linux-toradex.git/kernel/sched.c, branch tegra-10.9.4

mutex: Don't spin when the owner CPU is offline or other weird cases

2010-07-28T17:02:56+00:00

Due to recent load-balancer changes that delay the task migration to
the next wakeup, the adaptive mutex spinning ends up in a live lock
when the owner's CPU gets offlined because the cpu_online() check
lives before the owner running check.

This patch changes mutex_spin_on_owner() to return 0 (don't spin) in
any case where we aren't sure about the owner struct validity or CPU
number, and if the said CPU is offline. There is no point going back &
re-evaluate spinning in corner cases like that, let's just go to
sleep.

Cherry-picked commit: 4b402210486c6414fe5fbfd85934a0a22da56b04
URL: http://android.git.kernel.org/?p=kernel/linux-2.6.git;a=summary
Kernel version picked from: v2.6.34

Re-enable HAVE_DEFAULT_NO_SPIN_MUTEXES as root-cause of spin-lock is
now fixed in sched.c

For bug 713808

Change-Id: I06a7c85aa46be3cdd27da0a4e62ffa442a9805b4
Reviewed-on: http://git-master/r/4500
Tested-by: Bharat Nihalani 
Reviewed-by: Gary King

Merge commit 'v2.6.32.9' into android-2.6.32

2010-03-11T00:38:33+00:00

cgroup: Add generic cgroup subsystem permission checks.

2010-02-08T23:09:13+00:00

    Rather than using explicit euid == 0 checks when trying to move
tasks into a cgroup via CFS, move permission checks into each
specific cgroup subsystem. If a subsystem does not specify a
'can_attach' handler, then we fall back to doing our checks the old way.

    This way non-root processes can add arbitrary processes to
a cgroup if all the registered subsystems on that cgroup agree.

    Also change explicit euid == 0 check to CAP_SYS_ADMIN

Signed-off-by: San Mehat

sched: make task dump print all 15 chars of proc comm

2010-02-04T05:26:58+00:00

Change-Id: I1a5c9676baa06c9f9b4424bbcab01b9b2fbfcd99
Signed-off-by: Erik Gilling

sched: Enable might_sleep before initializing drivers.

2010-02-04T05:26:58+00:00

This allows detection of init bugs in built-in drivers.

Signed-off-by: Arve Hjønnevåg

sched: Fix task priority bug

2010-02-04T04:48:07+00:00

83f9ac removed a call to effective_prio() in wake_up_new_task(), which
leads to tasks running at MAX_PRIO.

This is caused by the idle thread being set to MAX_PRIO before forking
off init. O(1) used that to make sure idle was always preempted, CFS
uses check_preempt_curr_idle() for that so we can savely remove this bit
of legacy code.

Reported-by: Mike Galbraith 
Tested-by: Mike Galbraith 
Signed-off-by: Peter Zijlstra 
LKML-Reference: <1259754383.4003.610.camel@laptop>
Signed-off-by: Ingo Molnar

sched: Fix missing sched tunable recalculation on cpu add/remove

2010-01-28T23:01:11+00:00

commit 0bcdcf28c979869f44e05121b96ff2cfb05bd8e6 upstream.

Based on Peter Zijlstras patch suggestion this enables recalculation of
the scheduler tunables in response of a change in the number of cpus. It
also adds a max of eight cpus that are considered in that scaling.

Signed-off-by: Christian Ehrhardt 
Signed-off-by: Peter Zijlstra 
LKML-Reference: <1259579808-11357-2-git-send-email-ehrhardt@linux.vnet.ibm.com>
Signed-off-by: Ingo Molnar 
Signed-off-by: Greg Kroah-Hartman

sched: Fix isolcpus boot option

2010-01-28T23:01:09+00:00

commit bdddd2963c0264c56f18043f6fa829d3c1d3d1c0 upstream.

Anton Blanchard wrote:

> We allocate and zero cpu_isolated_map after the isolcpus
> __setup option has run. This means cpu_isolated_map always
> ends up empty and if CPUMASK_OFFSTACK is enabled we write to a
> cpumask that hasn't been allocated.

I introduced this regression in 49557e620339cb13 (sched: Fix
boot crash by zalloc()ing most of the cpu masks).

Use the bootmem allocator if they set isolcpus=, otherwise
allocate and zero like normal.

Reported-by: Anton Blanchard 
Signed-off-by: Rusty Russell 
Cc: peterz@infradead.org
Cc: Linus Torvalds 
Cc: 
LKML-Reference: <200912021409.17013.rusty@rustcorp.com.au>
Signed-off-by: Ingo Molnar 
Tested-by: Anton Blanchard

sched: Fix task priority bug

2010-01-22T23:18:40+00:00

commit 57785df5ac53c70da9fb53696130f3c551bfe1f9 upstream.

83f9ac removed a call to effective_prio() in wake_up_new_task(), which
leads to tasks running at MAX_PRIO.

This is caused by the idle thread being set to MAX_PRIO before forking
off init. O(1) used that to make sure idle was always preempted, CFS
uses check_preempt_curr_idle() for that so we can savely remove this bit
of legacy code.

Reported-by: Mike Galbraith 
Tested-by: Mike Galbraith 
Signed-off-by: Peter Zijlstra 
LKML-Reference: <1259754383.4003.610.camel@laptop>
Signed-off-by: Ingo Molnar 
Signed-off-by: Greg Kroah-Hartman

sched: Sched_rt_periodic_timer vs cpu hotplug

2010-01-06T23:05:17+00:00

commit 047106adcc85e3023da210143a6ab8a55df9e0fc upstream.

Heiko reported a case where a timer interrupt managed to
reference a root_domain structure that was already freed by a
concurrent hot-un-plug operation.

Solve this like the regular sched_domain stuff is also
synchronized, by adding a synchronize_sched() stmt to the free
path, this ensures that a root_domain stays present for any
atomic section that could have observed it.

Reported-by: Heiko Carstens 
Signed-off-by: Peter Zijlstra 
Acked-by: Heiko Carstens 
Cc: Gregory Haskins 
Cc: Siddha Suresh B 
Cc: Martin Schwidefsky 
LKML-Reference: <1258363873.26714.83.camel@laptop>
Signed-off-by: Ingo Molnar 
Signed-off-by: Greg Kroah-Hartman