Small changes to tracing

- Trace "Handling remote" once per batch, rather than per element - Remote queue events also log the associated metaslab; we'll use this to assess the efficacy of microsoft#634
nwf-msr · Jun 19, 2024 · e0188ad · e0188ad
1 parent 72f26b8
commit e0188ad
Show file tree

Hide file tree

Showing 4 changed files with 21 additions and 16 deletions.
diff --git a/src/snmalloc/mem/corealloc.h b/src/snmalloc/mem/corealloc.h
@@ -323,7 +323,7 @@ namespace snmalloc
 
 #ifdef SNMALLOC_TRACING
       message<1024>(
-        "Slab {}  is unused, Object sizeclass {}",
+        "Slab {} is unused, Object sizeclass {}",
         start_of_slab.unsafe_ptr(),
         sizeclass);
 #endif
@@ -490,10 +490,6 @@ namespace snmalloc
                            };
       auto cb = [this,
                  &need_post](freelist::HeadPtr msg) SNMALLOC_FAST_PATH_LAMBDA {
-#ifdef SNMALLOC_TRACING
-        message<1024>("Handling remote");
-#endif
-
         auto& entry =
           Config::Backend::template get_metaentry(snmalloc::address_cast(msg));
 
@@ -502,6 +498,10 @@ namespace snmalloc
         return true;
       };
 
+#ifdef SNMALLOC_TRACING
+      message<1024>("Handling remote queue before proceeding...");
+#endif
+
       if constexpr (Config::Options.QueueHeadsAreTame)
       {
         /*
@@ -935,9 +935,11 @@ namespace snmalloc
         else
           report_fatal_error(
             "debug_is_empty: found non-empty allocator: size={} on "
-            "slab_start {}",
+            "slab_start {} meta {} entry {}",
             sizeclass_full_to_size(size_class),
-            slab_start);
+            slab_start,
+            address_cast(slab_metadata),
+            address_cast(&entry));
       };
 
       auto test = [&error](auto& queue) {

diff --git a/src/snmalloc/mem/localalloc.h b/src/snmalloc/mem/localalloc.h
@@ -274,18 +274,18 @@ namespace snmalloc
      * In the second case we need to recheck if this is a remote deallocation,
      * as we might acquire the originating allocator.
      */
-    SNMALLOC_SLOW_PATH void dealloc_remote_slow(capptr::Alloc<void> p)
+    SNMALLOC_SLOW_PATH void
+    dealloc_remote_slow(const PagemapEntry& entry, capptr::Alloc<void> p)
     {
       if (core_alloc != nullptr)
       {
 #ifdef SNMALLOC_TRACING
         message<1024>(
-          "Remote dealloc post {} ({})",
+          "Remote dealloc post {} ({}, {})",
           p.unsafe_ptr(),
-          alloc_size(p.unsafe_ptr()));
+          alloc_size(p.unsafe_ptr()),
+          address_cast(entry.get_slab_metadata()));
 #endif
-        const PagemapEntry& entry =
-          Config::Backend::template get_metaentry(address_cast(p));
         local_cache.remote_dealloc_cache.template dealloc<sizeof(CoreAlloc)>(
           entry.get_remote()->trunc_id(), p);
         post_remote_cache();
@@ -681,12 +681,15 @@ namespace snmalloc
             remote->trunc_id(), p_tame);
 #  ifdef SNMALLOC_TRACING
           message<1024>(
-            "Remote dealloc fast {} ({})", p_raw, alloc_size(p_raw));
+            "Remote dealloc fast {} ({}, {})",
+            p_raw,
+            alloc_size(p_raw),
+            address_cast(entry.get_slab_metadata()));
 #  endif
           return;
         }
 
-        dealloc_remote_slow(p_tame);
+        dealloc_remote_slow(entry, p_tame);
         return;
       }
 

diff --git a/src/snmalloc/mem/remotecache.h b/src/snmalloc/mem/remotecache.h
@@ -151,7 +151,7 @@ namespace snmalloc
         }
       }
 
-      // Reset capacity as we have empty everything
+      // Reset capacity as we have emptied everything
       capacity = REMOTE_CACHE;
 
       return sent_something;

diff --git a/src/test/perf/contention/contention.cc b/src/test/perf/contention/contention.cc
@@ -137,7 +137,7 @@ void test_tasks(size_t num_tasks, size_t count, size_t size)
     ParallelTest<test_tasks_f> test(num_tasks);
 
     std::cout << "Task test, " << num_tasks << " threads, " << count
-              << " swaps per thread " << test.time() << "ticks" << std::endl;
+              << " swaps per thread " << test.time() << " ticks" << std::endl;
 
     for (size_t n = 0; n < swapsize; n++)
     {