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| author | Jitendra Kolhe <jitendra.kolhe@hpe.com> | 2017-03-21 02:50:06 -0400 |
|---|---|---|
| committer | Paolo Bonzini <pbonzini@redhat.com> | 2017-03-24 11:50:11 +0100 |
| commit | dfd0dcc71724b11e125f67c8710c50c41da6ee4a (patch) | |
| tree | 3b04f7c11560309afd136408fc20be996f24f18a /util/oslib-posix.c | |
| parent | 30663fd26c0307e414622c7a8607fbc04f92ec14 (diff) | |
| download | qemu-dfd0dcc71724b11e125f67c8710c50c41da6ee4a.tar.gz | |
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>
Diffstat (limited to 'util/oslib-posix.c')
| -rw-r--r-- | util/oslib-posix.c | 16 |
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); |