diff options
Diffstat (limited to 'Documentation/cgroups')
-rw-r--r-- | Documentation/cgroups/memory.txt | 8 |
1 files changed, 3 insertions, 5 deletions
diff --git a/Documentation/cgroups/memory.txt b/Documentation/cgroups/memory.txt index a22df3ad35ff..f456b4315e86 100644 --- a/Documentation/cgroups/memory.txt +++ b/Documentation/cgroups/memory.txt | |||
@@ -275,11 +275,6 @@ When oom event notifier is registered, event will be delivered. | |||
275 | 275 | ||
276 | 2.7 Kernel Memory Extension (CONFIG_MEMCG_KMEM) | 276 | 2.7 Kernel Memory Extension (CONFIG_MEMCG_KMEM) |
277 | 277 | ||
278 | WARNING: Current implementation lacks reclaim support. That means allocation | ||
279 | attempts will fail when close to the limit even if there are plenty of | ||
280 | kmem available for reclaim. That makes this option unusable in real | ||
281 | life so DO NOT SELECT IT unless for development purposes. | ||
282 | |||
283 | With the Kernel memory extension, the Memory Controller is able to limit | 278 | With the Kernel memory extension, the Memory Controller is able to limit |
284 | the amount of kernel memory used by the system. Kernel memory is fundamentally | 279 | the amount of kernel memory used by the system. Kernel memory is fundamentally |
285 | different than user memory, since it can't be swapped out, which makes it | 280 | different than user memory, since it can't be swapped out, which makes it |
@@ -345,6 +340,9 @@ set: | |||
345 | In this case, the admin could set up K so that the sum of all groups is | 340 | In this case, the admin could set up K so that the sum of all groups is |
346 | never greater than the total memory, and freely set U at the cost of his | 341 | never greater than the total memory, and freely set U at the cost of his |
347 | QoS. | 342 | QoS. |
343 | WARNING: In the current implementation, memory reclaim will NOT be | ||
344 | triggered for a cgroup when it hits K while staying below U, which makes | ||
345 | this setup impractical. | ||
348 | 346 | ||
349 | U != 0, K >= U: | 347 | U != 0, K >= U: |
350 | Since kmem charges will also be fed to the user counter and reclaim will be | 348 | Since kmem charges will also be fed to the user counter and reclaim will be |