Re: scheduler starvation running irman with 2.5.64bk2

Re: scheduler starvation running irman with 2.5.64bk2

[rwhron]

> OK, can you do the following to determine whether we're both seeing the
> _same_ problem?

> 1.)  build the attached rtnice utility (don't remember who wrote/posted this)
> 2.)  login on vt1 and set the shell SCHED_RR via rtnice -n 1 -p <pid_of_sh>
> -d RR
> 3.)  login on vt2 and renice that shell to -10
> 4.)  login on another vt as a normal user, and start irman
> 5.)  try login/out on another vt, or ps or _whatever_ (doesn't matter)
> until box is starving
> 6.)  on vt2, try to do ps (it should hang despite -10 priority)
> 7.)  on vt1, try to do ps (it should work just fine)

Here is the test as I understand it, splitted by tty.  Quick summary, 
only new process seems starved.  RR and nice -10 process behave okay.

BTW, this is now with 2.5.64bk5.

Below shows irman started, and it gets into the PROCESS
load.  Only thing odd here is the PROCESS load never completes.
(or I am not patient enough)

root@mountain:/usr/src/sources/i/irman# tty
/dev/pts/0
root@mountain:/usr/src/sources/i/irman# ./irman
Response time measurements (milliseconds) for: 2.5.64bk5
      Load       Max       Min       Avg Std. Dev.
      NULL     0.177     0.022     0.026     0.003
    MEMORY  1074.825     0.020     0.044     1.424
   FILE_IO   408.013     0.016     0.039     2.469


This is the RR shell.  It functions okay throughout the 
irman run.

root@mountain:~# tty
/dev/pts/1
root@mountain:~# rtnice -n 1 -p $$ -d RR
root@mountain:~# uptime
 18:46:33  up 8 min,  3 users,  load average: 3.21, 2.06, 0.89


This is the nice -10 shell.  It does okay too.

root@mountain:~# tty
/dev/pts/2
root@mountain:~# renice -10 $$
787: old priority 0, new priority -10
root@mountain:~# uptime
 18:45:18  up 7 min,  3 users,  load average: 3.39, 1.76, 0.70
root@mountain:~# uptime
 18:50:19  up 12 min,  3 users,  load average: 3.88, 2.98, 1.50
root@mountain:~# ps aux
USER       PID %CPU %MEM   VSZ  RSS TTY      STAT START   TIME COMMAND
root         1  0.5  0.0  1312  100 ?        S    18:37   0:04 init [3]
root         2  0.0  0.0     0    0 ?        SWN  18:37   0:00 [ksoftirqd/0]
root         3  0.0  0.0     0    0 ?        SW<  18:37   0:00 [events/0]
root         4  0.0  0.0     0    0 ?        SW   18:37   0:00 [pdflush]
root         5  0.0  0.0     0    0 ?        SW   18:37   0:00 [pdflush]
root         6  0.2  0.0     0    0 ?        SW   18:37   0:02 [kswapd0]
root         7  0.0  0.0     0    0 ?        SW<  18:37   0:00 [aio/0]
root       326  0.0  0.0     0    0 ?        SW   18:37   0:00 [eth0]
root       396  0.0  0.0  1368   92 ?        S    18:37   0:00 syslogd -m 0
root       401  0.0  0.0  1300   48 ?        S    18:37   0:00 klogd -x
rpc        421  0.0  0.0  1444   40 ?        S    18:37   0:00 portmap
root       534  0.0  0.0  2568  224 ?        S    18:37   0:00 /usr/sbin/sshd
root       544  0.0  0.0  1284   44 tty1     S    18:37   0:00 /sbin/mingetty tty1
root       545  0.0  0.0  1300   44 ttyS1    S    18:37   0:00 /sbin/agetty -h ttyS1 38400 linux
root       548  0.0  0.0  3352  256 ?        S    18:38   0:00 /usr/sbin/sshd
rwhron     549  0.0  0.0  2404   32 pts/0    S    18:38   0:00 -bash
root       593  0.0  0.0  2268   48 pts/0    S    18:38   0:00 su -
root       594  0.0  0.0  2400   32 pts/0    S    18:38   0:00 -bash
root       645  0.0  0.0  3352  300 ?        S    18:38   0:00 /usr/sbin/sshd
rwhron     646  0.0  0.0  2404   32 pts/1    S    18:38   0:00 -bash
root       690  0.0  0.0  2268   48 pts/1    S    18:38   0:00 su -
root       691  0.0  0.1  2400  512 pts/1    S    18:38   0:00 -bash
root       741  0.0  0.0  3352  300 ?        S    18:38   0:00 /usr/sbin/sshd
rwhron     742  0.0  0.0  2404   32 pts/2    S    18:38   0:00 -bash
root       786  0.0  0.0  2268   48 pts/2    S    18:38   0:00 su -
root       787  0.0  0.1  2400  520 pts/2    S<   18:38   0:00 -bash
root       844 23.0  0.0  1460  224 pts/0    R    18:41   2:10 ./irman
root       845  0.0  0.0     0    0 pts/0    Z    18:41   0:00 [irman <defunct>]
root       846  2.1  0.0     0    0 pts/0    Z    18:41   0:12 [irman <defunct>]
root       848  5.9  0.0     0    0 pts/0    Z    18:41   0:32 [mem_load <defunct>]
root       849  2.3  0.0     0    0 pts/0    Z    18:41   0:12 [irman <defunct>]
root       850  0.0  0.0     0    0 pts/0    Z    18:43   0:00 [io_load <defunct>]
root       851  1.7  0.0     0    0 pts/0    Z    18:43   0:07 [irman <defunct>]
root       855  8.9  0.0  1300  324 pts/0    S    18:44   0:32 process_load --processes 10 --recordsize 10000 --injections 2
root       857  7.4  0.0  1288  276 pts/0    S    18:44   0:27 child_process 10000 0 10
root       858  7.9  0.0  1288  276 pts/0    S    18:44   0:28 child_process 10000 3 12
root       859 13.0  0.0  1288  276 pts/0    R    18:44   0:47 child_process 10000 11 14
root       860 13.4  0.0  1288  276 pts/0    S    18:44   0:49 child_process 10000 13 16
root       861  8.0  0.0  1288  276 pts/0    R    18:44   0:29 child_process 10000 15 18
root       862 10.5  0.0  1288  276 pts/0    S    18:44   0:38 child_process 10000 17 20
root       863 11.2  0.0  1288  276 pts/0    S    18:44   0:41 child_process 10000 19 22
root       864  8.7  0.0  1288  276 pts/0    S    18:44   0:31 child_process 10000 21 24
root       865  7.9  0.0  1288  276 pts/0    S    18:44   0:28 child_process 10000 23 26
root       868  0.0  0.0  2568  108 ?        R    18:47   0:00 /usr/sbin/sshd
root       874  0.0  0.1  2544  668 pts/2    R<   18:50   0:00 ps aux


However if I start a new connection, it never gives a prompt.


rwhron@rushmore:~$ ssh mt
..  wait several minutes ... still no prompt.


>From the RR shell, one can see the new PID 876 for the sshd above.

root@mountain:~# ps aux
USER       PID %CPU %MEM   VSZ  RSS TTY      STAT START   TIME COMMAND
root         1  0.4  0.0  1312  100 ?        S    18:37   0:04 init [3]
root         2  0.0  0.0     0    0 ?        SWN  18:37   0:00 [ksoftirqd/0]
root         3  0.0  0.0     0    0 ?        SW<  18:37   0:00 [events/0]
root         4  0.0  0.0     0    0 ?        SW   18:37   0:00 [pdflush]
root         5  0.0  0.0     0    0 ?        SW   18:37   0:00 [pdflush]
root         6  0.2  0.0     0    0 ?        SW   18:37   0:02 [kswapd0]
root         7  0.0  0.0     0    0 ?        SW<  18:37   0:00 [aio/0]
root       326  0.0  0.0     0    0 ?        SW   18:37   0:00 [eth0]
root       396  0.0  0.0  1368   92 ?        S    18:37   0:00 syslogd -m 0
root       401  0.0  0.0  1300   52 ?        S    18:37   0:00 klogd -x
rpc        421  0.0  0.0  1444   44 ?        S    18:37   0:00 portmap
root       534  0.0  0.0  2568  224 ?        S    18:37   0:00 /usr/sbin/sshd
root       544  0.0  0.0  1284   48 tty1     S    18:37   0:00 /sbin/mingetty tty1
root       545  0.0  0.0  1300   48 ttyS1    S    18:37   0:00 /sbin/agetty -h ttyS1 38400 linux
root       548  0.0  0.0  3352  256 ?        S    18:38   0:00 /usr/sbin/sshd
rwhron     549  0.0  0.0  2404   36 pts/0    S    18:38   0:00 -bash
root       593  0.0  0.0  2268   52 pts/0    S    18:38   0:00 su -
root       594  0.0  0.0  2400   36 pts/0    S    18:38   0:00 -bash
root       645  0.0  0.0  3352  304 ?        R    18:38   0:00 /usr/sbin/sshd
rwhron     646  0.0  0.0  2404   36 pts/1    S    18:38   0:00 -bash
root       690  0.0  0.0  2268   52 pts/1    S    18:38   0:00 su -
root       691  0.0  0.1  2400  520 pts/1    S    18:38   0:00 -bash
root       741  0.0  0.0  3352  304 ?        S    18:38   0:00 /usr/sbin/sshd
rwhron     742  0.0  0.0  2404   36 pts/2    S    18:38   0:00 -bash
root       786  0.0  0.0  2268   52 pts/2    S    18:38   0:00 su -
root       787  0.0  0.1  2400  520 pts/2    S<   18:38   0:00 -bash
root       844 18.6  0.0  1460  224 pts/0    R    18:41   2:10 ./irman
root       845  0.0  0.0     0    0 pts/0    Z    18:41   0:00 [irman <defunct>]
root       846  1.7  0.0     0    0 pts/0    Z    18:41   0:12 [irman <defunct>]
root       848  4.8  0.0     0    0 pts/0    Z    18:41   0:32 [mem_load <defunct>]
root       849  1.8  0.0     0    0 pts/0    Z    18:41   0:12 [irman <defunct>]
root       850  0.0  0.0     0    0 pts/0    Z    18:43   0:00 [io_load <defunct>]
root       851  1.3  0.0     0    0 pts/0    Z    18:43   0:07 [irman <defunct>]
