Impact: kill unused functions
percpu_alloc() and its friends never saw much action. It was supposed
to replace the cpu-mask unaware __alloc_percpu() but it never happened
and in fact __percpu_alloc_mask() itself never really grew proper
up/down handling interface either (no exported interface for
populate/depopulate).
percpu allocation is about to go through major reimplementation and
there's no reason to carry this unused interface around. Replace it
with __alloc_percpu() and free_percpu().
Signed-off-by: Tejun Heo <tj@kernel.org>
This prepares for a real __alloc_percpu, by adding an alignment argument.
Only one place uses __alloc_percpu directly, and that's for a string.
tj: af_inet also uses __alloc_percpu(), update it.
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Cc: Christoph Lameter <cl@linux-foundation.org>
Cc: Jens Axboe <axboe@kernel.dk>
Impact: cleanup
There are two allocated per-cpu accessor macros with almost identical
spelling. The original and far more popular is per_cpu_ptr (44
files), so change over the other 4 files.
tj: kill percpu_ptr() and update UP too
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Cc: mingo@redhat.com
Cc: lenb@kernel.org
Cc: cpufreq@vger.kernel.org
Signed-off-by: Tejun Heo <tj@kernel.org>
Impact: bug fix
IA-64 needs to put percpu data in the seperate section even on UP.
Fixes regression caused by "percpu: refactor percpu.h"
Signed-off-by: Brian Gerst <brgerst@gmail.com>
Acked-by: Tony Luck <tony.luck@intel.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
This patch makes the following needlessly global functions static:
- percpu_depopulate()
- __percpu_depopulate_mask()
- percpu_populate()
- __percpu_populate_mask()
Signed-off-by: Adrian Bunk <bunk@kernel.org>
Acked-by: Christoph Lameter <cl@linux-foundation.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
While examining holes in percpu section I found this :
c05f5000 D per_cpu__current_task
c05f5000 D __per_cpu_start
c05f5004 D per_cpu__cpu_number
c05f5008 D per_cpu__irq_regs
c05f500c d per_cpu__cpu_devices
c05f5040 D per_cpu__cyc2ns
<Big Hole of about 4000 bytes>
c05f6000 d per_cpu__cpuid4_info
c05f6004 d per_cpu__cache_kobject
c05f6008 d per_cpu__index_kobject
<Big Hole of about 4000 bytes>
c05f7000 D per_cpu__gdt_page
This is because gdt_page is a percpu variable, defined with
a page alignement, and linker is doing its job, two times because of .o
nesting in the build process.
I introduced a new macro DEFINE_PER_CPU_PAGE_ALIGNED() to avoid
wasting this space. All page aligned variables (only one at this time)
are put in a separate
subsection .data.percpu.page_aligned, at the very begining of percpu zone.
Before patch , on a x86_32 machine :
.data.percpu 30232 3227471872
.data.percpu 22168 3227471872
Thats 8064 bytes saved for each CPU.
Signed-off-by: Eric Dumazet <dada1@cosmosbay.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Current module loader lookups ".data.percpu" ELF section to perform
per_cpu relocation. But DEFINE_PER_CPU_SHARED_ALIGNED() uses another
section (".data.percpu.shared_aligned"), currently only handled in
vmlinux.lds, not by module loader.
To correct this problem, instead of adding logic into module loader, or
using at build time a module.lds file for all arches to group
".data.percpu.shared_aligned" into ".data.percpu", just use ".data.percpu"
for modules.
Alignment requirements are correctly handled by ld and module loader.
Signed-off-by: Eric Dumazet <dada1@cosmosbay.com>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: Fenghua Yu <fenghua.yu@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
There's nothing in percpu.h that requires an explicit inclusion of
string.h.
Signed-off-by: Robert P. J. Day <rpjday@crashcourse.ca>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Instead of allocating a fix sized array of NR_CPUS pointers for percpu_data,
we can use nr_cpu_ids, which is generally < NR_CPUS.
Signed-off-by: Eric Dumazet <dada1@cosmosbay.com>
Cc: Christoph Lameter <clameter@sgi.com>
Cc: "David S. Miller" <davem@davemloft.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
ia64 has a special processor specific mapping that can be used to locate the
offset for the current per cpu area.
