util: Add virProcessSetScheduler() function for scheduler settings

This function uses sched_setscheduler() function so it works with
processes and threads as well (even threads not created by us, which is
what we'll need in the future).

Signed-off-by: Martin Kletzander <mkletzan@redhat.com>
This commit is contained in:
Martin Kletzander 2015-01-08 15:36:54 +01:00
parent 89d26890ee
commit b6a2828e53
4 changed files with 131 additions and 5 deletions

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@ -1,6 +1,6 @@
dnl Process this file with autoconf to produce a configure script.
dnl Copyright (C) 2005-2014 Red Hat, Inc.
dnl Copyright (C) 2005-2015 Red Hat, Inc.
dnl
dnl This library is free software; you can redistribute it and/or
dnl modify it under the terms of the GNU Lesser General Public
@ -275,7 +275,7 @@ dnl and various less common threadsafe functions
AC_CHECK_FUNCS_ONCE([cfmakeraw fallocate geteuid getgid getgrnam_r \
getmntent_r getpwuid_r getuid kill mmap newlocale posix_fallocate \
posix_memalign prlimit regexec sched_getaffinity setgroups setns \
setrlimit symlink sysctlbyname getifaddrs])
setrlimit symlink sysctlbyname getifaddrs sched_setscheduler])
dnl Availability of pthread functions. Because of $LIB_PTHREAD, we
dnl cannot use AC_CHECK_FUNCS_ONCE. LIB_PTHREAD and LIBMULTITHREAD

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@ -1916,11 +1916,14 @@ virProcessGetStartTime;
virProcessKill;
virProcessKillPainfully;
virProcessRunInMountNamespace;
virProcessSchedPolicyTypeFromString;
virProcessSchedPolicyTypeToString;
virProcessSetAffinity;
virProcessSetMaxFiles;
virProcessSetMaxMemLock;
virProcessSetMaxProcesses;
virProcessSetNamespaces;
virProcessSetScheduler;
virProcessTranslateStatus;
virProcessWait;

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@ -1,7 +1,7 @@
/*
* virprocess.c: interaction with processes
*
* Copyright (C) 2010-2014 Red Hat, Inc.
* Copyright (C) 2010-2015 Red Hat, Inc.
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
@ -32,7 +32,9 @@
# include <sys/time.h>
# include <sys/resource.h>
#endif
#include <sched.h>
#if HAVE_SCHED_SETSCHEDULER
# include <sched.h>
#endif
#if defined(__FreeBSD__) || HAVE_BSD_CPU_AFFINITY
# include <sys/param.h>
@ -104,6 +106,13 @@ static inline int setns(int fd ATTRIBUTE_UNUSED, int nstype ATTRIBUTE_UNUSED)
}
#endif
VIR_ENUM_IMPL(virProcessSchedPolicy, VIR_PROC_POLICY_LAST,
"none",
"batch",
"idle",
"fifo",
"rr");
/**
* virProcessTranslateStatus:
* @status: child exit status to translate
@ -1052,3 +1061,99 @@ virProcessExitWithStatus(int status)
}
exit(value);
}
#if HAVE_SCHED_SETSCHEDULER
static int
virProcessSchedTranslatePolicy(virProcessSchedPolicy policy)
{
switch (policy) {
case VIR_PROC_POLICY_NONE:
return SCHED_OTHER;
case VIR_PROC_POLICY_BATCH:
return SCHED_BATCH;
case VIR_PROC_POLICY_IDLE:
return SCHED_IDLE;
case VIR_PROC_POLICY_FIFO:
return SCHED_FIFO;
case VIR_PROC_POLICY_RR:
return SCHED_RR;
case VIR_PROC_POLICY_LAST:
/* nada */
break;
}
return -1;
}
int
virProcessSetScheduler(pid_t pid, virProcessSchedPolicy policy, int priority)
{
struct sched_param param = {0};
int pol = virProcessSchedTranslatePolicy(policy);
VIR_DEBUG("pid=%d, policy=%d, priority=%u", pid, policy, priority);
if (!policy)
return 0;
if (pol == SCHED_FIFO || pol == SCHED_RR) {
int min = 0;
int max = 0;
if ((min = sched_get_priority_min(pol)) < 0) {
virReportSystemError(errno, "%s",
_("Cannot get minimum scheduler "
"priority value"));
return -1;
}
if ((max = sched_get_priority_max(pol)) < 0) {
virReportSystemError(errno, "%s",
_("Cannot get maximum scheduler "
"priority value"));
return -1;
}
if (priority < min || priority > max) {
virReportError(VIR_ERR_CONFIG_UNSUPPORTED,
_("Scheduler priority %d out of range [%d, %d]"),
priority, min, max);
return -1;
}
param.sched_priority = priority;
}
if (sched_setscheduler(pid, pol, &param) < 0) {
virReportSystemError(errno,
_("Cannot set scheduler parameters for pid %d"),
pid);
return -1;
}
return 0;
}
#else /* ! HAVE_SCHED_SETSCHEDULER */
int
virProcessSetScheduler(pid_t pid ATTRIBUTE_UNUSED,
int policy,
int priority ATTRIBUTE_UNUSED)
{
if (!policy)
return 0;
virReportSystemError(ENOSYS, "%s",
_("Process CPU scheduling is not supported "
"on this platform"));
return -1;
}
#endif /* !HAVE_SCHED_SETSCHEDULER */

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@ -1,7 +1,7 @@
/*
* virprocess.h: interaction with processes
*
* Copyright (C) 2010-2014 Red Hat, Inc.
* Copyright (C) 2010-2015 Red Hat, Inc.
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
@ -26,6 +26,19 @@
# include "internal.h"
# include "virbitmap.h"
# include "virutil.h"
typedef enum {
VIR_PROC_POLICY_NONE = 0,
VIR_PROC_POLICY_BATCH,
VIR_PROC_POLICY_IDLE,
VIR_PROC_POLICY_FIFO,
VIR_PROC_POLICY_RR,
VIR_PROC_POLICY_LAST
} virProcessSchedPolicy;
VIR_ENUM_DECL(virProcessSchedPolicy);
char *
virProcessTranslateStatus(int status);
@ -73,4 +86,9 @@ typedef int (*virProcessNamespaceCallback)(pid_t pid, void *opaque);
int virProcessRunInMountNamespace(pid_t pid,
virProcessNamespaceCallback cb,
void *opaque);
int virProcessSetScheduler(pid_t pid,
virProcessSchedPolicy policy,
int priority);
#endif /* __VIR_PROCESS_H__ */