linux.git/include/asm-powerpc/percpu.h, branch master

powerpc: Move include files to arch/powerpc/include/asm

2008-08-04T02:02:00+00:00

from include/asm-powerpc.  This is the result of a

mkdir arch/powerpc/include/asm
git mv include/asm-powerpc/* arch/powerpc/include/asm

Followed by a few documentation/comment fixups and a couple of places
where  was being used explicitly.  Of the latter only
one was outside the arch code and it is a driver only built for powerpc.

Signed-off-by: Stephen Rothwell 
Signed-off-by: Paul Mackerras

percpu: fix DEBUG_PREEMPT per_cpu checking

2008-02-23T20:09:28+00:00

2.6.25-rc1 percpu changes broke CONFIG_DEBUG_PREEMPT's per_cpu checking
on several architectures.  On s390, sparc64 and x86 it's been weakened to
not checking at all; whereas on powerpc64 it's become too strict, issuing
warnings from __raw_get_cpu_var in io_schedule and init_timer for example.

Fix this by weakening powerpc's __my_cpu_offset to use the non-checking
local_paca instead of get_paca (which itself contains such a check);
and strengthening the generic my_cpu_offset to go the old slow way via
smp_processor_id when CONFIG_DEBUG_PREEMPT (debug_smp_processor_id is
where all the knowledge of what's correct when lives).

Signed-off-by: Hugh Dickins 
Reviewed-by: Mike Travis 
Signed-off-by: Linus Torvalds

POWERPC: use generic per cpu

2008-01-30T22:27:58+00:00

Powerpc has a way to determine the address of the per cpu area of the
currently executing processor via the paca and the array of per cpu
offsets is avoided by looking up the per cpu area from the remote
paca's (copying x86_64).

Cc: Paul Mackerras 
Cc: Geert Uytterhoeven 
Signed-off-by: Mike Travis 
Signed-off-by: Ingo Molnar 
Acked-by: Olof Johansson 
Tested-by: Geoff Levand

modules: fold percpu_modcopy into module.c

2008-01-30T22:27:58+00:00

percpu_modcopy() is defined multiple times in arch files. However, the only
user is module.c. Put a static definition into module.c and remove
the definitions from the arch files.

Signed-off-by: Ingo Molnar

percpu: move arch XX_PER_CPU_XX definitions into linux/percpu.h

2008-01-30T12:32:52+00:00

- Special consideration for IA64: Add the ability to specify
  arch specific per cpu flags

- remove .data.percpu attribute from DEFINE_PER_CPU for non-smp case.

The arch definitions are all the same. So move them into linux/percpu.h.

We cannot move DECLARE_PER_CPU since some include files just include
asm/percpu.h to avoid include recursion problems.

Cc: Rusty Russell 
Cc: Andi Kleen 
Signed-off-by: Christoph Lameter 
Signed-off-by: Mike Travis 
Signed-off-by: Thomas Gleixner 
Signed-off-by: Ingo Molnar

[POWERPC] ppc64: support CONFIG_DEBUG_PREEMPT

2007-10-03T01:48:44+00:00

Add CONFIG_DEBUG_PREEMPT support to ppc64: it was useful for testing
get_paca() preemption.  Cheat a little, just use debug_smp_processor_id()
in the debug version of get_paca(): it contains all the right checks and
reporting, though get_paca() doesn't really use smp_processor_id().

Use local_paca for what might have been called __raw_get_paca().
Silence harmless warnings from io.h and lparcfg.c with local_paca -
it is okay for iseries_lparcfg_data to be referencing shared_proc
with preemption enabled: all cpus should show the same value for
shared_proc.

Why do other architectures need TRACE_IRQFLAGS_SUPPORT for DEBUG_PREEMPT?
I don't know, ppc64 appears to get along fine without it.

Signed-off-by: Hugh Dickins 
Signed-off-by: Paul Mackerras

define new percpu interface for shared data

2007-07-19T17:04:44+00:00

per cpu data section contains two types of data.  One set which is
exclusively accessed by the local cpu and the other set which is per cpu,
but also shared by remote cpus.  In the current kernel, these two sets are
not clearely separated out.  This can potentially cause the same data
cacheline shared between the two sets of data, which will result in
unnecessary bouncing of the cacheline between cpus.

One way to fix the problem is to cacheline align the remotely accessed per
cpu data, both at the beginning and at the end.  Because of the padding at
both ends, this will likely cause some memory wastage and also the
interface to achieve this is not clean.

This patch:

Moves the remotely accessed per cpu data (which is currently marked
as ____cacheline_aligned_in_smp) into a different section, where all the data
elements are cacheline aligned. And as such, this differentiates the local
only data and remotely accessed data cleanly.

Signed-off-by: Fenghua Yu 
Acked-by: Suresh Siddha 
Cc: Rusty Russell 
Cc: Christoph Lameter 
Cc: 
Cc: "Luck, Tony" 
Cc: Andi Kleen 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

[PATCH] lockdep: add per_cpu_offset()

2006-07-03T22:27:00+00:00

Add the per_cpu_offset() generic method. (used by the lock validator)

Signed-off-by: Ingo Molnar 
Signed-off-by: Arjan van de Ven 
Cc: Rusty Russell 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

[PATCH] Define __raw_get_cpu_var and use it

2006-06-25T17:01:01+00:00

There are several instances of per_cpu(foo, raw_smp_processor_id()), which
is semantically equivalent to __get_cpu_var(foo) but without the warning
that smp_processor_id() can give if CONFIG_DEBUG_PREEMPT is enabled.  For
those architectures with optimized per-cpu implementations, namely ia64,
powerpc, s390, sparc64 and x86_64, per_cpu() turns into more and slower
code than __get_cpu_var(), so it would be preferable to use __get_cpu_var
on those platforms.

This defines a __raw_get_cpu_var(x) macro which turns into per_cpu(x,
raw_smp_processor_id()) on architectures that use the generic per-cpu
implementation, and turns into __get_cpu_var(x) on the architectures that
have an optimized per-cpu implementation.

Signed-off-by: Paul Mackerras 
Acked-by: David S. Miller 
Acked-by: Ingo Molnar 
Acked-by: Martin Schwidefsky 
Cc: Rusty Russell 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

[PATCH] for_each_possible_cpu: powerpc

2006-03-29T02:44:15+00:00

for_each_cpu() actually iterates across all possible CPUs.  We've had mistakes
in the past where people were using for_each_cpu() where they should have been
iterating across only online or present CPUs.  This is inefficient and
possibly buggy.

We're renaming for_each_cpu() to for_each_possible_cpu() to avoid this in the
future.

This patch replaces for_each_cpu with for_each_possible_cpu.

Signed-off-by: KAMEZAWA Hiroyuki 
Signed-off-by: Andrew Morton 
Signed-off-by: Paul Mackerras