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Message-ID: <B96B8719-29B1-4D7F-9E00-E21A51DA148C@fb.com>
Date: Tue, 29 Mar 2022 22:12:00 +0000
From: Song Liu <songliubraving@...com>
To: "Edgecombe, Rick P" <rick.p.edgecombe@...el.com>
CC: "linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>,
"daniel@...earbox.net" <daniel@...earbox.net>,
"peterz@...radead.org" <peterz@...radead.org>,
"ast@...nel.org" <ast@...nel.org>,
"bpf@...r.kernel.org" <bpf@...r.kernel.org>,
Kernel Team <Kernel-team@...com>,
"song@...nel.org" <song@...nel.org>, "hch@....de" <hch@....de>,
"pmenzel@...gen.mpg.de" <pmenzel@...gen.mpg.de>,
"andrii@...nel.org" <andrii@...nel.org>,
"x86@...nel.org" <x86@...nel.org>,
"iii@...ux.ibm.com" <iii@...ux.ibm.com>,
"netdev@...r.kernel.org" <netdev@...r.kernel.org>,
"urezki@...il.com" <urezki@...il.com>,
"npiggin@...il.com" <npiggin@...il.com>
Subject: Re: [PATCH v9 bpf-next 1/9] x86/Kconfig: select
HAVE_ARCH_HUGE_VMALLOC with HAVE_ARCH_HUGE_VMAP
> On Mar 29, 2022, at 2:36 PM, Edgecombe, Rick P <rick.p.edgecombe@...el.com> wrote:
>
> On Tue, 2022-03-29 at 19:13 +0000, Song Liu wrote:
>>>
>>> I don't think we should tie this to vmap_allow_huge by definition.
>>> Also, what it does is try 2MB pages for allocations larger than
>>> 2MB.
>>> For smaller allocations it doesn't try or "prefer" them.
>>
>> How about something like:
>>
>> #define VM_TRY_HUGE_VMAP 0x00001000 /* try PMD_SIZE
>> mapping if size-per-node >= PMD_SIZE */
>
> Seems reasonable name. I don't know if "size-per-node >= PMD_SIZE" is
> going to be useful information. Maybe something like:
>
> /* Allow for huge pages on HAVE_ARCH_HUGE_VMALLOC_FLAG arch's */
Sounds great. I updated the version based on this (below). I will split it
into two patches, I guess.
@Paul, could you please test whether this version fixes the issue you were
seeing?
Thanks,
Song
diff --git a/arch/Kconfig b/arch/Kconfig
index 84bc1de02720..0fb2bd5fd1f8 100644
--- a/arch/Kconfig
+++ b/arch/Kconfig
@@ -858,6 +858,15 @@ config HAVE_ARCH_HUGE_VMALLOC
depends on HAVE_ARCH_HUGE_VMAP
bool
+#
+# HAVE_ARCH_HUGE_VMALLOC_FLAG allows users of __vmalloc_node_range to allocate
+# huge page without HAVE_ARCH_HUGE_VMALLOC. To allocate huge pages, the user
+# need to call __vmalloc_node_range with VM_TRY_HUGE_VMAP.
+#
+config HAVE_ARCH_HUGE_VMALLOC_FLAG
+ depends on HAVE_ARCH_HUGE_VMAP
+ bool
+
config ARCH_WANT_HUGE_PMD_SHARE
bool
diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
index 7340d9f01b62..e64f00415575 100644
--- a/arch/x86/Kconfig
+++ b/arch/x86/Kconfig
@@ -45,7 +45,7 @@ config FORCE_DYNAMIC_FTRACE
in order to test the non static function tracing in the
generic code, as other architectures still use it. But we
only need to keep it around for x86_64. No need to keep it
- for x86_32. For x86_32, force DYNAMIC_FTRACE.
+ for x86_32. For x86_32, force DYNAMIC_FTRACE.
