Thank you for continuing to work on this. Some comments below.
On 8/26/21 6:58 PM, yaozhenguo wrote:
> 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 hugepags in one node. For example: DPDK needs hugepages
> which is in the same node as NIC. if DPDK needs four hugepags of 1G
> size in node1 and system has 16 numa nodes. We must reserve 64 hugepags
> in kernel cmdline. But, only four hugepages is 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 hugepags in node0 and 3 hugepages in node1.
hugepages
>
> Signed-off-by: yaozhenguo <yaozhenguo1@xxxxxxxxx>
> ---
> v2: 1. add checking for max node to avoid array out of bounds.
> 2. fix wrong max_huge_pages after failed allocation.
> 3. fix wrong behavior when parsing parameter: hugepages=0:1,2,3:4.
> 4. return 0 when parsing invalid parameter in hugepages_setup
> ---
> .../admin-guide/kernel-parameters.txt | 8 +-
> include/linux/hugetlb.h | 1 +
> mm/hugetlb.c | 133 ++++++++++++++++--
> 3 files changed, 126 insertions(+), 16 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.
Documentation/admin-guide/mm/hugetlbpage.rst also describes the
hugepages parameter. It should also be updated.
> + Format: <integer> or (node format)
> + <node>:<numbers>[,<node>:<numbers>]
>
> hugepagesz=
> [HW] The size of the HugeTLB pages. This is used in
> 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..9e9d94b2a 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 +2843,65 @@ 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 */
> + }
> + }
> + 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;
> +
> + /* 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;
> + }
> + }
How does this interact with the hugetlb_cma parameter? Currently, boot
time allocation of gigantic pages is skipped if hugetlb_cma is
specified. Looks like the above code will allocate them.
This also brings up the quesiton, Should hugetlb_cma be changed to be
node specific as well?
For now, I would keep the current behavior and skip all boot time
allocation of gigantic pages if hugetlb_cma.
> +
> + if (hugetlb_node_set)
> + return;
>
> if (!hstate_is_gigantic(h)) {
> /*
> @@ -3580,6 +3636,9 @@ 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 +3708,11 @@ static int __init hugepages_setup(char *s)
> {
> unsigned long *mhp;
> static unsigned long *last_mhp;
> + unsigned int node = NUMA_NO_NODE;
> + int ret;
> + 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);
> @@ -3656,25 +3720,68 @@ static int __init hugepages_setup(char *s)
> return 0;
> }
>
> - /*
> - * !hugetlb_max_hstate means we haven't parsed a hugepagesz= parameter
> - * yet, so this hugepages= parameter goes to the "default hstate".
> - * Otherwise, it goes with the previously parsed hugepagesz or
> - * default_hugepagesz.
> - */
> - else if (!hugetlb_max_hstate)
> - mhp = &default_hstate_max_huge_pages;
> - else
> - mhp = &parsed_hstate->max_huge_pages;
> + while (*p) {
> + count = 0;
> + ret = sscanf(p, "%lu%n", &tmp, &count);
> + if (ret != 1) {
> + pr_warn("HugeTLB: Invalid hugepages parameter %s\n", p);
> + return 0;
> + }
> + /* Parameter is node format */
> + if (p[count] == ':') {
> + node = tmp;
> + p += count + 1;
> + if (node < 0 || node >= nodes_weight(node_states[N_MEMORY])) {
> + pr_warn("HugeTLB: Invalid hugepages parameter node:%d\n", node);
> + return 0;
> + }
> + if (!hugetlb_max_hstate)
> + mhp = (unsigned long *)
> + &(default_hugepages_in_node[node]);
> + else
> + mhp = (unsigned long *)
> + &(parsed_hstate->max_huge_pages_node[node]);
> + /* Parse hugepages */
> + ret = sscanf(p, "%lu%n", mhp, &count);
> + if (ret != 1) {
> + pr_warn("HugeTLB: Invalid hugepages parameter %s\n", p);
> + return 0;
> + }
> + if (!hugetlb_max_hstate)
> + default_hstate_max_huge_pages += *mhp;
> + else
> + parsed_hstate->max_huge_pages += *mhp;
> + /* Go to parse next node*/
> + if (p[count] == ',')
> + p += count + 1;
> + else
> + break;
> + } else if (p == s) {
> +
> + /*
> + * !hugetlb_max_hstate means we haven't parsed a hugepagesz= parameter
> + * yet, so this hugepages= parameter goes to the "default hstate".
