linux-toradex.git/include/linux/sched.h, branch v3.2.8-rt13

mm, rt: kmap_atomic scheduling

2012-02-15T16:33:02+00:00

In fact, with migrate_disable() existing one could play games with
kmap_atomic. You could save/restore the kmap_atomic slots on context
switch (if there are any in use of course), this should be esp easy now
that we have a kmap_atomic stack.

Something like the below.. it wants replacing all the preempt_disable()
stuff with pagefault_disable() && migrate_disable() of course, but then
you can flip kmaps around like below.

Signed-off-by: Peter Zijlstra 
[dvhart@linux.intel.com: build fix]
Link: http://lkml.kernel.org/r/1311842631.5890.208.camel@twins

softirq-local-lock.patch

2012-02-15T16:32:52+00:00

Signed-off-by: Thomas Gleixner

sched: teach migrate_disable about atomic contexts

2012-02-15T16:32:50+00:00

   [] spin_bug+0x94/0xa8
 [] do_raw_spin_lock+0x43/0xea
 [] _raw_spin_lock_irqsave+0x6b/0x85
 [] ? migrate_disable+0x75/0x12d
 [] ? pin_current_cpu+0x36/0xb0
 [] migrate_disable+0x75/0x12d
 [] pagefault_disable+0xe/0x1f
 [] copy_from_user_nmi+0x74/0xe6
 [] perf_callchain_user+0xf3/0x135

Now clearly we can't go around taking locks from NMI context, cure
this by short-circuiting migrate_disable() when we're in an atomic
context already.

Add some extra debugging to avoid things like:

  preempt_disable()
  migrate_disable();

  preempt_enable();
  migrate_enable();

Signed-off-by: Peter Zijlstra 
Link: http://lkml.kernel.org/r/1314967297.1301.14.camel@twins
Signed-off-by: Thomas Gleixner 
Link: http://lkml.kernel.org/n/tip-wbot4vsmwhi8vmbf83hsclk6@git.kernel.org

sched: Generic migrate_disable

2012-02-15T16:32:50+00:00

Make migrate_disable() be a preempt_disable() for !rt kernels. This
allows generic code to use it but still enforces that these code
sections stay relatively small.

A preemptible migrate_disable() accessible for general use would allow
people growing arbitrary per-cpu crap instead of clean these things
up.

Signed-off-by: Peter Zijlstra 
Link: http://lkml.kernel.org/n/tip-275i87sl8e1jcamtchmehonm@git.kernel.org

sched-migrate-disable.patch

2012-02-15T16:32:49+00:00

Signed-off-by: Thomas Gleixner

stomp-machine-mark-stomper-thread.patch

2012-02-15T16:32:48+00:00

Signed-off-by: Thomas Gleixner

cond-resched-lock-rt-tweak.patch

2012-02-15T16:32:48+00:00

Signed-off-by: Thomas Gleixner

sched-no-work-when-pi-blocked.patch

2012-02-15T16:32:48+00:00

Signed-off-by: Thomas Gleixner

cond-resched-softirq-fix.patch

2012-02-15T16:32:47+00:00

Signed-off-by: Thomas Gleixner

sched-rt-mutex-wakeup.patch

2012-02-15T16:32:47+00:00

Signed-off-by: Thomas Gleixner