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| author | Karel Zak | 2016-10-03 11:02:35 +0200 |
|---|---|---|
| committer | Karel Zak | 2016-10-03 11:02:35 +0200 |
| commit | 88b60f0bdee6a4379d5579918eec919bec94089f (patch) | |
| tree | 4aceb8d788e9d628b5f1b18fb7feba2ee4a4ee74 /schedutils | |
| parent | tools: make ko-release-gen usable with gpg2 (diff) | |
| download | kernel-qcow2-util-linux-88b60f0bdee6a4379d5579918eec919bec94089f.tar.gz kernel-qcow2-util-linux-88b60f0bdee6a4379d5579918eec919bec94089f.tar.xz kernel-qcow2-util-linux-88b60f0bdee6a4379d5579918eec919bec94089f.zip | |
chrt: follow nice setting, prefer sched_setscheduler()
* do not reset 'nice' setting by sched_setattr(), if 'nice' setting
is not zero then chrt ends with EPERM for non-root users:
$ renice -n 5 -p $$; chrt -v -b 0 date
12475 (process ID) old priority 0, new priority 5
chrt: failed to set pid 0's policy: Operation not permitted
* it seems more elegant to always use old sched_setscheduler() API for
non-deadline policies; in this case we do not need getpriority()
to keep 'nice' unchanged.
Addresses: https://github.com/karelzak/util-linux/issues/359
Signed-off-by: Karel Zak <kzak@redhat.com>
Diffstat (limited to 'schedutils')
| -rw-r--r-- | schedutils/chrt.c | 34 |
1 files changed, 18 insertions, 16 deletions
diff --git a/schedutils/chrt.c b/schedutils/chrt.c index edae0d9f4..0a51c1088 100644 --- a/schedutils/chrt.c +++ b/schedutils/chrt.c @@ -26,6 +26,8 @@ #include <unistd.h> #include <getopt.h> #include <errno.h> +#include <sys/time.h> +#include <sys/resource.h> #include "c.h" #include "nls.h" @@ -340,6 +342,7 @@ static int set_sched_one_by_setscheduler(struct chrt_ctl *ctl, pid_t pid) struct sched_param sp = { .sched_priority = ctl->priority }; int policy = ctl->policy; + errno = 0; # ifdef SCHED_RESET_ON_FORK if (ctl->reset_on_fork) policy |= SCHED_RESET_ON_FORK; @@ -357,29 +360,28 @@ static int set_sched_one(struct chrt_ctl *ctl, pid_t pid) #else /* !HAVE_SCHED_SETATTR */ static int set_sched_one(struct chrt_ctl *ctl, pid_t pid) { + struct sched_attr sa = { .size = sizeof(struct sched_attr) }; + + /* old API is good enough for non-deadline */ + if (ctl->policy != SCHED_DEADLINE) + return set_sched_one_by_setscheduler(ctl, pid); + + /* no changeed by chrt, follow the current setting */ + sa.sched_nice = getpriority(PRIO_PROCESS, pid); + /* use main() to check if the setting makes sense */ - struct sched_attr sa = { - .size = sizeof(struct sched_attr), - .sched_policy = ctl->policy, - .sched_priority = ctl->priority, - .sched_runtime = ctl->runtime, - .sched_period = ctl->period, - .sched_deadline = ctl->deadline - }; - int rc; + sa.sched_policy = ctl->policy; + sa.sched_priority = ctl->priority; + sa.sched_runtime = ctl->runtime; + sa.sched_period = ctl->period; + sa.sched_deadline = ctl->deadline; # ifdef SCHED_RESET_ON_FORK if (ctl->reset_on_fork) sa.sched_flags |= SCHED_RESET_ON_FORK; # endif errno = 0; - rc = sched_setattr(pid, &sa, 0); - - if (rc != 0 && errno == ENOSYS && ctl->policy != SCHED_DEADLINE) - /* fallback -- build with new kernel/libc, but executed on old kernels */ - rc = set_sched_one_by_setscheduler(ctl, pid); - - return rc; + return sched_setattr(pid, &sa, 0); } #endif /* HAVE_SCHED_SETATTR */ |