[PATCH v7] hugetlbfs: Extend the definition of hugepages parameter to support node allocation

Zhenguo Yao
2021-09-27T10:42:25Z

We can specify the number of hugepages to allocate at boot. But the
hugepages is balanced in all nodes at present. In some scenarios,
we only need hugepages in one node. For example: DPDK needs hugepages
which are in the same node as NIC. if DPDK needs four hugepages of 1G
size in node1 and system has 16 numa nodes. We must reserve 64 hugepages
in kernel cmdline. But, only four hugepages are used. The others should
be free after boot. If the system memory is low(for example: 64G), it will
be an impossible task. So, Extending hugepages parameter to support
specifying hugepages at a specific node.
For example add following parameter:

hugepagesz=1G hugepages=0:1,1:3

It will allocate 1 hugepage in node0 and 3 hugepages in node1.

Signed-off-by: Zhenguo Yao <yaozhenguo1@gmail.com>
---
v6->v7 changes:
- replace nodes_weight(node_states[N_MEMORY] with nr_online_nodes.
v5->v6 changes:
- Remove v5 codes: using return value to disable node specific alloc.
- Add node_specific_alloc_support weak function to disable node
specific alloc when arch can't support it.
- Remove useless variable addr in alloc_bootmem_huge_page.
- Add powerpc version of node_specific_alloc_support when
CONFIG_PPC_BOOK3S_64 is defined.
v4->v5 changes:
- remove BUG_ON in __alloc_bootmem_huge_page.
- add nid parameter in __alloc_bootmem_huge_page to support
called in both specific node alloc and normal alloc.
- do normal alloc if architecture can't support node specific alloc.
- return -1 in powerpc version of alloc_bootmem_huge_page when
nid is not NUMA_NO_NODE.
v3->v4 changes:
- fix wrong behavior for parameter:
hugepages=0:1,1:3 default_hugepagesz=1G
- make the change of documentation more reasonable.
v2->v3 changes:
- Skip gigantic hugepages allocation if hugetlb_cma is enabled.
- Fix wrong behavior for parameter:
hugepagesz=2M hugepages=2 hugepages=5.
- Update hugetlbpage.rst.
- Fix side effects which v2 brings in.
- add cond_resched in hugetlb_hstate_alloc_pages_onenode.
v1->v2 changes:
- add checking for max node to avoid array out of bounds.
- fix wrong max_huge_pages after failed allocation.
- fix wrong behavior when parsing parameter: hugepages=0:1,2,3:4.
- return 0 when parsing invalid parameter in hugepages_setup
---
.../admin-guide/kernel-parameters.txt | 8 +-
Documentation/admin-guide/mm/hugetlbpage.rst | 12 +-
arch/powerpc/mm/hugetlbpage.c | 9 +-
include/linux/hugetlb.h | 6 +-
mm/hugetlb.c | 153 +++++++++++++++---
5 files changed, 157 insertions(+), 31 deletions(-)

diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt
index 91ba391f9b32..9b3d8791586d 100644
--- a/Documentation/admin-guide/kernel-parameters.txt
+++ b/Documentation/admin-guide/kernel-parameters.txt
@@ -1599,9 +1599,11 @@
the number of pages of hugepagesz to be allocated.
If this is the first HugeTLB parameter on the command
line, it specifies the number of pages to allocate for
- the default huge page size. See also
- Documentation/admin-guide/mm/hugetlbpage.rst.
- Format: <integer>
+ the default huge page size. If using node format, the
+ number of pages to allocate per-node can be specified.
+ See also Documentation/admin-guide/mm/hugetlbpage.rst.
+ Format: <integer> or (node format)
+ <node>:<integer>[,<node>:<integer>]

hugepagesz=
[HW] The size of the HugeTLB pages. This is used in
diff --git a/Documentation/admin-guide/mm/hugetlbpage.rst b/Documentation/admin-guide/mm/hugetlbpage.rst
index 8abaeb144e44..d70828c07658 100644
--- a/Documentation/admin-guide/mm/hugetlbpage.rst
+++ b/Documentation/admin-guide/mm/hugetlbpage.rst
@@ -128,7 +128,9 @@ hugepages
implicitly specifies the number of huge pages of default size to
allocate. If the number of huge pages of default size is implicitly
specified, it can not be overwritten by a hugepagesz,hugepages
- parameter pair for the default size.
+ parameter pair for the default size. This parameter also has a
+ node format. The node format specifies the number of huge pages
+ to allocate on specific nodes.

