perf(libc): count private collect calls only in the collect test

The private collect counted its GetWriteWatch calls and pieces on every
call, under the mappings mutex, for agc_private_collect to read. They
are now compiled only where APS5_COUNT_MAPPING_QUERIES is set, as the
address-space query counter is: agc_private_collect_tests sets it, and
the runtime's Collect updates no counter. libc's GuestArenaCollectWork
export, which nothing calls (the test reads its own WindowsMappings),
is removed.

Adapts fable-void's 2760ad808.

core/libs/prx/libSceAgcDriver/CMakeLists.txt

@@ -484,6 +484,7 @@ if(BUILD_TESTING)
         add_test_executable(agc_private_collect_tests EXCLUDE_FROM_ALL tests/PrivateCollect.cpp)
         target_include_directories(agc_private_collect_tests PRIVATE ${LIBS_INCLUDE_DIR})
         target_link_libraries(agc_private_collect_tests PRIVATE libc)
+        target_compile_definitions(agc_private_collect_tests PRIVATE APS5_COUNT_MAPPING_QUERIES=1)
         set_target_properties(agc_private_collect_tests PROPERTIES CXX_EXTENSIONS OFF)
         configure_windows_unwind(agc_private_collect_tests)
         add_test(NAME agc_private_collect COMMAND agc_private_collect_tests)

core/libs/prx/libc/include/GuestArena.hpp

@@ -46,7 +46,6 @@ bool GuestArenaProtection_nid_postfix(std::uintptr_t address, std::uint32_t* pro
 bool GuestArenaCollectWrites_nid_postfix(std::uintptr_t address, std::size_t bytes, void** pages, std::size_t* count, bool clear);
 bool GuestArenaCollectArmedWrites_nid_postfix(std::uintptr_t address, std::size_t bytes, void** pages, std::size_t* count, bool clear);
 bool GuestArenaCollectFreshWrites_nid_postfix(std::uintptr_t address, std::size_t bytes, void** pages, std::size_t* count, bool clear);
-void GuestArenaCollectWork_nid_postfix(std::uint64_t* systemCalls, std::uint64_t* pieces);
 bool GuestArenaHostRegionOverlaps_nid_postfix(std::uintptr_t address, std::size_t bytes);
 std::uint64_t GuestArenaCommitGeneration_nid_postfix();
 void GuestArenaSetPrivateMappingObserver_nid_postfix(void (*callback)(std::uintptr_t address, std::size_t bytes, std::uint64_t generation));

core/libs/prx/libc/include/WindowsMappings.hpp

@@ -381,11 +381,13 @@ public:
         return true;
     }
 
+#ifdef APS5_COUNT_MAPPING_QUERIES
     void CollectWork(std::uint64_t* systemCalls, std::uint64_t* pieces) {
         std::lock_guard lock(mutex);
         *systemCalls = collectSystemCalls;
         *pieces = collectPieces;
     }
+#endif
 
     bool Collect(std::uintptr_t address, std::size_t bytes, void** pages, std::size_t* count, bool clear, Collection collection = Collection::All) {
         std::lock_guard lock(mutex);
@@ -528,8 +530,10 @@ public:
                 const auto touched = (((stop + 4095) & ~static_cast<std::uintptr_t>(4095)) - (cursor & ~static_cast<std::uintptr_t>(4095))) / 4096;
                 ULONG_PTR available = std::min<ULONG_PTR>(capacity - *count, touched);
                 DWORD granularity = 0;
+#ifdef APS5_COUNT_MAPPING_QUERIES
                 ++collectSystemCalls;
                 collectPieces += (stop + pageBytes - 1) / pageBytes - cursor / pageBytes;
+#endif
                 const bool committed = !verifyDirect() || committedPrivate(cursor, stop);
                 if (GetWriteWatch(clear ? WRITE_WATCH_FLAG_RESET : 0, reinterpret_cast<void*>(cursor), stop - cursor, pages + *count, &available, &granularity) != 0) {
                     const auto memory = query(cursor);
@@ -1148,8 +1152,10 @@ private:
     Ranges cleanRanges;
     Ranges collectableRanges;
     Ranges privateAllocations;
+#ifdef APS5_COUNT_MAPPING_QUERIES
     std::uint64_t collectSystemCalls = 0;
     std::uint64_t collectPieces = 0;
+#endif
     Ranges freshRanges;
     std::map<std::uintptr_t, View> views;
 

core/libs/prx/libc/src/GuestArena.cpp

@@ -438,10 +438,6 @@ bool GuestArenaCollectFreshWrites_nid_postfix(std::uintptr_t address, std::size_
     return WindowsMappings::Get().Collect(address, bytes, pages, count, clear, WindowsMappings::Collection::Fresh);
 }
 
-void GuestArenaCollectWork_nid_postfix(std::uint64_t* systemCalls, std::uint64_t* pieces) {
-    WindowsMappings::Get().CollectWork(systemCalls, pieces);
-}
-
 bool GuestArenaHostRegionOverlaps_nid_postfix(std::uintptr_t address, std::size_t bytes) {
     return Arena::Get().OverlapsHostRegion(address, bytes);
 }