user/sven/linux.git/kernel/sched_debug.c, branch v2.6.34.6

sched: Fix an RCU warning in print_task()

2010-05-04T16:25:01Z

With CONFIG_PROVE_RCU=y, a warning can be triggered: $ cat /proc/sched_debug ... kernel/cgroup.c:1649 invoked rcu_dereference_check() without protection! ... Both cgroup_path() and task_group() should be called with either rcu_read_lock or cgroup_mutex held. The rcu_dereference_check() does include cgroup_lock_is_held(), so we know that this lock is not held. Therefore, in a CONFIG_PREEMPT kernel, to say nothing of a CONFIG_PREEMPT_RT kernel, the original code could have ended up copying a string out of the freelist. This patch inserts RCU read-side primitives needed to prevent this scenario. Signed-off-by: Li Zefan Signed-off-by: Paul E. McKenney

sched: Fix proc_sched_set_task()

2010-04-02T18:06:40Z

Latencytop clearing sum_exec_runtime via proc_sched_set_task() breaks task_times(). Other places in kernel use nvcsw and nivcsw, which are being cleared as well, Clear task statistics only. Reported-by: Török Edwin Signed-off-by: Mike Galbraith Cc: Hidetoshi Seto Cc: Arjan van de Ven Signed-off-by: Peter Zijlstra LKML-Reference: <1269940193.19286.14.camel@marge.simson.net> Signed-off-by: Ingo Molnar

sched: Convert rq->lock to raw_spinlock

2009-12-14T22:55:33Z

Convert locks which cannot be sleeping locks in preempt-rt to raw_spinlocks. Signed-off-by: Thomas Gleixner Acked-by: Peter Zijlstra Acked-by: Ingo Molnar

sched: Remove forced2_migrations stats

2009-12-10T19:32:39Z

This build warning: kernel/sched.c: In function 'set_task_cpu': kernel/sched.c:2070: warning: unused variable 'old_rq' Made me realize that the forced2_migrations stat looks pretty pointless (and a misnomer) - remove it. Cc: Peter Zijlstra Cc: Mike Galbraith LKML-Reference: Signed-off-by: Ingo Molnar

sched: Make tunable scaling style configurable

2009-12-09T09:04:01Z

As scaling now takes place on all kind of cpu add/remove events a user that configures values via proc should be able to configure if his set values are still rescaled or kept whatever happens. As the comments state that log2 was just a second guess that worked the interface is not just designed for on/off, but to choose a scaling type. Currently this allows none, log and linear, but more important it allwos us to keep the interface even if someone has an even better idea how to scale the values. Signed-off-by: Christian Ehrhardt Signed-off-by: Peter Zijlstra LKML-Reference: <1259579808-11357-3-git-send-email-ehrhardt@linux.vnet.ibm.com> Signed-off-by: Ingo Molnar

sched: Discard some old bits

2009-12-09T09:03:07Z

WAKEUP_RUNNING was an experiment, not sure why that ever ended up being merged... Signed-off-by: Peter Zijlstra LKML-Reference: Signed-off-by: Ingo Molnar

sched: Rate-limit newidle

2009-11-04T18:13:48Z

Rate limit newidle to migration_cost. It's a win for all stages of sysbench oltp tests. Signed-off-by: Mike Galbraith Cc: Peter Zijlstra LKML-Reference: Signed-off-by: Ingo Molnar

sched: Add new wakeup preemption mode: WAKEUP_RUNNING

2009-09-17T08:17:25Z

Create a new wakeup preemption mode, preempt towards tasks that run shorter on avg. It sets next buddy to be sure we actually run the task we preempted for. Test results: root@twins:~# while :; do :; done & [1] 6537 root@twins:~# while :; do :; done & [2] 6538 root@twins:~# while :; do :; done & [3] 6539 root@twins:~# while :; do :; done & [4] 6540 root@twins:/home/peter# ./latt -c4 sleep 4 Entries: 48 (clients=4) Averages: ------------------------------ Max 4750 usec Avg 497 usec Stdev 737 usec root@twins:/home/peter# echo WAKEUP_RUNNING > /debug/sched_features root@twins:/home/peter# ./latt -c4 sleep 4 Entries: 48 (clients=4) Averages: ------------------------------ Max 14 usec Avg 5 usec Stdev 3 usec Disabled by default - needs more testing. Signed-off-by: Peter Zijlstra Acked-by: Mike Galbraith Signed-off-by: Ingo Molnar LKML-Reference:

sched: Provide iowait counters

2009-09-02T06:44:08Z

For counting how long an application has been waiting for (disk) IO, there currently is only the HZ sample driven information available, while for all other counters in this class, a high resolution version is available via CONFIG_SCHEDSTATS. In order to make an improved bootchart tool possible, we also need a higher resolution version of the iowait time. This patch below adds this scheduler statistic to the kernel. Signed-off-by: Arjan van de Ven Signed-off-by: Peter Zijlstra LKML-Reference: <4A64B813.1080506@linux.intel.com> Signed-off-by: Ingo Molnar

sched: Hide runqueues from direct refer at source code level

2009-06-17T16:29:42Z

There are some points which refer the per-cpu value "runqueues" directly. sched.c provides nice abstraction, such as cpu_rq() and this_rq(), so we should use these macros when looking runqueues. Signed-off-by: Hitoshi Mitake LKML-Reference: <20090617.222055.374768827975756908.mitake@dcl.info.waseda.ac.jp> Signed-off-by: Ingo Molnar