linux/include
Tejun Heo bbddff0545 percpu: use percpu allocator on UP too
On UP, percpu allocations were redirected to kmalloc.  This has the
following problems.

* For certain amount of allocations (determined by
  PERCPU_DYNAMIC_EARLY_SLOTS and PERCPU_DYNAMIC_EARLY_SIZE), percpu
  allocator can be used before the usual kernel memory allocator is
  brought online.  On SMP, this is used to initialize the kernel
  memory allocator.

* percpu allocator honors alignment upto PAGE_SIZE but kmalloc()
  doesn't.  For example, workqueue makes use of larger alignments for
  cpu_workqueues.

Currently, users of percpu allocators need to handle UP differently,
which is somewhat fragile and ugly.  Other than small amount of
memory, there isn't much to lose by enabling percpu allocator on UP.
It can simply use kernel memory based chunk allocation which was added
for SMP archs w/o MMUs.

This patch removes mm/percpu_up.c, builds mm/percpu.c on UP too and
makes UP build use percpu-km.  As percpu addresses and kernel
addresses are always identity mapped and static percpu variables don't
need any special treatment, nothing is arch dependent and mm/percpu.c
implements generic setup_per_cpu_areas() for UP.

Signed-off-by: Tejun Heo <tj@kernel.org>
Reviewed-by: Christoph Lameter <cl@linux-foundation.org>
Acked-by: Pekka Enberg <penberg@cs.helsinki.fi>
2010-09-08 11:11:23 +02:00
..
acpi Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jbarnes/pci-2.6 2010-09-07 16:00:17 -07:00
asm-generic Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/percpu 2010-09-07 14:08:37 -07:00
crypto
drm Merge branch 'drm-core-next' of git://git.kernel.org/pub/scm/linux/kernel/git/airlied/drm-2.6 2010-08-23 18:28:03 -07:00
keys
linux percpu: use percpu allocator on UP too 2010-09-08 11:11:23 +02:00
math-emu
media
mtd
net tcp: Combat per-cpu skew in orphan tests. 2010-08-25 02:27:49 -07:00
pcmcia
rdma
rxrpc
scsi scsi: use __uX types for headers exported to user space 2010-08-11 08:59:01 -07:00
sound ALSA: emu10k1 - delay the PCM interrupts (add pcm_irq_delay parameter) 2010-08-18 15:10:59 +02:00
trace Merge branch 'perf-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip 2010-08-24 12:21:49 -07:00
video include: replace unifdef-y with header-y 2010-08-14 22:26:51 +02:00
xen xen: pvhvm: make it clearer that XEN_UNPLUG_* define bits in a bitfield 2010-08-23 12:01:35 +01:00
Kbuild