Groups | Search | Server Info | Keyboard shortcuts | Login | Register [http] [https] [nntp] [nntps]
Groups > linux.kernel > #1684159 > unrolled thread
| Started by | Anshuman Khandual <khandual@linux.vnet.ibm.com> |
|---|---|
| First post | 2017-07-10 13:40 +0200 |
| Last post | 2017-07-11 04:20 +0200 |
| Articles | 4 — 3 participants |
Back to article view | Back to linux.kernel
[PATCH] mm/mremap: Document MREMAP_FIXED dependency on MREMAP_MAYMOVE Anshuman Khandual <khandual@linux.vnet.ibm.com> - 2017-07-10 13:40 +0200
Re: [PATCH] mm/mremap: Document MREMAP_FIXED dependency on MREMAP_MAYMOVE Michal Hocko <mhocko@kernel.org> - 2017-07-10 15:50 +0200
Re: [PATCH] mm/mremap: Document MREMAP_FIXED dependency on MREMAP_MAYMOVE Mike Kravetz <mike.kravetz@oracle.com> - 2017-07-10 19:40 +0200
Re: [PATCH] mm/mremap: Document MREMAP_FIXED dependency on MREMAP_MAYMOVE Anshuman Khandual <khandual@linux.vnet.ibm.com> - 2017-07-11 04:20 +0200
| From | Anshuman Khandual <khandual@linux.vnet.ibm.com> |
|---|---|
| Date | 2017-07-10 13:40 +0200 |
| Subject | [PATCH] mm/mremap: Document MREMAP_FIXED dependency on MREMAP_MAYMOVE |
| Message-ID | <u1FcL-4qZ-39@gated-at.bofh.it> |
In the header file, just specify the dependency of MREMAP_FIXED on MREMAP_MAYMOVE and make it explicit for the user space. Signed-off-by: Anshuman Khandual <khandual@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
[toc] | [next] | [standalone]
| From | Michal Hocko <mhocko@kernel.org> |
|---|---|
| Date | 2017-07-10 15:50 +0200 |
| Subject | Re: [PATCH] mm/mremap: Document MREMAP_FIXED dependency on MREMAP_MAYMOVE |
| Message-ID | <u1Hey-5Fo-13@gated-at.bofh.it> |
| In reply to | #1684159 |
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? > Signed-off-by: Anshuman Khandual <khandual@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 majordomo@kvack.org. For more info on Linux MM, > see: http://www.linux-mm.org/ . > Don't email: <a href=mailto:"dont@kvack.org"> email@kvack.org </a> -- Michal Hocko SUSE Labs
[toc] | [prev] | [next] | [standalone]
| From | Mike Kravetz <mike.kravetz@oracle.com> |
|---|---|
| Date | 2017-07-10 19:40 +0200 |
| Subject | Re: [PATCH] mm/mremap: Document MREMAP_FIXED dependency on MREMAP_MAYMOVE |
| Message-ID | <u1KP8-7Xs-37@gated-at.bofh.it> |
| In reply to | #1684248 |
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 <khandual@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 majordomo@kvack.org. For more info on Linux MM, >> see: http://www.linux-mm.org/ . >> Don't email: <a href=mailto:"dont@kvack.org"> email@kvack.org </a> >
[toc] | [prev] | [next] | [standalone]
| From | Anshuman Khandual <khandual@linux.vnet.ibm.com> |
|---|---|
| Date | 2017-07-11 04:20 +0200 |
| Subject | Re: [PATCH] mm/mremap: Document MREMAP_FIXED dependency on MREMAP_MAYMOVE |
| Message-ID | <u1SWm-4Ny-7@gated-at.bofh.it> |
| In reply to | #1684532 |
On 07/10/2017 11:01 PM, Mike Kravetz wrote: > 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." Yeah the idea was to assist the programmer and I missed the man page's details on this. My bad.
[toc] | [prev] | [standalone]
Back to top | Article view | linux.kernel
csiph-web