diff options
Diffstat (limited to 'Documentation/admin-guide/sysctl')
| -rw-r--r-- | Documentation/admin-guide/sysctl/abi.rst | 2 | ||||
| -rw-r--r-- | Documentation/admin-guide/sysctl/kernel.rst | 18 | ||||
| -rw-r--r-- | Documentation/admin-guide/sysctl/vm.rst | 19 |
3 files changed, 22 insertions, 17 deletions
diff --git a/Documentation/admin-guide/sysctl/abi.rst b/Documentation/admin-guide/sysctl/abi.rst index ac87eafdb54f..77b1d1b2ad42 100644 --- a/Documentation/admin-guide/sysctl/abi.rst +++ b/Documentation/admin-guide/sysctl/abi.rst @@ -28,7 +28,7 @@ vsyscall32 (x86) Determines whether the kernels maps a vDSO page into 32-bit processes; can be set to 1 to enable, or 0 to disable. Defaults to enabled if -``CONFIG_COMPAT_VDSO`` is set, disabled otherwide. +``CONFIG_COMPAT_VDSO`` is set, disabled otherwise. This controls the same setting as the ``vdso32`` kernel boot parameter. diff --git a/Documentation/admin-guide/sysctl/kernel.rst b/Documentation/admin-guide/sysctl/kernel.rst index d4b32cc32bb7..1d56a6b73a4e 100644 --- a/Documentation/admin-guide/sysctl/kernel.rst +++ b/Documentation/admin-guide/sysctl/kernel.rst @@ -14,7 +14,7 @@ For general info and legal blurb, please look in :doc:`index`. ------------------------------------------------------------------------------ This file contains documentation for the sysctl files in -``/proc/sys/kernel/`` and is valid for Linux kernel version 2.2. +``/proc/sys/kernel/``. The files in this directory can be used to tune and monitor miscellaneous and general things in the operation of the Linux @@ -879,7 +879,7 @@ The default value is 127. perf_event_mlock_kb =================== -Control size of per-cpu ring buffer not counted agains mlock limit. +Control size of per-cpu ring buffer not counted against mlock limit. The default value is 512 + 1 page @@ -1095,8 +1095,8 @@ Enables/disables scheduler statistics. Enabling this feature incurs a small amount of overhead in the scheduler but is useful for debugging and performance tuning. -sched_util_clamp_min: -===================== +sched_util_clamp_min +==================== Max allowed *minimum* utilization. @@ -1106,8 +1106,8 @@ It means that any requested uclamp.min value cannot be greater than sched_util_clamp_min, i.e., it is restricted to the range [0:sched_util_clamp_min]. -sched_util_clamp_max: -===================== +sched_util_clamp_max +==================== Max allowed *maximum* utilization. @@ -1117,8 +1117,8 @@ It means that any requested uclamp.max value cannot be greater than sched_util_clamp_max, i.e., it is restricted to the range [0:sched_util_clamp_max]. -sched_util_clamp_min_rt_default: -================================ +sched_util_clamp_min_rt_default +=============================== By default Linux is tuned for performance. Which means that RT tasks always run at the highest frequency and most capable (highest capacity) CPU (in @@ -1336,7 +1336,7 @@ ORed together. The letters are seen in "Tainted" line of Oops reports. ====== ===== ============================================================== 1 `(P)` proprietary module was loaded 2 `(F)` module was force loaded - 4 `(S)` SMP kernel oops on an officially SMP incapable processor + 4 `(S)` kernel running on an out of specification system 8 `(R)` module was force unloaded 16 `(M)` processor reported a Machine Check Exception (MCE) 32 `(B)` bad page referenced or some unexpected page flags diff --git a/Documentation/admin-guide/sysctl/vm.rst b/Documentation/admin-guide/sysctl/vm.rst index f455fa00c00f..e35a3f2fb006 100644 --- a/Documentation/admin-guide/sysctl/vm.rst +++ b/Documentation/admin-guide/sysctl/vm.rst @@ -146,7 +146,7 @@ This should be used on systems where stalls for minor page faults are an acceptable trade for large contiguous free memory. Set to 0 to prevent compaction from moving pages that are unevictable. Default value is 1. On CONFIG_PREEMPT_RT the default value is 0 in order to avoid a page fault, due -to compaction, which would block the task from becomming active until the fault +to compaction, which would block the task from becoming active until the fault is resolved. @@ -428,7 +428,7 @@ While most applications need less than a thousand maps, certain programs, particularly malloc debuggers, may consume lots of them, e.g., up to one or two maps per allocation. -The default value is 65536. +The default value is 65530. memory_failure_early_kill: @@ -873,12 +873,17 @@ file-backed pages is less than the high watermark in a zone. unprivileged_userfaultfd ======================== -This flag controls whether unprivileged users can use the userfaultfd -system calls. Set this to 1 to allow unprivileged users to use the -userfaultfd system calls, or set this to 0 to restrict userfaultfd to only -privileged users (with SYS_CAP_PTRACE capability). +This flag controls the mode in which unprivileged users can use the +userfaultfd system calls. Set this to 0 to restrict unprivileged users +to handle page faults in user mode only. In this case, users without +SYS_CAP_PTRACE must pass UFFD_USER_MODE_ONLY in order for userfaultfd to +succeed. Prohibiting use of userfaultfd for handling faults from kernel +mode may make certain vulnerabilities more difficult to exploit. -The default value is 1. +Set this to 1 to allow unprivileged users to use the userfaultfd system +calls without any restrictions. + +The default value is 0. user_reserve_kbytes |