We should change the maximum length of the thread hangs stack to the value of the 99th percentile rather than the 95th percentile as the most interesting stacks tend to be longer. We need to run an updated spark job [0] to find the 99th percentile and then change the constant in [1]. [0] - https://gist.github.com/Dexterp37/fc4a043fb442d4e4be90 [1] - https://dxr.mozilla.org/mozilla-central/rev/1e700005a0ddf2b17803213e1f3f8d78a7a618b8/xpcom/threads/BackgroundHangMonitor.cpp#36

Let's set the limit to 30 (99.9%).

https://hg.mozilla.org/integration/fx-team/rev/134bb8fdb24418730e1ed5940fafc42cdfc5e972 Bug 1219751 - Change the the depth limit of the thread hangs stack to use the 99th percentile. r=gfritzsche

removing the b2g 2.5 flag since this commit has been reverted due to an incorrect merge, sorry for the confusion

Can we uplift this to Aurora 44 & Beta 43? See https://bugzilla.mozilla.org/show_bug.cgi?id=1211411#c11

Comment on attachment 8680654 [details] [diff] [review] bug1219751.patch Approval Request Comment [Feature/regressing bug #]: Tweaks the constant that controls the number of thread hang stacks sent. [User impact if declined]: This isn't a user-facing feature. However, without this patches bug 1222894 could potentially cause sending a lot of oversized pings, wasting both storage and processing time server side, thus increasing costs. [Describe test coverage new/current, TreeHerder]: This has been on m-c for 2 weeks without any reported issue. [Risks and why]: Low risk, the changed constant controls how many stacks we are sending. [String/UUID change made/needed]: None. Please note that this is part of an uplift stack required for bug 1222894. This is the stack (the patches correctly apply in order to mozilla-beta): 1213780, 1211411, 1215540, 1219751.

Comment on attachment 8680654 [details] [diff] [review] bug1219751.patch This also needs to be uplifted on Aurora: the rest of the stack is already there and it's just missing this one patch.

Marking this as affected for 43 and 44 since we intend to uplift.

Comment on attachment 8680654 [details] [diff] [review] bug1219751.patch Please uplift this patch to both aurora and beta.

https://hg.mozilla.org/releases/mozilla-aurora/rev/8efe7a54bafe https://hg.mozilla.org/releases/mozilla-beta/rev/6cabb1a43af6

(In reply to Vladan Djeric (:vladan) -- please needinfo! PTO Nov 16/19/20 from comment #13) > https://hg.mozilla.org/releases/mozilla-aurora/rev/8efe7a54bafe > https://hg.mozilla.org/releases/mozilla-beta/rev/6cabb1a43af6 setting the flags for this checkin