1036692 - single-thread deadlock of CacheStorageService:mLock after hitting "Measure" in about:memory

Status: RESOLVED INCOMPLETE

(Core :: Networking: Cache, defect)

Description

[David Baron :dbaron: (⌚️UTC-4, no longer working on Mozilla)]

Attachment: debugging

I was trying to debug why my session had gotten bogged down, and went to about:memory, and about:memory crashed because of what appears to be a single-thread deadlock in the cache, although gdb wasn't kind enough to give me the whole stack.

I was running mozilla-central revision afa67a2f7905 plus my patch queue as of state https://hg.mozilla.org/users/dbaron_mozilla.com/patches/rev/74252f4f5cbc pushed up to the patch share-find-reference-frame.

I'll attach what I got out of gdb.

Comment 1

[Honza Bambas (:mayhemer)]

Isn't think dup of bug 991669?

Comment 2

[Honza Bambas (:mayhemer)]

No it's not duplicate of that bug.  The word CRASH confused me first.

Comment 3

[Honza Bambas (:mayhemer)]

Going to take a look.  trace-malloc enabled build would give the whole stack in the deadlock detector warning.  But would be super-slow...

Comment 4

[David Baron :dbaron: (⌚️UTC-4, no longer working on Mozilla)]

Attachment: debugging, again

I hit it a second time, again trying to open the slow script dialog during about:memory.

Comment 5

[David Baron :dbaron: (⌚️UTC-4, no longer working on Mozilla)]

(I think I hit this much more reliably if I check the "Verbose" checkbox before hitting Measure.)

Comment 7

[Honza Bambas (:mayhemer)]

David, are you still able to reproduce this?

Comment 8

[Honza Bambas (:mayhemer)]

Closing for insufficient data.