tombstone最大允许有多少个

对于eng/userdebug版本，是50个；
对于user版本，是10个
$ adb shell getprop tombstoned.max_tombstone_count
50

//build/target/product/media_system.mk
# On userdebug builds, collect more tombstones by default.
ifneq (,$(filter userdebug eng,$(TARGET_BUILD_VARIANT)))
PRODUCT_SYSTEM_DEFAULT_PROPERTIES += \
    tombstoned.max_tombstone_count=50
endif

//system/core/debuggerd/tombstoned/tombstoned.cpp
static CrashQueue* for_tombstones() {
  static CrashQueue queue("/data/tombstones", "tombstone_" /* file_name_prefix */,
                          GetIntProperty("tombstoned.max_tombstone_count", 10),
                          1 /* max_concurrent_dumps */);
  return &queue;
}