Oleg Nesterov 8dc3e9099e [PATCH] sched_setscheduler: fix? policy checks ...

I am not sure this patch is correct: I can't understand what the current
code does, and I don't know what it was supposed to do.

The comment says:

		 * can't change policy, except between SCHED_NORMAL
		 * and SCHED_BATCH:

The code:

		if (((policy != SCHED_NORMAL && p->policy != SCHED_BATCH) &&
			(policy != SCHED_BATCH && p->policy != SCHED_NORMAL)) &&

But this is equivalent to:

		if ( (is_rt_policy(policy) && has_rt_policy(p)) &&

which means something different.  We can't _decrease_ the current
->rt_priority with such a check (if rlim[RLIMIT_RTPRIO] == 0).

Probably, it was supposed to be:

		if (	!(policy == SCHED_NORMAL && p->policy == SCHED_BATCH)  &&
			!(policy == SCHED_BATCH  && p->policy == SCHED_NORMAL)

this matches the comment, but strange: it doesn't allow to _drop_ the
realtime priority when rlim[RLIMIT_RTPRIO] == 0.

I think the right check would be:

		/* can't set/change rt policy */
		if (is_rt_policy(policy) &&
				policy != p->policy &&
				!rlim_rtprio)
			return -EPERM;

Signed-off-by: Oleg Nesterov <[email protected]>
Cc: Thomas Gleixner <[email protected]>
Cc: Ingo Molnar <[email protected]>
Cc: Steven Rostedt <[email protected]>
Cc: Nick Piggin <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>

2006-09-29 09:18:17 -07:00

..

irq

[PATCH] irq: remove a extra line

2006-09-29 09:18:07 -07:00

power

Merge master.kernel.org:/pub/scm/linux/kernel/git/gregkh/driver-2.6

2006-09-26 11:49:46 -07:00

time

…

.gitignore

…

acct.c

[PATCH] Fix sighand->siglock usage in kernel/acct.c

2006-07-14 21:53:54 -07:00

audit.c

[PATCH] selinux: rename selinux_ctxid_to_string

2006-09-26 08:48:52 -07:00

audit.h

[PATCH] audit: AUDIT_PERM support

2006-09-11 13:32:30 -04:00

auditfilter.c

[PATCH] selinux: rename selinux_ctxid_to_string

2006-09-26 08:48:52 -07:00

auditsc.c

[PATCH] selinux: rename selinux_ctxid_to_string

2006-09-26 08:48:52 -07:00

capability.c

[PATCH] pidspace: is_init()

2006-09-29 09:18:12 -07:00

compat.c

[PATCH] posix-timers: Fix clock_nanosleep() doesn't return the remaining time in compatibility mode

2006-09-29 09:18:15 -07:00

configs.c

…

cpu.c

[PATCH] Disable CPU hotplug during suspend

2006-09-26 08:48:59 -07:00

cpuset.c

[PATCH] pidspace: is_init()

2006-09-29 09:18:12 -07:00

delayacct.c

[PATCH] task delay accounting fixes

2006-09-01 11:39:08 -07:00

dma.c

…

exec_domain.c

…

exit.c

[PATCH] exit: fix crash case

2006-09-29 09:18:16 -07:00

extable.c

…

fork.c

[PATCH] ifdef blktrace debugging fields

2006-09-29 09:18:09 -07:00

futex_compat.c

[PATCH] futex: Apply recent futex fixes to futex_compat

2006-08-06 08:57:49 -07:00

futex.c

[PATCH] Use the correct restart option for futex_lock_pi

2006-09-08 10:22:50 -07:00

hrtimer.c

[PATCH] posix-timers: Fix clock_nanosleep() doesn't return the remaining time in compatibility mode

