diff options
Diffstat (limited to 'Documentation/vm')
| -rw-r--r-- | Documentation/vm/hugetlbpage.txt | 25 | ||||
| -rw-r--r-- | Documentation/vm/numa_memory_policy.txt | 4 |
2 files changed, 26 insertions, 3 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 to put this command in one of the local rc init files. This will enable the kernel to request huge pages early in the boot process (when the possibility of getting physical contiguous pages is still very high). In either -case, adminstrators will want to verify the number of hugepages actually +case, administrators will want to verify the number of hugepages actually allocated by checking the sysctl or meminfo. /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 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: diff --git a/Documentation/vm/numa_memory_policy.txt b/Documentation/vm/numa_memory_policy.txt index bad16d3f6a47..6aaaeb38730c 100644 --- a/Documentation/vm/numa_memory_policy.txt +++ b/Documentation/vm/numa_memory_policy.txt @@ -58,7 +58,7 @@ most general to most specific: the policy at the time they were allocated. VMA Policy: A "VMA" or "Virtual Memory Area" refers to a range of a task's - virtual adddress space. A task may define a specific policy for a range + virtual address space. A task may define a specific policy for a range of its virtual address space. See the MEMORY POLICIES APIS section, below, for an overview of the mbind() system call used to set a VMA policy. @@ -353,7 +353,7 @@ follows: Because of this extra reference counting, and because we must lookup shared policies in a tree structure under spinlock, shared policies are - more expensive to use in the page allocation path. This is expecially + more expensive to use in the page allocation path. This is especially true for shared policies on shared memory regions shared by tasks running on different NUMA nodes. This extra overhead can be avoided by always falling back to task or system default policy for shared memory regions, |