For example, on an architecture with 2M default huge page size::

@@ -138,6 +140,14 @@ hugepages
indicating that the hugepages=512 parameter is ignored. If a hugepages
parameter is preceded by an invalid hugepagesz parameter, it will
be ignored.
+
+ Node format example::
+
+ hugepagesz=2M hugepages=0:1,1:2
+
+ It will allocate 1 2M hugepage on node0 and 2 2M hugepages on node1.
+ If the node number is invalid, the parameter will be ignored.
+
default_hugepagesz
Specify the default huge page size. This parameter can
only be specified once on the command line. default_hugepagesz can
diff --git a/arch/powerpc/mm/hugetlbpage.c b/arch/powerpc/mm/hugetlbpage.c
index 9a75ba078e1b..dd40ce6e7565 100644
--- a/arch/powerpc/mm/hugetlbpage.c
+++ b/arch/powerpc/mm/hugetlbpage.c
@@ -229,17 +229,22 @@ static int __init pseries_alloc_bootmem_huge_page(struct hstate *hstate)
m->hstate = hstate;
return 1;
}
+
+bool __init node_specific_alloc_support(void)
+{
+ return false;
+}
#endif

-int __init alloc_bootmem_huge_page(struct hstate *h)
+int __init alloc_bootmem_huge_page(struct hstate *h, int nid)
{

#ifdef CONFIG_PPC_BOOK3S_64
if (firmware_has_feature(FW_FEATURE_LPAR) && !radix_enabled())
return pseries_alloc_bootmem_huge_page(h);
#endif
- return __alloc_bootmem_huge_page(h);
+ return __alloc_bootmem_huge_page(h, nid);
}

#ifndef CONFIG_PPC_BOOK3S_64
diff --git a/include/linux/hugetlb.h b/include/linux/hugetlb.h
index 1faebe1cd0ed..3504e407567c 100644
--- a/include/linux/hugetlb.h
+++ b/include/linux/hugetlb.h
@@ -605,6 +605,7 @@ struct hstate {
unsigned long nr_overcommit_huge_pages;
struct list_head hugepage_activelist;
struct list_head hugepage_freelists[MAX_NUMNODES];
+ unsigned int max_huge_pages_node[MAX_NUMNODES];
unsigned int nr_huge_pages_node[MAX_NUMNODES];
unsigned int free_huge_pages_node[MAX_NUMNODES];
unsigned int surplus_huge_pages_node[MAX_NUMNODES];
@@ -637,8 +638,9 @@ void restore_reserve_on_error(struct hstate *h, struct vm_area_struct *vma,
unsigned long address, struct page *page);

/* arch callback */
-int __init __alloc_bootmem_huge_page(struct hstate *h);
-int __init alloc_bootmem_huge_page(struct hstate *h);
+int __init __alloc_bootmem_huge_page(struct hstate *h, int nid);
+int __init alloc_bootmem_huge_page(struct hstate *h, int nid);
+bool __init node_specific_alloc_support(void);

void __init hugetlb_add_hstate(unsigned order);
bool __init arch_hugetlb_valid_size(unsigned long size);
diff --git a/mm/hugetlb.c b/mm/hugetlb.c
index 95dc7b83381f..ca00676a1bdd 100644
--- a/mm/hugetlb.c
+++ b/mm/hugetlb.c
@@ -66,6 +66,7 @@ static struct hstate * __initdata parsed_hstate;
static unsigned long __initdata default_hstate_max_huge_pages;
static bool __initdata parsed_valid_hugepagesz = true;
static bool __initdata parsed_default_hugepagesz;
+static unsigned int default_hugepages_in_node[MAX_NUMNODES] __initdata;

/*
* Protects updates to hugepage_freelists, hugepage_activelist, nr_huge_pages,
@@ -2868,33 +2869,41 @@ struct page *alloc_huge_page(struct vm_area_struct *vma,
return ERR_PTR(-ENOSPC);
}

