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[PATCH] cpumask: uninline first_cpu() text data bss dec hex filename before: 3490577 1322408 360000 5172985 4eeef9 vmlinux after: 3488027 1322496 360128 5170651 4ee5db vmlinux Cc: Paul Jackson <pj@sgi.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org> 2006-03-25 03:08:08 -08:00










[PATCH] cpumask: uninline next_cpu() text data bss dec hex filename before: 3488027 1322496 360128 5170651 4ee5db vmlinux after: 3485112 1322480 359968 5167560 4ed9c8 vmlinux 2931 bytes saved Cc: Paul Jackson <pj@sgi.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org> 2006-03-25 03:08:09 -08:00




[PATCH] cpumask: uninline highest_possible_processor_id() 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 <pj@sgi.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org> 2006-03-25 03:08:09 -08:00
x86: Add performance variants of cpumask operators * 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 <= 64 then most assembler bitmask operators execute faster with a constant range, so the operator will continue to use NR_CPUS. Another consideration is that nr_cpu_ids is initialized to NR_CPUS and isn't lowered until the possible cpus are discovered (including any disabled cpus). So early uses will span the entire range of NR_CPUS. (The net effect is that for systems with 64 or less CPU's there are no functional changes.) For inclusion into sched-devel/latest tree. Based on: git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux-2.6.git + sched-devel/latest .../mingo/linux-2.6-sched-devel.git Cc: Paul Jackson <pj@sgi.com> Cc: Christoph Lameter <clameter@sgi.com> Reviewed-by: Paul Jackson <pj@sgi.com> Reviewed-by: Christoph Lameter <clameter@sgi.com> Signed-off-by: Mike Travis <travis@sgi.com> Signed-off-by: Ingo Molnar <mingo@elte.hu> 2008-05-12 21:21:13 +02:00








[PATCH] cpumask: uninline any_online_cpu() text data bss dec hex filename before: 3605597 1363528 363328 5332453 515de5 vmlinux after: 3605295 1363612 363200 5332107 515c8b vmlinux 218 bytes saved. 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 <pj@sgi.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org> 2006-03-25 03:08:10 -08:00

37 lines 752 B Raw Normal View History

37 lines

752 B

Raw Normal View History