1168981 - OdinMonkey: share asm.js code between workers

Status: RESOLVED WONTFIX

(Core :: JavaScript: WebAssembly, defect)

Description

[Luke Wagner [:luke]]

This work breaks down into two main pieces:
 - compile thread- (and thus JSRuntime-) independent code by indirecting through TLS (via the pinned GlobalReg) where necessary
 - improve dom/asmjscache so that simultaneous and staggered compilation requests for the same asm.js code can share compiled code

Comment 1

[Jukka Jylänki]

A good testcase for this is:

live: https://dl.dropboxusercontent.com/u/40949268/emcc/bugs/PhysicsStressTest_16threads/12_PhysicsStressTest.html

offline zip of the above: https://dl.dropboxusercontent.com/u/40949268/emcc/bugs/PhysicsStressTest_16threads/PhysicsStressTest_16threads.zip

Comment 2

[Jukka Jylänki]

In the above test case, each worker consumes 15.25MB of compiled asm.js memory, so the estimated waste in that case is 16*15.25MB = 244 MB of memory. (see bug 1244845 and bug 1244841 for related items on about:memory for this test page)

Luke mentions a method in comment 0 for fixing this. How difficult is this? It's been a while since that comment, what's the latest thinking here?

Comment 3

[Luke Wagner [:luke]]

I looked into doing this a while back and while it's quite possible, it's not super-easy.  I don't have the bandwidth to do this at the moment.  I'll note that wasm threads would share the code by construction and, if other browsers ship SAB, they will have the same code duplication, so the priority of this bug is a question of whether devs will ship many-Worker asm.js+SAB or just wait for wasm.

Comment 4

[BMO Automation]

Per policy at https://wiki.mozilla.org/Bug_Triage/Projects/Bug_Handling/Bug_Husbandry#Inactive_Bugs. If this bug is not an enhancement request or a bug not present in a supported release of Firefox, then it may be reopened.

Comment 5

[Benjamin Bouvier [:bbouvier] (inactive)]

Wasm is now here. Closing as wontfix, considering this was a proposal for asm.js, but you can consider it fixed as it's implemented in wasm.