root       855  9.0  0.0  1300  324 pts/0    S    18:44   0:45 process_load --processes 10 --recordsize 10000 --injections 2
root       857  7.5  0.0  1288  276 pts/0    S    18:44   0:37 child_process 10000 0 10
root       858  7.9  0.0  1288  276 pts/0    S    18:44   0:39 child_process 10000 3 12
root       859 13.1  0.0  1288  276 pts/0    S    18:44   1:05 child_process 10000 11 14
root       860 13.5  0.0  1288  276 pts/0    R    18:44   1:07 child_process 10000 13 16
root       861  8.0  0.0  1288  276 pts/0    R    18:44   0:40 child_process 10000 15 18
root       862 10.6  0.0  1288  276 pts/0    S    18:44   0:53 child_process 10000 17 20
root       863 11.3  0.0  1288  276 pts/0    S    18:44   0:56 child_process 10000 19 22
root       864  8.8  0.0  1288  276 pts/0    S    18:44   0:43 child_process 10000 21 24
root       865  7.9  0.0  1288  276 pts/0    S    18:44   0:39 child_process 10000 23 26
root       868  0.0  0.0  2568  108 ?        R    18:47   0:00 /usr/sbin/sshd
root       876  0.0  0.0  2568  252 ?        R    18:52   0:00 /usr/sbin/sshd
root       877  0.0  0.1  2544  668 pts/1    R    18:53   0:00 ps aux


This is some info on PID 876 (sshd child):

root@mountain:/proc/876# cat cmdline
/usr/sbin/sshd
root@mountain:/proc/876# cat status
Name:   sshd
State:  R (running)
Tgid:   876
Pid:    876
PPid:   534
TracerPid:      0
Uid:    0       0       0       0
Gid:    0       0       0       0
FDSize: 32
Groups:
VmSize:     2568 kB
VmLck:         0 kB
VmRSS:       252 kB
VmData:      100 kB
VmStk:        12 kB
VmExe:       248 kB
VmLib:      2108 kB
SigPnd: 0000000000000000
ShdPnd: 0000000000000000
SigBlk: 0000000000000000
SigIgn: 8000000000001000
SigCgt: 0000000000000000
CapInh: 0000000000000000
CapPrm: 00000000fffffeff
CapEff: 00000000fffffeff
root@mountain:/proc/876# cat wchan
0
-- 
Randy Hron
http://home.earthlink.net/~rwhron/kernel/bigbox.html

Re: scheduler starvation running irman with 2.5.64bk2

[Mike Galbraith]

At 07:09 PM 3/10/2003 -0500, rwhron@earthlink.net wrote:
> > OK, can you do the following to determine whether we're both seeing the
> > _same_ problem?
>
> > 1.)  build the attached rtnice utility (don't remember who wrote/posted 
> this)
> > 2.)  login on vt1 and set the shell SCHED_RR via rtnice -n 1 -p <pid_of_sh>
> > -d RR
> > 3.)  login on vt2 and renice that shell to -10
> > 4.)  login on another vt as a normal user, and start irman
> > 5.)  try login/out on another vt, or ps or _whatever_ (doesn't matter)
> > until box is starving
> > 6.)  on vt2, try to do ps (it should hang despite -10 priority)
> > 7.)  on vt1, try to do ps (it should work just fine)
>
>Here is the test as I understand it, splitted by tty.  Quick summary,
>only new process seems starved.  RR and nice -10 process behave okay.
>
>BTW, this is now with 2.5.64bk5.