#
# Arch settings
#
@@ -161,7 +161,7 @@ config X86
select HAVE_ALIGNED_STRUCT_PAGE if SLUB
select HAVE_ARCH_AUDITSYSCALL
select HAVE_ARCH_HUGE_VMAP if X86_64 || X86_PAE
- select HAVE_ARCH_HUGE_VMALLOC if X86_64
+ select HAVE_ARCH_HUGE_VMALLOC_FLAG if X86_64
select HAVE_ARCH_JUMP_LABEL
select HAVE_ARCH_JUMP_LABEL_RELATIVE
select HAVE_ARCH_KASAN if X86_64
diff --git a/include/linux/vmalloc.h b/include/linux/vmalloc.h
index 3b1df7da402d..a48d0690b66f 100644
--- a/include/linux/vmalloc.h
+++ b/include/linux/vmalloc.h
@@ -35,6 +35,11 @@ struct notifier_block; /* in notifier.h */
#define VM_DEFER_KMEMLEAK 0
#endif
+#ifdef CONFIG_HAVE_ARCH_HUGE_VMALLOC_FLAG
+#define VM_TRY_HUGE_VMAP 0x00001000 /* Allow for huge pages on HAVE_ARCH_HUGE_VMALLOC_FLAG arch's */
+#else
+#define VM_TRY_HUGE_VMAP 0
+#endif
/* bits [20..32] reserved for arch specific ioremap internals */
/*
@@ -51,7 +56,7 @@ struct vm_struct {
unsigned long size;
unsigned long flags;
struct page **pages;
-#ifdef CONFIG_HAVE_ARCH_HUGE_VMALLOC
+#if (defined(CONFIG_HAVE_ARCH_HUGE_VMALLOC) || defined(CONFIG_HAVE_ARCH_HUGE_VMALLOC_FLAG))
unsigned int page_order;
#endif
unsigned int nr_pages;
@@ -225,7 +230,7 @@ static inline bool is_vm_area_hugepages(const void *addr)
* prevents that. This only indicates the size of the physical page
* allocated in the vmalloc layer.
*/
-#ifdef CONFIG_HAVE_ARCH_HUGE_VMALLOC
+#if (defined(CONFIG_HAVE_ARCH_HUGE_VMALLOC) || defined(CONFIG_HAVE_ARCH_HUGE_VMALLOC_FLAG))
return find_vm_area(addr)->page_order > 0;
#else
return false;
diff --git a/kernel/bpf/core.c b/kernel/bpf/core.c
index 13e9dbeeedf3..5659677b18f3 100644
--- a/kernel/bpf/core.c
+++ b/kernel/bpf/core.c
@@ -851,13 +851,28 @@ static LIST_HEAD(pack_list);
#define BPF_HPAGE_MASK PAGE_MASK
#endif
+static void *bpf_prog_pack_vmalloc(unsigned long size)
+{
+#if defined(MODULES_VADDR)
+ unsigned long start = MODULES_VADDR;
+ unsigned long end = MODULES_END;
+#else
+ unsigned long start = VMALLOC_START;
+ unsigned long end = VMALLOC_END;
+#endif
+
+ return __vmalloc_node_range(size, PAGE_SIZE, start, end, GFP_KERNEL, PAGE_KERNEL,
+ VM_DEFER_KMEMLEAK | VM_TRY_HUGE_VMAP,
+ NUMA_NO_NODE, __builtin_return_address(0));
+}
+
static size_t select_bpf_prog_pack_size(void)
{
size_t size;
void *ptr;
size = BPF_HPAGE_SIZE * num_online_nodes();
- ptr = module_alloc(size);
+ ptr = bpf_prog_pack_vmalloc(size);
/* Test whether we can get huge pages. If not just use PAGE_SIZE
* packs.
