01 Jan, 2009
2 commits
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Impact: extra safety checks during transition
When CONFIG_CPUMASKS_OFFSTACK is set, the new cpumask_ operators only
use bits up to nr_cpu_ids, not NR_CPUS. Using the old cpus_ operators
on these masks can mean accessing undefined bits.After some discussion, Mike and I decided to err on the side of caution;
we zero the "undefined" bits in alloc_cpumask_var_node() until all the
old cpumask functions are removed.Signed-off-by: Rusty Russell
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Impact: fix kernel-doc
alloc_bootmem_cpumask_var() returns avoid.
Signed-off-by: Li Zefan
Signed-off-by: Rusty Russell
19 Dec, 2008
2 commits
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Impact: New kerneldoc comments
Additional documentation added to all the alloc_cpumask and free_cpumask
functions.Signed-off-by: Mike Travis
Signed-off-by: Rusty Russell (minor additions) -
Impact: New API
This will be needed in x86 code to allocate the domain and old_domain
cpumasks on the same node as where the containing irq_cfg struct is
allocated.(Also fixes double-dump_stack on rare CONFIG_DEBUG_PER_CPU_MAPS case)
Signed-off-by: Mike Travis
Signed-off-by: Rusty Russell (re-impl alloc_cpumask_var)
10 Nov, 2008
1 commit
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Impact: cleanup
Clean up based on feedback from Andrew Morton and others:
- change to inline functions instead of macros
- add __init to bootmem method
- add a missing debug checkSigned-off-by: Rusty Russell
Signed-off-by: Ingo Molnar
07 Nov, 2008
1 commit
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- add cpumask_of()
- add free_bootmem_cpumask_var()Signed-off-by: Rusty Russell
Signed-off-by: Ingo Molnar
06 Nov, 2008
1 commit
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Impact: introduce new APIs
We want to deprecate cpumasks on the stack, as we are headed for
gynormous numbers of CPUs. Eventually, we want to head towards an
undefined 'struct cpumask' so they can never be declared on stack.1) New cpumask functions which take pointers instead of copies.
(cpus_* -> cpumask_*)2) Several new helpers to reduce requirements for temporary cpumasks
(cpumask_first_and, cpumask_next_and, cpumask_any_and)3) Helpers for declaring cpumasks on or offstack for large NR_CPUS
(cpumask_var_t, alloc_cpumask_var and free_cpumask_var)4) 'struct cpumask' for explicitness and to mark new-style code.
5) Make iterator functions stop at nr_cpu_ids (a runtime constant),
not NR_CPUS for time efficiency and for smaller dynamic allocations
in future.6) cpumask_copy() so we can allocate less than a full cpumask eventually
(for alloc_cpumask_var), and so we can eliminate the 'struct cpumask'
definition eventually.7) work_on_cpu() helper for doing task on a CPU, rather than saving old
cpumask for current thread and manipulating it.8) smp_call_function_many() which is smp_call_function_mask() except
taking a cpumask pointer.Note that this patch simply introduces the new functions and leaves
the obsolescent ones in place. This is to simplify the transition
patches.Signed-off-by: Rusty Russell
Signed-off-by: Ingo Molnar
24 May, 2008
1 commit
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* Increase performance for systems with large count NR_CPUS by limiting
the range of the cpumask operators that loop over the bits in a cpumask_t
variable. This removes a large amount of wasted cpu cycles.* Add performance variants of the cpumask operators:
int cpus_weight_nr(mask) Same using nr_cpu_ids instead of NR_CPUS
int first_cpu_nr(mask) Number lowest set bit, or nr_cpu_ids
int next_cpu_nr(cpu, mask) Next cpu past 'cpu', or nr_cpu_ids
for_each_cpu_mask_nr(cpu, mask) for-loop cpu over mask using nr_cpu_ids* Modify following to use performance variants:
#define num_online_cpus() cpus_weight_nr(cpu_online_map)
#define num_possible_cpus() cpus_weight_nr(cpu_possible_map)
#define num_present_cpus() cpus_weight_nr(cpu_present_map)#define for_each_possible_cpu(cpu) for_each_cpu_mask_nr((cpu), ...)
