diff options
Diffstat (limited to 'Documentation/admin-guide/sysctl')
| -rw-r--r-- | Documentation/admin-guide/sysctl/kernel.rst | 4 | ||||
| -rw-r--r-- | Documentation/admin-guide/sysctl/vm.rst | 6 |
2 files changed, 8 insertions, 2 deletions
diff --git a/Documentation/admin-guide/sysctl/kernel.rst b/Documentation/admin-guide/sysctl/kernel.rst index dd49a89a62d3..19224eeac1c2 100644 --- a/Documentation/admin-guide/sysctl/kernel.rst +++ b/Documentation/admin-guide/sysctl/kernel.rst @@ -1465,7 +1465,7 @@ stack_erasing ============= This parameter can be used to control kernel stack erasing at the end -of syscalls for kernels built with ``CONFIG_GCC_PLUGIN_STACKLEAK``. +of syscalls for kernels built with ``CONFIG_KSTACK_ERASE``. That erasing reduces the information which kernel stack leak bugs can reveal and blocks some uninitialized stack variable attacks. @@ -1473,7 +1473,7 @@ The tradeoff is the performance impact: on a single CPU system kernel compilation sees a 1% slowdown, other systems and workloads may vary. = ==================================================================== -0 Kernel stack erasing is disabled, STACKLEAK_METRICS are not updated. +0 Kernel stack erasing is disabled, KSTACK_ERASE_METRICS are not updated. 1 Kernel stack erasing is enabled (default), it is performed before returning to the userspace at the end of syscalls. = ==================================================================== diff --git a/Documentation/admin-guide/sysctl/vm.rst b/Documentation/admin-guide/sysctl/vm.rst index d385985b305f..9bef46151d53 100644 --- a/Documentation/admin-guide/sysctl/vm.rst +++ b/Documentation/admin-guide/sysctl/vm.rst @@ -132,6 +132,12 @@ to latency spikes in unsuspecting applications. The kernel employs various heuristics to avoid wasting CPU cycles if it detects that proactive compaction is not being effective. +Setting the value above 80 will, in addition to lowering the acceptable level +of fragmentation, make the compaction code more sensitive to increases in +fragmentation, i.e. compaction will trigger more often, but reduce +fragmentation by a smaller amount. +This makes the fragmentation level more stable over time. + Be careful when setting it to extreme values like 100, as that may cause excessive background compaction activity. |