linux/kernel/sched.c, branch v2.6.13

[PATCH] Make RLIMIT_NICE ranges consistent with getpriority(2)

2005-08-18T19:53:58Z

As suggested by Michael Kerrisk , make RLIMIT_NICE consistent with getpriority before it becomes available in released glibc. Signed-off-by: Matt Mackall Acked-by: Ingo Molnar Acked-by: Chris Wright Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

[PATCH] fix MAX_USER_RT_PRIO and MAX_RT_PRIO

2005-07-26T22:40:00Z

Here's the patch again to fix the code to handle if the values between MAX_USER_RT_PRIO and MAX_RT_PRIO are different. Without this patch, an SMP system will crash if the values are different. Signed-off-by: Steven Rostedt Cc: Ingo Molnar Signed-off-by: Dean Nelson Signed-off-by: Linus Torvalds

[PATCH] Fix RLIMIT_RTPRIO breakage

2005-07-26T22:30:51Z

RLIMIT_RTPRIO is supposed to grant non privileged users the right to use SCHED_FIFO/SCHED_RR scheduling policies with priorites bounded by the RLIMIT_RTPRIO value via sched_setscheduler(). This is usually used by audio users. Unfortunately this is broken in 2.6.13rc3 as you can see in the excerpt from sched_setscheduler below: /* * Allow unprivileged RT tasks to decrease priority: */ if (!capable(CAP_SYS_NICE)) { /* can't change policy */ if (policy != p->policy) return -EPERM; After the above unconditional test which causes sched_setscheduler to fail with no regard to the RLIMIT_RTPRIO value the following check is made: /* can't increase priority */ if (policy != SCHED_NORMAL && param->sched_priority > p->rt_priority && param->sched_priority > p->signal->rlim[RLIMIT_RTPRIO].rlim_cur) return -EPERM; Thus I do believe that the RLIMIT_RTPRIO value must be taken into account for the policy check, especially as the RLIMIT_RTPRIO limit is of no use without this change. The attached patch fixes this problem. Signed-off-by: Andreas Steinmetz Acked-by: Ingo Molnar Signed-off-by: Linus Torvalds

[PATCH] cond_resched(): fix bogus might_sleep() warning

2005-07-08T01:23:47Z

The BKS might be reacquired before we have dropped PREEMPT_ACTIVE, which could trigger a second could trigger a second cond_resched() call. Bug found by Hirofumi Ogawa. Signed-off-by: Ingo Molnar Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

[PATCH] Tweak idle thread setup semantics

2005-06-28T21:56:51Z

This patch tweaks idle thread setup semantics a bit: instead of setting NEED_RESCHED in init_idle(), we do an explicit schedule() before calling into cpu_idle(). This patch, while having no negative side-effects, enables wider use of cond_resched()s. (which might happen in the stock kernel too, but it's particulary important for voluntary-preempt) Signed-off-by: Ingo Molnar Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

[PATCH] Update cfq io scheduler to time sliced design

2005-06-27T21:33:29Z

This updates the CFQ io scheduler to the new time sliced design (cfq v3). It provides full process fairness, while giving excellent aggregate system throughput even for many competing processes. It supports io priorities, either inherited from the cpu nice value or set directly with the ioprio_get/set syscalls. The latter closely mimic set/getpriority. This import is based on my latest from -mm. Signed-off-by: Jens Axboe Signed-off-by: Linus Torvalds

Merge Christoph's freeze cleanup patch

2005-06-26T00:16:53Z

[PATCH] Cleanup patch for process freezing

2005-06-26T00:10:13Z

1. Establish a simple API for process freezing defined in linux/include/sched.h: frozen(process) Check for frozen process freezing(process) Check if a process is being frozen freeze(process) Tell a process to freeze (go to refrigerator) thaw_process(process) Restart process frozen_process(process) Process is frozen now 2. Remove all references to PF_FREEZE and PF_FROZEN from all kernel sources except sched.h 3. Fix numerous locations where try_to_freeze is manually done by a driver 4. Remove the argument that is no longer necessary from two function calls. 5. Some whitespace cleanup 6. Clear potential race in refrigerator (provides an open window of PF_FREEZE cleared before setting PF_FROZEN, recalc_sigpending does not check PF_FROZEN). This patch does not address the problem of freeze_processes() violating the rule that a task may only modify its own flags by setting PF_FREEZE. This is not clean in an SMP environment. freeze(process) is therefore not SMP safe! Signed-off-by: Christoph Lameter Signed-off-by: Linus Torvalds

[PATCH] Dynamic sched domains: sched changes

2005-06-25T23:24:45Z

The following patches add dynamic sched domains functionality that was extensively discussed on lkml and lse-tech. I would like to see this added to -mm o The main advantage with this feature is that it ensures that the scheduler load balacing code only balances against the cpus that are in the sched domain as defined by an exclusive cpuset and not all of the cpus in the system. This removes any overhead due to load balancing code trying to pull tasks outside of the cpu exclusive cpuset only to be prevented by the tasks' cpus_allowed mask. o cpu exclusive cpusets are useful for servers running orthogonal workloads such as RT applications requiring low latency and HPC applications that are throughput sensitive o It provides a new API partition_sched_domains in sched.c that makes dynamic sched domains possible. o cpu_exclusive cpusets sets are now associated with a sched domain. Which means that the users can dynamically modify the sched domains through the cpuset file system interface o ia64 sched domain code has been updated to support this feature as well o Currently, this does not support hotplug. (However some of my tests indicate hotplug+preempt is currently broken) o I have tested it extensively on x86. o This should have very minimal impact on performance as none of the fast paths are affected Signed-off-by: Dinakar Guniguntala Acked-by: Paul Jackson Acked-by: Nick Piggin Acked-by: Matthew Dobson Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

[PATCH] Changing RT priority without CAP_SYS_NICE

2005-06-25T23:24:44Z

Presently, a process without the capability CAP_SYS_NICE can not change its own policy, which is OK. But it can also not decrease its RT priority (if scheduled with policy SCHED_RR or SCHED_FIFO), which is what this patch changes. The rationale is the same as for the nice value: a process should be able to require less priority for itself. Increasing the priority is still not allowed. This is for example useful if you give a multithreaded user process a RT priority, and the process would like to organize its internal threads using priorities also. Then you can give the process the highest priority needed N, and the process starts its threads with lower priorities: N-1, N-2... The POSIX norm says that the permissions are implementation specific, so I think we can do that. In a sense, it makes the permissions consistent whatever the policy is: with this patch, process scheduled by SCHED_FIFO, SCHED_RR and SCHED_OTHER can all decrease their priority. From: Ingo Molnar cleaned up and merged to -mm. Signed-off-by: Ingo Molnar Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds