On Wed, Oct 10, 2012 at 05:57:53PM -0400, Justin Lebar wrote: > By "turning off Linux PGO testing", you really mean "stop making and > distributing Linux PGO builds," right? > > The main reason I'd want Linux PGO is for mobile. On desktop Linux, > most users (I expect) don't run our builds, so it's not a big deal if > they're some percent slower.
Many people have made claims about that at several different occasions. Can we once and for all come up with actual data on that? That being said, PGO on Linux is between 5 and 20% improvement on our various talos tests. That's with the version of gcc we currently use, which is 4.5. I'd expect 4.7 to do a better job even, especially if we added lto to the equation (and since we are now building on x86-64 machines, we wouldn't have to worry about memory usage ; link time could be a problem, though). Also note that disabling PGO currently also means disabling the optimizations we do on omni.ja (central directory optimizations and reordering). This is somehow covered by bug 773171. Mike _______________________________________________ dev-platform mailing list dev-platform@lists.mozilla.org https://lists.mozilla.org/listinfo/dev-platform
