aboutsummaryrefslogtreecommitdiff
diff options
context:
space:
mode:
authorJitendra Kolhe <jitendra.kolhe@hpe.com>2017-03-21 02:50:06 -0400
committerPaolo Bonzini <pbonzini@redhat.com>2017-03-24 11:50:11 +0100
commitdfd0dcc71724b11e125f67c8710c50c41da6ee4a (patch)
tree3b04f7c11560309afd136408fc20be996f24f18a
parent30663fd26c0307e414622c7a8607fbc04f92ec14 (diff)
mem-prealloc: fix sysconf(_SC_NPROCESSORS_ONLN) failure case.
This was spotted by Coverity, in case where sysconf(_SC_NPROCESSORS_ONLN) fails and returns -1. This results in memset_num_threads getting set to -1. Which we then pass to g_new0(). The patch replaces MAX_MEM_PREALLOC_THREAD_COUNT macro with a function call get_memset_num_threads() to handle sysconf() failure gracefully. In case sysconf() fails, we fall back to single threaded. (Spotted by Coverity, CID 1372465.) Signed-off-by: Jitendra Kolhe <jitendra.kolhe@hpe.com> Message-Id: <1490079006-32495-1-git-send-email-jitendra.kolhe@hpe.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
-rw-r--r--util/oslib-posix.c16
1 files changed, 14 insertions, 2 deletions
diff --git a/util/oslib-posix.c b/util/oslib-posix.c
index 3fe6089c3e..4d9189e9ef 100644
--- a/util/oslib-posix.c
+++ b/util/oslib-posix.c
@@ -55,7 +55,7 @@
#include "qemu/error-report.h"
#endif
-#define MAX_MEM_PREALLOC_THREAD_COUNT (MIN(sysconf(_SC_NPROCESSORS_ONLN), 16))
+#define MAX_MEM_PREALLOC_THREAD_COUNT 16
struct MemsetThread {
char *addr;
@@ -381,6 +381,18 @@ static void *do_touch_pages(void *arg)
return NULL;
}
+static inline int get_memset_num_threads(int smp_cpus)
+{
+ long host_procs = sysconf(_SC_NPROCESSORS_ONLN);
+ int ret = 1;
+
+ if (host_procs > 0) {
+ ret = MIN(MIN(host_procs, MAX_MEM_PREALLOC_THREAD_COUNT), smp_cpus);
+ }
+ /* In case sysconf() fails, we fall back to single threaded */
+ return ret;
+}
+
static bool touch_all_pages(char *area, size_t hpagesize, size_t numpages,
int smp_cpus)
{
@@ -389,7 +401,7 @@ static bool touch_all_pages(char *area, size_t hpagesize, size_t numpages,
int i = 0;
memset_thread_failed = false;
- memset_num_threads = MIN(smp_cpus, MAX_MEM_PREALLOC_THREAD_COUNT);
+ memset_num_threads = get_memset_num_threads(smp_cpus);
memset_thread = g_new0(MemsetThread, memset_num_threads);
numpages_per_thread = (numpages / memset_num_threads);
size_per_thread = (hpagesize * numpages_per_thread);