This builder has always been around 6, 7 hours range a week before. Not sure what's triggering this.

Oh, I think this has to do with BOT_DIED issue. The pattern here is any time a build has infra failure due to BOT_DIED, the next build will have a bunch of timed out tasks. For example:
In https://build.chromium.org/p/chromium.perf/builders/Mac%20Retina%20Perf/builds/660, machine 'build8-b1' died at step 313.

In the next build, all the run on 'build8-b1' failed: https://build.chromium.org/p/chromium.perf/builders/Mac%20Retina%20Perf/builds/661