c21b080f3d
Under Linux to sched_[g|s]etaffinity() functions the value returned from a call to gettid(2) (thread id) can be passed in the argument pid. Specifying pid as 0 will set the attribute for the calling thread, and passing the value returned from a call to getpid(2) (process id) will set the attribute for the main thread of the thread group. Native cpuset(2) family of system calls has "which" argument to determine how the value of id argument is interpreted, i.e., CPU_WHICH_TID is used to pass a thread id and CPU_WHICH_PID - to pass a process id. For now native sched_[g|s]etaffinity() implementation is wrong as uses "which" CPU_WHICH_PID to pass both (process and thread id) to the kernel. To fix this adding a new "which" CPU_WHICH_TIDPID intended to handle both id's. Reviewed by: kib Differential Revision: https://reviews.freebsd.org/D38209 MFC after: 1 week
68 lines
2.3 KiB
C
68 lines
2.3 KiB
C
/*-
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* Copyright (c) 2021 The FreeBSD Foundation
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*
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* This software were developed by Konstantin Belousov <kib@FreeBSD.org>
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* under sponsorship from the FreeBSD Foundation.
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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* 1. Redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer.
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* 2. Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in the
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* documentation and/or other materials provided with the distribution.
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*
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* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
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* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
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* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
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* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
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* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
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* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
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* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
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* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
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* SUCH DAMAGE.
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*/
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#include <sys/param.h>
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#include <sys/sysctl.h>
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#include <errno.h>
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#include <sched.h>
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#include <string.h>
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int
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sched_setaffinity(pid_t pid, size_t cpusetsz, const cpuset_t *cpuset)
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{
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static int mp_maxid;
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cpuset_t c;
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int error, lbs, cpu;
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size_t len, sz;
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sz = cpusetsz > sizeof(cpuset_t) ? sizeof(cpuset_t) : cpusetsz;
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memset(&c, 0, sizeof(c));
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memcpy(&c, cpuset, sz);
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/* Linux ignores high bits */
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if (mp_maxid == 0) {
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len = sizeof(mp_maxid);
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error = sysctlbyname("kern.smp.maxid", &mp_maxid, &len,
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NULL, 0);
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if (error == -1)
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return (error);
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}
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lbs = CPU_FLS(&c) - 1;
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if (lbs > mp_maxid) {
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CPU_FOREACH_ISSET(cpu, &c)
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if (cpu > mp_maxid)
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CPU_CLR(cpu, &c);
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}
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error = cpuset_setaffinity(CPU_LEVEL_WHICH, CPU_WHICH_TIDPID,
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pid == 0 ? -1 : pid, sizeof(cpuset_t), &c);
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if (error == -1 && errno == EDEADLK)
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errno = EINVAL;
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return (error);
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}
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