Date: Tue, 25 Jan 2005 10:31:06 -0800 (PST) From: Yan Yu <yanyu@CS.UCLA.EDU> To: Jose Hidalgo Herrera <jose@hostarica.com> Cc: freebsd-hackers@freebsd.org Subject: Re: seg fault on kse_release () (fwd) Message-ID: <Pine.GSO.4.58.0501251028210.8888@panther.cs.ucla.edu> In-Reply-To: <1106669661.9523.7.camel@jose.hostarica.net> References: <Pine.GSO.4.58.0501241426470.2472@panther.cs.ucla.edu> <1106669661.9523.7.camel@jose.hostarica.net>
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Hi, thanks a LOT for looking into this. yes, that is exactly my output before the SEG fault happens (btw, i add "if (p)" before "p[id]++ ", the prob remains.. what confuses me is that, if the system is out of memory, then i should see the error returned from pthread_create() or calloc(), but not SEG fault, or i must have missed something? Thanks, yan On Tue, 25 Jan 2005, Jose Hidalgo Herrera wrote: > I ran it into: > 4.11-STABLE FreeBSD Wed Jan 19 15:23:33 CST 2005 > What you find in > http://www1.cr.freebsd.org/~jose/stress.tgz > is the output of: > ktrace ./a.out > stress.txt > > > On Mon, 2005-01-24 at 14:27 -0800, Yan Yu wrote: > > Hi, all, I have a newbie Q: > > I am trying to use creating large number of threads and allocting > > memory to stress the system. > > My user program causes SEG fault in the kernel code, kse_release () in > > kern_kse.c. > > (it SEG fault before the system can be stressed;( > > > > the stack when the SEG fault happens are: > > #0 0x08064e54 in kse_release () > > #1 0x080531c4 in kse_sched_single () > > #2 0x00000000 in ?? () > > > > My simple program is: > > I have a simple function to create threads: > > > > #define NUM_THREADS 5000 > > #define THREADS_IN_ONE_PROCESS 5 > > #define BSIZE 500000 > > static int cc; > > > > void CreateThread(int n) > > { > > assert( n <= NUM_THREADS ); > > pthread_t threads[NUM_THREADS]; > > int rc, t; > > for(t=0;t < n;t++){ > > printf("#%d: Creating thread %d\n", cc, t); > > cc++; > > rc = pthread_create(&threads[t], NULL, PrintHello, (void *)t); > > if (rc){ > > printf("ERROR; return code from pthread_create() is %d\n", rc); > > } > > } > > > > unsigned long id; > > char * p = (char *) calloc(BSIZE, sizeof(char) ); > > if ( p == NULL ) > > { > > fprintf(stderr, "calloc error\n"); > > } > > while (1) > > { > > while (BSIZE <= (id = rand() / (RAND_MAX/BSIZE))); > > p[id] ++; > > } > > } > > > > void *PrintHello(void *threadid) > > { > > printf("\n%d: Hello World!\n", threadid); > > CreateThread(THREADS_IN_ONE_PROCESS); > > pthread_exit(NULL); > > } > > > > int main (int argc, char *argv[]) > > { > > CreateThread(THREADS_IN_ONE_PROCESS); > > } > > > > The SEG fault happens after creating nearly 5000 threads. > > and I use the default pthread.h coming w/ freeBSD 5.3 > > #define PTHREAD_KEYS_MAX 256 > > #define PTHREAD_STACK_MIN (1 << 22) > > #define PTHREAD_THREADS_MAX ULONG_MAX > > > > > > Any idea on what might happen? > > > > Many Thanks! > > yan > > _______________________________________________ > > freebsd-hackers@freebsd.org mailing list > > http://lists.freebsd.org/mailman/listinfo/freebsd-hackers > > To unsubscribe, send any mail to "freebsd-hackers-unsubscribe@freebsd.org" >
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