linux-toradex.git/include/linux/cpumask.h, branch v4.9.6

cpumask: fix code comment

2016-08-02T23:35:24+00:00

Fix code comment for cpumask_parse().

Link: http://lkml.kernel.org/r/71aae2c60ae5dae0cf554199ce6aea8f88c69347.1465380581.git.geliangtang@gmail.com
Signed-off-by: Geliang Tang 
Acked-by: Rusty Russell 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

sched: Allow per-cpu kernel threads to run on online && !active

2016-05-06T12:58:22+00:00

In order to enable symmetric hotplug, we must mirror the online &&
!active state of cpu-down on the cpu-up side.

However, to retain sanity, limit this state to per-cpu kthreads.

Aside from the change to set_cpus_allowed_ptr(), which allow moving
the per-cpu kthreads on, the other critical piece is the cpu selection
for pinned tasks in select_task_rq(). This avoids dropping into
select_fallback_rq().

select_fallback_rq() cannot be allowed to select !active cpus because
its used to migrate user tasks away. And we do not want to move user
tasks onto cpus that are in transition.

Requested-by: Thomas Gleixner 
Signed-off-by: Peter Zijlstra (Intel) 
Tested-by: Thomas Gleixner 
Cc: Lai Jiangshan 
Cc: Jan H. Schönherr 
Cc: Oleg Nesterov 
Cc: rt@linutronix.de
Link: http://lkml.kernel.org/r/20160301152303.GV6356@twins.programming.kicks-ass.net
Signed-off-by: Thomas Gleixner

cpumask: remove incorrect information from comment

2016-03-22T22:36:02+00:00

Since commit cdfdef75e795 ("cpumask: only allocate nr_cpumask_bits."),
this comment above cpumask_size() is no longer relevant.

Signed-off-by: Eric Biggers 
Cc: Rusty Russell 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

kernel/cpu.c: make set_cpu_* static inlines

2016-01-21T01:09:18+00:00

Almost all callers of the set_cpu_* functions pass an explicit true or
false.  Making them static inline thus replaces the function calls with a
simple set_bit/clear_bit, saving some .text.

Signed-off-by: Rasmus Villemoes 
Acked-by: Rusty Russell 
Cc: Greg Kroah-Hartman 
Cc: Michael Ellerman 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

kernel/cpu.c: eliminate cpu_*_mask

2016-01-21T01:09:18+00:00

Replace the variables cpu_possible_mask, cpu_online_mask, cpu_present_mask
and cpu_active_mask with macros expanding to expressions of the same type
and value, eliminating some indirection.

Signed-off-by: Rasmus Villemoes 
Acked-by: Rusty Russell 
Cc: Greg Kroah-Hartman 
Cc: Michael Ellerman 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

kernel/cpu.c: export __cpu_*_mask

2016-01-21T01:09:18+00:00

Exporting the cpumasks __cpu_possible_mask and friends will allow us to
remove the extra indirection through the cpu_*_mask variables.  It will
also allow the set_cpu_* functions to become static inlines, which will
give a .text reduction.

Signed-off-by: Rasmus Villemoes 
Acked-by: Rusty Russell 
Cc: Greg Kroah-Hartman 
Cc: Michael Ellerman 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

cpumask_set_cpu_local_first => cpumask_local_spread, lament

2015-05-28T01:35:20+00:00

da91309e0a7e (cpumask: Utility function to set n'th cpu...) created a
genuinely weird function.  I never saw it before, it went through DaveM.
(He only does this to make us other maintainers feel better about our own
mistakes.)

cpumask_set_cpu_local_first's purpose is say "I need to spread things
across N online cpus, choose the ones on this numa node first"; you call
it in a loop.

It can fail.  One of the two callers ignores this, the other aborts and
fails the device open.

It can fail in two ways: allocating the off-stack cpumask, or through a
convoluted codepath which AFAICT can only occur if cpu_online_mask
changes.  Which shouldn't happen, because if cpu_online_mask can change
while you call this, it could return a now-offline cpu anyway.

It contains a nonsensical test "!cpumask_of_node(numa_node)".  This was
drawn to my attention by Geert, who said this causes a warning on Sparc.
It sets a single bit in a cpumask instead of returning a cpu number,
because that's what the callers want.

It could be made more efficient by passing the previous cpu rather than
an index, but that would be more invasive to the callers.

Fixes: da91309e0a7e8966d916a74cce42ed170fde06bf
Signed-off-by: Rusty Russell  (then rebased)
Tested-by: Amir Vadai 
Acked-by: Amir Vadai 
Acked-by: David S. Miller

cpumask: resurrect CPU_MASK_CPU0

2015-04-16T03:03:51+00:00

We removed it in 2f0f267ea072 (cpumask: remove deprecated functions.),
but grep shows it still used by MIPS, and not unreasonably.

Signed-off-by: Rusty Russell

linux/cpumask.h: add typechecking to cpumask_test_cpu

2015-03-31T03:25:31+00:00

The Subtlety (1) referred to vanished with 6ba2ef7baac2 ("cpumask:
Move deprecated functions to end of header."). That used to mention
some suboptimal code generation by a, by now, rather ancient gcc. With
gcc 4.7, I don't see any change in the generated code by making it a
static inline, so let's add type checking and get rid of the ghost
reference.

Signed-off-by: Rasmus Villemoes 
Signed-off-by: Rusty Russell

cpumask: only allocate nr_cpumask_bits.

2015-03-10T03:24:42+00:00

Now we'll find out the hard way if anyone has CPUMASK_OFFSTACK and is
returning these or assigning them.

Signed-off-by: Rusty Russell