[PATCH v2] mm: introduce MADV_RESET_HUGEPAGE
STALE3412d
REVIEWED: 1 (0M)
From: Mike Rapoport <hidden>
Date: 2017-05-29 05:32:17
Also in:
linux-mm, lkml
Subsystem:
alpha port, generic include/asm header files, memory management, memory management - thp (transparent huge page), memory mapping - madvise (memory advice), mips, parisc architecture, tensilica xtensa port (xtensa), the rest · Maintainers:
Richard Henderson, Matt Turner, Magnus Lindholm, Arnd Bergmann, Andrew Morton, David Hildenbrand, Liam R. Howlett, Lorenzo Stoakes, Thomas Bogendoerfer, "James E.J. Bottomley", Helge Deller, Chris Zankel, Max Filippov, Linus Torvalds
1 review trailer.
Currently applications can explicitly enable or disable THP for a memory region using MADV_HUGEPAGE or MADV_NOHUGEPAGE. However, once either of these advises is used, the region will always have VM_HUGEPAGE/VM_NOHUGEPAGE flag set in vma->vm_flags. The MADV_RESET_HUGEPAGE resets both these flags and allows managing THP in the region according to system-wide settings. Signed-off-by: Mike Rapoport <redacted> Acked-by: Kirill A. Shutemov <redacted> --- v2 changes: * Use _RESET_ instead of _CLR_ as per Kirill's suggestion * Fix build on arches that do not include mman-common.h arch/alpha/include/uapi/asm/mman.h | 3 +++ arch/mips/include/uapi/asm/mman.h | 3 +++ arch/parisc/include/uapi/asm/mman.h | 3 +++ arch/xtensa/include/uapi/asm/mman.h | 3 +++ include/uapi/asm-generic/mman-common.h | 3 +++ mm/khugepaged.c | 7 +++++++ mm/madvise.c | 5 +++++ 7 files changed, 27 insertions(+)
diff --git a/arch/alpha/include/uapi/asm/mman.h b/arch/alpha/include/uapi/asm/mman.h
index 02760f6..cb3095f 100644
--- a/arch/alpha/include/uapi/asm/mman.h
+++ b/arch/alpha/include/uapi/asm/mman.h@@ -64,6 +64,9 @@ overrides the coredump filter bits */ #define MADV_DODUMP 17 /* Clear the MADV_NODUMP flag */ +#define MADV_RESET_HUGEPAGE 18 /* Reset flags controlling backing with + hugepages */ + /* compatibility flags */ #define MAP_FILE 0
diff --git a/arch/mips/include/uapi/asm/mman.h b/arch/mips/include/uapi/asm/mman.h
index 655e2fb..b5a181b 100644
--- a/arch/mips/include/uapi/asm/mman.h
+++ b/arch/mips/include/uapi/asm/mman.h@@ -91,6 +91,9 @@ overrides the coredump filter bits */ #define MADV_DODUMP 17 /* Clear the MADV_NODUMP flag */ +#define MADV_RESET_HUGEPAGE 18 /* Reset flags controlling backing with + hugepages */ + /* compatibility flags */ #define MAP_FILE 0
diff --git a/arch/parisc/include/uapi/asm/mman.h b/arch/parisc/include/uapi/asm/mman.h
index 5979745..d671906 100644
--- a/arch/parisc/include/uapi/asm/mman.h
+++ b/arch/parisc/include/uapi/asm/mman.h@@ -60,6 +60,9 @@ overrides the coredump filter bits */ #define MADV_DODUMP 70 /* Clear the MADV_NODUMP flag */ +#define MADV_RESET_HUGEPAGE 71 /* Reset flags controlling backing with + hugepages */ + /* compatibility flags */ #define MAP_FILE 0 #define MAP_VARIABLE 0
diff --git a/arch/xtensa/include/uapi/asm/mman.h b/arch/xtensa/include/uapi/asm/mman.h
index 24365b3..9c038d0 100644
--- a/arch/xtensa/include/uapi/asm/mman.h
+++ b/arch/xtensa/include/uapi/asm/mman.h@@ -103,6 +103,9 @@ overrides the coredump filter bits */ #define MADV_DODUMP 17 /* Clear the MADV_NODUMP flag */ +#define MADV_RESET_HUGEPAGE 18 /* Reset flags controlling backing with + hugepages */ + /* compatibility flags */ #define MAP_FILE 0
diff --git a/include/uapi/asm-generic/mman-common.h b/include/uapi/asm-generic/mman-common.h
index 8c27db0..fa62825 100644
--- a/include/uapi/asm-generic/mman-common.h
+++ b/include/uapi/asm-generic/mman-common.h@@ -58,6 +58,9 @@ overrides the coredump filter bits */ #define MADV_DODUMP 17 /* Clear the MADV_DONTDUMP flag */ +#define MADV_RESET_HUGEPAGE 18 /* Reset flags controlling backing with + hugepages */ + /* compatibility flags */ #define MAP_FILE 0
diff --git a/mm/khugepaged.c b/mm/khugepaged.c
index 945fd1c..32c66e7 100644
--- a/mm/khugepaged.c
+++ b/mm/khugepaged.c@@ -336,6 +336,13 @@ int hugepage_madvise(struct vm_area_struct *vma, * it got registered before VM_NOHUGEPAGE was set. */ break; + case MADV_RESET_HUGEPAGE: + *vm_flags &= ~(VM_HUGEPAGE | VM_NOHUGEPAGE); + /* + * The vma will be treated according to the + * system-wide settings in transparent_hugepage_flags + */ + break; } return 0;
diff --git a/mm/madvise.c b/mm/madvise.c
index 25b78ee..6d6dd09 100644
--- a/mm/madvise.c
+++ b/mm/madvise.c@@ -105,6 +105,7 @@ static long madvise_behavior(struct vm_area_struct *vma, break; case MADV_HUGEPAGE: case MADV_NOHUGEPAGE: + case MADV_RESET_HUGEPAGE: error = hugepage_madvise(vma, &new_flags, behavior); if (error) { /*
@@ -684,6 +685,7 @@ madvise_behavior_valid(int behavior) #ifdef CONFIG_TRANSPARENT_HUGEPAGE case MADV_HUGEPAGE: case MADV_NOHUGEPAGE: + case MADV_RESET_HUGEPAGE: #endif case MADV_DONTDUMP: case MADV_DODUMP:
@@ -739,6 +741,9 @@ madvise_behavior_valid(int behavior) * MADV_NOHUGEPAGE - mark the given range as not worth being backed by * transparent huge pages so the existing pages will not be * coalesced into THP and new pages will not be allocated as THP. + * MADV_RESET_HUGEPAGE - clear MADV_HUGEPAGE/MADV_NOHUGEPAGE marking; + * the range will be treated by khugepaged according to the + * system wide settings * MADV_DONTDUMP - the application wants to prevent pages in the given range * from being included in its core dump. * MADV_DODUMP - cancel MADV_DONTDUMP: no longer exclude from core dump.
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2.7.4
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