| Message ID | 20170407035539.21688-1-khandual@linux.vnet.ibm.com (mailing list archive) |
|---|---|
| State | Accepted |
| Commit | 2c9faa7675fec57f6ac0372688fae2e10fc4c272 |
| Headers | show |
Anshuman Khandual <khandual@linux.vnet.ibm.com> writes: > This just adds user space exported ABI definitions for 2MB, 16MB, 1GB, > 16GB non default huge page sizes to be used with mmap() system call. I updated this for you to include all the sizes. > diff --git a/arch/powerpc/include/uapi/asm/mman.h b/arch/powerpc/include/uapi/asm/mman.h > index 03c06ba..ebe99c7 100644 > --- a/arch/powerpc/include/uapi/asm/mman.h > +++ b/arch/powerpc/include/uapi/asm/mman.h > @@ -29,4 +29,18 @@ > #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 */ > > +/* > + * These constant defines should be used for creating the > + * 'flags' argument (26:31 bit positions) for mmap() system > + * call should the caller decide to use non default HugeTLB > + * page size. > + */ And I reworded the comment the make it clearer (I think) that most users shouldn't need to use these, and should just use the default size: /* * When MAP_HUGETLB is set bits [26:31] encode the log2 of the huge page size. * A value of zero indicates that the default huge page size should be used. * To use a non-default huge page size, one of these defines can be used, or the * size can be encoded by hand. Note that on most systems only a subset, or * possibly none, of these sizes will be available. */ Also do you want to send a patch to the man page? https://git.kernel.org/pub/scm/docs/man-pages/man-pages.git/tree/man2/mmap.2#n248 cheers
On 04/07/2017 06:31 PM, Michael Ellerman wrote: > Anshuman Khandual <khandual@linux.vnet.ibm.com> writes: > >> This just adds user space exported ABI definitions for 2MB, 16MB, 1GB, >> 16GB non default huge page sizes to be used with mmap() system call. > > I updated this for you to include all the sizes. > >> diff --git a/arch/powerpc/include/uapi/asm/mman.h b/arch/powerpc/include/uapi/asm/mman.h >> index 03c06ba..ebe99c7 100644 >> --- a/arch/powerpc/include/uapi/asm/mman.h >> +++ b/arch/powerpc/include/uapi/asm/mman.h >> @@ -29,4 +29,18 @@ >> #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 */ >> >> +/* >> + * These constant defines should be used for creating the >> + * 'flags' argument (26:31 bit positions) for mmap() system >> + * call should the caller decide to use non default HugeTLB >> + * page size. >> + */ > > And I reworded the comment the make it clearer (I think) that most users > shouldn't need to use these, and should just use the default size: > > /* > * When MAP_HUGETLB is set bits [26:31] encode the log2 of the huge page size. > * A value of zero indicates that the default huge page size should be used. > * To use a non-default huge page size, one of these defines can be used, or the > * size can be encoded by hand. Note that on most systems only a subset, or > * possibly none, of these sizes will be available. > */ Yeah its clearer, thanks. > > > Also do you want to send a patch to the man page? > > https://git.kernel.org/pub/scm/docs/man-pages/man-pages.git/tree/man2/mmap.2#n248 > Sure, will do it.