Cc: linux-ia64@vger.kernel.org
Signed-off-by: Mike Travis <travis@sgi.com>
Acked-by: Tony Luck <tony.luck@intel.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
- 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 <rusty@rustcorp.com.au>
Cc: Andi Kleen <ak@suse.de>
Signed-off-by: Christoph Lameter <clameter@sgi.com>
Signed-off-by: Mike Travis <travis@sgi.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Remove the obviously unnecessary includes of <linux/spinlock.h> under the
include/linux/ directory, and fix the couple errors that are introduced as
a result of that.
Signed-off-by: Robert P. J. Day <rpjday@mindspring.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Rather than using a single constant PERCPU_ENOUGH_ROOM, compute it as
the sum of kernel_percpu + PERCPU_MODULE_RESERVE. This is now common
to all architectures; if an architecture wants to set
PERCPU_ENOUGH_ROOM to something special, then it may do so (ia64 is
the only one which does).
Signed-off-by: Jeremy Fitzhardinge <jeremy@xensource.com>
Signed-off-by: Andi Kleen <ak@suse.de>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: Eric W. Biederman <ebiederm@xmission.com>
Cc: Andi Kleen <ak@suse.de>
Trivial typo fix in the "syntax error if percpu macros are incorrectly
used" patch. I misspelled "identifier" in all places. D'Oh!
Thanks to Dirk Mueller to point this out.
Signed-off-by: Jan Blunck <jblunck@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
... or we'll end up with cpu_online_map being evaluated on UP. In
modules. cpumask.h is very careful to avoid that, and for a very good
reason. So should we...
PS: yes, it really triggers (on alpha).
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This patch splits alloc_percpu() up into two phases. Likewise for
free_percpu(). This allows clients to limit initial allocations to online
cpu's, and to populate or depopulate per-cpu data at run time as needed:
struct my_struct *obj;
/* initial allocation for online cpu's */
obj = percpu_alloc(sizeof(struct my_struct), GFP_KERNEL);
...
/* populate per-cpu data for cpu coming online */
ptr = percpu_populate(obj, sizeof(struct my_struct), GFP_KERNEL, cpu);
...
/* access per-cpu object */
ptr = percpu_ptr(obj, smp_processor_id());
...
/* depopulate per-cpu data for cpu going offline */
percpu_depopulate(obj, cpu);
...
/* final removal */
percpu_free(obj);
Signed-off-by: Martin Peschke <mp3@de.ibm.com>
Cc: Paul Jackson <pj@sgi.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
get_cpu_var()/per_cpu()/__get_cpu_var() arguments must be simple
identifiers. Otherwise the arch dependent implementations might break.
This patch enforces the correct usage of the macros by producing a syntax
error if the variable is not a simple identifier.
Signed-off-by: Jan Blunck <jblunck@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
I found that blkp field was not used in kernel tree.
As most of the times NR_CPUS is a power of two and kmalloc() memory blocks
too, this extra field basically doubles the memory space allocated in
__alloc_percpu() to store the 'struct percpu_data'
(for example, if NR_CPUS=8 on i386, kmalloc(4*8+4) returns a 64 bytes block
instead of a 32 bytes block after this patch)
Signed-off-by: Eric Dumazet <dada1@cosmosbay.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
__alloc_percpu and alloc_percpu both take an 'align' argument which is
completely ignored. snmp6_mib_init() in net/ipv6/af_inet6.c attempts to use
it, but it will be ignored. Therefore, remove the 'align' argument and fixup
the lone caller.
Signed-off-by: Matthew Dobson <colpatch@us.ibm.com>
Acked-by: Manfred Spraul <manfred@colorfullife.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Currently per_cpu_ptr() doesn't really do anything with 'cpu' in the UP
case. This is problematic in the cases where this is the only place the
variable is referenced:
CC kernel/workqueue.o
kernel/workqueue.c: In function `current_is_keventd':
kernel/workqueue.c:460: warning: unused variable `cpu'
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.
Let it rip!
