diff options
Diffstat (limited to 'Documentation/sysctl')
-rw-r--r-- | Documentation/sysctl/kernel.txt | 50 |
1 files changed, 40 insertions, 10 deletions
diff --git a/Documentation/sysctl/kernel.txt b/Documentation/sysctl/kernel.txt index ccd42589e124..ab7d16efa96b 100644 --- a/Documentation/sysctl/kernel.txt +++ b/Documentation/sysctl/kernel.txt | |||
@@ -70,12 +70,12 @@ show up in /proc/sys/kernel: | |||
70 | - shmall | 70 | - shmall |
71 | - shmmax [ sysv ipc ] | 71 | - shmmax [ sysv ipc ] |
72 | - shmmni | 72 | - shmmni |
73 | - softlockup_thresh | ||
74 | - stop-a [ SPARC only ] | 73 | - stop-a [ SPARC only ] |
75 | - sysrq ==> Documentation/sysrq.txt | 74 | - sysrq ==> Documentation/sysrq.txt |
76 | - tainted | 75 | - tainted |
77 | - threads-max | 76 | - threads-max |
78 | - unknown_nmi_panic | 77 | - unknown_nmi_panic |
78 | - watchdog_thresh | ||
79 | - version | 79 | - version |
80 | 80 | ||
81 | ============================================================== | 81 | ============================================================== |
@@ -427,6 +427,32 @@ This file shows up if CONFIG_DEBUG_STACKOVERFLOW is enabled. | |||
427 | 427 | ||
428 | ============================================================== | 428 | ============================================================== |
429 | 429 | ||
430 | perf_cpu_time_max_percent: | ||
431 | |||
432 | Hints to the kernel how much CPU time it should be allowed to | ||
433 | use to handle perf sampling events. If the perf subsystem | ||
434 | is informed that its samples are exceeding this limit, it | ||
435 | will drop its sampling frequency to attempt to reduce its CPU | ||
436 | usage. | ||
437 | |||
438 | Some perf sampling happens in NMIs. If these samples | ||
439 | unexpectedly take too long to execute, the NMIs can become | ||
440 | stacked up next to each other so much that nothing else is | ||
441 | allowed to execute. | ||
442 | |||
443 | 0: disable the mechanism. Do not monitor or correct perf's | ||
444 | sampling rate no matter how CPU time it takes. | ||
445 | |||
446 | 1-100: attempt to throttle perf's sample rate to this | ||
447 | percentage of CPU. Note: the kernel calculates an | ||
448 | "expected" length of each sample event. 100 here means | ||
449 | 100% of that expected length. Even if this is set to | ||
450 | 100, you may still see sample throttling if this | ||
451 | length is exceeded. Set to 0 if you truly do not care | ||
452 | how much CPU is consumed. | ||
453 | |||
454 | ============================================================== | ||
455 | |||
430 | 456 | ||
431 | pid_max: | 457 | pid_max: |
432 | 458 | ||
@@ -604,15 +630,6 @@ without users and with a dead originative process will be destroyed. | |||
604 | 630 | ||
605 | ============================================================== | 631 | ============================================================== |
606 | 632 | ||
607 | softlockup_thresh: | ||
608 | |||
609 | This value can be used to lower the softlockup tolerance threshold. The | ||
610 | default threshold is 60 seconds. If a cpu is locked up for 60 seconds, | ||
611 | the kernel complains. Valid values are 1-60 seconds. Setting this | ||
612 | tunable to zero will disable the softlockup detection altogether. | ||
613 | |||
614 | ============================================================== | ||
615 | |||
616 | tainted: | 633 | tainted: |
617 | 634 | ||
618 | Non-zero if the kernel has been tainted. Numeric values, which | 635 | Non-zero if the kernel has been tainted. Numeric values, which |
@@ -648,3 +665,16 @@ that time, kernel debugging information is displayed on console. | |||
648 | 665 | ||
649 | NMI switch that most IA32 servers have fires unknown NMI up, for | 666 | NMI switch that most IA32 servers have fires unknown NMI up, for |
650 | example. If a system hangs up, try pressing the NMI switch. | 667 | example. If a system hangs up, try pressing the NMI switch. |
668 | |||
669 | ============================================================== | ||
670 | |||
671 | watchdog_thresh: | ||
672 | |||
673 | This value can be used to control the frequency of hrtimer and NMI | ||
674 | events and the soft and hard lockup thresholds. The default threshold | ||
675 | is 10 seconds. | ||
676 | |||
677 | The softlockup threshold is (2 * watchdog_thresh). Setting this | ||
678 | tunable to zero will disable lockup detection altogether. | ||
679 | |||
680 | ============================================================== | ||