diff options
Diffstat (limited to 'Documentation')
| -rw-r--r-- | Documentation/filesystems/proc.txt | 9 | ||||
| -rw-r--r-- | Documentation/sysctl/vm.txt | 12 | ||||
| -rw-r--r-- | Documentation/vm/overcommit-accounting | 7 |
3 files changed, 25 insertions, 3 deletions
diff --git a/Documentation/filesystems/proc.txt b/Documentation/filesystems/proc.txt index 22d89aa37218..8533f5f9bb2d 100644 --- a/Documentation/filesystems/proc.txt +++ b/Documentation/filesystems/proc.txt @@ -767,6 +767,7 @@ The "Locked" indicates whether the mapping is locked in memory or not. MemTotal: 16344972 kB MemFree: 13634064 kB +MemAvailable: 14836172 kB Buffers: 3656 kB Cached: 1195708 kB SwapCached: 0 kB @@ -799,6 +800,14 @@ AnonHugePages: 49152 kB MemTotal: Total usable ram (i.e. physical ram minus a few reserved bits and the kernel binary code) MemFree: The sum of LowFree+HighFree +MemAvailable: An estimate of how much memory is available for starting new + applications, without swapping. Calculated from MemFree, + SReclaimable, the size of the file LRU lists, and the low + watermarks in each zone. + The estimate takes into account that the system needs some + page cache to function well, and that not all reclaimable + slab will be reclaimable, due to items being in use. The + impact of those factors will vary from system to system. Buffers: Relatively temporary storage for raw disk blocks shouldn't get tremendously large (20MB or so) Cached: in-memory cache for files read from the disk (the diff --git a/Documentation/sysctl/vm.txt b/Documentation/sysctl/vm.txt index 1fbd4eb7b64a..9f5481bdc5a4 100644 --- a/Documentation/sysctl/vm.txt +++ b/Documentation/sysctl/vm.txt @@ -47,6 +47,7 @@ Currently, these files are in /proc/sys/vm: - numa_zonelist_order - oom_dump_tasks - oom_kill_allocating_task +- overcommit_kbytes - overcommit_memory - overcommit_ratio - page-cluster @@ -574,6 +575,17 @@ The default value is 0. ============================================================== +overcommit_kbytes: + +When overcommit_memory is set to 2, the committed address space is not +permitted to exceed swap plus this amount of physical RAM. See below. + +Note: overcommit_kbytes is the counterpart of overcommit_ratio. Only one +of them may be specified at a time. Setting one disables the other (which +then appears as 0 when read). + +============================================================== + overcommit_memory: This value contains a flag that enables memory overcommitment. diff --git a/Documentation/vm/overcommit-accounting b/Documentation/vm/overcommit-accounting index 8eaa2fc4b8fa..cbfaaa674118 100644 --- a/Documentation/vm/overcommit-accounting +++ b/Documentation/vm/overcommit-accounting @@ -14,8 +14,8 @@ The Linux kernel supports the following overcommit handling modes 2 - Don't overcommit. The total address space commit for the system is not permitted to exceed swap + a - configurable percentage (default is 50) of physical RAM. - Depending on the percentage you use, in most situations + configurable amount (default is 50%) of physical RAM. + Depending on the amount you use, in most situations this means a process will not be killed while accessing pages but will receive errors on memory allocation as appropriate. @@ -26,7 +26,8 @@ The Linux kernel supports the following overcommit handling modes The overcommit policy is set via the sysctl `vm.overcommit_memory'. -The overcommit percentage is set via `vm.overcommit_ratio'. +The overcommit amount can be set via `vm.overcommit_ratio' (percentage) +or `vm.overcommit_kbytes' (absolute value). The current overcommit limit and amount committed are viewable in /proc/meminfo as CommitLimit and Committed_AS respectively. |