+++ /dev/null
-.\" Copyright 2003 Andries E. Brouwer (aeb@cwi.nl)
-.\"
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-.\"
-.TH ALLOC_HUGEPAGES 2 2007-05-31 "Linux" "Linux Programmer's Manual"
-.SH NAME
-alloc_hugepages, free_hugepages \- allocate or free huge pages
-.SH SYNOPSIS
-.nf
-.BI "void *alloc_hugepages(int " key ", void *" addr ", size_t " len ,
-.BI " int " prot ", int " flag );
-.\" asmlinkage unsigned long sys_alloc_hugepages(int key, unsigned long addr,
-.\" unsigned long len, int prot, int flag);
-.sp
-.BI "int free_hugepages(void *" addr );
-.\" asmlinkage int sys_free_hugepages(unsigned long addr);
-.fi
-.SH DESCRIPTION
-The system calls
-.BR alloc_hugepages ()
-and
-.BR free_hugepages ()
-were introduced in Linux 2.5.36 and removed again in 2.5.54.
-They existed only on i386 and ia64 (when built with
-.BR CONFIG_HUGETLB_PAGE ).
-In Linux 2.4.20, the syscall numbers exist,
-but the calls fail with the error
-.BR ENOSYS .
-.LP
-On i386 the memory management hardware knows about ordinary pages (4 KiB)
-and huge pages (2 or 4 MiB).
-Similarly ia64 knows about huge pages of
-several sizes.
-These system calls serve to map huge pages into the
-process's memory or to free them again.
-Huge pages are locked into memory, and are not swapped.
-.LP
-The
-.I key
-argument is an identifier.
-When zero the pages are private, and
-not inherited by children.
-When positive the pages are shared with other applications using the same
-.IR key ,
-and inherited by child processes.
-.LP
-The
-.I addr
-argument of
-.BR free_hugepages ()
-tells which page is being freed: it was the return value of a
-call to
-.BR alloc_hugepages ().
-(The memory is first actually freed when all users have released it.)
-The
-.I addr
-argument of
-.BR alloc_hugepages ()
-is a hint, that the kernel may or may not follow.
-Addresses must be properly aligned.
-.LP
-The
-.I len
-argument is the length of the required segment.
-It must be a multiple of the huge page size.
-.LP
-The
-.I prot
-argument specifies the memory protection of the segment.
-It is one of
-.BR PROT_READ ,
-.BR PROT_WRITE ,
-.BR PROT_EXEC .
-.LP
-The
-.I flag
-argument is ignored, unless
-.I key
-is positive.
-In that case, if
-.I flag
-is
-.BR IPC_CREAT ,
-then a new huge page segment is created when none
-with the given key existed.
-If this flag is not set, then
-.B ENOENT
-is returned when no segment with the given key exists.
-.SH RETURN VALUE
-On success,
-.BR alloc_hugepages ()
-returns the allocated virtual address, and
-.BR free_hugepages ()
-returns zero.
-On error, \-1 is returned, and
-.I errno
-is set appropriately.
-.SH ERRORS
-.TP
-.B ENOSYS
-The system call is not supported on this kernel.
-.SH FILES
-.I /proc/sys/vm/nr_hugepages
-Number of configured hugetlb pages.
-This can be read and written.
-.LP
-.I /proc/meminfo
-Gives info on the number of configured hugetlb pages and on their size
-in the three variables HugePages_Total, HugePages_Free, Hugepagesize.
-.SH CONFORMING TO
-These calls are specific to Linux on Intel processors, and should not be
-used in programs intended to be portable.
-.SH NOTES
-These system calls are gone;
-they existed only in Linux 2.5.36 through to 2.5.54.
-Now the hugetlbfs filesystem can be used instead.
-Memory backed by huge pages (if the CPU supports them) is obtained by
-using
-.BR mmap (2)
-to map files in this virtual filesystem.
-.LP
-The maximal number of huge pages can be specified using the
-.B hugepages=
-boot parameter.
-
-.\" requires CONFIG_HUGETLB_PAGE (under "Processor type and features")
-.\" and CONFIG_HUGETLBFS (under "Filesystems").
-.\" mount -t hugetlbfs hugetlbfs /huge
-.\" SHM_HUGETLB
-.SH COLOPHON
-This page is part of release 3.79 of the Linux
-.I man-pages
-project.
-A description of the project,
-information about reporting bugs,
-and the latest version of this page,
-can be found at
-\%http://www.kernel.org/doc/man\-pages/.
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