lkml.org 
[lkml]   [2001]   [Aug]   [19]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
From
Date

> $ cat /proc/interrupts
> CPU0
> 0: 1116302985 XT-PIC timer
> 1: 2 XT-PIC keyboard
> 2: 0 XT-PIC cascade
> 8: 1 XT-PIC rtc
> 9: 28980016 XT-PIC usb-uhci, eth0
> 14: 698146587 XT-PIC ide0
> 15: 5 XT-PIC ide1
> NMI: 0
> ERR: 0
>
> Shock horror - I can continually poll this and spot
> when an IRQ occurs.

To what level of accuracy do you think you can measure when interrupts
occur? From my tests, you can (if you max the processor and do no math on
the results) read /proc/interrupts about once every 30,000 instruction
cycles. This would still leave about 14 bits of entropy in each interrupt.

Overall, you're just making the system busier.

DS

-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/

\
 
 \ /
  Last update: 2005-03-22 12:57    [W:0.080 / U:0.172 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site