lib/cpuinfo: Increase the file descriptors limit to handle more CPUs

lib/common.c

@@ -43,6 +43,7 @@
 #include <stdlib.h>
 #include <string.h>
 #include <sys/mman.h>
+#include <sys/resource.h>
 #include <unistd.h>
 
 FILE *
@@ -392,3 +393,24 @@ pqos_read(int fd, void *buf, size_t count)
 
         return count;
 }
+
+int
+pqos_set_no_files_limit(unsigned long max_core_count)
+{
+        struct rlimit files_limit;
+
+        if (getrlimit(RLIMIT_NOFILE, &files_limit))
+                return PQOS_RETVAL_ERROR;
+
+        /* Check if rlim_max can handle the number of CPUs */
+        if (files_limit.rlim_max < max_core_count * 4)
+                return PQOS_RETVAL_ERROR;
+
+        if (files_limit.rlim_cur < max_core_count * 4) {
+                files_limit.rlim_cur = max_core_count * 4;
+                if (setrlimit(RLIMIT_NOFILE, &files_limit))
+                        return PQOS_RETVAL_ERROR;
+        }
+
+        return PQOS_RETVAL_OK;
+}

lib/common.h

@@ -200,6 +200,17 @@ PQOS_LOCAL void pqos_munmap(void *mem, const uint64_t size);
  */
 PQOS_LOCAL ssize_t pqos_read(int fd, void *buf, size_t count);
 
+/**
+ * @brief Increase the number of open files limit to handle more
+ * than 256 CPUs.
+ *
+ * @param [in] Max CPUs on the system
+ *
+ * @return PQOS_RETVAL_OK for success
+ * @retval PQOS_RETVAL_ERROR for failure
+ */
+PQOS_LOCAL int pqos_set_no_files_limit(unsigned long max_core_count);
+
 #ifdef __cplusplus
 }
 #endif

lib/cpuinfo.c

@@ -39,6 +39,7 @@
 
 #include "allocation.h"
 #include "cap.h"
+#include "common.h"
 #include "cpu_registers.h"
 #include "log.h"
 #include "machine.h"
@@ -57,6 +58,7 @@
 #endif
 #ifdef __linux__
 #include <sched.h> /* sched affinity */
+#include <sys/resource.h>
 #include <sys/syscall.h>
 #endif
 
@@ -452,6 +454,11 @@ cpuinfo_build_topo(struct apic_info *apic)
                 return NULL;
         }
 
+        if (pqos_set_no_files_limit(max_core_count)) {
+                LOG_ERROR("Open files limit not sufficient!\n");
+                return NULL;
+        }
+
         const size_t mem_sz =
             sizeof(*l_cpu) + (max_core_count * sizeof(struct pqos_coreinfo));
 

lib/os_cpuinfo.c

@@ -43,6 +43,7 @@
 #include <limits.h>
 #include <stdlib.h>
 #include <string.h>
+#include <sys/resource.h>
 
 #define SYSTEM_CPU  "/sys/devices/system/cpu"
 #define SYSTEM_NODE "/sys/devices/system/node"
@@ -267,6 +268,11 @@ os_cpuinfo_topology(void)
                 return NULL;
         }
 
+        if (pqos_set_no_files_limit(max_core_count)) {
+                LOG_ERROR("Open files limit not sufficient!\n");
+                return NULL;
+        }
+
         const size_t mem_sz =
             sizeof(*cpu) + (max_core_count * sizeof(struct pqos_coreinfo));
 

pqos/alloc.c

@@ -840,7 +840,7 @@ set_allocation_assoc(const struct pqos_devinfo *dev)
 static void
 fill_core_tab(char *str)
 {
-        unsigned max_cores_count = 128;
+        unsigned max_cores_count = sysconf(_SC_NPROCESSORS_CONF);
         uint64_t *cores = calloc(max_cores_count, sizeof(uint64_t));
         unsigned i = 0, n = 0, cos = 0;
         char *p = NULL;