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-rw-r--r--Documentation/ABI/testing/sysfs-kernel-mm-hugepages15
-rw-r--r--Documentation/vm/hugetlbpage.txt23
2 files changed, 38 insertions, 0 deletions
diff --git a/Documentation/ABI/testing/sysfs-kernel-mm-hugepages b/Documentation/ABI/testing/sysfs-kernel-mm-hugepages
new file mode 100644
index 00000000000..e21c00571cf
--- /dev/null
+++ b/Documentation/ABI/testing/sysfs-kernel-mm-hugepages
@@ -0,0 +1,15 @@
+What: /sys/kernel/mm/hugepages/
+Date: June 2008
+Contact: Nishanth Aravamudan <nacc@us.ibm.com>, hugetlb maintainers
+Description:
+ /sys/kernel/mm/hugepages/ contains a number of subdirectories
+ of the form hugepages-<size>kB, where <size> is the page size
+ of the hugepages supported by the kernel/CPU combination.
+
+ Under these directories are a number of files:
+ nr_hugepages
+ nr_overcommit_hugepages
+ free_hugepages
+ surplus_hugepages
+ resv_hugepages
+ See Documentation/vm/hugetlbpage.txt for details.
diff --git a/Documentation/vm/hugetlbpage.txt b/Documentation/vm/hugetlbpage.txt
index 3102b81bef8..8a5b5763f0f 100644
--- a/Documentation/vm/hugetlbpage.txt
+++ b/Documentation/vm/hugetlbpage.txt
@@ -95,6 +95,29 @@ this condition holds, however, no more surplus huge pages will be
allowed on the system until one of the two sysctls are increased
sufficiently, or the surplus huge pages go out of use and are freed.
+With support for multiple hugepage pools at run-time available, much of
+the hugepage userspace interface has been duplicated in sysfs. The above
+information applies to the default hugepage size (which will be
+controlled by the proc interfaces for backwards compatibility). The root
+hugepage control directory is
+
+ /sys/kernel/mm/hugepages
+
+For each hugepage size supported by the running kernel, a subdirectory
+will exist, of the form
+
+ hugepages-${size}kB
+
+Inside each of these directories, the same set of files will exist:
+
+ nr_hugepages
+ nr_overcommit_hugepages
+ free_hugepages
+ resv_hugepages
+ surplus_hugepages
+
+which function as described above for the default hugepage-sized case.
+
If the user applications are going to request hugepages using mmap system
call, then it is required that system administrator mount a file system of
type hugetlbfs: