Re: [libvirt] [PATCH 1/3] 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(a)redhat.com&gt; --- src/libvirt_private.syms | 1 + src/util/virprocess.c | 46 ++++++++++++++++++++++++++++++++++++++++++++-- src/util/virprocess.h | 6 +++++- 3 files changed, 50 insertions(+), 3 deletions(-) diff --git a/src/libvirt_private.syms b/src/libvirt_private.syms index fb5d003..de3476e 100644 --- a/src/libvirt_private.syms +++ b/src/libvirt_private.syms @@ -1882,6 +1882,7 @@ virProcessSetMaxFiles; virProcessSetMaxMemLock; virProcessSetMaxProcesses; virProcessSetNamespaces; +virProcessSetScheduler; virProcessTranslateStatus; virProcessWait; diff --git a/src/util/virprocess.c b/src/util/virprocess.c index d0a1500..85da5e8 100644 --- a/src/util/virprocess.c +++ b/src/util/virprocess.c @@ -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 +32,6 @@ # include <sys/time.h> # include <sys/resource.h> #endif -#include <sched.h>

#if defined(__FreeBSD__) || HAVE_BSD_CPU_AFFINITY # include <sys/param.h> @@ -1052,3 +1051,46 @@ virProcessExitWithStatus(int status) } exit(value); } + +int +virProcessSetScheduler(pid_t pid, int policy, int priority) +{ + struct sched_param param = {0}; + + VIR_DEBUG("pid=%d, policy=%d, priority=%u", pid, policy, priority); + + if (policy == SCHED_FIFO || policy == SCHED_RR) { + int min = 0; + int max = 0; + + if ((min = sched_get_priority_min(policy)) < 0) { + virReportSystemError(errno, "%s", + _("Cannot get minimum scheduler priority value")); + return -1; + } + + if ((max = sched_get_priority_max(policy)) < 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, policy, &param) < 0) { + virReportSystemError(errno, + _("Cannot set scheduler parameters for pid %d"), + pid); + return -1; + } + + return 0; +} diff --git a/src/util/virprocess.h b/src/util/virprocess.h index bcaede5..34b15a4 100644 --- a/src/util/virprocess.h +++ b/src/util/virprocess.h @@ -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 @@ -23,6 +23,7 @@ # define __VIR_PROCESS_H__ # include <sys/types.h> +# include <sched.h>

# include "internal.h" # include "virbitmap.h" @@ -73,4 +74,7 @@ typedef int (*virProcessNamespaceCallback)(pid_t pid, void *opaque); int virProcessRunInMountNamespace(pid_t pid, virProcessNamespaceCallback cb, void *opaque); + +int virProcessSetScheduler(pid_t pid, int policy, int priority); + #endif /* __VIR_PROCESS_H__ */