diff options
Diffstat (limited to 'Documentation/vm/hugetlbpage.txt')
-rw-r--r-- | Documentation/vm/hugetlbpage.txt | 25 |
1 files changed, 24 insertions, 1 deletions
diff --git a/Documentation/vm/hugetlbpage.txt b/Documentation/vm/hugetlbpage.txt index 3102b81bef88..ea8714fcc3ad 100644 --- a/Documentation/vm/hugetlbpage.txt +++ b/Documentation/vm/hugetlbpage.txt | |||
@@ -77,7 +77,7 @@ memory that is preset in system at this time. System administrators may want | |||
77 | to put this command in one of the local rc init files. This will enable the | 77 | to put this command in one of the local rc init files. This will enable the |
78 | kernel to request huge pages early in the boot process (when the possibility | 78 | kernel to request huge pages early in the boot process (when the possibility |
79 | of getting physical contiguous pages is still very high). In either | 79 | of getting physical contiguous pages is still very high). In either |
80 | case, adminstrators will want to verify the number of hugepages actually | 80 | case, administrators will want to verify the number of hugepages actually |
81 | allocated by checking the sysctl or meminfo. | 81 | allocated by checking the sysctl or meminfo. |
82 | 82 | ||
83 | /proc/sys/vm/nr_overcommit_hugepages indicates how large the pool of | 83 | /proc/sys/vm/nr_overcommit_hugepages indicates how large the pool of |
@@ -95,6 +95,29 @@ this condition holds, however, no more surplus huge pages will be | |||
95 | allowed on the system until one of the two sysctls are increased | 95 | allowed on the system until one of the two sysctls are increased |
96 | sufficiently, or the surplus huge pages go out of use and are freed. | 96 | sufficiently, or the surplus huge pages go out of use and are freed. |
97 | 97 | ||
98 | With support for multiple hugepage pools at run-time available, much of | ||
99 | the hugepage userspace interface has been duplicated in sysfs. The above | ||
100 | information applies to the default hugepage size (which will be | ||
101 | controlled by the proc interfaces for backwards compatibility). The root | ||
102 | hugepage control directory is | ||
103 | |||
104 | /sys/kernel/mm/hugepages | ||
105 | |||
106 | For each hugepage size supported by the running kernel, a subdirectory | ||
107 | will exist, of the form | ||
108 | |||
109 | hugepages-${size}kB | ||
110 | |||
111 | Inside each of these directories, the same set of files will exist: | ||
112 | |||
113 | nr_hugepages | ||
114 | nr_overcommit_hugepages | ||
115 | free_hugepages | ||
116 | resv_hugepages | ||
117 | surplus_hugepages | ||
118 | |||
119 | which function as described above for the default hugepage-sized case. | ||
120 | |||
98 | If the user applications are going to request hugepages using mmap system | 121 | If the user applications are going to request hugepages using mmap system |
99 | call, then it is required that system administrator mount a file system of | 122 | call, then it is required that system administrator mount a file system of |
100 | type hugetlbfs: | 123 | type hugetlbfs: |