@ -3209,7 +3209,7 @@ static int __init hugetlb_init(void)
}
}

- hugetlb_cma_check();
+ hugepage_cma_check();
hugetlb_init_hstates();
gather_bootmem_prealloc();
report_hugepages();
@@ -5622,75 +5622,3 @@ void move_hugetlb_state(struct page *oldpage, struct page *newpage, int reason)
spin_unlock(&hugetlb_lock);
}
}
-
-#ifdef CONFIG_CMA
-static bool cma_reserve_called __initdata;
-
-static int __init cmdline_parse_hugetlb_cma(char *p)
-{
- hugetlb_cma_size = memparse(p, &p);
- return 0;
-}
-
-early_param("hugetlb_cma", cmdline_parse_hugetlb_cma);
-
-void __init hugetlb_cma_reserve(int order)
-{
- unsigned long size, reserved, per_node;
- int nid;
-
- cma_reserve_called = true;
-
- if (!hugetlb_cma_size)
- return;
-
- if (hugetlb_cma_size < (PAGE_SIZE << order)) {
- pr_warn("hugetlb_cma: cma area should be at least %lu MiB\n",
- (PAGE_SIZE << order) / SZ_1M);
- return;
- }
-
- /*
- * If 3 GB area is requested on a machine with 4 numa nodes,
- * let's allocate 1 GB on first three nodes and ignore the last one.
- */
- per_node = DIV_ROUND_UP(hugetlb_cma_size, nr_online_nodes);
- pr_info("hugetlb_cma: reserve %lu MiB, up to %lu MiB per node\n",
- hugetlb_cma_size / SZ_1M, per_node / SZ_1M);
-
- reserved = 0;
- for_each_node_state(nid, N_ONLINE) {
- int res;
- char name[20];
-
- size = min(per_node, hugetlb_cma_size - reserved);
- size = round_up(size, PAGE_SIZE << order);
-
- snprintf(name, 20, "hugetlb%d", nid);
- res = cma_declare_contiguous_nid(0, size, 0, PAGE_SIZE << order,
- 0, false, name,
- &hugetlb_cma[nid], nid);
- if (res) {
- pr_warn("hugetlb_cma: reservation failed: err %d, node %d",
- res, nid);
- continue;
- }
-
- reserved += size;
- pr_info("hugetlb_cma: reserved %lu MiB on node %d\n",
- size / SZ_1M, nid);
-
- if (reserved >= hugetlb_cma_size)
- break;
- }
-}
-
-void __init hugetlb_cma_check(void)
-{
- if (!hugetlb_cma_size || cma_reserve_called)
- return;
-
- pr_warn("hugetlb_cma: the option isn't supported by current arch\n");
-}
-
-#endif /* CONFIG_CMA */
--
2.28.0