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author | Benno Schulenberg | 2011-08-03 15:35:23 +0200 |
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committer | Karel Zak | 2011-08-08 11:58:51 +0200 |
commit | a92eea152b30880d208f84be069fb1068e752bfe (patch) | |
tree | 598e4772ddff4e9cd7f205fe8db723d6ddb28369 | |
parent | taskset: adjust style of man page (diff) | |
download | kernel-qcow2-util-linux-a92eea152b30880d208f84be069fb1068e752bfe.tar.gz kernel-qcow2-util-linux-a92eea152b30880d208f84be069fb1068e752bfe.tar.xz kernel-qcow2-util-linux-a92eea152b30880d208f84be069fb1068e752bfe.zip |
ionice: slightly improve grammar, spacing and consistency of man page
Signed-off-by: Benno Schulenberg <bensberg@justemail.net>
-rw-r--r-- | schedutils/ionice.1 | 72 |
1 files changed, 35 insertions, 37 deletions
diff --git a/schedutils/ionice.1 b/schedutils/ionice.1 index f2219535e..c6f0b47d7 100644 --- a/schedutils/ionice.1 +++ b/schedutils/ionice.1 @@ -21,78 +21,76 @@ PID .IR COMMAND [ ARG ]... .SH DESCRIPTION -This program sets or gets the io scheduling class and priority for a program. +This program sets or gets the I/O scheduling class and priority for a program. If no arguments or just \fB\-p\fR is given, \fBionice\fR will query the current -io scheduling class and priority for that process. +I/O scheduling class and priority for that process. -If no class is given than +If no class is given, then .I COMMAND -will be executed with "best-effort" scheduling class. The default +will be executed with the "best-effort" scheduling class. The default priority argument is 4. As of this writing, a process can be in one of three scheduling classes: .IP "\fBIdle\fP" -A program running with idle io priority will only get disk time when no other -program has asked for disk io for a defined grace period. The impact of idle -io processes on normal system activity should be zero. This scheduling -class does not take a priority argument. Presently, this scheduling class +A program running with idle I/O priority will only get disk time when no other +program has asked for disk I/O for a defined grace period. The impact of an +idle I/O process on normal system activity should be zero. This scheduling +class does not take a priority argument. Presently, this scheduling class is permitted for an ordinary user (since kernel 2.6.25). .IP "\fBBest-effort\fP" This is the effective scheduling class for any process that has not asked for -a specific io priority. -This class takes a priority argument from \fI0-7\fR, with lower -number being higher priority. Programs running at the same best effort +a specific I/O priority. +This class takes a priority argument from \fI0-7\fR, with a lower +number being higher priority. Programs running at the same best-effort priority are served in a round-robin fashion. -Note that before kernel 2.6.26 a process that has not asked for an io priority -formally uses "\fBnone\fP" as scheduling class, but the io scheduler will treat -such processes as if it were in the best effort class. The priority within the -best effort class will be dynamically derived from the cpu nice level of the +Note that before kernel 2.6.26 a process that has not asked for an I/O priority +formally uses "\fBnone\fP" as scheduling class, but the I/O scheduler will treat +such processes as if it were in the best-effort class. The priority within the +best-effort class will be dynamically derived from the CPU nice level of the process: io_priority = (cpu_nice + 20) / 5. -For kernels after 2.6.26 with CFQ io scheduler a process that has not asked for -an io priority inherits CPU scheduling class. The io priority is derived from -the cpu nice level of the process (same as before kernel 2.6.26). +For kernels after 2.6.26 with the CFQ I/O scheduler, a process that has not asked +for an I/O priority inherits its CPU scheduling class. The I/O priority is derived +from the CPU nice level of the process (same as before kernel 2.6.26). .IP "\fBRealtime\fP" The RT scheduling class is given first access to the disk, regardless of -what else is going on in the system. Thus the RT class needs to be used with -some care, as it can starve other processes. As with the best effort class, +what else is going on in the system. Thus the RT class needs to be used with +some care, as it can starve other processes. As with the best-effort class, 8 priority levels are defined denoting how big a time slice a given process -will receive on each scheduling window. This scheduling class is not +will receive on each scheduling window. This scheduling class is not permitted for an ordinary (i.e., non-root) user. .SH OPTIONS .TP \fB\-c\fR, \fB\-\-class\fR \fICLASS\fR -The scheduling class name or number. \fI0\fR for none, \fI1\fR for realtime, \fI2\fR for +The scheduling class name or number; \fI0\fR for none, \fI1\fR for realtime, \fI2\fR for best-effort, \fI3\fR for idle. .TP \fB\-n\fR, \fB\-\-classdata\fR \fINUM\fR -The scheduling class data. This defines the class data, if the class -accepts an argument. For real time and best-effort, \fI0-7\fR is valid -data. +The scheduling class data. This defines the class data, if the class +accepts an argument. For realtime and best-effort, \fI0-7\fR is valid data. .TP \fB\-p\fR, \fB\-\-pid\fR \fIPID\fR -Pass in process PID(s) to view or change already running processes. If this argument -is not given, \fBionice\fP will run the listed program with the given -parameters. +Pass in process PID(s) to view or change already running processes. If this argument +is not given, \fBionice\fP will run the listed program with the given parameters. .TP \fB\-t\fR, \fB\-\-ignore\fR -Ignore failure to set requested priority. If COMMAND or PID(s) is specified, run it -even in case it was not possible to set desired scheduling priority, what -can happen due to insufficient privileges or old kernel version. -.TP -\fB\-V\fR, \fB\-\-version\fR -Output version information and exit. +Ignore failure to set the requested priority. If COMMAND or PID(s) is specified, +run it even in case it was not possible to set the desired scheduling priority, +which can happen due to insufficient privileges or an old kernel version. .TP \fB\-h\fR, \fB\-\-help\fR Display help and exit. +.TP +\fB\-V\fR, \fB\-\-version\fR +Display version information and exit. .SH EXAMPLES .LP .TP 7 # \fBionice\fP -c 3 -p 89 .TP 7 -Sets process with PID 89 as an idle io process. +Sets process with PID 89 as an idle I/O process. .TP 7 # \fBionice\fP -c 2 -n 0 bash .TP 7 @@ -102,8 +100,8 @@ Runs 'bash' as a best-effort program with highest priority. .TP 7 Prints the class and priority of the processes with PID 89 and 91. .SH NOTES -Linux supports io scheduling priorities and classes since 2.6.13 with the CFQ -io scheduler. +Linux supports I/O scheduling priorities and classes since 2.6.13 with the CFQ +I/O scheduler. .SH AUTHORS .nf Jens Axboe <jens@axboe.dk> |