-int alloc_bootmem_huge_page(struct hstate *h)
+int alloc_bootmem_huge_page(struct hstate *h, int nid)
__attribute__ ((weak, alias("__alloc_bootmem_huge_page")));
-int __alloc_bootmem_huge_page(struct hstate *h)
+int __alloc_bootmem_huge_page(struct hstate *h, int nid)
{
struct huge_bootmem_page *m;
int nr_nodes, node;

+ if (nid >= nr_online_nodes)
+ return 0;
+ /* do node specific alloc */
+ if (nid != NUMA_NO_NODE) {
+ m = memblock_alloc_try_nid_raw(huge_page_size(h), huge_page_size(h),
+ 0, MEMBLOCK_ALLOC_ACCESSIBLE, nid);
+ if (m)
+ goto found;
+ else
+ return 0;
+ }
+ /* do all node balanced alloc */
for_each_node_mask_to_alloc(h, nr_nodes, node, &node_states[N_MEMORY]) {
- void *addr;
-
- addr = memblock_alloc_try_nid_raw(
+ m = memblock_alloc_try_nid_raw(
huge_page_size(h), huge_page_size(h),
0, MEMBLOCK_ALLOC_ACCESSIBLE, node);
- if (addr) {
- /*
- * Use the beginning of the huge page to store the
- * huge_bootmem_page struct (until gather_bootmem
- * puts them into the mem_map).
- */
- m = addr;
+ /*
+ * Use the beginning of the huge page to store the
+ * huge_bootmem_page struct (until gather_bootmem
+ * puts them into the mem_map).
+ */
+ if (m)
goto found;
- }
+ else
+ return 0;
}
- return 0;

found:
- BUG_ON(!IS_ALIGNED(virt_to_phys(m), huge_page_size(h)));
/* Put them into a private list first because mem_map is not up yet */
INIT_LIST_HEAD(&m->list);
list_add(&m->list, &huge_boot_pages);
@@ -2934,12 +2943,61 @@ static void __init gather_bootmem_prealloc(void)
cond_resched();
}
}
+static void __init hugetlb_hstate_alloc_pages_onenode(struct hstate *h, int nid)
+{
+ unsigned long i;
+ char buf[32];
+
+ for (i = 0; i < h->max_huge_pages_node[nid]; ++i) {
+ if (hstate_is_gigantic(h)) {
+ if (!alloc_bootmem_huge_page(h, nid))
+ break;
+ } else {
+ struct page *page;
+ gfp_t gfp_mask = htlb_alloc_mask(h) | __GFP_THISNODE;
+
+ page = alloc_fresh_huge_page(h, gfp_mask, nid,
+ &node_states[N_MEMORY], NULL);
+ if (!page)
+ break;
+ put_page(page); /* free it into the hugepage allocator */
+ }
+ cond_resched();
+ }
+ if (i == h->max_huge_pages_node[nid])
+ return;
+
+ string_get_size(huge_page_size(h), 1, STRING_UNITS_2, buf, 32);
+ pr_warn("HugeTLB: allocating %u of page size %s failed node%d. Only allocated %lu hugepages.\n",
+ h->max_huge_pages_node[nid], buf, nid, i);
+ h->max_huge_pages -= (h->max_huge_pages_node[nid] - i);
+ h->max_huge_pages_node[nid] = i;
+}

static void __init hugetlb_hstate_alloc_pages(struct hstate *h)
{
unsigned long i;
nodemask_t *node_alloc_noretry;
+ bool node_specific_alloc = false;
+
+ /* skip gigantic hugepages allocation if hugetlb_cma enabled */
+ if (hstate_is_gigantic(h) && hugetlb_cma_size) {
+ pr_warn_once("HugeTLB: hugetlb_cma is enabled, skip boot time allocation\n");
+ return;
+ }
+
+ /* do node specific alloc */
+ for (i = 0; i < nr_online_nodes; i++) {
+ if (h->max_huge_pages_node[i] > 0) {
+ hugetlb_hstate_alloc_pages_onenode(h, i);
+ node_specific_alloc = true;
+ }
+ }

