Re: [PATCH 1/2] mm: introduce MAP_FIXED_SAFE
From: Michal Hocko <mhocko@kernel.org>
Date: 2017-12-06 10:02:37
Also in:
linux-arch, linux-mm, lkml
Subsystem:
alpha port, generic include/asm header files, linux for powerpc (32-bit and 64-bit), memory mapping - madvise (memory advice), sparc + ultrasparc (sparc/sparc64), the rest · Maintainers:
Richard Henderson, Matt Turner, Magnus Lindholm, Arnd Bergmann, Madhavan Srinivasan, Michael Ellerman, Andrew Morton, Liam R. Howlett, Lorenzo Stoakes, David Hildenbrand, "David S. Miller", Andreas Larsson, Linus Torvalds
On Wed 06-12-17 10:27:24, Michal Hocko wrote:
On Wed 06-12-17 16:15:24, Michael Ellerman wrote:
[...]
quoted
So I think I proved above that all the arches that are using 0x80000 are also using mman-common.h, and vice-versa. So you can put this in mman-common.h can't your?Yes it seems I can. I would have to double check. It is true that defining the new flag closer to MAP_FIXED makes some sense
OK, so some recap
those which include generic mman-common.h directly
arch/sparc/include/uapi/asm/mman.h:#include <asm-generic/mman-common.h>
arch/powerpc/include/uapi/asm/mman.h:#include <asm-generic/mman-common.h>
arch/tile/include/uapi/asm/mman.h:#include <asm-generic/mman-common.h>
then we have
arch/metag/include/asm/mman.h
which includes uapi/asm/mman.h and that is a generic one
arch/metag/include/uapi/asm/Kbuild:generic-y += mman.h
others include generic mman.h
arch/arm/include/uapi/asm/mman.h:#include <asm-generic/mman.h>
arch/frv/include/uapi/asm/mman.h:#include <asm-generic/mman.h>
arch/ia64/include/uapi/asm/mman.h:#include <asm-generic/mman.h>
arch/m32r/include/uapi/asm/mman.h:#include <asm-generic/mman.h>
arch/mn10300/include/uapi/asm/mman.h:#include <asm-generic/mman.h>
arch/score/include/uapi/asm/mman.h:#include <asm-generic/mman.h>
arch/x86/include/uapi/asm/mman.h:#include <asm-generic/mman.h>
which includes mman-common.h as well
and then we are left with
arch/alpha/include/uapi/asm/mman.h
arch/mips/include/uapi/asm/mman.h
arch/parisc/include/uapi/asm/mman.h
arch/xtensa/include/uapi/asm/mman.h
which do not include anything. So the patch can be indeed simplified.
I will fold the following into the patch. I hope nothing got left behind
but my defconfig compile test on all arches which i have a cross
compiler for succeeded.
---
commit 52a9272f419f428cb079d340f64113325516ef9b
Author: Michal Hocko [off-list ref]
Date: Wed Dec 6 10:46:16 2017 +0100
- define MAP_FIXED_SAFE in asm-generic/mman-common.h as per Michael
Ellerman because all architecture which use this header can share
the same value. This will leave us with only 4 arches which need
special handling.
diff --git a/arch/alpha/include/uapi/asm/mman.h b/arch/alpha/include/uapi/asm/mman.h
index ef3770262925..7287dbf1e11b 100644
--- a/arch/alpha/include/uapi/asm/mman.h
+++ b/arch/alpha/include/uapi/asm/mman.h@@ -31,7 +31,6 @@ #define MAP_NONBLOCK 0x40000 /* do not block on IO */ #define MAP_STACK 0x80000 /* give out an address that is best suited for process/thread stacks */ #define MAP_HUGETLB 0x100000 /* create a huge page mapping */ - #define MAP_FIXED_SAFE 0x200000 /* MAP_FIXED which doesn't unmap underlying mapping */ #define MS_ASYNC 1 /* sync memory asynchronously */
diff --git a/arch/powerpc/include/uapi/asm/mman.h b/arch/powerpc/include/uapi/asm/mman.h
index 3ffd284e7160..e63bc37e33af 100644
--- a/arch/powerpc/include/uapi/asm/mman.h
+++ b/arch/powerpc/include/uapi/asm/mman.h@@ -29,6 +29,5 @@ #define MAP_NONBLOCK 0x10000 /* do not block on IO */ #define MAP_STACK 0x20000 /* give out an address that is best suited for process/thread stacks */ #define MAP_HUGETLB 0x40000 /* create a huge page mapping */ -#define MAP_FIXED_SAFE 0x800000 /* MAP_FIXED which doesn't unmap underlying mapping */ #endif /* _UAPI_ASM_POWERPC_MMAN_H */
diff --git a/arch/sparc/include/uapi/asm/mman.h b/arch/sparc/include/uapi/asm/mman.h
index 0c282c09fae8..d21bffd5d3dc 100644
--- a/arch/sparc/include/uapi/asm/mman.h
+++ b/arch/sparc/include/uapi/asm/mman.h@@ -24,7 +24,5 @@ #define MAP_NONBLOCK 0x10000 /* do not block on IO */ #define MAP_STACK 0x20000 /* give out an address that is best suited for process/thread stacks */ #define MAP_HUGETLB 0x40000 /* create a huge page mapping */ -#define MAP_FIXED_SAFE 0x80000 /* MAP_FIXED which doesn't unmap underlying mapping */ - #endif /* _UAPI__SPARC_MMAN_H__ */
diff --git a/arch/tile/include/uapi/asm/mman.h b/arch/tile/include/uapi/asm/mman.h
index b212f5fd5345..9b7add95926b 100644
--- a/arch/tile/include/uapi/asm/mman.h
+++ b/arch/tile/include/uapi/asm/mman.h@@ -30,7 +30,6 @@ #define MAP_DENYWRITE 0x0800 /* ETXTBSY */ #define MAP_EXECUTABLE 0x1000 /* mark it as an executable */ #define MAP_HUGETLB 0x4000 /* create a huge page mapping */ -#define MAP_FIXED_SAFE 0x8000 /* MAP_FIXED which doesn't unmap underlying mapping */ /*
diff --git a/include/uapi/asm-generic/mman-common.h b/include/uapi/asm-generic/mman-common.h
index 6d319c46fd90..1eca2cb10d44 100644
--- a/include/uapi/asm-generic/mman-common.h
+++ b/include/uapi/asm-generic/mman-common.h@@ -25,6 +25,7 @@ #else # define MAP_UNINITIALIZED 0x0 /* Don't support this flag */ #endif +#define MAP_FIXED_SAFE 0x80000 /* MAP_FIXED which doesn't unmap underlying mapping */ /* * Flags for mlock
diff --git a/include/uapi/asm-generic/mman.h b/include/uapi/asm-generic/mman.h
index 56cde132a80a..2dffcbf705b3 100644
--- a/include/uapi/asm-generic/mman.h
+++ b/include/uapi/asm-generic/mman.h@@ -13,7 +13,6 @@ #define MAP_NONBLOCK 0x10000 /* do not block on IO */ #define MAP_STACK 0x20000 /* give out an address that is best suited for process/thread stacks */ #define MAP_HUGETLB 0x40000 /* create a huge page mapping */ -#define MAP_FIXED_SAFE 0x80000 /* MAP_FIXED which doesn't unmap underlying mapping */ /* Bits [26:31] are reserved, see mman-common.h for MAP_HUGETLB usage */
--
Michal Hocko
SUSE Labs
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