In Neil's patch:
> + int ncpumask = (1<<(sysconf(_SC_NPROCESSORS_CONF)))-1;
> /*
> * The maximum line size consists of the string at the beginning plus
> * a digit for each 4 cpus and a comma for each 64 cpus.
> @@ -480,10 +481,22 @@ set_thread_constraints(void)
> fclose(f);
> free (buffer);
>
> - if (maxprocnode < 0) {
> + /*
> + * Cps_allowed in the kenrel can be defined to all f's
> + * i.e. it may be a superset of the actual available processors
> + * as such lets reduce maxproccpu with a mask of the actual
> + * available cpus
> + */
> + maxproccpu &= ncpumask;
I agree with the fix as long as the number of cpus does not exceed
the number of bits in an int. But that's a pretty small constraint.
I propose to trim maxprocnode to the number of configured cpus - 1.
(And fix the numa_all_cpus_ptr map of all cpus as well)
Then, in testing, I found that read_mask() was buggy. (the regression
tests don't uncover that). So that needed some tweaks as well.
Can you give that a try?
Signed-off-by: Cliff Wickman <cpw@xxxxxxx>
---
libnuma.c | 30 ++++++++++++++++++++++++++++--
1 file changed, 28 insertions(+), 2 deletions(-)
Index: numactl-dev/libnuma.c
===================================================================
--- numactl-dev.orig/libnuma.c
+++ numactl-dev/libnuma.c
@@ -394,6 +394,7 @@ int
read_mask(char *s, struct bitmask *bmp)
{
char *end = s;
+ char *prevend;
unsigned int *start = (unsigned int *)bmp->maskp;
unsigned int *p = start;
unsigned int *q;
@@ -402,9 +403,13 @@ read_mask(char *s, struct bitmask *bmp)
i = strtoul(s, &end, 16);
+ prevend = end;
/* Skip leading zeros */
- while (!i && *end++ == ',')
+ while (!i && *end++ == ',') {
+ prevend = end;
i = strtoul(end, &end, 16);
+ }
+ end = prevend;
if (!i)
/* End of string. No mask */
@@ -436,7 +441,7 @@ read_mask(char *s, struct bitmask *bmp)
/*
* Return the last bit set
*/
- return sizeof(unsigned int) * n + i;
+ return ((sizeof(unsigned int)*8) * n) + i;
}
/*
@@ -447,7 +452,9 @@ void
set_thread_constraints(void)
{
int max_cpus = numa_num_possible_cpus();
+ int hicpu = sysconf(_SC_NPROCESSORS_CONF)-1;
int buflen;
+ int i;
char *buffer;
FILE *f;
/*
@@ -480,6 +487,25 @@ set_thread_constraints(void)
fclose(f);
free (buffer);
+ /*
+ * Cpus_allowed in the kernel can be defined to all f's
+ * i.e. it may be a superset of the actual available processors.
+ * As such let's reduce maxproccpu to the number of actual
+ * available cpus - 1.
+ */
+ if (maxproccpu > hicpu) {
+ maxproccpu = hicpu;
+ for (i=hicpu+1; i<numa_all_cpus_ptr->size; i++) {
+ numa_bitmask_clearbit(numa_all_cpus_ptr, i);
+ }
+ }
+
+ /*
+ * Sanity checks
+ */
+ if (maxproccpu == 0)
+ numa_warn(W_cpumap, "Available cpus are empty set");
+
if (maxprocnode < 0) {
numa_warn(W_cpumap, "Cannot parse %s", mask_size_file);
return;
--
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