From mboxrd@z Thu Jan  1 00:00:00 1970
From: schindele@nentec.de (Juergen Schindele)
Date: Wed, 16 Sep 2009 09:26:01 +0200
Subject: Problems with pthread on ARM/PXA270
Message-ID: <200909160926.02036.schindele@nentec.de>
To: linux-arm-kernel@lists.infradead.org
List-Id: linux-arm-kernel.lists.infradead.org

Hello all,
we tried to implement a thread based software on our PXA270 based platform but
we had trouble with pthreads. So i modyfied a tiny progam to test. This little progam creates
10 threads and each thread does print something (an index an a pointer to itself). 

On my PC with Suse 11.0 Linux (kernel 2.6.27) this works fine as supposed to.
Each thread has his turn and print his own values.

But on our pxa270 platform the thread switch does not (or really rarely) happen
and only one thread is printing always the same values. So i suppose thread
switching is not working!

Any hints or experiences are welcome !!!

we use codesourcery compiler
arm-none-linux-gnueabi-gcc (CodeSourcery Sourcery G++ Lite 2007q1-10) 4.2.0 20070413 (prerelease)
Copyright (C) 2007 Free Software Foundation, Inc.
This is free software; see the source for copying conditions.  There is NO
warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.

and here the C-code compiled with  "arm-none-linux-gnueabi-gcc -o test test.c -lpthread"

#include <errno.h>
#include <error.h>
#include <stdio.h>
#include <stdlib.h>
#include <pthread.h>
#include <time.h>

#define NUM_THREADS 10
#define NUM_ITERS   50
#define TIMEOUT_NS  100000000L

static void *thread (void *);
static int argument[NUM_THREADS];
static pthread_mutex_t mutex = PTHREAD_MUTEX_INITIALIZER;
static pthread_attr_t defaultattr;

static void * print_thread (void *arg)
{
    int i;
    int number = *((int*)arg);

    for (;;) {
        pthread_t self = pthread_self ();
        printf ("Thread %d is [%d]\n", number, self);
    }
}

int main (void)
{
    pthread_t th;
    int i, retvalue;

    struct sched_param param;
    pthread_attr_init(&defaultattr);

    pthread_attr_setschedpolicy(&defaultattr, SCHED_RR);

    param.sched_priority = 10;
    if ((retvalue = pthread_attr_setschedparam(&defaultattr, &param))!=0) {
        printf ("ERROR\n");
        exit (0);
    }

    for (i = 0; i < NUM_THREADS; i++)
    {
        argument[i] = i;
        if (pthread_create (&th, &defaultattr, print_thread, &argument[i]) != 0)
            error (EXIT_FAILURE, 0, "cannot create thread");
        printf ("Thread [%d]\n", i);
    }

    while (1) {
        ;
    }

    /* notreached */
    return 0;
}

--------------------------------------------------------------
J?rgen Schindele  
Software-Entwicklung

NENTEC Netzwerktechnologie GmbH
Greschbachstr. 12
76229 Karlsruhe
Deutschland
Telefon: +49 721 94249-51
Telefax: +49 721 94249-10
E-Mail:  schindele@nentec.de
WEB:     www.nentec.de
 
Gesch?ftsf?hrung: Klaus Becker, Roland Knapp
Sitz der Gesellschaft: Karlsruhe
Handelsregister: Amtsgericht Mannheim HRB 107658
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