| # Android Version Notes |
| This page documents all the caveats of using Perfetto on older versions of |
| Android. Because of the yearly release cycle, it's often the case that a |
| feature is shipped but we later discover a bug/problem which makes the feature |
| not usable or needs to be used in a very specific way. |
| |
| ## U- |
| ### New features |
| * The CLONE_SNAPSHOT trigger mode was introduced. |
| * String field filtering in traces was introduced. |
| |
| ### Caveats |
| * On the CLONE_SNAPSHOT codepath, the trace UUID gets rewritten when the session |
| is clone but a statsd atom linking the two is not emitted. This means we |
| should be careful to exclude any "clone-only" sessions as being "failed" |
| sessions. |
| |
| ## T- |
| ### New features |
| * Reporting traces through the framework was introduced. |
| |
| ### Caveats |
| * CLONE_SNAPSHOT does not exist in T- but there is a subtle edge case |
| (b/274931668) which means it's quite dangerous to specify CLONE_SNAPSHOT on |
| configs being sent to T- devices. |
| |
| ## P |
| ### New features |
| * Perfetto was included in the system image! |
| |
| ### Caveats |
| * --txt option is not supported so configs must be binary encoded. |
