Hi all
This is very weird. A few days ago I started blanking a CD-RW with a
HP9500 IDE drive and after five seconds or so the system froze. I was
still able to ping it and SNAT worked properly too. All services (X,
ssh, smtp) stopped and were almost fully inacessible (I was still able
to see some applets working on X, but no more) and when it finished
blanking, system came back to normal as if nothing had happended.
At the time I thought it might be a 2.4.14 issue.
Today I repeated the test with 2.4.16 w/ preemption patch. The same
thing happened. This time I was running a 'vmstat 1':
....
....
....
0 4 1 50524 3932 2984 46168 0 0 0 0 102 151 0 0 100
0 4 1 50524 3932 2984 46168 0 0 0 0 102 154 0 0 100
0 4 1 50524 3928 2984 46168 0 0 0 0 101 149 0 0 100
0 4 1 50524 3928 2984 46168 0 0 0 0 101 154 0 0 100
1 4 1 50524 3928 2984 46168 0 0 0 0 101 150 0 0 100
0 4 1 50524 3928 2984 46168 0 0 0 0 102 151 0 0 100
0 4 1 50524 3924 2984 46168 0 0 0 0 101 156 0 0 100
0 4 1 50524 3924 2984 46168 0 0 0 0 101 152 0 0 100
0 4 1 50524 3924 2984 46168 0 0 0 0 102 155 0 0 100
0 4 1 50524 3924 2984 46168 0 0 0 0 101 150 0 0 100
0 4 1 50524 3916 2984 46168 0 0 0 0 101 150 0 0 100
0 4 1 50524 3916 2984 46168 0 0 0 0 101 151 0 0 100
when it got here, system froze.... and then:
1 5 1 50584 4216 2820 44996 2348 296 3032 348 113506 165193 0 0 100
1 4 1 50572 11416 3192 37112 348 0 668 596 319 1243 4 3 93
1 1 0 50552 11468 3520 37420 0 0 308 492 315 794 6 3 91
1 0 0 50552 11068 3544 37596 0 0 168 4 127 9301 65 6 29
1 0 0 50552 11064 3544 37596 0 0 0 0 104 652 75 0 25
2 0 0 50552 11064 3544 37596 0 0 0 0 102 604 75 0 25
1 0 procs memory swap io system
cpu
r b w swpd free buff cache si so bi bo in cs us sy id
1 0 1 50552 10992 3616 37596 0 0 0 140 154 721 75 1 25
2 0 0 50552 10992 3616 37596 0 0 0 32 118 679 75 0 25
1 0 0 50552 10988 3616 37596 0 0 0 0 101 610 75 0 25
1 0 0 50552 10988 3616 37596 0 0 0 0 102 602 74 0 26
0 0 0 50552 10104 3652 37664 220 0 308 0 139 741 47 1 52
0 0 0 50552 10104 3652 37664 0 0 0 0 107 491 0 0 100
0 0 0 50552 10012 3744 37664 0 0 0 160 155 598 1 0 99
0 0 0 50552 10320 3744 37704 32 0 84 0 181 1078 18 2 80
0 0 0 50552 10284 3780 37704 0 0 0 44 250 834 1 2 97
What is happening here ? Any clues ???
?lvaro Lopes
Well, did some sysrq show tasks while blanking and found processes
locked (D) in:
sleep_on()
wait_on_buffer()
lock_page()
___wait_on_page()
I issued a ^C to cdrecord but blanking kept on. System resumed normal
operation after end of blanking.
BTW I'm using ReiserFS .
?lvaro
On Qui, 2001-11-29 at 15:17, Alvaro Lopes wrote:
> Hi all
>
> This is very weird. A few days ago I started blanking a CD-RW with a
> HP9500 IDE drive and after five seconds or so the system froze. I was
> still able to ping it and SNAT worked properly too. All services (X,
> ssh, smtp) stopped and were almost fully inacessible (I was still able
> to see some applets working on X, but no more) and when it finished
> blanking, system came back to normal as if nothing had happended.
>
> At the time I thought it might be a 2.4.14 issue.
>
> Today I repeated the test with 2.4.16 w/ preemption patch. The same
> thing happened. This time I was running a 'vmstat 1':
>
> ....
> ....
> ....
> 0 4 1 50524 3932 2984 46168 0 0 0 0 102 151 0 0 100
> 0 4 1 50524 3932 2984 46168 0 0 0 0 102 154 0 0 100
> 0 4 1 50524 3928 2984 46168 0 0 0 0 101 149 0 0 100
> 0 4 1 50524 3928 2984 46168 0 0 0 0 101 154 0 0 100
> 1 4 1 50524 3928 2984 46168 0 0 0 0 101 150 0 0 100
> 0 4 1 50524 3928 2984 46168 0 0 0 0 102 151 0 0 100
> 0 4 1 50524 3924 2984 46168 0 0 0 0 101 156 0 0 100
> 0 4 1 50524 3924 2984 46168 0 0 0 0 101 152 0 0 100
> 0 4 1 50524 3924 2984 46168 0 0 0 0 102 155 0 0 100
> 0 4 1 50524 3924 2984 46168 0 0 0 0 101 150 0 0 100
> 0 4 1 50524 3916 2984 46168 0 0 0 0 101 150 0 0 100
> 0 4 1 50524 3916 2984 46168 0 0 0 0 101 151 0 0 100
>
> when it got here, system froze.... and then:
>
> 1 5 1 50584 4216 2820 44996 2348 296 3032 348 113506 165193 0 0 100
> 1 4 1 50572 11416 3192 37112 348 0 668 596 319 1243 4 3 93
> 1 1 0 50552 11468 3520 37420 0 0 308 492 315 794 6 3 91
> 1 0 0 50552 11068 3544 37596 0 0 168 4 127 9301 65 6 29
> 1 0 0 50552 11064 3544 37596 0 0 0 0 104 652 75 0 25
> 2 0 0 50552 11064 3544 37596 0 0 0 0 102 604 75 0 25
> 1 0 procs memory swap io system
> cpu
> r b w swpd free buff cache si so bi bo in cs us sy id
> 1 0 1 50552 10992 3616 37596 0 0 0 140 154 721 75 1 25
> 2 0 0 50552 10992 3616 37596 0 0 0 32 118 679 75 0 25
> 1 0 0 50552 10988 3616 37596 0 0 0 0 101 610 75 0 25
> 1 0 0 50552 10988 3616 37596 0 0 0 0 102 602 74 0 26
> 0 0 0 50552 10104 3652 37664 220 0 308 0 139 741 47 1 52
> 0 0 0 50552 10104 3652 37664 0 0 0 0 107 491 0 0 100
> 0 0 0 50552 10012 3744 37664 0 0 0 160 155 598 1 0 99
> 0 0 0 50552 10320 3744 37704 32 0 84 0 181 1078 18 2 80
> 0 0 0 50552 10284 3780 37704 0 0 0 44 250 834 1 2 97
>
>
> What is happening here ? Any clues ???
>
> ?lvaro Lopes
>
>
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On Thu, Nov 29 2001, Alvaro Lopes wrote:
> Well, did some sysrq show tasks while blanking and found processes
> locked (D) in:
>
> sleep_on()
> wait_on_buffer()
> lock_page()
> ___wait_on_page()
>
>
> I issued a ^C to cdrecord but blanking kept on. System resumed normal
> operation after end of blanking.
Those processes are likely waiting for I/O to complete (well start,
even) on a disk that is on the same channel as the cd drive doing the
blank command. If the program you are using to do the blank is not using
the IMMED bit, you will be stuck waiting for the command to complete
(ATA has no real disconnect).
--
Jens Axboe