lkml.org 
[lkml]   [2019]   [Feb]   [15]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
From
Subject[RFC PATCH 25/31] mm: thp: add a knob to enable/disable 1GB THPs.
Date
From: Zi Yan <ziy@nvidia.com>

It does not affect existing 1GB THPs. It is similar to the knob for
2MB THPs.

Signed-off-by: Zi Yan <ziy@nvidia.com>
---
include/linux/huge_mm.h | 14 ++++++++++++++
mm/huge_memory.c | 42 ++++++++++++++++++++++++++++++++++++++++-
mm/memory.c | 2 +-
3 files changed, 56 insertions(+), 2 deletions(-)

diff --git a/include/linux/huge_mm.h b/include/linux/huge_mm.h
index b1acada9ce8c..687c7d59df8b 100644
--- a/include/linux/huge_mm.h
+++ b/include/linux/huge_mm.h
@@ -84,6 +84,8 @@ enum transparent_hugepage_flag {
#ifdef CONFIG_DEBUG_VM
TRANSPARENT_HUGEPAGE_DEBUG_COW_FLAG,
#endif
+ TRANSPARENT_PUD_HUGEPAGE_FLAG,
+ TRANSPARENT_PUD_HUGEPAGE_REQ_MADV_FLAG,
};

struct kobject;
@@ -146,6 +148,18 @@ static inline bool __transparent_hugepage_enabled(struct vm_area_struct *vma)
}

bool transparent_hugepage_enabled(struct vm_area_struct *vma);
+static inline bool transparent_pud_hugepage_enabled(struct vm_area_struct *vma)
+{
+ if (transparent_hugepage_enabled(vma)) {
+ if (transparent_hugepage_flags & (1 << TRANSPARENT_PUD_HUGEPAGE_FLAG))
+ return true;
+ if (transparent_hugepage_flags &
+ (1 << TRANSPARENT_HUGEPAGE_REQ_MADV_FLAG))
+ return !!(vma->vm_flags & VM_HUGEPAGE);
+ }
+
+ return false;
+}

#define transparent_hugepage_use_zero_page() \
(transparent_hugepage_flags & \
diff --git a/mm/huge_memory.c b/mm/huge_memory.c
index 191261771452..fa3e12b17621 100644
--- a/mm/huge_memory.c
+++ b/mm/huge_memory.c
@@ -50,9 +50,11 @@
unsigned long transparent_hugepage_flags __read_mostly =
#ifdef CONFIG_TRANSPARENT_HUGEPAGE_ALWAYS
(1<<TRANSPARENT_HUGEPAGE_FLAG)|
+ (1<<TRANSPARENT_PUD_HUGEPAGE_FLAG)|
#endif
#ifdef CONFIG_TRANSPARENT_HUGEPAGE_MADVISE
(1<<TRANSPARENT_HUGEPAGE_REQ_MADV_FLAG)|
+ (1<<TRANSPARENT_PUD_HUGEPAGE_REQ_MADV_FLAG)|
#endif
(1<<TRANSPARENT_HUGEPAGE_DEFRAG_REQ_MADV_FLAG)|
(1<<TRANSPARENT_HUGEPAGE_DEFRAG_KHUGEPAGED_FLAG)|
@@ -276,6 +278,43 @@ static ssize_t enabled_store(struct kobject *kobj,
static struct kobj_attribute enabled_attr =
__ATTR(enabled, 0644, enabled_show, enabled_store);

+static ssize_t enabled_1gb_show(struct kobject *kobj,
+ struct kobj_attribute *attr, char *buf)
+{
+ if (test_bit(TRANSPARENT_PUD_HUGEPAGE_FLAG, &transparent_hugepage_flags))
+ return sprintf(buf, "[always] madvise never\n");
+ else if (test_bit(TRANSPARENT_PUD_HUGEPAGE_REQ_MADV_FLAG, &transparent_hugepage_flags))
+ return sprintf(buf, "always [madvise] never\n");
+ else
+ return sprintf(buf, "always madvise [never]\n");
+}
+
+static ssize_t enabled_1gb_store(struct kobject *kobj,
+ struct kobj_attribute *attr,
+ const char *buf, size_t count)
+{
+ ssize_t ret = count;
+
+ if (!memcmp("always", buf,
+ min(sizeof("always")-1, count))) {
+ clear_bit(TRANSPARENT_PUD_HUGEPAGE_REQ_MADV_FLAG, &transparent_hugepage_flags);
+ set_bit(TRANSPARENT_PUD_HUGEPAGE_FLAG, &transparent_hugepage_flags);
+ } else if (!memcmp("madvise", buf,
+ min(sizeof("madvise")-1, count))) {
+ clear_bit(TRANSPARENT_PUD_HUGEPAGE_FLAG, &transparent_hugepage_flags);
+ set_bit(TRANSPARENT_PUD_HUGEPAGE_REQ_MADV_FLAG, &transparent_hugepage_flags);
+ } else if (!memcmp("never", buf,
+ min(sizeof("never")-1, count))) {
+ clear_bit(TRANSPARENT_PUD_HUGEPAGE_FLAG, &transparent_hugepage_flags);
+ clear_bit(TRANSPARENT_PUD_HUGEPAGE_REQ_MADV_FLAG, &transparent_hugepage_flags);
+ } else
+ ret = -EINVAL;
+
+ return ret;
+}
+static struct kobj_attribute enabled_1gb_attr =
+ __ATTR(enabled_1gb, 0644, enabled_1gb_show, enabled_1gb_store);
+
ssize_t single_hugepage_flag_show(struct kobject *kobj,
struct kobj_attribute *attr, char *buf,
enum transparent_hugepage_flag flag)
@@ -405,6 +444,7 @@ static struct kobj_attribute debug_cow_attr =

static struct attribute *hugepage_attr[] = {
&enabled_attr.attr,
+ &enabled_1gb_attr.attr,
&defrag_attr.attr,
&use_zero_page_attr.attr,
&hpage_pmd_size_attr.attr,
@@ -1657,7 +1697,7 @@ int do_huge_pud_wp_page(struct vm_fault *vmf, pud_t orig_pud)
get_page(page);
spin_unlock(vmf->ptl);
alloc:
- if (transparent_hugepage_enabled(vma) &&
+ if (transparent_pud_hugepage_enabled(vma) &&
!transparent_hugepage_debug_cow()) {
huge_gfp = alloc_hugepage_direct_gfpmask(vma);
new_page = alloc_hugepage_vma(huge_gfp, vma, haddr, HPAGE_PUD_ORDER);
diff --git a/mm/memory.c b/mm/memory.c
index c875cc1a2600..5b8ad19cc439 100644
--- a/mm/memory.c
+++ b/mm/memory.c
@@ -3859,7 +3859,7 @@ static vm_fault_t __handle_mm_fault(struct vm_area_struct *vma,
vmf.pud = pud_alloc(mm, p4d, address);
if (!vmf.pud)
return VM_FAULT_OOM;
- if (pud_none(*vmf.pud) && __transparent_hugepage_enabled(vma)) {
+ if (pud_none(*vmf.pud) && transparent_pud_hugepage_enabled(vma)) {
ret = create_huge_pud(&vmf);
if (!(ret & VM_FAULT_FALLBACK))
return ret;
--
2.20.1
\
 
 \ /
  Last update: 2019-02-15 23:10    [W:0.278 / U:4.228 seconds]
©2003-2018 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site