2006-09-29 09:18:15 -07:00

itimer.c

…

kallsyms.c

…

Kconfig.hz

…

Kconfig.preempt

…

kexec.c

[PATCH] kexec warning fix

2006-09-29 09:18:15 -07:00

kfifo.c

[PATCH] memory ordering in __kfifo primitives

2006-09-29 09:18:13 -07:00

kmod.c

[PATCH] Fix ____call_usermodehelper errors being silently ignored

2006-09-29 09:18:16 -07:00

kprobes.c

[PATCH] IA64: kprobe invalidate icache of jump buffer

2006-07-31 13:28:38 -07:00

ksysfs.c

…

kthread.c

…

lockdep_internals.h

[PATCH] lockdep: double the number of stack-trace entries

2006-09-13 07:32:14 -07:00

lockdep_proc.c

…

lockdep.c

[PATCH] lockdep: print kernel version

2006-09-29 09:18:13 -07:00

Makefile

[PATCH] per-task-delay-accounting: taskstats interface

2006-07-14 21:53:56 -07:00

module.c

[PATCH] load_module: no BUG if module_subsys uninitialized

2006-09-25 17:38:36 -07:00

mutex-debug.c

…

mutex-debug.h

…

mutex.c

…

mutex.h

…

panic.c

[PATCH] Add the __stack_chk_fail() function

2006-09-26 10:52:39 +02:00

params.c

[PATCH] module_subsys: initialize earlier

2006-09-29 09:18:08 -07:00

pid.c

[PATCH] pid: remove temporary debug code in attach_pid

2006-09-27 08:26:19 -07:00

posix-cpu-timers.c

[PATCH] posix-timers: Fix the flags handling in posix_cpu_nsleep()

2006-09-29 09:18:15 -07:00

posix-timers.c

[PATCH] posix-timers: Fix clock_nanosleep() doesn't return the remaining time in compatibility mode

2006-09-29 09:18:15 -07:00

printk.c

[PATCH] PM: make it possible to disable console suspending

2006-09-26 08:49:03 -07:00

profile.c

[PATCH] Profiling: require buffer allocation on the correct node

2006-09-26 08:48:50 -07:00

ptrace.c

[PATCH] pidspace: is_init()

2006-09-29 09:18:12 -07:00

rcupdate.c

[PATCH] rcu_do_batch: make ->qlen decrement irq safe

2006-09-13 07:32:14 -07:00

rcutorture.c

[PATCH] rcu: add lock annotations to rcu{,_bh}_torture_read_{lock,unlock}

2006-09-29 09:18:08 -07:00

relay.c

[PATCH] kernel-doc for relay interface

2006-09-29 09:18:06 -07:00

resource.c

Resources: insert identical resources above existing resources

2006-09-26 17:43:52 -07:00

rtmutex_common.h

…

rtmutex-debug.c

…

rtmutex-debug.h

…

rtmutex-tester.c

…

rtmutex.c

[PATCH] clean up and remove some extra spinlocks from rtmutex

2006-09-29 09:18:09 -07:00

rtmutex.h

…

rwsem.c

…

sched.c

[PATCH] sched_setscheduler: fix? policy checks

2006-09-29 09:18:17 -07:00

seccomp.c

…

signal.c

[PATCH] __dequeue_signal() cleanup

2006-09-29 09:18:15 -07:00

softirq.c

[PATCH] check return value of cpu_callback

2006-09-29 09:18:14 -07:00

softlockup.c

[PATCH] check return value of cpu_callback

2006-09-29 09:18:14 -07:00

spinlock.c

[PATCH] remove generic__raw_read_trylock()

2006-09-29 09:18:03 -07:00

stacktrace.c

…

stop_machine.c

[PATCH] Remove redundant up() in stop_machine()

2006-08-27 11:01:31 -07:00

sys_ni.c

…

sys.c

[PATCH] kill extraneous printk in kernel_restart()

2006-09-29 09:18:16 -07:00

sysctl.c

[PATCH] pidspace: is_init()

2006-09-29 09:18:12 -07:00

taskstats.c

[NETLINK]: Extend netlink messaging interface

2006-09-22 14:53:43 -07:00

time.c

…

timer.c

[PATCH] simplify update_times (avoid jiffies/jiffies_64 aliasing problem)

2006-09-29 09:18:15 -07:00

uid16.c

…

unwind.c

[PATCH] unwind: fix unused variable warning when !CONFIG_MODULES

2006-09-29 09:18:11 -07:00

user.c

…

wait.c

…

workqueue.c

[PATCH] workqueue: remove lock_cpu_hotplug()

2006-08-14 12:54:29 -07:00