Thank you for the help! Same result with fflush :(.
Are you maybe wrong because you have tested 2.5 and it doesn't work? Or just uncertain? The only thing I have read that mentions glibc version is the work Ingo did against 2.4 glibc and in the 2.6.16-mm1 patches... http://people.redhat.com/mingo/PI-futex-patches/. I can not detrmine how this relates to the 2.6.22 priority based futex wakeup commit. I am currently fighting crosstool-0.43 to build a newer glibc and I will share results if/when I get that to work. -Michael Ilya Lipovsky wrote: > ...Or maybe I am wrong :). Could you put fflush(stdout) after > each printf, > just to be completely certain that it misbehaves? > > -----Original Message----- > From: [EMAIL PROTECTED] > [mailto:[EMAIL PROTECTED] g] On > Behalf Of Ilya Lipovsky Sent: Friday, September 07, 2007 12:41 PM > To: 'Benedict, Michael'; linuxppc-embedded@ozlabs.org > Subject: RE: futex priority based wakeup > > Looks like it is a libc issue. Apparently, GNU libc supports priority > futexes only in version 2.5 and higher. > > -----Original Message----- > From: [EMAIL PROTECTED] > [mailto:[EMAIL PROTECTED] g] On > Behalf Of Benedict, Michael Sent: Friday, September 07, 2007 11:02 AM > To: linuxppc-embedded@ozlabs.org > Subject: futex priority based wakeup > > I recently upgraded to 2.6.22 to get the priority based futex wakeup > behavior. However, when I run a simple program (see below), based on > either a pthread_mutex_t or a sem_t, it seems that threads > are woken up > in FIFO order. I am using glibc 2.3.6 with NPTL and TLS, based off > crossdev-0.43. Could someone help me get priority-based > wakeup or point > me to a better place to get this question answered? Thank you, > Michael > > Code: > > pthread_mutex_t mymutex = PTHREAD_MUTEX_INITIALIZER; > > void *important(void *ign) > { > sleep(1); > printf("important waiting for mutex\n"); > if(pthread_mutex_lock(&mymutex)) { > perror("sem_wait"); > exit(1); > } else { > printf("important got mutex!\n"); > pthread_mutex_unlock(&mymutex); > } > > return NULL; > } > > > void *unimportant(void *ign) > { > printf("unimportant waiting for mutex\n"); > if(pthread_mutex_lock(&mymutex)) { > perror("sem_wait"); > exit(1); > } else { > printf("unimportant got mutex!\n"); > pthread_mutex_unlock(&mymutex); > } > > return NULL; > } > > int main() > { > struct sched_param p; > pthread_attr_t attr; > pthread_t i, u; > > pthread_mutex_lock(&mymutex); > > p.__sched_priority = sched_get_priority_min(SCHED_FIFO); > if(-1 == p.__sched_priority) { > perror("sched_get_priority_min"); > return 1; > } > pthread_attr_init(&attr); > pthread_attr_setschedpolicy(&attr, SCHED_FIFO); > pthread_attr_setschedparam(&attr, &p); > pthread_create(&u, &attr, unimportant, NULL); > > p.__sched_priority = sched_get_priority_max(SCHED_FIFO); > pthread_attr_setschedparam(&attr, &p); > pthread_create(&i, &attr, important, NULL); > > sleep(5); > printf("main unlocking mutex\n"); > pthread_mutex_unlock(&mymutex); > > pthread_join(u, NULL); > pthread_join(i, NULL); > > return 0; > } > > Which produces: > unimportant waiting for mutex > important waiting for mutex > main unlocking mutex > unimportant got mutex! > important got mutex! > > _______________________________________________ > Linuxppc-embedded mailing list > Linuxppc-embedded@ozlabs.org > https://ozlabs.org/mailman/listinfo/linuxppc-embedded > > _______________________________________________ > Linuxppc-embedded mailing list > Linuxppc-embedded@ozlabs.org > https://ozlabs.org/mailman/listinfo/linuxppc-embedded _______________________________________________ Linuxppc-embedded mailing list Linuxppc-embedded@ozlabs.org https://ozlabs.org/mailman/listinfo/linuxppc-embedded
