[PATCH v2] rt-numa: ignore runtime cpumask if -a CPULIST is specified

[Marcelo Tosatti <mtosatti@redhat.com>]

 
When using isolcpus kernel command line option, the CPUs
specified at isolcpus= are not part of the run time environment
cpumask.

This causes "cyclictest -a isolatedcpus" to fail with:

WARN: Couldn't setaffinity in main thread: Invalid argument
FATAL: No allowable cpus to run on
# /dev/cpu_dma_latency set to 0us

To fix this, ignore the runtime cpumask if neither "+", "!"
or "all" are specified in the cpu list string.

Suggested by Sebastian Andrzej Siewior.

Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>

---

v2: fix changelog typo

diff --git a/src/lib/rt-numa.c b/src/lib/rt-numa.c
index ee5ab99..d887355 100644
--- a/src/lib/rt-numa.c
+++ b/src/lib/rt-numa.c
@@ -9,6 +9,7 @@
 #include <errno.h>
 #include <sched.h>
 #include <pthread.h>
+#include <stdlib.h>
 
 #include "rt-error.h"
 #include "rt-numa.h"
@@ -96,13 +97,21 @@ int cpu_for_thread_ua(int thread_num, int max_cpus)
  * the user supplied affinity mask and the affinity mask from the run
  * time environment
  */
-static void use_current_cpuset(int max_cpus, struct bitmask *cpumask)
+static void use_current_cpuset(char *str, int max_cpus, struct bitmask *cpumask)
 {
 	struct bitmask *curmask;
 	int i;
 
 	curmask = numa_allocate_cpumask();
-	numa_sched_getaffinity(getpid(), curmask);
+
+	if (strchr(str, '!') == NULL && strchr(str, '+') == NULL &&
+	    strstr(str, "all") == NULL) {
+		int conf_cpus = numa_num_configured_cpus();
+
+		for (i = 0; i < conf_cpus; i++)
+			numa_bitmask_setbit(curmask, i);
+	} else
+		numa_sched_getaffinity(getpid(), curmask);
 
 	/*
 	 * Clear bits that are not set in both the cpuset from the
@@ -131,7 +140,7 @@ int parse_cpumask(char *str, int max_cpus, struct bitmask **cpumask)
 		return 0;
 	}
 
-	use_current_cpuset(max_cpus, mask);
+	use_current_cpuset(str, max_cpus, mask);
 	*cpumask = mask;
 
 	return 0;