> + * Otherwise, it goes with the previously parsed hugepagesz or
> + * default_hugepagesz.
> + */
> + if (!hugetlb_max_hstate) {
> + default_hstate_max_huge_pages = tmp;
> + mhp = &default_hstate_max_huge_pages;
> + } else {
> + parsed_hstate->max_huge_pages = tmp;
> + mhp = &parsed_hstate->max_huge_pages;
> + }
> + break;
> + }
> + pr_warn("HugeTLB: Invalid hugepages parameter %s\n", p);
> + return 0;
> + }
>
> if (mhp == last_mhp) {
> pr_warn("HugeTLB: hugepages= specified twice without interleaving hugepagesz=, ignoring hugepages=%s\n", s);
> return 0;
> }
This check for 'mhp == last_mhp' after setting parameters will result in
a change of behavior. For example, consider the following command line
options:
hugepagesz=2M hugepages=2 hugepages=5
Before this change,
# dmesg | grep -i huge
[ 0.000000] Command line: BOOT_IMAGE=/vmlinuz-5.14.0+.old root=/dev/mapper/fedora_new--host-root ro rd.lvm.lv=fedora_new-host/root rd.lvm.lv=fedora_new-host/swap console=tty0 console=ttyS0,115200 audit=0 transparent_hugepage=always hugetlb_free_vmemmap=on hugepagesz=2M hugepages=2 hugepages=5
[ 0.054206] Kernel command line: BOOT_IMAGE=/vmlinuz-5.14.0+.old root=/dev/mapper/fedora_new--host-root ro rd.lvm.lv=fedora_new-host/root rd.lvm.lv=fedora_new-host/swap console=tty0 console=ttyS0,115200 audit=0 transparent_hugepage=always hugetlb_free_vmemmap=on hugepagesz=2M hugepages=2 hugepages=5
[ 0.054271] HugeTLB: can free 6 vmemmap pages for hugepages-2048kB
[ 0.054282] HugeTLB: hugepages= specified twice without interleaving hugepagesz=, ignoring hugepages=5
[ 0.054286] Unknown command line parameters: BOOT_IMAGE=/vmlinuz-5.14.0+.old hugepages=5
[ 0.412456] HugeTLB: can free 4094 vmemmap pages for hugepages-1048576kB
[ 0.424527] HugeTLB registered 2.00 MiB page size, pre-allocated 2 pages
[ 0.425459] HugeTLB registered 1.00 GiB page size, pre-allocated 0 pages
[ 5.168890] hugepages=5
After this change,
# dmesg | grep -i huge
[ 0.000000] Command line: BOOT_IMAGE=/vmlinuz-5.14.0+ root=/dev/mapper/fedora_new--host-root ro rd.lvm.lv=fedora_new-host/root rd.lvm.lv=fedora_new-host/swap console=tty0 console=ttyS0,115200 audit=0 transparent_hugepage=always hugetlb_free_vmemmap=on hugepagesz=2M hugepages=2 hugepages=5
[ 0.054569] Kernel command line: BOOT_IMAGE=/vmlinuz-5.14.0+ root=/dev/mapper/fedora_new--host-root ro rd.lvm.lv=fedora_new-host/root rd.lvm.lv=fedora_new-host/swap console=tty0 console=ttyS0,115200 audit=0 transparent_hugepage=always hugetlb_free_vmemmap=on hugepagesz=2M hugepages=2 hugepages=5
[ 0.054636] HugeTLB: can free 6 vmemmap pages for hugepages-2048kB
[ 0.054647] HugeTLB: hugepages= specified twice without interleaving hugepagesz=, ignoring hugepages=5
[ 0.054651] Unknown command line parameters: BOOT_IMAGE=/vmlinuz-5.14.0+ hugepages=5
[ 0.413714] HugeTLB: can free 4094 vmemmap pages for hugepages-1048576kB
[ 0.427774] HugeTLB registered 2.00 MiB page size, pre-allocated 5 pages
[ 0.428628] HugeTLB registered 1.
--
Mike Kravetz
>
> - if (sscanf(s, "%lu", mhp) <= 0)
> - *mhp = 0;
> -
> /*
> * Global state is always initialized later in hugetlb_init.
> * But we need to allocate gigantic hstates here early to still
>