#define for_each_online_cpu(cpu) for_each_cpu_mask_nr((cpu), ...)
#define for_each_present_cpu(cpu) for_each_cpu_mask_nr((cpu), ...)* Comment added to include/linux/cpumask.h:
Note: The alternate operations with the suffix "_nr" are used
to limit the range of the loop to nr_cpu_ids instead of
NR_CPUS when NR_CPUS > 64 for performance reasons.
If NR_CPUS is
Cc: Christoph Lameter
Reviewed-by: Paul Jackson
Reviewed-by: Christoph Lameter
Signed-off-by: Mike Travis
Signed-off-by: Ingo Molnar
08 May, 2007
1 commit
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The nr_cpu_ids value is currently only calculated in smp_init. However, it
may be needed before (SLUB needs it on kmem_cache_init!) and other kernel
components may also want to allocate dynamically sized per cpu array before
smp_init. So move the determination of possible cpus into sched_init()
where we already loop over all possible cpus early in boot.Also initialize both nr_node_ids and nr_cpu_ids with the highest value they
could take. If we have accidental users before these values are determined
then the current valud of 0 may cause too small per cpu and per node arrays
to be allocated. If it is set to the maximum possible then we only waste
some memory for early boot users.Signed-off-by: Christoph Lameter
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
21 Feb, 2007
1 commit
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We frequently need the maximum number of possible processors in order to
allocate arrays for all processors. So far this was done using
highest_possible_processor_id(). However, we do need the number of
processors not the highest id. Moreover the number was so far dynamically
calculated on each invokation. The number of possible processors does not
change when the system is running. We can therefore calculate that number
once.Signed-off-by: Christoph Lameter
Cc: Frederik Deweerdt
Cc: Neil Brown
Cc: Trond Myklebust
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
21 Oct, 2006
1 commit
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Qooting Adrian:
- net/sunrpc/svc.c uses highest_possible_node_id()
- include/linux/nodemask.h says highest_possible_node_id() is
out-of-line #if MAX_NUMNODES > 1- the out-of-line highest_possible_node_id() is in lib/cpumask.c
- lib/Makefile: lib-$(CONFIG_SMP) += cpumask.o
CONFIG_ARCH_DISCONTIGMEM_ENABLE=y, CONFIG_SMP=n, CONFIG_SUNRPC=y-> highest_possible_node_id() is used in net/sunrpc/svc.c
CONFIG_NODES_SHIFT defined and > 0-> include/linux/numa.h: MAX_NUMNODES > 1
-> compile error
The bug is not present on architectures where ARCH_DISCONTIGMEM_ENABLE
depends on NUMA (but m32r isn't the only affected architecture).So move the function into page_alloc.c
Cc: Adrian Bunk
Cc: Paul Jackson
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
02 Oct, 2006
1 commit
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cpumask: add highest_possible_node_id(), analogous to
highest_possible_processor_id().[pj@sgi.com: fix typo]
Signed-off-by: Greg Banks
Signed-off-by: Paul Jackson
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
26 Mar, 2006
4 commits
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Also, optimise any_online_cpu() out of existence on CONFIG_SMP=n.
This function seems inefficient. Can't we simply AND the two masks, then use
find_first_bit()?Cc: Paul Jackson
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
Shrinks the only caller (net/bridge/netfilter/ebtables.c) by 174 bytes.
Also, optimise highest_possible_processor_id() out of existence on
CONFIG_SMP=n.Cc: Paul Jackson
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
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Cc: Paul Jackson
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
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after: 3488027 1322496 360128 5170651 4ee5db vmlinuxCc: Paul Jackson
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds