diff options
Diffstat (limited to 'Documentation/sysctl')
| -rw-r--r-- | Documentation/sysctl/00-INDEX | 16 | ||||
| -rw-r--r-- | Documentation/sysctl/fs.txt | 28 | ||||
| -rw-r--r-- | Documentation/sysctl/kernel.txt | 35 | ||||
| -rw-r--r-- | Documentation/sysctl/net.txt | 8 | ||||
| -rw-r--r-- | Documentation/sysctl/vm.txt | 21 |
5 files changed, 82 insertions, 26 deletions
diff --git a/Documentation/sysctl/00-INDEX b/Documentation/sysctl/00-INDEX deleted file mode 100644 index 8cf5d493fd03..000000000000 --- a/Documentation/sysctl/00-INDEX +++ /dev/null @@ -1,16 +0,0 @@ -00-INDEX - - this file. -README - - general information about /proc/sys/ sysctl files. -abi.txt - - documentation for /proc/sys/abi/*. -fs.txt - - documentation for /proc/sys/fs/*. -kernel.txt - - documentation for /proc/sys/kernel/*. -net.txt - - documentation for /proc/sys/net/*. -sunrpc.txt - - documentation for /proc/sys/sunrpc/*. -vm.txt - - documentation for /proc/sys/vm/*. diff --git a/Documentation/sysctl/fs.txt b/Documentation/sysctl/fs.txt index 819caf8ca05f..ebc679bcb2dc 100644 --- a/Documentation/sysctl/fs.txt +++ b/Documentation/sysctl/fs.txt @@ -56,26 +56,34 @@ of any kernel data structures. dentry-state: -From linux/fs/dentry.c: +From linux/include/linux/dcache.h: -------------------------------------------------------------- -struct { +struct dentry_stat_t dentry_stat { int nr_dentry; int nr_unused; int age_limit; /* age in seconds */ int want_pages; /* pages requested by system */ - int dummy[2]; -} dentry_stat = {0, 0, 45, 0,}; --------------------------------------------------------------- - -Dentries are dynamically allocated and deallocated, and -nr_dentry seems to be 0 all the time. Hence it's safe to -assume that only nr_unused, age_limit and want_pages are -used. Nr_unused seems to be exactly what its name says. + int nr_negative; /* # of unused negative dentries */ + int dummy; /* Reserved for future use */ +}; +-------------------------------------------------------------- + +Dentries are dynamically allocated and deallocated. + +nr_dentry shows the total number of dentries allocated (active ++ unused). nr_unused shows the number of dentries that are not +actively used, but are saved in the LRU list for future reuse. + Age_limit is the age in seconds after which dcache entries can be reclaimed when memory is short and want_pages is nonzero when shrink_dcache_pages() has been called and the dcache isn't pruned yet. +nr_negative shows the number of unused dentries that are also +negative dentries which do not map to any files. Instead, +they help speeding up rejection of non-existing files provided +by the users. + ============================================================== dquot-max & dquot-nr: diff --git a/Documentation/sysctl/kernel.txt b/Documentation/sysctl/kernel.txt index 37a679501ddc..c0527d8a468a 100644 --- a/Documentation/sysctl/kernel.txt +++ b/Documentation/sysctl/kernel.txt @@ -60,6 +60,7 @@ show up in /proc/sys/kernel: - panic_on_stackoverflow - panic_on_unrecovered_nmi - panic_on_warn +- panic_print - panic_on_rcu_stall - perf_cpu_time_max_percent - perf_event_paranoid @@ -89,6 +90,7 @@ show up in /proc/sys/kernel: - shmmni - softlockup_all_cpu_backtrace - soft_watchdog +- stack_erasing - stop-a [ SPARC only ] - sysrq ==> Documentation/admin-guide/sysrq.rst - sysctl_writes_strict @@ -653,6 +655,22 @@ a kernel rebuild when attempting to kdump at the location of a WARN(). ============================================================== +panic_print: + +Bitmask for printing system info when panic happens. User can chose +combination of the following bits: + +bit 0: print all tasks info +bit 1: print system memory info +bit 2: print timer info +bit 3: print locks info if CONFIG_LOCKDEP is on +bit 4: print ftrace buffer + +So for example to print tasks and memory info on panic, user can: + echo 3 > /proc/sys/kernel/panic_print + +============================================================== + panic_on_rcu_stall: When set to 1, calls panic() after RCU stall detection messages. This @@ -987,6 +1005,23 @@ detect a hard lockup condition. ============================================================== +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. + +That erasing reduces the information which kernel stack leak bugs +can reveal and blocks some uninitialized stack variable attacks. +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. + + 1: kernel stack erasing is enabled (default), it is performed before + returning to the userspace at the end of syscalls. + +============================================================== + tainted: Non-zero if the kernel has been tainted. Numeric values, which can be diff --git a/Documentation/sysctl/net.txt b/Documentation/sysctl/net.txt index 9ecde517728c..2793d4eac55f 100644 --- a/Documentation/sysctl/net.txt +++ b/Documentation/sysctl/net.txt @@ -92,6 +92,14 @@ Values : 0 - disable JIT kallsyms export (default value) 1 - enable JIT kallsyms export for privileged users only +bpf_jit_limit +------------- + +This enforces a global limit for memory allocations to the BPF JIT +compiler in order to reject unprivileged JIT requests once it has +been surpassed. bpf_jit_limit contains the value of the global limit +in bytes. + dev_weight -------------- diff --git a/Documentation/sysctl/vm.txt b/Documentation/sysctl/vm.txt index 7d73882e2c27..187ce4f599a2 100644 --- a/Documentation/sysctl/vm.txt +++ b/Documentation/sysctl/vm.txt @@ -63,6 +63,7 @@ Currently, these files are in /proc/sys/vm: - swappiness - user_reserve_kbytes - vfs_cache_pressure +- watermark_boost_factor - watermark_scale_factor - zone_reclaim_mode @@ -856,6 +857,26 @@ ten times more freeable objects than there are. ============================================================= +watermark_boost_factor: + +This factor controls the level of reclaim when memory is being fragmented. +It defines the percentage of the high watermark of a zone that will be +reclaimed if pages of different mobility are being mixed within pageblocks. +The intent is that compaction has less work to do in the future and to +increase the success rate of future high-order allocations such as SLUB +allocations, THP and hugetlbfs pages. + +To make it sensible with respect to the watermark_scale_factor parameter, +the unit is in fractions of 10,000. The default value of 15,000 means +that up to 150% of the high watermark will be reclaimed in the event of +a pageblock being mixed due to fragmentation. The level of reclaim is +determined by the number of fragmentation events that occurred in the +recent past. If this value is smaller than a pageblock then a pageblocks +worth of pages will be reclaimed (e.g. 2MB on 64-bit x86). A boost factor +of 0 will disable the feature. + +============================================================= + watermark_scale_factor: This factor controls the aggressiveness of kswapd. It defines the |