+ if (node_specific_alloc)
+ return;
+
+ /* bellow will do all node balanced alloc */
if (!hstate_is_gigantic(h)) {
/*
* Bit mask controlling how hard we retry per-node allocations.
@@ -2960,11 +3018,7 @@ 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");
- goto free;
- }
- if (!alloc_bootmem_huge_page(h))
+ if (!alloc_bootmem_huge_page(h, NUMA_NO_NODE))
break;
} else if (!alloc_pool_huge_page(h,
&node_states[N_MEMORY],
@@ -2980,7 +3034,6 @@ static void __init hugetlb_hstate_alloc_pages(struct hstate *h)
h->max_huge_pages, buf, i);
h->max_huge_pages = i;
}
-free:
kfree(node_alloc_noretry);
}

@@ -3671,6 +3724,11 @@ static int __init hugetlb_init(void)
}
default_hstate.max_huge_pages =
default_hstate_max_huge_pages;
+
+ for (i = 0; i < nr_online_nodes; i++)
+ if (default_hugepages_in_node[i] > 0)
+ default_hstate.max_huge_pages_node[i] =
+ default_hugepages_in_node[i];
}
}

@@ -3731,6 +3789,10 @@ void __init hugetlb_add_hstate(unsigned int order)
parsed_hstate = h;
}

+bool __init __weak node_specific_alloc_support(void)
+{
+ return true;
+}
/*
* hugepages command line processing
* hugepages normally follows a valid hugepagsz or default_hugepagsz
@@ -3742,6 +3804,10 @@ static int __init hugepages_setup(char *s)
{
unsigned long *mhp;
static unsigned long *last_mhp;
+ int node = NUMA_NO_NODE;
+ int count;
+ unsigned long tmp;
+ char *p = s;

if (!parsed_valid_hugepagesz) {
pr_warn("HugeTLB: hugepages=%s does not follow a valid hugepagesz, ignoring\n", s);
@@ -3765,8 +3831,40 @@ static int __init hugepages_setup(char *s)
return 0;
}

- if (sscanf(s, "%lu", mhp) <= 0)
- *mhp = 0;
+ while (*p) {
+ count = 0;
+ if (sscanf(p, "%lu%n", &tmp, &count) != 1)
+ goto invalid;
+ /* Parameter is node format */
+ if (p[count] == ':') {
+ if (!node_specific_alloc_support()) {
+ pr_warn("HugeTLB: architecture can't support node specific alloc, ignoring!\n");
+ return 0;
+ }
+ node = tmp;
+ p += count + 1;
+ if (node < 0 || node >= nr_online_nodes)
+ goto invalid;
+ /* Parse hugepages */
+ if (sscanf(p, "%lu%n", &tmp, &count) != 1)
+ goto invalid;
+ if (!hugetlb_max_hstate)
+ default_hugepages_in_node[node] = tmp;
+ else
+ parsed_hstate->max_huge_pages_node[node] = tmp;
+ *mhp += tmp;
+ /* Go to parse next node*/
+ if (p[count] == ',')
+ p += count + 1;
+ else
+ break;
+ } else {
+ if (p != s)
+ goto invalid;
+ *mhp = tmp;
+ break;
+ }
+ }

/*
* Global state is always initialized later in hugetlb_init.
@@ -3779,6 +3877,10 @@ static int __init hugepages_setup(char *s)
last_mhp = mhp;

return 1;
+
+invalid:
+ pr_warn("HugeTLB: Invalid hugepages parameter %s\n", p);
+ return 0;
}
__setup("hugepages=", hugepages_setup);

@@ -3840,6 +3942,7 @@ __setup("hugepagesz=", hugepagesz_setup);
static int __init default_hugepagesz_setup(char *s)
{
unsigned long size;
+ int i;

parsed_valid_hugepagesz = false;
if (parsed_default_hugepagesz) {
@@ -3868,6 +3971,10 @@ static int __init default_hugepagesz_setup(char *s)
*/
if (default_hstate_max_huge_pages) {
default_hstate.max_huge_pages = default_hstate_max_huge_pages;
+ for (i = 0; i < nr_online_nodes; i++)
+ if (default_hugepages_in_node[i] > 0)
+ default_hstate.max_huge_pages_node[i] =
+ default_hugepages_in_node[i];
if (hstate_is_gigantic(&default_hstate))
hugetlb_hstate_alloc_pages(&default_hstate);
default_hstate_max_huge_pages = 0;
--
2.27.0