[Webkit-unassigned] [Bug 173908] New: WebAssembly: don't tier up when out of executable memory

[bugzilla-daemon at webkit.org]

https://bugs.webkit.org/show_bug.cgi?id=173908

            Bug ID: 173908
           Summary: WebAssembly: don't tier up when out of executable
                    memory
           Product: WebKit
           Version: WebKit Nightly Build
          Hardware: Unspecified
                OS: Unspecified
            Status: NEW
          Severity: Normal
          Priority: P2
         Component: JavaScriptCore
          Assignee: webkit-unassigned at lists.webkit.org
          Reporter: jfbastien at apple.com
                CC: fpizlo at apple.com, jfbastien at apple.com,
                    keith_miller at apple.com, mark.lam at apple.com,
                    msaboff at apple.com, sbarati at apple.com
        Depends on: 171537

In https://bugs.webkit.org/show_bug.cgi?id=171537 I made our implementation throw when instantiating a new module fails because there isn't enough executable memory. I also made it abort the installation of a tiered up function if we run out of executable memory.

I now want to make sure that the second case (tier up fail) doesn't end up in infinite recompile.

A few ideas:
  - Before compiling for tier up, check that at least $SOMETHING executable memory is available, where $SOMETHING is a heuristic we pick (percentage of total?).
  - Before compiling for tier up, check that at least $MULTIPLE * (end - start) executable memory is available, where (end - start) refer to the original binary, and $SOMETHING is a number we can measure from compiling existing code (average or max of what we typically see).
  - Connect with the GC better, maybe we can clean things up and find more executable memory (similar to what I did to WebAssembly.Memory + GC?).

We can do all or some of these, and base tier up backoff on these heuristics.


Referenced Bugs:

https://bugs.webkit.org/show_bug.cgi?id=171537
[Bug 171537] WebAssembly: running out of executable memory should throw OoM
-- 
You are receiving this mail because:
You are the assignee for the bug.
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.webkit.org/pipermail/webkit-unassigned/attachments/20170628/e5c86530/attachment.html>