MINOR: thread: turn thread_cpu_mask_forced() into an init-time variable

The function is not convenient because it doesn't allow us to undo the
startup changes, and depending on where it's being used, we don't know
whether the values read have already been altered (this is not the case
right now but it's going to evolve).

Let's just compute the status during cpu_detect_usable() and set a
variable accordingly. This way we'll always read the init value, and
if needed we can even afford to reset it. Also, placing it in cpu_topo.c
limits cross-file dependencies (e.g. threads without affinity etc).

diff --git a/include/haproxy/cpu_topo.h b/include/haproxy/cpu_topo.h
index 1ef64189839b746d653bd55c6489ef3fdb7ba073..72c611380d50d509fafdb278c5670cb13653f662 100644 (file)
--- a/include/haproxy/cpu_topo.h
+++ b/include/haproxy/cpu_topo.h
@@ -9,6 +9,9 @@ extern int cpu_topo_maxcpus;
 extern int cpu_topo_lastcpu;
 extern struct ha_cpu_topo *ha_cpu_topo;
 
+/* non-zero if we're certain that taskset or similar was used to force CPUs */
+extern int cpu_mask_forced;
+
 /* Detects CPUs that are online on the system. It may rely on FS access (e.g.
  * /sys on Linux). Returns the number of CPUs detected or 0 if the detection
  * failed.

diff --git a/include/haproxy/thread.h b/include/haproxy/thread.h
index 0984c67272bb6b278a6ba5c2c70ca704f9c6663b..7233b675409373cf73c163d5ea078589af129cf9 100644 (file)
--- a/include/haproxy/thread.h
+++ b/include/haproxy/thread.h
@@ -298,11 +298,6 @@ static inline unsigned long thread_isolated()
        return _HA_ATOMIC_LOAD(&isolated_thread) == tid;
 }
 
-/* Returns 1 if the cpu set is currently restricted for the process else 0.
- * Currently only implemented for the Linux platform.
- */
-int thread_cpu_mask_forced(void);
-
 #if !defined(DEBUG_THREAD) && !defined(DEBUG_FULL)
 
 /* Thread debugging is DISABLED, these are the regular locking functions */

diff --git a/src/cfgparse.c b/src/cfgparse.c
index 9f93f6c34b8d666dff0c1dc9532457f5cbf677af..f63c259923c3bbfb0361488f98b3361e4b894a5b 100644 (file)
--- a/src/cfgparse.c
+++ b/src/cfgparse.c
@@ -2922,7 +2922,7 @@ int check_config_validity()
                {
                        int numa_cores = 0;
 #if defined(USE_CPU_AFFINITY)
-                       if (global.numa_cpu_mapping && !thread_cpu_mask_forced() && !cpu_map_configured())
+                       if (global.numa_cpu_mapping && !cpu_mask_forced && !cpu_map_configured())
                                numa_cores = numa_detect_topology();
 #endif
                        global.nbthread = numa_cores ? numa_cores :

diff --git a/src/cpu_topo.c b/src/cpu_topo.c
index 90ae35d4d19c9cdd4d3a344a65d55c5c01da4494..15dd5b5a9c9394eaad0788345b113e55b402828e 100644 (file)
--- a/src/cpu_topo.c
+++ b/src/cpu_topo.c
@@ -17,6 +17,8 @@ int cpu_topo_lastcpu  = -1;  // last supposed online CPU (no need to look beyond
 struct ha_cpu_topo *ha_cpu_topo = NULL;
 struct cpu_map *cpu_map;
 
+/* non-zero if we're certain that taskset or similar was used to force CPUs */
+int cpu_mask_forced = 0;
 
 /* Detects CPUs that are online on the system. It may rely on FS access (e.g.
  * /sys on Linux). Returns the number of CPUs detected or 0 if the detection
@@ -91,14 +93,19 @@ int cpu_detect_usable(void)
 
        /* Update the list of currently offline CPUs. Normally it's a subset
         * of the unbound ones, but we cannot infer anything if we don't have
-        * the info so we only update what we know.
+        * the info so we only update what we know. We take this opportunity
+        * for detecting that some online CPUs are not bound, indicating that
+        * taskset or equivalent was used.
         */
        if (ha_cpuset_detect_online(&boot_set)) {
                for (cpu = 0; cpu < cpu_topo_maxcpus; cpu++) {
-                       if (!ha_cpuset_isset(&boot_set, cpu))
+                       if (!ha_cpuset_isset(&boot_set, cpu)) {
                                ha_cpu_topo[cpu].st |= HA_CPU_F_OFFLINE;
-                       else
+                       } else {
                                cpu_topo_lastcpu = cpu;
+                               if (ha_cpu_topo[cpu].st & HA_CPU_F_EXCLUDED)
+                                       cpu_mask_forced = 1;
+                       }
                }
        }
 

diff --git a/src/thread.c b/src/thread.c
index 1606249938ab91b4ae54158e2e5dd195f7dabd05..64d16acd39cfb334b4a31efec570f77551b0039a 100644 (file)
--- a/src/thread.c
+++ b/src/thread.c
@@ -390,19 +390,6 @@ static int thread_cpus_enabled()
        return ret;
 }
 
-/* Returns 1 if the cpu set is currently restricted for the process else 0.
- * Currently only implemented for the Linux platform.
- */
-int thread_cpu_mask_forced()
-{
-#if defined(__linux__)
-       const int cpus_avail = sysconf(_SC_NPROCESSORS_ONLN);
-       return cpus_avail != thread_cpus_enabled();
-#else
-       return 0;
-#endif
-}
-
 /* Below come the lock-debugging functions */
 
 #if defined(DEBUG_THREAD) || defined(DEBUG_FULL)