Impact: prevents panic from stack overflow on numa-capable machines.

Some of the "removal of stack hogs" changes in kernel/sched.c by using
node_to_cpumask_ptr were undone by the early cpumask API updates, and
causes a panic due to stack overflow.  This patch undoes those changes
by using cpumask_of_node() which returns a 'const struct cpumask *'.

In addition, cpu_coregoup_map is replaced with cpu_coregroup_mask further
reducing stack usage.  (Both of these updates removed 9 FIXME's!)

Also:
   Pick up some remaining changes from the old 'cpumask_t' functions to
   the new 'struct cpumask *' functions.

   Optimize memory traffic by allocating each percpu local_cpu_mask on the
   same node as the referring cpu.
Signed-off-by: NMike Travis <travis@sgi.com>
Acked-by: NRusty Russell <rusty@rustcorp.com.au>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Impact: enables /sys/devices/system/cpu/{kernel_max,offline} user interface

By setting total_cpus, the drivers/base/cpu.c will display the
values of kernel_max (NR_CPUS-1) and the offlined cpu map.
Signed-off-by: NMike Travis <travis@sgi.com>
Acked-by: NRusty Russell <rusty@rustcorp.com.au>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Impact: build fix on ia64

ia64's default_affinity_write() still had old cpumask_t usage:

 /home/mingo/tip/kernel/irq/proc.c: In function `default_affinity_write':
 /home/mingo/tip/kernel/irq/proc.c:114: error: incompatible type for argument 1 of `is_affinity_mask_valid'
 make[3]: *** [kernel/irq/proc.o] Error 1
 make[3]: *** Waiting for unfinished jobs....

update it to cpumask_var_t.
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Impact: cleanup

This warning:

 kernel/rcuclassic.c: In function ‘rcu_start_batch’:
 kernel/rcuclassic.c:397: warning: passing argument 1 of ‘cpumask_andnot’ from incompatible pointer type

triggers because one usage site of rcp->cpumask was not converted
to to_cpumask(rcp->cpumask). There's no ill effects of this bug.
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Merge branch 'master' of git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux-2.6-cpumask into cpus4096-v2

Merge branch 'master' of git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux-2.6-cpumask into merge-rr-cpumask

Conflicts:
	arch/x86/kernel/io_apic.c
	kernel/rcuclassic.c
	kernel/sched.c
	kernel/time/tick-sched.c
Signed-off-by: NMike Travis <travis@sgi.com>
[ mingo@elte.hu: backmerged typo fix for io_apic.c ]
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Like fls, but can't be handed 0 and returns the bit number.
Signed-off-by: NRusty Russell <rusty@rustcorp.com.au>

Like fls, but can't be handed 0 and returns the bit number.
Signed-off-by: NRusty Russell <rusty@rustcorp.com.au>

Like fls, but can't be handed 0 and returns the bit number.
Signed-off-by: NRusty Russell <rusty@rustcorp.com.au>

Like fls, but can't be handed 0 and returns the bit number.
Signed-off-by: NRusty Russell <rusty@rustcorp.com.au>

Like fls, but can't be handed 0 and returns the bit number.
Signed-off-by: NRusty Russell <rusty@rustcorp.com.au>

Like fls, but can't be handed 0 and returns the bit number.
Signed-off-by: NRusty Russell <rusty@rustcorp.com.au>

Impact: new debug CONFIG options

This helps find unconverted code.  It currently breaks compile horribly,
but we never wanted a flag day so that's expected.
Signed-off-by: NRusty Russell <rusty@rustcorp.com.au>

Impact: extra safety checks during transition

When CONFIG_CPUMASKS_OFFSTACK is set, the new cpumask_ operators only
use bits up to nr_cpu_ids, not NR_CPUS.  Using the old cpus_ operators
on these masks can mean accessing undefined bits.

After some discussion, Mike and I decided to err on the side of caution;
we zero the "undefined" bits in alloc_cpumask_var_node() until all the
old cpumask functions are removed.
Signed-off-by: NRusty Russell <rusty@rustcorp.com.au>

Impact: cleanup

Simple replacement, now the _nr is redundant.
Signed-off-by: NRusty Russell <rusty@rustcorp.com.au>
Signed-off-by: NMike Travis <travis@sgi.com>
Cc: Ingo Molnar <mingo@redhat.com>

Impact: Use new API

Convert kernel mm functions to use struct cpumask.

