reactor: don't call set_heap_profiling_enable() if not needed

Seastar has a `heapprof` configuration option, which will cause the
reactor to enable heap-profiling on all shards. It does this by
unconditionally calling `memory::set_heap_profiling_enable()` with the
value of the configuration option, which might be false.
Since a091b5d `memory::set_heap_profiling_enable()` will print a
warning if called when `SEASTAR_HEAPPROF` is not defined. This results
in this message being printed on startup from each shard, which is
confusing and unexpected when one didn't set the `heapprof`
configuration at all. Change the code to only call
`memory::set_heap_profiling_enable()` if `heapprof` was set to true,
avoiding the noise when no heap-profiling is attempted to be used.

Signed-off-by: Botond Dénes <[email protected]>
Message-Id: <[email protected]>

src/core/reactor.cc

@@ -3803,7 +3803,9 @@ void smp::configure(boost::program_options::variables_map configuration, reactor
     }
 
     bool heapprof_enabled = configuration.count("heapprof");
-    memory::set_heap_profiling_enabled(heapprof_enabled);
+    if (heapprof_enabled) {
+        memory::set_heap_profiling_enabled(heapprof_enabled);
+    }
 
 #ifdef SEASTAR_HAVE_DPDK
     if (smp::_using_dpdk) {
@@ -3870,7 +3872,9 @@ void smp::configure(boost::program_options::variables_map configuration, reactor
                 smp::pin(allocation.cpu_id);
             }
             memory::configure(allocation.mem, mbind, hugepages_path);
-            memory::set_heap_profiling_enabled(heapprof_enabled);
+            if (heapprof_enabled) {
+                memory::set_heap_profiling_enabled(heapprof_enabled);
+            }
             sigset_t mask;
             sigfillset(&mask);
             for (auto sig : { SIGSEGV }) {