linux-stable.git/lib/cpumask.c, branch v3.16.78

cpumask_set_cpu_local_first => cpumask_local_spread, lament

2017-11-11T13:33:43+00:00

commit f36963c9d3f6f415732710da3acdd8608a9fa0e upstream.

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 
Signed-off-by: Arnd Bergmann 
Signed-off-by: Ben Hutchings

sched/fair, cpumask: Export for_each_cpu_wrap()

2017-10-12T14:27:42+00:00

commit c743f0a5c50f2fcbc628526279cfa24f3dabe182 upstream.

More users for for_each_cpu_wrap() have appeared. Promote the construct
to generic cpumask interface.

The implementation is slightly modified to reduce arguments.

Signed-off-by: Peter Zijlstra (Intel) 
Cc: Lauro Ramos Venancio 
Cc: Linus Torvalds 
Cc: Mike Galbraith 
Cc: Peter Zijlstra 
Cc: Rik van Riel 
Cc: Thomas Gleixner 
Cc: lwang@redhat.com
Link: http://lkml.kernel.org/r/20170414122005.o35me2h5nowqkxbv@hirez.programming.kicks-ass.net
Signed-off-by: Ingo Molnar 
[bwh: Backported to 3.16: there's no old version of the function to delete]
Signed-off-by: Ben Hutchings

lib/cpumask: cpumask_set_cpu_local_first to use all cores when numa node is not defined

2014-07-03T01:29:23+00:00

When device is non numa aware (numa_node == -1), use all online cpu's.

Signed-off-by: Amir Vadai 
Signed-off-by: David S. Miller

cpumask: Utility function to set n'th cpu - local cpu first

2014-06-11T21:58:16+00:00

This function sets the n'th cpu - local cpu's first.
For example: in a 16 cores server with even cpu's local, will get the
following values:
cpumask_set_cpu_local_first(0, numa, cpumask) => cpu 0 is set
cpumask_set_cpu_local_first(1, numa, cpumask) => cpu 2 is set
...
cpumask_set_cpu_local_first(7, numa, cpumask) => cpu 14 is set
cpumask_set_cpu_local_first(8, numa, cpumask) => cpu 1 is set
cpumask_set_cpu_local_first(9, numa, cpumask) => cpu 3 is set
...
cpumask_set_cpu_local_first(15, numa, cpumask) => cpu 15 is set

Curently this function will be used by multi queue networking devices to
calculate the irq affinity mask, such that as many local cpu's as
possible will be utilized to handle the mq device irq's.

Signed-off-by: Amir Vadai 
Signed-off-by: David S. Miller

net: Revert mlx4 cpumask changes.

2014-06-02T04:58:02+00:00

This reverts commit 70a640d0dae3a9b1b222ce673eb5d92c263ddd61
("net/mlx4_en: Use affinity hint") and commit
c8865b64b05b2f4eeefd369373e9c8aeb069e7a1 ("cpumask: Utility function
to set n'th cpu - local cpu first") because these changes break
the build when SMP is disabled amongst other things.

Reported-by: Eric Dumazet 
Signed-off-by: David S. Miller

cpumask: Utility function to set n'th cpu - local cpu first

2014-06-02T02:16:29+00:00

This function sets the n'th cpu - local cpu's first.
For example: in a 16 cores server with even cpu's local, will get the
following values:
cpumask_set_cpu_local_first(0, numa, cpumask) => cpu 0 is set
cpumask_set_cpu_local_first(1, numa, cpumask) => cpu 2 is set
...
cpumask_set_cpu_local_first(7, numa, cpumask) => cpu 14 is set
cpumask_set_cpu_local_first(8, numa, cpumask) => cpu 1 is set
cpumask_set_cpu_local_first(9, numa, cpumask) => cpu 3 is set
...
cpumask_set_cpu_local_first(15, numa, cpumask) => cpu 15 is set

Curently this function will be used by multi queue networking devices to
calculate the irq affinity mask, such that as many local cpu's as
possible will be utilized to handle the mq device irq's.

Signed-off-by: Amir Vadai 
Signed-off-by: David S. Miller

lib/cpumask.c: use memblock apis for early memory allocations

2014-01-22T00:19:47+00:00

Switch to memblock interfaces for early memory allocator instead of
bootmem allocator.  No functional change in beahvior than what it is in
current code from bootmem users points of view.

Archs already converted to NO_BOOTMEM now directly use memblock
interfaces instead of bootmem wrappers build on top of memblock.  And
the archs which still uses bootmem, these new apis just fallback to
exiting bootmem APIs.

Signed-off-by: Santosh Shilimkar 
Cc: "Rafael J. Wysocki" 
Cc: Arnd Bergmann 
Cc: Christoph Lameter 
Cc: Greg Kroah-Hartman 
Cc: Grygorii Strashko 
Cc: H. Peter Anvin 
Cc: Johannes Weiner 
Cc: KAMEZAWA Hiroyuki 
Cc: Konrad Rzeszutek Wilk 
Cc: Michal Hocko 
Cc: Paul Walmsley 
Cc: Pavel Machek 
Cc: Russell King 
Cc: Tejun Heo 
Cc: Tony Lindgren 
Cc: Yinghai Lu 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

bootmem: fix wrong call parameter for free_bootmem()

2012-12-12T01:22:28+00:00

It is strange that alloc_bootmem() returns a virtual address and
free_bootmem() requires a physical address.  Anyway, free_bootmem()'s
first parameter should be physical address.

There are some call sites for free_bootmem() with virtual address.  So fix
them.

[akpm@linux-foundation.org: improve free_bootmem() and free_bootmem_pate() documentation]
Signed-off-by: Joonsoo Kim 
Cc: Haavard Skinnemoen 
Cc: Hans-Christian Egtvedt 
Cc: Johannes Weiner 
Cc: FUJITA Tomonori 
Cc: Benjamin Herrenschmidt 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

lib/cpumask.c: remove __any_online_cpu()

2012-03-29T00:14:35+00:00

__any_online_cpu() is not optimal and also unnecessary.  So, replace its
use by faster cpumask_* operations.

Signed-off-by: Srivatsa S. Bhat 
Cc: Eric Dumazet 
Cc: Venkatesh Pallipadi 
Cc: Rusty Russell 
Cc: KOSAKI Motohiro 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

lib: reduce the use of module.h wherever possible

2012-03-07T20:04:04+00:00

For files only using THIS_MODULE and/or EXPORT_SYMBOL, map
them onto including export.h -- or if the file isn't even
using those, then just delete the include.  Fix up any implicit
include dependencies that were being masked by module.h along
the way.

Signed-off-by: Paul Gortmaker