The only difference I see is that reniced task wasn't starved with this 
kernel... wonder what the difference is.  Thanks for running the test.

         -Mike 

Re: scheduler starvation running irman with 2.5.64bk2

[rwhron]

> The only difference I see is that reniced task wasn't starved with this
> kernel... wonder what the difference is.  

One more thing.  After <ctrl c> interrupting irman process load, 
ssh into the box works.
-- 
Randy Hron
http://home.earthlink.net/~rwhron/kernel/bigbox.html

Re: scheduler starvation running irman with 2.5.64bk2

[Mike Galbraith]

At 09:46 PM 3/10/2003 -0500, rwhron@earthlink.net wrote:
> > The only difference I see is that reniced task wasn't starved with this
> > kernel... wonder what the difference is.
>
>One more thing.  After <ctrl c> interrupting irman process load,
>ssh into the box works.

Yup.  It should also work fine if you renice the shell you run irman from 
to a low enough priority.  Anyhoo, we definitely were experiencing the same 
exact problem, as was Con with contest. Mission accomplished.  I'm off to 
fiddle with Jim Houston's patch until Ingo does his magic :)

         -Mike 

scheduler starvation running irman with 2.5.64bk2

[rwhron]

irman triggers some odd behavior with 2.5.64bk2 on uniprocessor 
K6/2 475.  "ps aux" hasn't returned for a couple hours, though
irman appears to be doing it's thing.  I haven't tried irman on smp.

Time to run irman 3x.

2.5.63			4066 seconds
2.5.63-mjb1		2993 seconds
2.5.63-mm2-dline	2856 seconds
2.5.64			3473 seconds
2.5.64bk2		??

Time to complete irman is variable because the amount of work
done in 3 runs is also variable.

vmstat looks fairly typical, and it prints every 60 seconds.

vmstat 60
   procs                      memory      swap          io     system      cpu
 r  b  w   swpd   free   buff  cache   si   so    bi    bo   in    cs us sy id
 4  0  0   2564 376368    108   1916    0    0     0     0 1092 25978  2 98  0
 4  0  0   2564 376368    108   1920    0    0     0     0 1092 26102  2 98  0

This is vmstat 60 from 2.5.64

   procs                      memory      swap          io     system      cpu
 r  b  w   swpd   free   buff  cache   si   so    bi    bo   in    cs us sy id
 4  0  0   2552 377024    116   1520    0    0     0     0 1092 32649  4 96  0
 3  0  0   2552 377024    116   1520    0    0     0     0 1092 32865  5 95  0


There are probably less than 50 processes running.  
"ps aux" doesn't hear <ctrl z> or <ctrl c>.

Machine doesn't accept new ssh connections.

It's as if after starting irman, new processes don't get any CPU time.

-- 
Randy Hron
http://home.earthlink.net/~rwhron/kernel/bigbox.html

Re: scheduler starvation running irman with 2.5.64bk2

[Zwane Mwaikambo]

On Sat, 8 Mar 2003 rwhron@earthlink.net wrote:

> There are probably less than 50 processes running.  
> "ps aux" doesn't hear <ctrl z> or <ctrl c>.
> 
> Machine doesn't accept new ssh connections.
> 
> It's as if after starting irman, new processes don't get any CPU time.

Try doing a sysrq-T to get task state for all the processes and even 
sysrq-P at any random point will give you an idea of where the cpu is.

	Zwane
-- 
function.linuxpower.ca

Re: scheduler starvation running irman with 2.5.64bk2

[Mike Galbraith]

At 09:50 PM 3/8/2003 -0500, rwhron@earthlink.net wrote:
>irman triggers some odd behavior with 2.5.64bk2 on uniprocessor
>K6/2 475.  "ps aux" hasn't returned for a couple hours, though
>irman appears to be doing it's thing.  I haven't tried irman on smp.
>
>Time to run irman 3x.
>
>2.5.63                  4066 seconds
>2.5.63-mjb1             2993 seconds
>2.5.63-mm2-dline        2856 seconds
>2.5.64                  3473 seconds
>2.5.64bk2               ??

