improve the doc of the context factories

[simgrid.git] / src / smpi / smpi_bench.cpp

diff --git a/src/smpi/smpi_bench.cpp b/src/smpi/smpi_bench.cpp
index adbbd3d..3b01c90 100644 (file)
--- a/src/smpi/smpi_bench.cpp
+++ b/src/smpi/smpi_bench.cpp
@@ -1,5 +1,4 @@
-/* Copyright (c) 2007, 2009-2015. The SimGrid Team.
- * All rights reserved.                                                     */
+/* Copyright (c) 2007, 2009-2017. The SimGrid Team. All rights reserved.    */
 
 /* This program is free software; you can redistribute it and/or modify it
  * under the terms of the license (GNU LGPL) which comes with this package. */
@@ -21,11 +20,11 @@
 #include "simgrid/modelchecker.h"
 #include "src/mc/mc_replay.h"
 
+#include <sys/types.h>
 #ifndef WIN32
 #include <sys/mman.h>
 #endif
 #include <sys/stat.h>
-#include <sys/types.h>
 #include <errno.h>
 #include <fcntl.h>
 #include <math.h> // sqrt
@@ -80,7 +79,7 @@ xbt_dict_t samples = nullptr;         /* Allocated on first use */
 xbt_dict_t calls = nullptr;           /* Allocated on first use */
 
 double smpi_cpu_threshold;
-double smpi_running_power;
+double smpi_host_speed;
 
 int smpi_loaded_page = -1;
 char* smpi_start_data_exe = nullptr;
@@ -165,7 +164,6 @@ static size_t shm_size(int fd) {
 
 #ifndef WIN32
 static void* shm_map(int fd, size_t size, shared_data_key_type* data) {
-  void* mem;
   char loc[PTR_STRLEN];
   shared_metadata_t meta;
 
@@ -173,9 +171,14 @@ static void* shm_map(int fd, size_t size, shared_data_key_type* data) {
       xbt_die("Could not truncate fd %d to %zu: %s", fd, size, strerror(errno));
   }
 
-  mem = mmap(nullptr, size, PROT_READ | PROT_WRITE, MAP_SHARED, fd, 0);
+  void* mem = mmap(nullptr, size, PROT_READ | PROT_WRITE, MAP_SHARED, fd, 0);
   if(mem == MAP_FAILED) {
-    xbt_die("Could not map fd %d with size %zu: %s", fd, size, strerror(errno));
+    xbt_die(
+        "Failed to map fd %d with size %zu: %s\n"
+        "If you are running a lot of ranks, you may be exceeding the amount of mappings allowed per process.\n"
+        "On Linux systems, change this value with sudo sysctl -w vm.max_map_count=newvalue (default value: 65536)\n"
+        "Please see http://simgrid.gforge.inria.fr/simgrid/latest/doc/html/options.html#options_virt for more info.",
+        fd, size, strerror(errno));
   }
   snprintf(loc, PTR_STRLEN, "%p", mem);
   meta.size = size;
@@ -186,7 +189,7 @@ static void* shm_map(int fd, size_t size, shared_data_key_type* data) {
 }
 #endif
 
-void smpi_bench_destroy(void)
+void smpi_bench_destroy()
 {
   allocs.clear();
   allocs_metadata.clear();
@@ -207,9 +210,8 @@ void smpi_execute_(double *duration)
 }
 
 void smpi_execute_flops(double flops) {
-  smx_synchro_t action;
   XBT_DEBUG("Handle real computation time: %f flops", flops);
-  action = simcall_execution_start("computation", flops, 1, 0, 0);
+  smx_activity_t action = simcall_execution_start("computation", flops, 1, 0);
   simcall_set_category (action, TRACE_internal_smpi_get_category());
   simcall_execution_wait(action);
   smpi_switch_data_segment(smpi_process_index());
@@ -219,12 +221,13 @@ void smpi_execute(double duration)
 {
   if (duration >= smpi_cpu_threshold) {
     XBT_DEBUG("Sleep for %g to handle real computation time", duration);
-    double flops = duration * smpi_running_power;
+    double flops = duration * smpi_host_speed;
     int rank = smpi_process_index();
     instr_extra_data extra = xbt_new0(s_instr_extra_data_t,1);
     extra->type=TRACING_COMPUTING;
     extra->comp_size=flops;
     TRACE_smpi_computing_in(rank, extra);
+
     smpi_execute_flops(flops);
 
     TRACE_smpi_computing_out(rank);
@@ -235,7 +238,7 @@ void smpi_execute(double duration)
   }
 }
 
-void smpi_bench_begin(void)
+void smpi_bench_begin()
 {
   if (smpi_privatize_global_variables) {
     smpi_switch_data_segment(smpi_process_index());
@@ -260,7 +263,7 @@ void smpi_bench_begin(void)
   xbt_os_threadtimer_start(smpi_process_timer());
 }
 
-void smpi_bench_end(void)
+void smpi_bench_end()
 {
   if (MC_is_active() || MC_record_replay_is_active())
     return;
@@ -403,7 +406,7 @@ int smpi_clock_gettime(clockid_t clk_id, struct timespec *tp)
 #endif
 
 extern double sg_surf_precision;
-unsigned long long smpi_rastro_resolution (void)
+unsigned long long smpi_rastro_resolution ()
 {
   smpi_bench_end();
   double resolution = (1/sg_surf_precision);
@@ -411,7 +414,7 @@ unsigned long long smpi_rastro_resolution (void)
   return static_cast<unsigned long long>(resolution);
 }
 
-unsigned long long smpi_rastro_timestamp (void)
+unsigned long long smpi_rastro_timestamp ()
 {
   smpi_bench_end();
   double now = SIMIX_get_clock();
@@ -747,11 +750,15 @@ void smpi_initialize_global_memory_segments(){
 
   for (int i=0; i< smpi_process_count(); i++){
       //create SIMIX_process_count() mappings of this size with the same data inside
+      int file_descriptor;
       void *address = nullptr;
-      char path[] = "/dev/shm/my-buffer-XXXXXX";
+      char path[24];
       int status;
 
-      int file_descriptor= mkstemp (path);
+      do {
+        snprintf(path, sizeof(path), "/smpi-buffer-%06x", rand()%0xffffff);
+        file_descriptor = shm_open(path, O_RDWR|O_CREAT|O_EXCL, S_IRUSR|S_IWUSR);
+      } while (file_descriptor == -1 && errno == EEXIST);
       if (file_descriptor < 0) {
         if (errno==EMFILE) {
           xbt_die("Impossible to create temporary file for memory mapping: %s\n\
@@ -772,10 +779,6 @@ Ask the Internet about tutorials on how to increase the files limit such as: htt
             strerror(errno));
       }
 
-      status = unlink (path);
-      if (status)
-        xbt_die("Impossible to unlink temporary file for memory mapping");
-
       status = ftruncate(file_descriptor, smpi_size_data_exe);
       if(status)
         xbt_die("Impossible to set the size of the temporary file for memory mapping");
@@ -785,6 +788,10 @@ Ask the Internet about tutorials on how to increase the files limit such as: htt
       if (address == MAP_FAILED)
         xbt_die("Couldn't find a free region for memory mapping");
 
+      status = shm_unlink(path);
+      if (status)
+        xbt_die("Impossible to unlink temporary file for memory mapping");
+
       //initialize the values
       memcpy(address, TOPAGE(smpi_start_data_exe), smpi_size_data_exe);