X-Git-Url: https://git.saurik.com/apple/system_cmds.git/blobdiff_plain/709a58224ea43109dc10bfd6a67de1e432174197..34d340d711a2b033f5da480ed7b5eb147679a588:/latency.tproj/latency.1 diff --git a/latency.tproj/latency.1 b/latency.tproj/latency.1 index 94ce927..8978522 100644 --- a/latency.tproj/latency.1 +++ b/latency.tproj/latency.1 @@ -9,8 +9,8 @@ .Sh SYNOPSIS .Nm latency .Op Fl rt -.Op Fl c Ar codefile -.Op Fl l Ar logfile +.Op Fl c Ar code_file +.Op Fl l Ar log_file .Op Fl st Ar threshold .Op Fl it Ar threshold .Op Fl s Ar sleep_in_usecs @@ -19,57 +19,58 @@ .Sh DESCRIPTION The .Nm latency -utility provides scheduling and interrupt latency statistics. -It requires root privileges due to the kernel tracing facility it uses to -operate. +utility provides scheduling and interrupt-latency statistics. +Due to the kernel tracing facility it uses to operate, +the command requires root privileges. .Pp The arguments are as follows: .Bl -tag -width Ds -.It Fl rt -Set real time scheduling policy. -Default policy is timeshare. -.It Fl c +.\" ========== +.It Fl c Ar code_file When the .Fl c -option is specified, it takes a path to a -.Ar codefile +option is specified, it takes a path to a code file that contains the mappings for the system calls. -This option overrides the default location of the system call codefile which is -found in /usr/share/misc/trace.codes. -.It Fl l -Specifies a -.Ar logfile -that is written to when either the interrupt or scheduling latency is exceeded. -.It Fl st -Set the scheduler latency threshold in microseconds. -If latency exceeds this, and a logfile has been specified, a record of what -occurred during this time is recorded. -.It Fl it -Set the interrupt latency threshold in microseconds. -If latency exceeds this, and a logfile has been specified, a record of what -occurred during this time is recorded. -.It Fl s -The -.Fl s -option sets the timer. -It takes microseconds as an argument, the default timer is set to 1000 -microseconds. -.It Fl d -The -.Fl d -option sets the decrementer. -It takes microseconds as an argument. -The decrementer is set back to the system default on exit. -.It Fl n +This option overrides the default location of the system call code file, +which is found in /usr/share/misc/trace.codes. +.\" ========== +.It Fl d Ar decrementer_in_usecs +Sets the decrementer, using a value expressed in microseconds. +On exit, the decrementer is set back to the system default value. +.\" ========== +.It Fl it Ar threshold +Set the interrupt latency threshold, +expressed in microseconds. +If the latency exceeds this value, +and a log file has been specified, +a record of what occurred during this time is recorded. +.\" ========== +.It Fl l Ar log_file +Specifies a log file that is written to when +either the interrupt or scheduling latency is exceeded. +.\" ========== +.It Fl n Ar kernel By default, .Nm latency acts on the default /mach_kernel. This option allows you to specify an alternate booted kernel. +.\" ========== +.It Fl rt +Sets the real-time scheduling policy. +Default policy is timeshare. +.\" ========== +.It Fl s Ar sleep_in_usecs +Sets the timer, taking an argument expressed in microseconds. +The default timer is set to 1000 microseconds. +.\" ========== +.It Fl st Ar threshold +Set the scheduler latency threshold in microseconds. +If latency exceeds this, and a log file has been specified, +a record of what occurred during this time is recorded. .El .Pp The data columns displayed are as follows: -.Bl -tag -width LAST_PATHNAME_WAITED_FOR -compact -.Pp +.Bl -tag -width LAST_PATHNAME_WAITED_FOR .It SCHEDULER The number of context switches that fall within the described delay. .It INTERRUPTS @@ -91,6 +92,6 @@ The threshold for the scheduler is set to 20000 microseconds. The threshold for interrupts is set to 1000 microseconds. Latencies that exceed these thresholds will be logged in /var/tmp/latency.log. .Sh SEE ALSO -.Xr top 1 , .Xr fs_usage 1 , -.Xr sc_usage 1 +.Xr sc_usage 1 , +.Xr top 1