Here is a program that exposes the issue on a 2.4
and 2.6 kernel. It pretty easy to reproduce on an 8-way -
takes about 1 or 2 minutes on a 2-way it has not been
reproduced or tried on a 4-way (i.e. no available
system).
- mario
----------------------------
gcc -g -pthread foo.cpp -o foo -lpthread
#include <stdio.h>
#include <errno.h>
#include <pthread.h>
#include <string.h>
#include <unistd.h>
#include <stdlib.h>
#include <sys/wait.h>
void * worker(void *self) {
int x = -1;
FILE *pp = 0;
long junk[8192];
char buf[1024];
x = -1;
errno = 0;
pp = popen("ls", "r");
x = errno;
if(pp) {
memset(buf, 0, sizeof(buf));
while(fgets(buf, sizeof(buf)-1, pp) != 0) {
;
}
pclose(pp);
}
else printf("popen failed: %s\n", strerror(errno));
pthread_exit(NULL);
}
int main(void) {
pthread_t pt[128];
pthread_t pthr;
int x = 0;
while(1) {
for (x = 0; x < 5; x++)
pthread_create(&(pt[x]), 0, worker, (void *)&x);
for (x = 0; x < 5; x++)
pthread_join( pt[x], NULL);
usleep(5000);
}
return 0;
}
-----Original Message-----
From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of david mosberger
Sent: Tuesday, July 26, 2005 12:23 AM
To: Luck, Tony
Cc: [email protected]
Subject: Re: fix possible mm_context wrap-around race
Argh, some day I'll hopefully remember to attach the actual patch...
--david
On 7/25/05, david mosberger <[EMAIL PROTECTED]> wrote:
> Tony, since I can't test the patch on anything but a UP machine at
> this time (which is uninteresting, since the race doesn't trigger
> there), I'd suggest to put this into the "testing" tree. Hopefully,
> somebody could run some tests which involve multi-threaded apps doing
> a lot of fork/exec'ing.
>
> Thanks,
>
> --david
> --
> Mosberger Consulting LLC, voice/fax: 510-744-9372,
> http://www.mosberger-consulting.com/
> 35706 Runckel Lane, Fremont, CA 94536
>
--
Mosberger Consulting LLC, voice/fax: 510-744-9372,
http://www.mosberger-consulting.com/
35706 Runckel Lane, Fremont, CA 94536
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