On 07/10/2017 06:41 AM, Michal Hocko wrote: > On Mon 10-07-17 17:02:11, Anshuman Khandual wrote: >> In the header file, just specify the dependency of MREMAP_FIXED >> on MREMAP_MAYMOVE and make it explicit for the user space. > > I really fail to see a point of this patch. The depency belongs to the > code and it seems that we already enforce it > if (flags & MREMAP_FIXED && !(flags & MREMAP_MAYMOVE)) > return ret; > > So what is the point here?
Agree, I am not sure of your reasoning. If to assist the programmer, there is no need as this is clearly specified in the man page: "If MREMAP_FIXED is specified, then MREMAP_MAYMOVE must also be specified." -- Mike Kravetz > >> Signed-off-by: Anshuman Khandual <khand...@linux.vnet.ibm.com> >> --- >> include/uapi/linux/mman.h | 6 ++++-- >> 1 file changed, 4 insertions(+), 2 deletions(-) >> >> diff --git a/include/uapi/linux/mman.h b/include/uapi/linux/mman.h >> index ade4acd..8cae3f6 100644 >> --- a/include/uapi/linux/mman.h >> +++ b/include/uapi/linux/mman.h >> @@ -3,8 +3,10 @@ >> >> #include <asm/mman.h> >> >> -#define MREMAP_MAYMOVE 1 >> -#define MREMAP_FIXED 2 >> +#define MREMAP_MAYMOVE 1 /* VMA can move after remap and resize */ >> +#define MREMAP_FIXED 2 /* VMA can remap at particular address */ >> + >> +/* NOTE: MREMAP_FIXED must be set with MREMAP_MAYMOVE, not alone */ >> >> #define OVERCOMMIT_GUESS 0 >> #define OVERCOMMIT_ALWAYS 1 >> -- >> 1.8.5.2 >> >> -- >> To unsubscribe, send a message with 'unsubscribe linux-mm' in >> the body to majord...@kvack.org. For more info on Linux MM, >> see: http://www.linux-mm.org/ . >> Don't email: <a href=mailto:"d...@kvack.org";> em...@kvack.org </a> >