@@ -881,7 +896,7 @@ static struct bpf_prog_pack *alloc_new_pack(void)
GFP_KERNEL);
if (!pack)
return NULL;
- pack->ptr = module_alloc(bpf_prog_pack_size);
+ pack->ptr = bpf_prog_pack_vmalloc(bpf_prog_pack_size);
if (!pack->ptr) {
kfree(pack);
return NULL;
diff --git a/mm/vmalloc.c b/mm/vmalloc.c
index e163372d3967..179200bce285 100644
--- a/mm/vmalloc.c
+++ b/mm/vmalloc.c
@@ -46,7 +46,7 @@
#include "internal.h"
#include "pgalloc-track.h"
-#ifdef CONFIG_HAVE_ARCH_HUGE_VMAP
+#if (defined(CONFIG_HAVE_ARCH_HUGE_VMALLOC) || defined(CONFIG_HAVE_ARCH_HUGE_VMALLOC_FLAG))
static unsigned int __ro_after_init ioremap_max_page_shift = BITS_PER_LONG - 1;
static int __init set_nohugeiomap(char *str)
@@ -55,11 +55,11 @@ static int __init set_nohugeiomap(char *str)
return 0;
}
early_param("nohugeiomap", set_nohugeiomap);
-#else /* CONFIG_HAVE_ARCH_HUGE_VMAP */
+#else /* CONFIG_HAVE_ARCH_HUGE_VMAP || CONFIG_HAVE_ARCH_HUGE_VMALLOC_FLAG */
static const unsigned int ioremap_max_page_shift = PAGE_SHIFT;
-#endif /* CONFIG_HAVE_ARCH_HUGE_VMAP */
+#endif /* CONFIG_HAVE_ARCH_HUGE_VMAP || CONFIG_HAVE_ARCH_HUGE_VMALLOC_FLAG*/
-#ifdef CONFIG_HAVE_ARCH_HUGE_VMALLOC
+#if (defined(CONFIG_HAVE_ARCH_HUGE_VMALLOC) || defined(CONFIG_HAVE_ARCH_HUGE_VMALLOC_FLAG))
static bool __ro_after_init vmap_allow_huge = true;
static int __init set_nohugevmalloc(char *str)
@@ -582,8 +582,9 @@ int vmap_pages_range_noflush(unsigned long addr, unsigned long end,
WARN_ON(page_shift < PAGE_SHIFT);
- if (!IS_ENABLED(CONFIG_HAVE_ARCH_HUGE_VMALLOC) ||
- page_shift == PAGE_SHIFT)
+ if ((!IS_ENABLED(CONFIG_HAVE_ARCH_HUGE_VMALLOC) &&
+ !IS_ENABLED(CONFIG_HAVE_ARCH_HUGE_VMALLOC_FLAG)) ||
+ (page_shift == PAGE_SHIFT))
return vmap_small_pages_range_noflush(addr, end, prot, pages);
for (i = 0; i < nr; i += 1U << (page_shift - PAGE_SHIFT)) {
@@ -2252,7 +2253,7 @@ static struct vm_struct *vmlist __initdata;
static inline unsigned int vm_area_page_order(struct vm_struct *vm)
{
-#ifdef CONFIG_HAVE_ARCH_HUGE_VMALLOC
+#if (defined(CONFIG_HAVE_ARCH_HUGE_VMALLOC) || defined(CONFIG_HAVE_ARCH_HUGE_VMALLOC_FLAG))
return vm->page_order;
#else
return 0;
@@ -2261,7 +2262,7 @@ static inline unsigned int vm_area_page_order(struct vm_struct *vm)
static inline void set_vm_area_page_order(struct vm_struct *vm, unsigned int order)
{
-#ifdef CONFIG_HAVE_ARCH_HUGE_VMALLOC
+#if (defined(CONFIG_HAVE_ARCH_HUGE_VMALLOC) || defined(CONFIG_HAVE_ARCH_HUGE_VMALLOC_FLAG))
vm->page_order = order;
#else
BUG_ON(order != 0);
@@ -3056,6 +3057,15 @@ static void *__vmalloc_area_node(struct vm_struct *area, gfp_t gfp_mask,
return NULL;
}
+static bool vmalloc_try_huge_page(unsigned long vm_flags)
+{
+ if (!vmap_allow_huge || (vm_flags & VM_NO_HUGE_VMAP))
+ return false;
+
+ /* VM_TRY_HUGE_VMAP only works for CONFIG_HAVE_ARCH_HUGE_VMALLOC_FLAG */
+ return vm_flags & VM_TRY_HUGE_VMAP;
+}
+
/**
* __vmalloc_node_range - allocate virtually contiguous memory
* @size: allocation size
@@ -3106,7 +3116,7 @@ void *__vmalloc_node_range(unsigned long size, unsigned long align,
return NULL;
}
- if (vmap_allow_huge && !(vm_flags & VM_NO_HUGE_VMAP)) {
+ if (vmalloc_try_huge_page(vm_flags)) {
unsigned long size_per_node;
/*
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