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Member "stress-ng-0.09.56/stress-kill.c" (15 Mar 2019, 2726 Bytes) of package /linux/privat/stress-ng-0.09.56.tar.xz:


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    1 /*
    2  * Copyright (C) 2013-2019 Canonical, Ltd.
    3  *
    4  * This program is free software; you can redistribute it and/or
    5  * modify it under the terms of the GNU General Public License
    6  * as published by the Free Software Foundation; either version 2
    7  * of the License, or (at your option) any later version.
    8  *
    9  * This program is distributed in the hope that it will be useful,
   10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
   11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   12  * GNU General Public License for more details.
   13  *
   14  * You should have received a copy of the GNU General Public License
   15  * along with this program; if not, write to the Free Software
   16  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
   17  *
   18  * This code is a complete clean re-write of the stress tool by
   19  * Colin Ian King <colin.king@canonical.com> and attempts to be
   20  * backwardly compatible with the stress tool by Amos Waterland
   21  * <apw@rossby.metr.ou.edu> but has more stress tests and more
   22  * functionality.
   23  *
   24  */
   25 #include "stress-ng.h"
   26 
   27 /*
   28  *  stress on sched_kill()
   29  *  stress system by rapid kills
   30  */
   31 static int stress_kill(const args_t *args)
   32 {
   33     uint64_t udelay = 5000;
   34 
   35     if (stress_sighandler(args->name, SIGUSR1, SIG_IGN, NULL) < 0)
   36         return EXIT_FAILURE;
   37 
   38     do {
   39         int ret;
   40 
   41         /*
   42          *  With many kill stressors we get into a state
   43          *  where they all hammer on kill system calls and
   44          *  this stops the parent from getting scheduling
   45          *  time to spawn off the rest of the kill stressors
   46          *  causing some lag in getting all the stressors
   47          *  running. Ease this pressure off to being with
   48          *  with some small sleeps that shrink to zero over
   49          *  time. The alternative was to re-nice all the
   50          *  processes, but even then one gets the child
   51          *  stressors all contending and causing a bottle
   52          *  neck.  Any simpler and/or better solutions would
   53          *  be appreciated!
   54          */
   55         if (udelay >= 1000) {
   56             (void)shim_usleep(udelay);
   57             udelay -= 500;
   58         }
   59 
   60         ret = kill(args->pid, SIGUSR1);
   61         if ((ret < 0) && (g_opt_flags & OPT_FLAGS_VERIFY))
   62             pr_fail_err("kill");
   63 
   64         /* Zero signal can be used to see if process exists */
   65         ret = kill(args->pid, 0);
   66         if ((ret < 0) && (g_opt_flags & OPT_FLAGS_VERIFY))
   67             pr_fail_err("kill");
   68 
   69         /*
   70          * Zero signal can be used to see if process exists,
   71          * -1 pid means signal sent to every process caller has
   72          * permission to send to
   73          */
   74         ret = kill(-1, 0);
   75         if ((ret < 0) && (g_opt_flags & OPT_FLAGS_VERIFY))
   76             pr_fail_err("kill");
   77 
   78         inc_counter(args);
   79     } while (keep_stressing());
   80 
   81     return EXIT_SUCCESS;
   82 }
   83 
   84 stressor_info_t stress_kill_info = {
   85     .stressor = stress_kill,
   86     .class = CLASS_INTERRUPT | CLASS_SCHEDULER | CLASS_OS
   87 };