nits... take 'em or leave 'em... On 04/07/2017 08:01 AM, Michael Ellerman wrote: > Anshuman Khandual <khandual@linux.vnet.ibm.com> writes: > And I reworded the comment the make it clearer (I think) that most users > shouldn't need to use these, and should just use the default size: > > /* > * When MAP_HUGETLB is set bits [26:31] encode the log2 of the huge page size. need a comma after "set". also, "bits [26:31]" of what? > * A value of zero indicates that the default huge page size should be used. > * To use a non-default huge page size, one of these defines can be used, or the > * size can be encoded by hand. Note that on most systems only a subset, or > * possibly none, of these sizes will be available. > */ PC
Paul Clarke <pc@us.ibm.com> writes: > nits... take 'em or leave 'em... > > On 04/07/2017 08:01 AM, Michael Ellerman wrote: >> Anshuman Khandual <khandual@linux.vnet.ibm.com> writes: >> And I reworded the comment the make it clearer (I think) that most users >> shouldn't need to use these, and should just use the default size: >> >> /* >> * When MAP_HUGETLB is set bits [26:31] encode the log2 of the huge page size. > > need a comma after "set". Hmm, 'spose. > also, "bits [26:31]" of what? Flags! But yeah fair cop, as it happened I was rebasing it anyway, so: /* * When MAP_HUGETLB is set, bits [26:31] of the flags argument to mmap(2), * encode the log2 of the huge page size. A value of zero indicates that the * default huge page size should be used. To use a non-default huge page size, * one of these defines can be used, or the size can be encoded by hand. Note * that on most systems only a subset, or possibly none, of these sizes will be * available. */ Thanks for the review. cheers
On Fri, 2017-04-07 at 03:55:39 UTC, Anshuman Khandual wrote: > This just adds user space exported ABI definitions for 2MB, 16MB, 1GB, > 16GB non default huge page sizes to be used with mmap() system call. > > Signed-off-by: Anshuman Khandual <khandual@linux.vnet.ibm.com> Applied to powerpc next, thanks. https://git.kernel.org/powerpc/c/2c9faa7675fec57f6ac0372688fae2 cheers
diff --git a/arch/powerpc/include/uapi/asm/mman.h b/arch/powerpc/include/uapi/asm/mman.h index 03c06ba..ebe99c7 100644 --- a/arch/powerpc/include/uapi/asm/mman.h +++ b/arch/powerpc/include/uapi/asm/mman.h @@ -29,4 +29,18 @@ #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 */ +/* + * These constant defines should be used for creating the + * 'flags' argument (26:31 bit positions) for mmap() system + * call should the caller decide to use non default HugeTLB + * page size. + */ +#define MAP_HUGE_512KB (19 << MAP_HUGE_SHIFT) /* 512KB HugeTLB Page */ +#define MAP_HUGE_1MB (20 << MAP_HUGE_SHIFT) /* 1MB HugeTLB Page */ +#define MAP_HUGE_2MB (21 << MAP_HUGE_SHIFT) /* 2MB HugeTLB Page */ +#define MAP_HUGE_8MB (23 << MAP_HUGE_SHIFT) /* 8MB HugeTLB Page */ +#define MAP_HUGE_16MB (24 << MAP_HUGE_SHIFT) /* 16MB HugeTLB Page */ +#define MAP_HUGE_1GB (30 << MAP_HUGE_SHIFT) /* 1GB HugeTLB Page */ +#define MAP_HUGE_16GB (34 << MAP_HUGE_SHIFT) /* 16GB HugeTLB Page */ + #endif /* _UAPI_ASM_POWERPC_MMAN_H */
This just adds user space exported ABI definitions for 2MB, 16MB, 1GB, 16GB non default huge page sizes to be used with mmap() system call. Signed-off-by: Anshuman Khandual <khandual@linux.vnet.ibm.com> --- These defined values will be used along with MAP_HUGETLB while calling mmap() system call if the desired HugeTLB page size is not the default one. Follows similar definitions present in x86. arch/x86/include/uapi/asm/mman.h:#define MAP_HUGE_2MB (21 << MAP_HUGE_SHIFT) arch/x86/include/uapi/asm/mman.h:#define MAP_HUGE_1GB (30 << MAP_HUGE_SHIFT) Changes in V4: - Added defines for 512KB and 8MB HugeTLB page sizes per Christophe Changes in V3: - Added comment about how these defines will help create 'flags' argument for mmap() system call per Balbir Changes in V2: - Added definitions for 2MB and 1GB HugeTLB pages per Aneesh arch/powerpc/include/uapi/asm/mman.h | 14 ++++++++++++++ 1 file changed, 14 insertions(+)