Messages in this thread | | | From | "Fleischer, Julie N" <> | Subject | [BUG - HRT patch] disabling timer hangs system when multiple over runs | Date | Mon, 13 Jan 2003 10:26:46 -0800 |
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George - I'm testing your 2.5.54-bk1 high-res-timers patches and am working on debugging an issue I'm seeing where my system hangs (i.e., doesn't accept input and I have to reboot). It happens when I'm disabling the timer by setting the it_value to 0. I've been able to nail it down to know that it only happens when you have generated multiple overruns (i.e., when I set up a repeating timer and block it for > 1 timer expiry, my system then hangs when I try to disable that timer -- I'm disabling before unblocking the signals).
I know "system hang" is not very descriptive. If you have input on what types of logs I should be looking at to figure out what's really going on or other ways I can debug, I'll do that.
I have added the tests I'm using to reproduce this issue to http://posixtest.sf.net. The original one where I noticed it was posixtestsuite/conformance/interfaces/timer_gettime/2-3.c after Jim Houston's bug fix. Then, I added posixtestsuite/conformance/interfaces/timer_settime/3-2.c and 3-3.c to help me get to root cause. To view the issue, you can either run timer_gettime/2-3.c, or change timer_settime/3-3.c to use a repeating timer (in nsecs). I have included the latter below.
==> One related ignorant question I had is I wanted to test this against your latest version (2.5.54-bk6), but when I went today to get the bk patches for 2.5.54, I couldn't find them. Are those only available for the current kernel version? That makes sense -- I should have been quicker. But, just wanted to check if there was another way for me to get that version.
Additional information is below: kernel used = 2.5.54-bk1 HRT patches applied = hrtimers-core-2.5.54-bk1-1.0.patch hrtimers-hrposix-2.5.54-bk1-1.0.patch hrtimers-i386-2.5.54-bk1-1.0.patch hrtimers-posix-2.5.54-bk1-1.0.patch hrtimers-support-2.5.52-1.0.patch
Thanks. - Julie Fleischer
timer_settime/3-3.c - with modifications to show issue /* * Copyright (c) 2002, Intel Corporation. All rights reserved. * Created by: julie.n.fleischer REMOVE-THIS AT intel DOT com * This file is licensed under the GPL license. For the full content * of this license, see the COPYING file at the top level of this * source tree.
* Test that if value.it_value = 0, the timer is disarmed. Test by * disarming a currently armed and blocked timer. * * For this test, signal SIGTOTEST will be used, clock CLOCK_REALTIME * will be used. */
#include <time.h> #include <signal.h> #include <stdio.h> #include <unistd.h> #include <stdlib.h> #include "posixtest.h"
#define TIMEREXPIRENSEC 10000000 #define SLEEPTIME 1
#define SIGTOTEST SIGALRM
void handler(int signo) { printf("OK to be in once\n"); }
int main(int argc, char *argv[]) { sigset_t set; struct sigevent ev; struct sigaction act; timer_t tid; struct itimerspec its; struct timespec ts;
ev.sigev_notify = SIGEV_SIGNAL; ev.sigev_signo = SIGTOTEST;
if (sigemptyset(&set) != 0) { perror("sigemptyset() did not return success\n"); return PTS_UNRESOLVED; }
if (sigaddset(&set, SIGTOTEST) != 0) { perror("sigaddset() did not return success\n"); return PTS_UNRESOLVED; }
if (sigprocmask(SIG_SETMASK, &set, NULL) != 0) { perror("sigprocmask() did not return success\n"); return PTS_UNRESOLVED; }
if (timer_create(CLOCK_REALTIME, &ev, &tid) != 0) { perror("timer_create() did not return success\n"); return PTS_UNRESOLVED; }
/* * First set up timer to be blocked */ its.it_interval.tv_sec = 0; its.it_interval.tv_nsec = 5*TIMEREXPIRENSEC; its.it_value.tv_sec = 0; its.it_value.tv_nsec = TIMEREXPIRENSEC;
printf("setup first timer\n"); if (timer_settime(tid, 0, &its, NULL) != 0) { perror("timer_settime() did not return success\n"); return PTS_UNRESOLVED; }
printf("sleep\n"); sleep(SLEEPTIME); printf("awoke\n");
/* * Second, set value.it_value = 0 and set up handler to catch * signal. */ act.sa_handler=handler; act.sa_flags=0;
if (sigemptyset(&act.sa_mask) == -1) { perror("Error calling sigemptyset\n"); return PTS_UNRESOLVED; } if (sigaction(SIGTOTEST, &act, 0) == -1) { perror("Error calling sigaction\n"); return PTS_UNRESOLVED; }
its.it_interval.tv_sec = 0; its.it_interval.tv_nsec = 0; its.it_value.tv_sec = 0; its.it_value.tv_nsec = 0;
printf("setup second timer\n"); if (timer_settime(tid, 0, &its, NULL) != 0) { perror("timer_settime() did not return success\n"); return PTS_UNRESOLVED; }
printf("unblock\n"); if (sigprocmask(SIG_UNBLOCK, &set, NULL) != 0) { perror("sigprocmask() did not return success\n"); return PTS_UNRESOLVED; }
/* * Ensure sleep for TIMEREXPIRE seconds not interrupted */ ts.tv_sec=SLEEPTIME; ts.tv_nsec=0;
printf("sleep again\n"); if (nanosleep(&ts, NULL) == -1) { printf("nanosleep() interrupted\n"); printf("Test FAILED\n"); return PTS_FAIL; }
printf("Test PASSED\n"); return PTS_PASS; }
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