We skip include/linux/percpu.h and mm/allocpercpu.c, which are in flux.
Signed-off-by: NRusty Russell <rusty@rustcorp.com.au>
Signed-off-by: NMike Travis <travis@sgi.com>
Reviewed-by: NChristoph Lameter <cl@linux-foundation.org>

Impact: Reduce stack usage, use new cpumask API.

Mainly changing cpumask_t to 'struct cpumask' and similar simple API
conversion.  Two conversions worth mentioning:

1) we use cpumask_any_but to avoid a temporary in kernel/softlockup.c,
2) Use cpumask_var_t in taskstats_user_cmd().
Signed-off-by: NRusty Russell <rusty@rustcorp.com.au>
Signed-off-by: NMike Travis <travis@sgi.com>
Cc: Balbir Singh <balbir@linux.vnet.ibm.com>
Cc: Ingo Molnar <mingo@redhat.com>

Impact: Reduce kernel stack and memory usage, use new cpumask API.

Use cpumask_var_t for take_cpu_down() stack var, and frozen_cpus.

Note that notify_cpu_starting() can be called before core_initcall
allocates frozen_cpus, but the NULL check is optimized out by gcc for
the CONFIG_CPUMASK_OFFSTACK=n case.
Signed-off-by: NRusty Russell <rusty@rustcorp.com.au>

Impact: Reduce kernel memory usage, use new cpumask API.

Avoid a static cpumask_t for prof_cpu_mask, and an on-stack cpumask_t
in prof_cpu_mask_write_proc.  Both become cpumask_var_t.

prof_cpu_mask is only allocated when profiling is on, but the NULL
checks are optimized out by gcc for the !CPUMASK_OFFSTACK case.

Also removed some strange and unnecessary casts.
Signed-off-by: NRusty Russell <rusty@rustcorp.com.au>

Impact: use new cpumask API.

rcu_ctrlblk contains a cpumask, and it's highly optimized so I don't want
a cpumask_var_t (ie. a pointer) for the CONFIG_CPUMASK_OFFSTACK case.  It
could use a dangling bitmap, and be allocated in __rcu_init to save memory,
but for the moment we use a bitmap.

(Eventually 'struct cpumask' will be undefined for CONFIG_CPUMASK_OFFSTACK,
so we use a bitmap here to show we really mean it).

We remove on-stack cpumasks, using cpumask_var_t for
rcu_torture_shuffle_tasks() and for_each_cpu_and in force_quiescent_state().
Signed-off-by: NRusty Russell <rusty@rustcorp.com.au>

Impact: Reduce stack usage, use new cpumask API.  ALPHA mod!

Main change is that irq_default_affinity becomes a cpumask_var_t, so
treat it as a pointer (this effects alpha).
Signed-off-by: NRusty Russell <rusty@rustcorp.com.au>

Impact: Use new APIs

Convert kernel/time functions to use struct cpumask *.

Note the ugly bitmap declarations in tick-broadcast.c.  These should
be cpumask_var_t, but there was no obvious initialization function to
put the alloc_cpumask_var() calls in.  This was safe.

(Eventually 'struct cpumask' will be undefined for CONFIG_CPUMASK_OFFSTACK,
so we use a bitmap here to show we really mean it).
Signed-off-by: NRusty Russell <rusty@rustcorp.com.au>
Signed-off-by: NMike Travis <travis@sgi.com>

Impact: Reduce memory usage, use new cpumask API.

cpu_populated_map becomes a cpumask_var_t, and cpu_singlethread_map is
simply a cpumask pointer: it's simply the cpumask containing the first
possible CPU anyway.
Signed-off-by: NRusty Russell <rusty@rustcorp.com.au>

Impact: Reduce stack usage, use new cpumask API.

Straightforward conversion; cpumasks' size is given by cpumask_size() (now
a variable rather than fixed) and on-stack cpu masks use cpumask_var_t.
Signed-off-by: NRusty Russell <rusty@rustcorp.com.au>

Impact: Remove obsolete API usage

any_online_cpu() is a good name, but it takes a cpumask_t, not a
pointer.

