linux-toradex.git/include/linux/sched.h, branch v2.6.29

cpumask: tsk_cpumask for accessing the struct task_struct's cpus_allowed.

2009-03-12T04:05:44+00:00

This allows us to change the representation (to a dangling bitmap or
cpumask_var_t) without breaking all the callers: they can use
tsk_cpumask() now and won't see a difference as the changes roll into
linux-next.

Signed-off-by: Rusty Russell

sched: don't allow setuid to succeed if the user does not have rt bandwidth

2009-02-27T10:11:53+00:00

Impact: fix hung task with certain (non-default) rt-limit settings

Corey Hickey reported that on using setuid to change the uid of a
rt process, the process would be unkillable and not be running.
This is because there was no rt runtime for that user group. Add
in a check to see if a user can attach an rt task to its task group.
On failure, return EINVAL, which is also returned in
CONFIG_CGROUP_SCHED.

Reported-by: Corey Hickey 
Signed-off-by: Dhaval Giani 
Acked-by: Peter Zijlstra 
Signed-off-by: Ingo Molnar

timers: fix TIMER_ABSTIME for process wide cpu timers

2009-02-11T13:04:21+00:00

The POSIX timer interface allows for absolute time expiry values through the
TIMER_ABSTIME flag, therefore we have to synchronize the timer to the clock
every time we start it.

Signed-off-by: Peter Zijlstra 
Signed-off-by: Ingo Molnar

timers: split process wide cpu clocks/timers, fix

2009-02-11T13:04:19+00:00

To decrease the chance of a missed enable, always enable the timer when we
sample it, we'll always disable it when we find that there are no active timers
in the jiffy tick.

This fixes a flood of warnings reported by Mike Galbraith.

Reported-by: Mike Galbraith 
Signed-off-by: Peter Zijlstra 
Signed-off-by: Ingo Molnar

timers: split process wide cpu clocks/timers, remove spurious warning

2009-02-06T13:57:51+00:00

Mike Galbraith reported that the new warning in thread_group_cputimer()
triggers en masse with Amarok running.

Oleg Nesterov observed:

  Can't fastpath_timer_check()->thread_group_cputimer() have the
  false warning too? Suppose we had the timer, then posix_cpu_timer_del()
  removes this timer, but task_cputime_zero(&sig->cputime_expires) still
  not true.

Remove the spurious debug warning.

Reported-by: Mike Galbraith 
Explained-by: Oleg Nesterov 
Signed-off-by: Ingo Molnar

timers: split process wide cpu clocks/timers

2009-02-05T12:04:33+00:00

Change the process wide cpu timers/clocks so that we:

 1) don't mess up the kernel with too many threads,
 2) don't have a per-cpu allocation for each process,
 3) have no impact when not used.

In order to accomplish this we're going to split it into two parts:

 - clocks; which can take all the time they want since they run
           from user context -- ie. sys_clock_gettime(CLOCK_PROCESS_CPUTIME_ID)

 - timers; which need constant time sampling but since they're
           explicity used, the user can pay the overhead.

The clock readout will go back to a full sum of the thread group, while the
timers will run of a global 'clock' that only runs when needed, so only
programs that make use of the facility pay the price.

Signed-off-by: Peter Zijlstra 
Reviewed-by: Ingo Molnar 
Signed-off-by: Ingo Molnar

signal: re-add dead task accumulation stats.

2009-02-05T12:04:33+00:00

We're going to split the process wide cpu accounting into two parts:

 - clocks; which can take all the time they want since they run
           from user context.

 - timers; which need constant time tracing but can affort the overhead
           because they're default off -- and rare.

The clock readout will go back to a full sum of the thread group, for this
we need to re-add the exit stats that were removed in the initial itimer
rework (f06febc9: timers: fix itimer/many thread hang).

Furthermore, since that full sum can be rather slow for large thread groups
and we have the complete dead task stats, revert the do_notify_parent time
computation.

Signed-off-by: Peter Zijlstra 
Reviewed-by: Ingo Molnar 
Signed-off-by: Ingo Molnar

sched: add missing kernel-doc in sched.h

2009-02-03T05:32:10+00:00

Add kernel-doc notation for @lock:

include/linux/sched.h:457: No description found for parameter 'lock'

Signed-off-by: Randy Dunlap 
Signed-off-by: Ingo Molnar

epoll: drop max_user_instances and rely only on max_user_watches

2009-01-30T02:04:45+00:00

Linus suggested to put limits where the money is, and max_user_watches
already does that w/out the need of max_user_instances.  That has the
advantage to mitigate the potential DoS while allowing pretty generous
default behavior.

Allowing top 4% of low memory (per user) to be allocated in epoll watches,
we have:

LOMEM    MAX_WATCHES (per user)
512MB    ~178000
1GB      ~356000
2GB      ~712000

A box with 512MB of lomem, will meet some challenge in hitting 180K
watches, socket buffers math teaches us.  No more max_user_instances
limits then.

Signed-off-by: Davide Libenzi 
Cc: Willy Tarreau 
Cc: Michael Kerrisk 
Cc: Bron Gondwana 
Cc: 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

Merge branch 'core-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip

2009-01-26T17:47:56+00:00

* 'core-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
  debugobjects: add and use INIT_WORK_ON_STACK
  rcu: remove duplicate CONFIG_RCU_CPU_STALL_DETECTOR
  relay: fix lock imbalance in relay_late_setup_files
  oprofile: fix uninitialized use of struct op_entry
  rcu: move Kconfig menu
  softlock: fix false panic which can occur if softlockup_thresh is reduced
  rcu: add __cpuinit to rcu_init_percpu_data()