It _appears_ to be a valid test-case. I can reproduce this with 
2.5.64+combo and B2.  I can also influence it to behave.  (that doesn't 
mean that the scheduler changes are bust... could be that the test-case is 
doing something bad)

Q/indicator:  do you ever see ksoftirqd _wanting_ to run?  (set top SCHED_RR)

         -Mike 

Re: scheduler starvation running irman with 2.5.64bk2

[Mike Galbraith]

At 07:59 PM 3/9/2003 +0100, Mike Galbraith wrote:
>At 09:50 PM 3/8/2003 -0500, rwhron@earthlink.net wrote:
>>irman triggers some odd behavior with 2.5.64bk2 on uniprocessor
>>K6/2 475.  "ps aux" hasn't returned for a couple hours, though
>>irman appears to be doing it's thing.  I haven't tried irman on smp.
>>
>>Time to run irman 3x.
>>
>>2.5.63                  4066 seconds
>>2.5.63-mjb1             2993 seconds
>>2.5.63-mm2-dline        2856 seconds
>>2.5.64                  3473 seconds
>>2.5.64bk2               ??

(btw, it's only the process load that hangs) 

Re: scheduler starvation running irman with 2.5.64bk2

[Mike Galbraith]

[-- Attachment #1: Type: text/plain, Size: 925 bytes --]

At 09:50 PM 3/8/2003 -0500, rwhron@earthlink.net wrote:
>irman triggers some odd behavior with 2.5.64bk2 on uniprocessor
>K6/2 475.  "ps aux" hasn't returned for a couple hours, though
>irman appears to be doing it's thing.  I haven't tried irman on smp.

OK, can you do the following to determine whether we're both seeing the 
_same_ problem?

1.)  build the attached rtnice utility (don't remember who wrote/posted this)
2.)  login on vt1 and set the shell SCHED_RR via rtnice -n 1 -p <pid_of_sh> 
-d RR
3.)  login on vt2 and renice that shell to -10
4.)  login on another vt as a normal user, and start irman
5.)  try login/out on another vt, or ps or _whatever_ (doesn't matter) 
until box is starving
6.)  on vt2, try to do ps (it should hang despite -10 priority)
7.)  on vt1, try to do ps (it should work just fine)

cc to Ingo since stock .64 doesn't show this problem, and .64-combo and 
.64-B2 do.

         -Mike 

[-- Attachment #2: rtnice.c --]
[-- Type: text/plain, Size: 3933 bytes --]

#include <stdio.h>
#include <unistd.h>
#include <getopt.h>
#include <string.h>
#include <sys/types.h>
#include <sched.h>
#include <sys/time.h>

/*
 * Gross hack, just in case glibc isn't up to date yet.
 * (it wasn't when SCHED_IDLE was added to the kernel)
 */
#ifndef SCHED_IDLE
#define SCHED_IDLE 3
#endif

static char *usage = "Usage: %s -n <priority> -p <pid> -d FF|TS|RR|ID [command...]\n";

static char progname[128];

main(int argc, char *argv[])
	{

	int minpri, maxpri;
	int ch;
	char *p;
	struct timeval interval;
	static struct sched_param param;
	pid_t pid = 0;
	int do_priority = 0;
	int do_policy = 0;
	int policy = 0;
	int priority = 0;
	int args = 0;
	extern char *optarg;
	extern int optind;
	
	(void) strcpy(progname, argv[0]);

	while ((ch = getopt(argc, argv, "p:d:n:")) != EOF)	{

		switch (ch)	{
			case 'p':
				if (sscanf(optarg, "%d", &pid) != 1)	{
					fprintf(stderr,"%s: Bad pid.\n", progname);
					fprintf(stderr, usage, progname);
					exit(3);
		 		}
				args++;
#ifdef DEBUG
				fprintf(stderr, "pid = %d.\n", pid);
#endif

			break;

			case 'd':

