diff options
Diffstat (limited to 'Documentation/sysctl')
| -rw-r--r-- | Documentation/sysctl/fs.txt | 23 | ||||
| -rw-r--r-- | Documentation/sysctl/kernel.txt | 38 | ||||
| -rw-r--r-- | Documentation/sysctl/vm.txt | 33 |
3 files changed, 84 insertions, 10 deletions
diff --git a/Documentation/sysctl/fs.txt b/Documentation/sysctl/fs.txt index 88152f214..302b5ed61 100644 --- a/Documentation/sysctl/fs.txt +++ b/Documentation/sysctl/fs.txt @@ -32,6 +32,8 @@ Currently, these files are in /proc/sys/fs: - nr_open - overflowuid - overflowgid +- pipe-user-pages-hard +- pipe-user-pages-soft - protected_hardlinks - protected_symlinks - suid_dumpable @@ -159,6 +161,27 @@ The default is 65534. ============================================================== +pipe-user-pages-hard: + +Maximum total number of pages a non-privileged user may allocate for pipes. +Once this limit is reached, no new pipes may be allocated until usage goes +below the limit again. When set to 0, no limit is applied, which is the default +setting. + +============================================================== + +pipe-user-pages-soft: + +Maximum total number of pages a non-privileged user may allocate for pipes +before the pipe size gets limited to a single page. Once this limit is reached, +new pipes will be limited to a single page in size for this user in order to +limit total memory usage, and trying to increase them using fcntl() will be +denied until usage goes below the limit again. The default value allows to +allocate up to 1024 pipes at their default size. When set to 0, no limit is +applied. + +============================================================== + protected_hardlinks: A long-standing class of security issues is the hardlink-based diff --git a/Documentation/sysctl/kernel.txt b/Documentation/sysctl/kernel.txt index af70d1541..87119dc9b 100644 --- a/Documentation/sysctl/kernel.txt +++ b/Documentation/sysctl/kernel.txt @@ -551,6 +551,21 @@ the recommended setting is 60. ============================================================== +panic_on_io_nmi: + +Controls the kernel's behavior when a CPU receives an NMI caused by +an IO error. + +0: try to continue operation (default) + +1: panic immediately. The IO error triggered an NMI. This indicates a + serious system condition which could result in IO data corruption. + Rather than continuing, panicking might be a better choice. Some + servers issue this sort of NMI when the dump button is pushed, + and you can use this option to take a crash dump. + +============================================================== + panic_on_oops: Controls the kernel's behaviour when an oops or BUG is encountered. @@ -745,6 +760,14 @@ rtsig-nr shows the number of RT signals currently queued. ============================================================== +sched_schedstats: + +Enables/disables scheduler statistics. Enabling this feature +incurs a small amount of overhead in the scheduler but is +useful for debugging and performance tuning. + +============================================================== + sg-big-buff: This file shows the size of the generic SCSI (sg) buffer. @@ -810,14 +833,13 @@ via the /proc/sys interface: Each write syscall must fully contain the sysctl value to be written, and multiple writes on the same sysctl file descriptor will rewrite the sysctl value, regardless of file position. - 0 - (default) Same behavior as above, but warn about processes that - perform writes to a sysctl file descriptor when the file position - is not 0. - 1 - Respect file position when writing sysctl strings. Multiple writes - will append to the sysctl value buffer. Anything past the max length - of the sysctl value buffer will be ignored. Writes to numeric sysctl - entries must always be at file position 0 and the value must be - fully contained in the buffer sent in the write syscall. + 0 - Same behavior as above, but warn about processes that perform writes + to a sysctl file descriptor when the file position is not 0. + 1 - (default) Respect file position when writing sysctl strings. Multiple + writes will append to the sysctl value buffer. Anything past the max + length of the sysctl value buffer will be ignored. Writes to numeric + sysctl entries must always be at file position 0 and the value must + be fully contained in the buffer sent in the write syscall. ============================================================== diff --git a/Documentation/sysctl/vm.txt b/Documentation/sysctl/vm.txt index f72370b44..89a887c76 100644 --- a/Documentation/sysctl/vm.txt +++ b/Documentation/sysctl/vm.txt @@ -42,6 +42,8 @@ Currently, these files are in /proc/sys/vm: - min_slab_ratio - min_unmapped_ratio - mmap_min_addr +- mmap_rnd_bits +- mmap_rnd_compat_bits - nr_hugepages - nr_overcommit_hugepages - nr_trim_pages (only if CONFIG_MMU=n) @@ -135,7 +137,7 @@ Contains, as a percentage of total available memory that contains free pages and reclaimable pages, the number of pages at which the background kernel flusher threads will start writing out dirty data. -The total avaiable memory is not equal to total system memory. +The total available memory is not equal to total system memory. ============================================================== @@ -170,7 +172,7 @@ Contains, as a percentage of total available memory that contains free pages and reclaimable pages, the number of pages at which a process which is generating disk writes will itself start writing out dirty data. -The total avaiable memory is not equal to total system memory. +The total available memory is not equal to total system memory. ============================================================== @@ -485,6 +487,33 @@ against future potential kernel bugs. ============================================================== +mmap_rnd_bits: + +This value can be used to select the number of bits to use to +determine the random offset to the base address of vma regions +resulting from mmap allocations on architectures which support +tuning address space randomization. This value will be bounded +by the architecture's minimum and maximum supported values. + +This value can be changed after boot using the +/proc/sys/vm/mmap_rnd_bits tunable + +============================================================== + +mmap_rnd_compat_bits: + +This value can be used to select the number of bits to use to +determine the random offset to the base address of vma regions +resulting from mmap allocations for applications run in +compatibility mode on architectures which support tuning address +space randomization. This value will be bounded by the +architecture's minimum and maximum supported values. + +This value can be changed after boot using the +/proc/sys/vm/mmap_rnd_compat_bits tunable + +============================================================== + nr_hugepages Change the minimum size of the hugepage pool. |