1#!/bin/sh 2 3# 4# Copyright (c) 2014 EMC Corp. 5# All rights reserved. 6# 7# Redistribution and use in source and binary forms, with or without 8# modification, are permitted provided that the following conditions 9# are met: 10# 1. Redistributions of source code must retain the above copyright 11# notice, this list of conditions and the following disclaimer. 12# 2. Redistributions in binary form must reproduce the above copyright 13# notice, this list of conditions and the following disclaimer in the 14# documentation and/or other materials provided with the distribution. 15# 16# THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 17# ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 18# IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 19# ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 20# FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 21# DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 22# OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 23# HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 24# LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 25# OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 26# SUCH DAMAGE. 27# 28 29[ `id -u ` -ne 0 ] && echo "Must be root!" && exit 1 30 31# Demonstrate starvation: Thread stuck in "ufs" for minutes. 32# Only seen with >= 16 CPUs. 33# Not a problem with 4BSD. 34# http://people.freebsd.org/~pho/stress/log/spin.txt 35# Fixed by r273966. 36 37. ../default.cfg 38 39timeout=1200 40 41here=`pwd` 42cd /tmp 43sed '1,/^EOF/d' < $here/$0 > spin.c 44mycc -o spin -Wall -Wextra -O0 spin.c || exit 1 45rm -f spin.c 46cd $here 47 48mount | grep $mntpoint | grep -q /dev/md && umount -f $mntpoint 49mdconfig -l | grep -q md$mdstart && mdconfig -d -u $mdstart 50 51mdconfig -a -t swap -s 1g -u $mdstart || exit 1 52bsdlabel -w md$mdstart auto 53newfs $newfs_flags -n md${mdstart}$part > /dev/null 54mount /dev/md${mdstart}$part $mntpoint 55 56cpus=`sysctl hw.ncpu | sed 's/.*: //'` 57(cd $mntpoint; /tmp/spin $((cpus + 1))) & 58error=0 59n=0 60while kill -0 $! 2>/dev/null; do 61 sleep 1 62 if [ $((n += 1)) -gt $timeout ]; then 63 echo FAIL 64 ps -l | grep -v sed | sed -n '1p;/ufs/p' 65 pkill spin 66 error=1 67 fi 68done 69wait 70 71while mount | grep $mntpoint | grep -q /dev/md; do 72 umount $mntpoint || sleep 1 73done 74mdconfig -d -u $mdstart 75rm -f /tmp/spin 76exit $error 77EOF 78#include <sys/param.h> 79#include <sys/wait.h> 80 81#include <err.h> 82#include <fcntl.h> 83#include <stdio.h> 84#include <stdlib.h> 85#include <unistd.h> 86 87void 88work(void) 89{ 90 91 while (access("rendezvous", R_OK) != 0) 92 ; 93 94 _exit(0); 95} 96 97int 98main(int argc, char **argv) 99{ 100 int fd, i, parallel; 101 102 if (argc == 2) 103 parallel = atoi(argv[1]); 104 else 105 errx(1, "Usage: %s <cpus>", argv[0]); 106 107 for (i = 0; i < parallel; i++) { 108 if (fork() == 0) 109 work(); 110 } 111 112 /* open(2) blocked on "ufs" for minutes */ 113 if ((fd = open("rendezvous", O_CREAT, 0644)) == -1) 114 err(1, "open()"); 115 close(fd); 116 117 for (i = 0; i < parallel; i++) 118 wait(NULL); 119 120 if (unlink("rendezvous") == -1) 121 err(1, "unlink()"); 122 123 return (0); 124} 125