My goal is to make SPS's stack easier to grab. SPS provides native stack (if possible) plus pseudo stack. So it generally has more data then just a native stack and is much more portable.
That being said making the unwind library independent is a win-win. On Thu, Jan 2, 2014 at 11:03 AM, Jim Chen <nc...@mozilla.com> wrote: > This is great! Thanks for working on it! Can the new library be used > independently outside of SPS? For hang detection (bug 909974) we'd > like to have the ability to unwind the hung thread's stack, and this > library would be perfect for that. > > Cheers, > Jim > > > On 12/19/13 2:04 PM, Julian Seward wrote: > > > > Here's a status update. > > > > Recap: I proposed to create a new library to do fast in process > > CFI and EXIDX based stack unwinding, so as to be able to profile > > on tablets and phones with less overhead than using Breakpad. > > > > The library now exists. Tracking bug is 938157. It does > > CFI unwinding on x86_64-linux and arm-android, EXIDX on arm-android, > > and stack scanning (as a last resort) on both. Initial > > integration with SPS has been completed and it produces plausible > > profiles at least on x86_64-linux. > > > > Compared with the best Breakpad based schemes, this library gives > > easily a factor of 10 cost reduction for CFI unwinding. My best > > attempts with Breakpad achieved a cost of about 6600 insns/frame > > on x86_64-linux. The new library comes in at around 470 insns/frame, > > without much attempt at optimisation. > > > > It also facilitates implementation of the the kind of space-saving > > techniques documented in > > > https://blog.mozilla.org/jseward/2013/09/03/how-compactly-can-cfiexidx-stack-unwinding-info-be-represented/ > > > > J > > > > _______________________________________________ > > dev-platform mailing list > > dev-platform@lists.mozilla.org > > https://lists.mozilla.org/listinfo/dev-platform > > > _______________________________________________ > dev-platform mailing list > dev-platform@lists.mozilla.org > https://lists.mozilla.org/listinfo/dev-platform > _______________________________________________ dev-platform mailing list dev-platform@lists.mozilla.org https://lists.mozilla.org/listinfo/dev-platform
