Query: get_hugepage_region
OS: centos
Section: 3
Format: Original Unix Latex Style Formatted with HTML and a Horizontal Scroll Bar
GET_HUGEPAGE_REGION(3) Library Functions Manual GET_HUGEPAGE_REGION(3)NAMEget_hugepage_region, free_hugepage_region - Allocate and free regions of memory that use hugepages where possibleSYNOPSIS#include <hugetlbfs.h> void *get_hugepage_region(size_t len, ghr_t flags); void free_hugepage_region(void *ptr);DESCRIPTIONget_hugepage_region() allocates a memory region len bytes in size backed by hugepages. Hugepages may be of benefit to applications that use large amounts of address space and suffer a performance hit due to TLB misses. Wall-clock time or oprofile can be used to determine if there is a performance benefit from using hugepages or not. Unlike get_huge_pages(), len does not have to be hugepage-aligned although memory may be wasted due to alignment. The caller may also spec- ify that base pages be used in the event there are no hugepages available. The flags argument changes the behaviour of the function. Flags may be or'd together. GHR_FALLBACK Use base pages if there are an insufficient number of huge pages. GHR_STRICT Use hugepages or return NULL. GHR_COLOR When specified, bytes that would be wasted due to alignment are used to color the buffer by offsetting it by a random cacheline within the hugepage. This avoids a performance problem whereby multiple buffers use the same cache lines at the same offsets. If it is not important that the start of the buffer be page-aligned, specify this flag. GHR_DEFAULT The library chooses a sensible combination of flags for allocating a region of memory. The current default is: GHR_FALLBACK | GHR_COLOR free_hugepage_region() frees a region of memory allocated by get_hugepage_region(). The behaviour of the function if another pointer is used, valid or otherwise, is undefined.RETURN VALUEOn success, a pointer is returned for to the allocated memory. On error, NULL is returned. errno will be set based on what the failure of mmap() was due to.SEE ALSOoprofile(1) , gethugepagesize(3) , get_huge_pages(3) , libhugetlbfs(7)AUTHORSlibhugetlbfs was written by various people on the libhugetlbfs-devel mailing list. November 7, 2008 GET_HUGEPAGE_REGION(3)
Related Man Pages |
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free_hugepages(2) - linux |
libhugetlbfs(7) - centos |
hugectl(8) - centos |
hugeadm(8) - centos |
free_hugepages(2) - sunos |
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Hugetlbfs and Shared Memory |