There are several places where any_online_cpu() doesn't really want a
mask arg at all.  Replace all callers with cpumask_any() and
cpumask_any_and().
Signed-off-by: NRusty Russell <rusty@rustcorp.com.au>
Signed-off-by: NMike Travis <travis@sgi.com>

Impact: Remove obsolete API usage

any_online_cpu() is a good name, but it takes a cpumask_t, not a
pointer.

There are several places where any_online_cpu() doesn't really want a
mask arg at all.  Replace all callers with cpumask_any() and
cpumask_any_and().
Signed-off-by: NRusty Russell <rusty@rustcorp.com.au>
Signed-off-by: NMike Travis <travis@sgi.com>

Impact: Reduce future memory usage, use new cpumask API.

Since the last patch was created and acked, more old cpumask users
slipped into kernel/trace.

Mostly trivial conversions, except struct trace_iterator's "started"
member becomes a cpumask_var_t.
Signed-off-by: NRusty Russell <rusty@rustcorp.com.au>

Impact: Reduce future memory usage, use new cpumask API.

(Eventually, cpumask_var_t will be allocated based on nr_cpu_ids, not NR_CPUS).

Convert kernel trace functions to use struct cpumask API:
1) Use cpumask_copy/cpumask_test_cpu/for_each_cpu.
2) Use cpumask_var_t and alloc_cpumask_var/free_cpumask_var everywhere.
3) Use on_each_cpu instead of playing with current->cpus_allowed.
Signed-off-by: NRusty Russell <rusty@rustcorp.com.au>
Signed-off-by: NMike Travis <travis@sgi.com>
Acked-by: NSteven Rostedt <rostedt@goodmis.org>

Impact: New API

The old topology_core_siblings() and topology_thread_siblings() return
a cpumask_t; these new ones return a (const) struct cpumask *.
Signed-off-by: NRusty Russell <rusty@rustcorp.com.au>
Signed-off-by: NMike Travis <travis@sgi.com>

Impact: New API

The old topology_core_siblings() and topology_thread_siblings() return
a cpumask_t; these new ones return a (const) struct cpumask *.
Signed-off-by: NRusty Russell <rusty@rustcorp.com.au>
Signed-off-by: NMike Travis <travis@sgi.com>

Impact: New API

The old topology_core_siblings() and topology_thread_siblings() return
a cpumask_t; these new ones return a (const) struct cpumask *.
Signed-off-by: NRusty Russell <rusty@rustcorp.com.au>
Signed-off-by: NMike Travis <travis@sgi.com>

Impact: New API

The old topology_core_siblings() and topology_thread_siblings() return
a cpumask_t; these new ones return a (const) struct cpumask *.
Signed-off-by: NRusty Russell <rusty@rustcorp.com.au>
Signed-off-by: NMike Travis <travis@sgi.com>

Impact: cleanup

There's one obvious place to use it: to find the highest possible cpu.
Signed-off-by: NRusty Russell <rusty@rustcorp.com.au>

Impact: New API

As the name suggests.  For the moment everyone uses the generic one.
Signed-off-by: NRusty Russell <rusty@rustcorp.com.au>

Like fls, but can't be handed 0 and returns the bit number.

(I broke this arch in linux-next by using __fls in generic code).
Signed-off-by: NRusty Russell <rusty@rustcorp.com.au>

Like fls, but can't be handed 0 and returns the bit number.

(I broke this arch in linux-next by using __fls in generic code).
Signed-off-by: NRusty Russell <rusty@rustcorp.com.au>

Like fls, but can't be handed 0 and returns the bit number.

(I broke this arch in linux-next by using __fls in generic code).
Signed-off-by: NRusty Russell <rusty@rustcorp.com.au>
Acked-by: NMike Frysinger <vapier@gentoo.org>

Like fls, but can't be handed 0 and returns the bit number.

(I broke this arch in linux-next by using __fls in generic code).
Signed-off-by: NRusty Russell <rusty@rustcorp.com.au>

This is defined in linux/cpumask.h (included in this file already),
and this is now defined differently.
Signed-off-by: NRusty Russell <rusty@rustcorp.com.au>
Cc: linux-parisc@vger.kernel.org

Impact: use new API

cpu_*_map are going away in favour of cpu_*_mask, but const pointers.
So we have accessors where we really do want to frob them.  Archs
will also need the (trivial) conversion before we can finally remove
cpu_*_map.
Signed-off-by: NRusty Russell <rusty@rustcorp.com.au>
Signed-off-by: NMike Travis <travis@sgi.com>