From bae91ecf07384f09fcf94903b7c3d7e565f4f66d Mon Sep 17 00:00:00 2001 From: Karel Zak Date: Fri, 28 May 2010 11:08:39 +0200 Subject: taskset: move NR_CPUS determination to lib/cpuset.c Signed-off-by: Karel Zak --- lib/cpuset.c | 41 ++++++++++++++++++++++++++++++++++++++++- 1 file changed, 40 insertions(+), 1 deletion(-) (limited to 'lib') diff --git a/lib/cpuset.c b/lib/cpuset.c index d6cbf5d3..27b23498 100644 --- a/lib/cpuset.c +++ b/lib/cpuset.c @@ -18,6 +18,7 @@ #include #include #include +#include #include "cpuset.h" @@ -53,6 +54,38 @@ static const char *nexttoken(const char *q, int sep) return q; } +/* + * Number of bits in a CPU bitmask on current system + */ +int get_max_number_of_cpus(void) +{ + int n, cpus = 2048; + size_t setsize; + cpu_set_t *set = cpuset_alloc(cpus, &setsize, NULL); + + if (!set) + return -1; /* error */ + + for (;;) { + CPU_ZERO_S(setsize, set); + + /* the library version does not return size of cpumask_t */ + n = syscall(SYS_sched_getaffinity, 0, setsize, set); + + if (n < 0 && errno == EINVAL && cpus < 1024 * 1024) { + cpuset_free(set); + cpus *= 2; + set = cpuset_alloc(cpus, &setsize, NULL); + if (!set) + return -1; /* error */ + continue; + } + cpuset_free(set); + return n * 8; + } + return -1; +} + /* * Allocates a new set for ncpus and returns size in bytes and size in bits */ @@ -200,7 +233,13 @@ int cpumask_parse(const char *str, cpu_set_t *set, size_t setsize) CPU_ZERO_S(setsize, set); while (ptr >= str) { - char val = char_to_val(*ptr); + char val; + + /* cpu masks in /sys uses comma as a separator */ + if (*ptr == ',') + ptr--; + + val = char_to_val(*ptr); if (val == (char) -1) return -1; if (val & 1) -- cgit v1.2.3