Some distros have changed CPU_SETSIZE in glibc to 4096 since that matches
the NR_CPUS in the linux kernel config file. Some distros have decided to
leave CPU_SETSIZE at 1024. This is a problem if you want to run that distro
on a very large machine.
CPU_SETSIZE is use by the struct cpu_set_t. This means you to deal with cpus
greater the 1024 you must use the dynamic cpu sets, which involves converting
from things like CPU_SET to CPU_SET_S.
Cc: Jens Axboe <axboe@xxxxxxxxx>
Signed-off-by: Nathan Zimmer <nzimmer@xxxxxxx>
---
blktrace.c | 16 +++++++++++-----
btreplay/btreplay.c | 37 ++++++++++++++++++++++++++-----------
2 files changed, 37 insertions(+), 16 deletions(-)
diff --git a/blktrace.c b/blktrace.c
index 63125ab..7e64c94 100644
--- a/blktrace.c
+++ b/blktrace.c
@@ -621,13 +621,19 @@ static void dpp_free(struct devpath *dpp)
static int lock_on_cpu(int cpu)
{
- cpu_set_t cpu_mask;
-
- CPU_ZERO(&cpu_mask);
- CPU_SET(cpu, &cpu_mask);
- if (sched_setaffinity(0, sizeof(cpu_mask), &cpu_mask) < 0)
+ cpu_set_t * cpu_mask;
+ size_t size;
+ cpu_mask = CPU_ALLOC(ncpus);
+ size = CPU_ALLOC_SIZE(ncpus);
+
+ CPU_ZERO_S(size, cpu_mask);
+ CPU_SET_S(cpu, size, cpu_mask);
+ if (sched_setaffinity(0, size, cpu_mask) < 0) {
+ CPU_FREE(cpu_mask);
return errno;
+ }
+ CPU_FREE(cpu_mask);
return 0;
}
diff --git a/btreplay/btreplay.c b/btreplay/btreplay.c
index fe6cd80..783b208 100644
--- a/btreplay/btreplay.c
+++ b/btreplay/btreplay.c
@@ -505,10 +505,20 @@ static void get_ncpus(void)
#ifdef _SC_NPROCESSORS_CONF
ncpus = sysconf(_SC_NPROCESSORS_CONF);
#else
- long last_cpu;
- cpu_set_t cpus;
-
- if (sched_getaffinity(getpid(), sizeof(cpus), &cpus)) {
+ int nrcpus = 4096;
+ cpu_set_t * cpus;
+
+realloc:
+ cpus = CPU_ALLOC(nrcpus);
+ size = CPU_ALLOC_SIZE(nrcpus);
+ CPU_ZERO_S(size, cpus);
+
+ if (sched_getaffinity(getpid(), size, cpus)) {
+ if( errno == EINVAL && nrcpus < (4096<<4) ) {
+ CPU_FREE(cpus);
+ nrcpus <= 1;
+ goto realloc;
+ }
fatal("sched_getaffinity", ERR_SYSCALL, "Can't get CPU info\n");
/*NOTREACHED*/
}
@@ -518,6 +528,7 @@ static void get_ncpus(void)
if (CPU_ISSET( last_cpu, &cpus) )
ncpus = last_cpu;
ncpus++;
+ CPU_FREE(cpus);
#endif
if (ncpus == 0) {
fatal(NULL, ERR_SYSCALL, "Insufficient number of CPUs\n");
@@ -531,25 +542,29 @@ static void get_ncpus(void)
*/
static void pin_to_cpu(struct thr_info *tip)
{
- cpu_set_t cpus;
+ cpu_set_t * cpus;
+ size_t size;
+
+ cpus = CPU_ALLOC(ncpus);
+ size = CPU_ALLOC_SIZE(ncpus);
assert(0 <= tip->cpu && tip->cpu < ncpus);
- CPU_ZERO(&cpus);
- CPU_SET(tip->cpu, &cpus);
- if (sched_setaffinity(getpid(), sizeof(cpus), &cpus)) {
+ CPU_ZERO_S(ncpus, &cpus);
+ CPU_SET_S(tip->cpu, size, &cpus);
+ if (sched_setaffinity(getpid(), size, cpus)) {
fatal("sched_setaffinity", ERR_SYSCALL, "Failed to pin CPU\n");
/*NOTREACHED*/
}
if (verbose > 1) {
int i;
- cpu_set_t now;
+ cpu_set_t * now = CPU_ALLOC(ncpus);
- (void)sched_getaffinity(getpid(), sizeof(now), &now);
+ (void)sched_getaffinity(getpid(), size, now);
fprintf(tip->vfp, "Pinned to CPU %02d ", tip->cpu);
for (i = 0; i < ncpus; i++)
- fprintf(tip->vfp, "%1d", CPU_ISSET(i, &now));
+ fprintf(tip->vfp, "%1d", CPU_ISSET_S(i, size, now));
fprintf(tip->vfp, "\n");
}
}
--
1.8.1.2
--
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