[v3] hugetlbfs: Extend the definition of hugepages parameter to support node allocation

From: yaozhenguo
Date: Thu Sep 02 2021 - 02:59:38 EST


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 is 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, extend hugepages kernel parameter to specify
node number of hugepages to allocate at boot.
For example add following parameter:

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

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

Signed-off-by: yaozhenguo <yaozhenguo1@xxxxxxxxx>
---
v3: 1. Skip gigantic hugepages allocation if hugetlb_cma is enabled.
2. Fix wrong behavior for parameter: hugepagesz=2M hugepages=2 hugepages=5.
3. Update hugetlbpage.rst.
4. Fix side effects which v2 brings in.
5. add cond_resched in hugetlb_hstate_alloc_pages_onenode.
---
.../admin-guide/kernel-parameters.txt | 8 +-
Documentation/admin-guide/mm/hugetlbpage.rst | 12 +-
include/linux/hugetlb.h | 1 +
mm/hugetlb.c | 116 ++++++++++++++++--
4 files changed, 126 insertions(+), 11 deletions(-)

diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt
index bdb22006f..64a128924 100644
--- a/Documentation/admin-guide/kernel-parameters.txt
+++ b/Documentation/admin-guide/kernel-parameters.txt
@@ -1588,9 +1588,11 @@
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, It
+ specifies numbers of hugepage in a specific node.
+ See also Documentation/admin-guide/mm/hugetlbpage.rst.
+ Format: <integer> or (node format)
+ <node>:<numbers>[,<node>:<numbers>]

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 8abaeb144..bc5f674ff 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 node
+ format. It specifies numbers of hugepage in a specific node when
+ using node format.

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 hugepages in node0 and 2 2M hugepages in node1.
+ If the node number exceeds the maximum node, 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/include/linux/hugetlb.h b/include/linux/hugetlb.h
index f7ca1a387..5939ecd4f 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];
diff --git a/mm/hugetlb.c b/mm/hugetlb.c
index dfc940d52..317f8fa21 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,
@@ -2842,10 +2843,75 @@ static void __init gather_bootmem_prealloc(void)
}
}

+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)) {
+ struct huge_bootmem_page *m;
+ void *addr;
+
+ addr = memblock_alloc_try_nid_raw(
+ huge_page_size(h), huge_page_size(h),
+ 0, MEMBLOCK_ALLOC_ACCESSIBLE, nid);
+ if (!addr)
+ break;
+ m = addr;
+ 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);
+ m->hstate = h;
+ } 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_node[nid] = i;
+ h->max_huge_pages -= (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 hugetlb_node_set = 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 alloc */
+ for (i = 0; i < nodes_weight(node_states[N_MEMORY]); i++) {
+ if (h->max_huge_pages_node[i] > 0) {
+ hugetlb_hstate_alloc_pages_onenode(h, i);
+ hugetlb_node_set = true;
+ }
+ }
+
+ if (hugetlb_node_set)
+ return;

if (!hstate_is_gigantic(h)) {
/*
@@ -2867,10 +2933,6 @@ 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))
break;
} else if (!alloc_pool_huge_page(h,
@@ -2887,7 +2949,6 @@ 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);
}

@@ -3580,6 +3641,10 @@ static int __init hugetlb_init(void)
default_hstate_max_huge_pages;
}
}
+ for (i = 0; i < nodes_weight(node_states[N_MEMORY]); i++)
+ if (default_hugepages_in_node[i] > 0)
+ default_hstate.max_huge_pages_node[i] =
+ default_hugepages_in_node[i];

hugetlb_cma_check();
hugetlb_init_hstates();
@@ -3649,6 +3714,10 @@ static int __init hugepages_setup(char *s)
{
unsigned long *mhp;
static unsigned long *last_mhp;
+ unsigned 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);
@@ -3672,8 +3741,37 @@ 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] == ':') {
+ node = tmp;
+ p += count + 1;
+ if (node < 0 ||
+ node >= nodes_weight(node_states[N_MEMORY]))
+ 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.
@@ -3686,6 +3784,10 @@ 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);

--
2.27.0