10 More Discussions You Might Find Interesting
1. Red Hat
Hello,
I have a problem in my server:
HP ProLiant DL580 G5
My OS is REDHAT 4.6
I have an error when I start the server:
Badness in do_unblank_screen at drivers/char/vt.c:2878
...
Your time source seems to be instable or some driver is hogging interupts
rip __smp_call_function +... (1 Reply)
Discussion started by: markke
1 Replies
2. UNIX for Advanced & Expert Users
Hi
I added a new user using root... now i need to enable sqlplus for that particular user... when i give sqlplus schemaname/pwd it gives
$ sqlplus
-bash: sqlplus: command not found
PFB the OS am using
$ uname -a
Linux gs-portal-04 2.4.21-57.ELsmp #1 SMP Wed Apr 23... (4 Replies)
Discussion started by: Whiteboard
4 Replies
3. UNIX for Dummies Questions & Answers
hi
I am very new to UNIX.
I need to retrieve data from a unix system and store it and display as output on a windows system.
Initiation of procedure is through JAVASCRIPT-based buttons on a HTML page.
This should cause a set of commands to run which colllect data from a unix based server and... (1 Reply)
Discussion started by: rossalyn_maxter
1 Replies
4. UNIX for Dummies Questions & Answers
how can I let a regular user enable a printer? (0 Replies)
Discussion started by: naes
0 Replies
5. UNIX for Advanced & Expert Users
Does anyone know some support issues on unix? I've worked on unix for years at the lower end and the only support I've done is reset print queues, send jobs to printer, kill phantom processes. I'm looking for a new job and I'm curious as to what other problems occur so I can research them. (1 Reply)
Discussion started by: moodswingz
1 Replies
6. UNIX for Dummies Questions & Answers
Hello all! My boss wants we to learn a little bit of Unix in the next couple of months so I can broaden my opportunities. What processors will Unix run on? Intel... AMD32.... AMD64... Help Please. I need to build a computer that can support Unix to begin learning. Thanks (3 Replies)
Discussion started by: hkypro7
3 Replies
7. UNIX for Dummies Questions & Answers
I am very new to Unix. We have a Unix user account that was disabled due to multiple tries with an invalid password. How to enable the account? (1 Reply)
Discussion started by: kajap
1 Replies
8. SuSE
I have a ATI Radeon 9600 Pro gfx card and was trying to figure out how to enable 3d support in linux. I had downloaded the ATI driver before and installed it and I ended up having to reinstall linux because it told me I was supposed to do something to some file that I didn't do so it restarted and... (3 Replies)
Discussion started by: CTroxtell21
3 Replies
9. UNIX for Dummies Questions & Answers
If the strength of Unix based operating systems such as Linux and Red Hat are based on the fact that they are open-source. Who will provide support for personal computers or average users that uses these operating systems. Wouldn't the absence of some structured and formal support system inhibit... (8 Replies)
Discussion started by: wmosley2
8 Replies
10. UNIX for Dummies Questions & Answers
Hello guys, I am in desperate need for this information:
I have an apache server running on linux (suse 8.1)
I am unable to run php or java code on it, and I wonder what is wrong.
for the php case, the browser asks me how he should treat the file, namely download it to my local drive or... (5 Replies)
Discussion started by: bionicfysh
5 Replies
EVENTTIMERS(4) BSD Kernel Interfaces Manual EVENTTIMERS(4)
NAME
eventtimers -- kernel event timers subsystem
SYNOPSIS
Kernel uses several types of time-related devices, such as: real time clocks, time counters and event timers. Real time clocks responsible
for tracking real world time, mostly when system is down. Time counters are responsible for generation of monotonically increasing time-
stamps for precise uptime tracking purposes, when system is running. Event timers are responsible for generating interrupts at specified
time or periodically, to run different time-based events. This page is about the last.
DESCRIPTION
Kernel uses time-based events for many different purposes: scheduling, statistics, time keeping, profiling and many other things, based on
callout(9) mechanism. These purposes now grouped into three main callbacks:
hardclock() callout(9) and timekeeping events entry. Called with frequency defined by hz variable, usually 1000Hz.
statclock() statistics and scheduler events entry. Called with frequency about 128Hz.
profclock() profiler events entry. When enabled, called with frequency about 8KHz.
Different platforms provide different kinds of timer hardware. The goal of the event timers subsystem is to provide unified way to control
that hardware, and to use it, supplying kernel with all required time-based events.
Each driver implementing event timers, registers them at the subsystem. It is possible to see the list of present event timers, like this,
via kern.eventtimer sysctl:
kern.eventtimer.choice: HPET(550) LAPIC(400) i8254(100) RTC(0)
kern.eventtimer.et.LAPIC.flags: 15
kern.eventtimer.et.LAPIC.frequency: 0
kern.eventtimer.et.LAPIC.quality: 400
kern.eventtimer.et.i8254.flags: 1
kern.eventtimer.et.i8254.frequency: 1193182
kern.eventtimer.et.i8254.quality: 100
kern.eventtimer.et.RTC.flags: 17
kern.eventtimer.et.RTC.frequency: 32768
kern.eventtimer.et.RTC.quality: 0
kern.eventtimer.et.HPET.flags: 7
kern.eventtimer.et.HPET.frequency: 14318180
kern.eventtimer.et.HPET.quality: 550
where:
kern.eventtimer.et.X.flags is a bitmask, defining event timer capabilities:
1 periodic mode supported,
2 one-shot mode supported,
4 timer is per-CPU,
8 timer may stop when CPU goes to sleep state,
16 timer supports only power-of-2 divisors.
kern.eventtimer.et.X.frequency is a timer base frequency,
kern.eventtimer.et.X.quality is an integral value, defining how good is this timer, comparing to others.
Timers management code of the kernel chooses one timer from that list. Current choice can be read and affected via kern.eventtimer.timer
tunable/sysctl. Several other tunables/sysctls are affecting how exactly this timer is used:
kern.eventtimer.periodic allows to choose periodic and one-shot operation mode. In periodic mode, periodic interrupts from timer hardware
are taken as the only source of time for time events. One-shot mode instead uses currently selected time counter to precisely schedule all
needed events and programs event timer to generate interrupt exactly in specified time. Default value depends of chosen timer capabilities,
but one-shot mode is preferred, until other is forced by user or hardware.
kern.eventtimer.singlemul in periodic mode specifies how much times higher timer frequency should be, to not strictly alias hardclock() and
statclock() events. Default values are 1, 2 or 4, depending on configured HZ value.
kern.eventtimer.idletick makes each CPU to receive every timer interrupt independently of whether they busy or not. By default this options
is disabled. If chosen timer is per-CPU and runs in periodic mode, this option has no effect - all interrupts are always generating.
SEE ALSO
apic(4), atrtc(4), attimer(4), hpet(4), timecounters(4), eventtimers(9)
BSD
March 13, 2012 BSD