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| author | Peter Zijlstra <peterz@infradead.org> | 2017-04-14 15:20:05 +0300 |
|---|---|---|
| committer | Ingo Molnar <mingo@kernel.org> | 2017-05-15 11:15:23 +0300 |
| commit | c743f0a5c50f2fcbc628526279cfa24f3dabe182 (patch) | |
| tree | f9f9f8c337e8e9a0366ee8e95032a21f19015c00 /lib | |
| parent | 8c0334697dc37eb3d6d7632304d3a3662248daac (diff) | |
| download | linux-c743f0a5c50f2fcbc628526279cfa24f3dabe182.tar.xz | |
sched/fair, cpumask: Export for_each_cpu_wrap()
More users for for_each_cpu_wrap() have appeared. Promote the construct
to generic cpumask interface.
The implementation is slightly modified to reduce arguments.
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Lauro Ramos Venancio <lvenanci@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Rik van Riel <riel@redhat.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: lwang@redhat.com
Link: http://lkml.kernel.org/r/20170414122005.o35me2h5nowqkxbv@hirez.programming.kicks-ass.net
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'lib')
| -rw-r--r-- | lib/cpumask.c | 32 |
1 files changed, 32 insertions, 0 deletions
diff --git a/lib/cpumask.c b/lib/cpumask.c index 81dedaab36cc..4731a0895760 100644 --- a/lib/cpumask.c +++ b/lib/cpumask.c @@ -43,6 +43,38 @@ int cpumask_any_but(const struct cpumask *mask, unsigned int cpu) } EXPORT_SYMBOL(cpumask_any_but); +/** + * cpumask_next_wrap - helper to implement for_each_cpu_wrap + * @n: the cpu prior to the place to search + * @mask: the cpumask pointer + * @start: the start point of the iteration + * @wrap: assume @n crossing @start terminates the iteration + * + * Returns >= nr_cpu_ids on completion + * + * Note: the @wrap argument is required for the start condition when + * we cannot assume @start is set in @mask. + */ +int cpumask_next_wrap(int n, const struct cpumask *mask, int start, bool wrap) +{ + int next; + +again: + next = cpumask_next(n, mask); + + if (wrap && n < start && next >= start) { + return nr_cpumask_bits; + + } else if (next >= nr_cpumask_bits) { + wrap = true; + n = -1; + goto again; + } + + return next; +} +EXPORT_SYMBOL(cpumask_next_wrap); + /* These are not inline because of header tangles. */ #ifdef CONFIG_CPUMASK_OFFSTACK /** |