reaper/CgroupAccounting: read "pids_peak"

debian/changelog

@@ -1,6 +1,6 @@
 cm4all-spawn (0.19) unstable; urgency=low
 
-  * 
+  * reaper: read "pids.peak"
 
  --   
 

doc/index.rst

@@ -69,6 +69,8 @@ The following attributes of the ``cgroup`` parameter can be queried:
 
 * ``memory_peak``: the peak memory usage [in bytes].
 
+* ``pids_peak``: the peak number of processes.
+
 
 libsodium
 ^^^^^^^^^

src/reaper/CgroupAccounting.cxx

@@ -60,5 +60,15 @@ ReadCgroupResourceUsage(FileDescriptor cgroup_fd) noexcept
 	} catch (...) {
 	}
 
+	try {
+		WithSmallTextFile<64>(FileAt{cgroup_fd, "pids.peak"}, [&result](std::string_view contents){
+			if (auto value = ParseInteger<uint_least32_t>(StripRight(contents))) {
+				result.pids_peak = *value;
+				result.have_pids_peak = true;
+			}
+		});
+	} catch (...) {
+	}
+
 	return result;
 }

src/reaper/CgroupAccounting.hxx

@@ -20,7 +20,11 @@ struct CgroupResourceUsage {
 
 	uint_least64_t memory_peak;
 
+	uint_least32_t pids_peak;
+
 	bool have_memory_peak = false;
+
+	bool have_pids_peak = false;
 };
 
 [[gnu::pure]]

src/reaper/LAccounting.cxx

@@ -78,6 +78,10 @@ Push(lua_State *L, Lua::AutoCloseList &auto_close,
 		SetField(L, RelativeStackIndex{-1}, "memory_peak",
 			 (lua_Integer)usage.memory_peak);
 
+	if (usage.have_pids_peak)
+		SetField(L, RelativeStackIndex{-1}, "pids_peak",
+			 (lua_Integer)usage.pids_peak);
+
 	lua_pop(L, 1);
 }
 

src/reaper/Released.cxx

@@ -54,6 +54,9 @@ CollectCgroupStats(const char *suffix,
 				   (u.memory_peak + MEGA / 2 - 1) / MEGA);
 	}
 
+	if (u.have_pids_peak)
+		p = fmt::format_to(p, " procs={}", u.pids_peak);
+
 	if (p > buffer)
 		fmt::print(stderr, "{}:{}\n", suffix,
 			   std::string_view{buffer, p});