Messages in this thread Patch in this message | | | Date | Sun, 19 Mar 2006 14:35:13 -0800 | From | Andrew Morton <> | Subject | Re: OOPS: 2.6.16-rc6 cpufreq_conservative |
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Linus Torvalds <torvalds@osdl.org> wrote: > > How does this patch look? >
Wonderful - coz it's just like mine ;)
(4 patches temp-joined below)
- I made SMP=n next_cpu() just a constant "1".
- It's odd that the code uses (NR_CPUS>1) rather than CONFIG_SMP. On x86 (at least), SMP=y,NR_CPUS==1 isn't allowed anyway.
From: Andrew Morton <akpm@osdl.org>
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> DESC cpumask: uninline next_cpu() EDESC From: Andrew Morton <akpm@osdl.org>
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> DESC cpumask: uninline highest_possible_processor_id() EDESC From: Andrew Morton <akpm@osdl.org>
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> DESC cpumask: uninline any_online_cpu() EDESC From: Andrew Morton <akpm@osdl.org>
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> ---
include/linux/cpumask.h | 46 ++++++++++++++------------------------ lib/Makefile | 2 + lib/cpumask.c | 45 +++++++++++++++++++++++++++++++++++++ 3 files changed, 64 insertions(+), 29 deletions(-)
diff -puN include/linux/cpumask.h~cpumask-uninline-first_cpu include/linux/cpumask.h --- devel/include/linux/cpumask.h~cpumask-uninline-first_cpu 2006-03-19 14:26:35.000000000 -0800 +++ devel-akpm/include/linux/cpumask.h 2006-03-19 14:28:45.000000000 -0800 @@ -212,17 +212,15 @@ static inline void __cpus_shift_left(cpu bitmap_shift_left(dstp->bits, srcp->bits, n, nbits); } -#define first_cpu(src) __first_cpu(&(src), NR_CPUS) -static inline int __first_cpu(const cpumask_t *srcp, int nbits) -{ - return min_t(int, nbits, find_first_bit(srcp->bits, nbits)); -} - -#define next_cpu(n, src) __next_cpu((n), &(src), NR_CPUS) -static inline int __next_cpu(int n, const cpumask_t *srcp, int nbits) -{ - return min_t(int, nbits, find_next_bit(srcp->bits, nbits, n+1)); -} +#ifdef CONFIG_SMP +int __first_cpu(const cpumask_t *srcp); +#define first_cpu(src) __first_cpu(&(src)) +int __next_cpu(int n, const cpumask_t *srcp); +#define next_cpu(n, src) __next_cpu((n), &(src)) +#else +#define first_cpu(src) 0 +#define next_cpu(n, src) 1 +#endif #define cpumask_of_cpu(cpu) \ ({ \ @@ -398,27 +396,17 @@ extern cpumask_t cpu_present_map; #define cpu_present(cpu) ((cpu) == 0) #endif -#define any_online_cpu(mask) \ -({ \ - int cpu; \ - for_each_cpu_mask(cpu, (mask)) \ - if (cpu_online(cpu)) \ - break; \ - cpu; \ -}) +#ifdef CONFIG_SMP +int highest_possible_processor_id(void); +#define any_online_cpu(mask) __any_online_cpu(&(mask)) +int __any_online_cpu(const cpumask_t *mask); +#else +#define highest_possible_processor_id() 0 +#define any_online_cpu(mask) 0 +#endif #define for_each_cpu(cpu) for_each_cpu_mask((cpu), cpu_possible_map) #define for_each_online_cpu(cpu) for_each_cpu_mask((cpu), cpu_online_map) #define for_each_present_cpu(cpu) for_each_cpu_mask((cpu), cpu_present_map) -/* Find the highest possible smp_processor_id() */ -#define highest_possible_processor_id() \ -({ \ - unsigned int cpu, highest = 0; \ - for_each_cpu_mask(cpu, cpu_possible_map) \ - highest = cpu; \ - highest; \ -}) - - #endif /* __LINUX_CPUMASK_H */ diff -puN /dev/null lib/cpumask.c --- /dev/null 2003-09-15 06:40:47.000000000 -0700 +++ devel-akpm/lib/cpumask.c 2006-03-19 14:28:45.000000000 -0800 @@ -0,0 +1,45 @@ +#include <linux/kernel.h> +#include <linux/bitops.h> +#include <linux/cpumask.h> +#include <linux/module.h> + +int __first_cpu(const cpumask_t *srcp) +{ + return min_t(int, NR_CPUS, find_first_bit(srcp->bits, NR_CPUS)); +} +EXPORT_SYMBOL(__first_cpu); + +int __next_cpu(int n, const cpumask_t *srcp) +{ + return min_t(int, NR_CPUS, find_next_bit(srcp->bits, NR_CPUS, n+1)); +} +EXPORT_SYMBOL(__next_cpu); + +/* + * Find the highest possible smp_processor_id() + * + * Note: if we're prepared to assume that cpu_possible_map never changes + * (reasonable) then this function should cache its return value. + */ +int highest_possible_processor_id(void) +{ + unsigned int cpu; + unsigned highest = 0; + + for_each_cpu_mask(cpu, cpu_possible_map) + highest = cpu; + return highest; +} +EXPORT_SYMBOL(highest_possible_processor_id); + +int __any_online_cpu(const cpumask_t *mask) +{ + int cpu; + + for_each_cpu_mask(cpu, *mask) { + if (cpu_online(cpu)) + break; + } + return cpu; +} +EXPORT_SYMBOL(__any_online_cpu); diff -puN lib/Makefile~cpumask-uninline-first_cpu lib/Makefile --- devel/lib/Makefile~cpumask-uninline-first_cpu 2006-03-19 14:26:35.000000000 -0800 +++ devel-akpm/lib/Makefile 2006-03-19 14:26:35.000000000 -0800 @@ -7,6 +7,8 @@ lib-y := errno.o ctype.o string.o vsprin idr.o div64.o int_sqrt.o bitmap.o extable.o prio_tree.o \ sha1.o +lib-$(CONFIG_SMP) += cpumask.o + lib-y += kobject.o kref.o kobject_uevent.o klist.o obj-y += sort.o parser.o halfmd4.o iomap_copy.o _ - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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