				if (!strcmp(optarg, "TS"))	{
					policy = SCHED_OTHER;
		 		}
		 		else
		 		if (!strcmp(optarg, "RR"))	{
		 			policy = SCHED_RR;
		 		}
				else
				if (!strcmp(optarg, "ID"))
					policy = SCHED_IDLE;
		 		else
		 		if (!strcmp(optarg, "FF") || !strcmp(optarg, "FIFO"))	{
		 			policy = SCHED_FIFO;
		 		}
		 		else	{
					fprintf(stderr,"%s: Bad scheduling domain '%s'.\n", progname, optarg);
					fprintf(stderr, usage, progname);
					exit(4);
		 		}
				args++;
				do_policy++;
#ifdef DEBUG
				fprintf(stderr,"policy = %d.\n", policy);
#endif

			break;

			case 'n':
					/* we have one digit, let's get more */
				if (sscanf(optarg, "%d", &priority) != 1)	{
					fprintf(stderr,"%s: Bad priority value.\n", progname);
					fprintf(stderr, usage, progname);
					exit(4);
		 		}
				do_priority++;
				args++;
#ifdef DEBUG
				fprintf(stderr, "priority = %d.\n", priority);
#endif

			break;

			default:
				fprintf(stderr,"%s: Unrecognized option '%c'.\n", progname, ch);
				fprintf(stderr, usage, progname);
				exit(6);

			break;
		}

	}

	argc -= optind;
	argv += optind;

	if (args == 0)	{
		fprintf(stderr, usage, progname);
		exit(7);
	}


	if ((maxpri = sched_get_priority_max(SCHED_FIFO)) == -1)	{
		perror("sched_get_priority_max fails");
		exit(8);
	}

	if ((minpri = sched_get_priority_min(SCHED_FIFO)) == -1)	{
		perror("sched_get_priority_min fails");
		exit(10);
	}

	if (do_priority)	{
		if (priority > maxpri)	{
			fprintf(stderr,"%s: maximum priority allowed is %d.\n", progname, maxpri);
			exit(9);
 		}

		if (priority < minpri)	{
			fprintf(stderr,"%s: minimum priority allowed is %d.\n", progname, minpri);
			exit(11);
 		}
	}

	if (!do_policy)	{
		if ((policy = sched_getscheduler(pid)) == -1)	{
			policy = SCHED_OTHER;
		}
	}

	if (!do_priority)	{
		if (sched_getparam(pid, &param) == 0)	{ /* will fail for TS! */
			priority = param.sched_priority;
 		}
 		else	{
 			priority = minpri;
 		}
 		if (!do_policy && pid)	{  /* print and exit */
 			static char *pol;  /* default */
 			if (policy == SCHED_OTHER) pol = "TS";
 			if (policy == SCHED_FIFO) pol = "FIFO";
 			if (policy == SCHED_RR) pol = "RR";

 			fprintf(stdout,"%s: scheduler %s priority %d.\n", progname, pol, priority);

			exit(0);
 		}
	}
	if (policy == SCHED_OTHER || policy == SCHED_IDLE)
		priority = 0;

	param.sched_priority = priority;

	if (sched_setscheduler(pid, policy, &param) == -1)	{
		perror("sched_setscheduler fails");
		exit(13);
	}

	if (pid != 0)	{  /* non-local target => exit */
		exit(0);
	}

	if (!argv[0])	{
		fprintf(stderr,"%s: no valid command args.\n", progname);
		fprintf(stderr, usage, progname);

		exit(14);  /* don't exec if target was not us or no args  */
	}

		/* the big leap! */
		/* hal: dave, will I dream? */

	if (!execvp(argv[0], &argv[0]))	{
		perror("rtrun exec fails");
		exit(-1);
	}
}

Re: scheduler starvation running irman with 2.5.64bk2

[Mike Galbraith]

P.S.  You can save a little time by only running the process load.  Edit 
irman.c:412 and set load_num to 3... no need to wait for the other two 
loads to complete first, it's the process load that starves the box to 
death here.

	-Mike

Re: scheduler starvation running irman with 2.5.64bk2

[Mike Galbraith]

At 05:46 AM 3/10/2003 +0100, Mike Galbraith wrote:
>P.S.  You can save a little time by only running the process load.  Edit 
>irman.c:412 and set load_num to 3... no need to wait for the other two 
>loads to complete first, it's the process load that starves the box to 
>death here.

P.P.S. (last one;)

To make it cease and desist starving your box, renice the shell you're 
running irman from.  12 is the magic (hmm) number here at which starvation 
ceases.

It's interesting to watch the response times irman reports.  The higher the 
renice level, the better response times it reports both in 2.5.64-virgin, 
and 2.5.64-combo (which looks like what is in bk2).  /me has no clue 
whether that means anything or not ;-)

         ciao,

         -Mike