302237 - Large increase in Lk (not Rlk) on balsa on 7/25

Status: RESOLVED INCOMPLETE

(Firefox :: General, defect, P3)

Description

[Boris Zbarsky [:bzbarsky]]

Lk on balsa went from about 340KB to 370KB.  The checkins for the relevant timer
range are
http://tinderbox.mozilla.org/bonsai/cvsquery.cgi?module=PhoenixTinderbox&date=explicit&mindate=1122312420&maxdate=1122316799

Given that Rlk did not change, we're probably leaking non-refcounted objects. 
The leak change log at the end of
http://tinderbox.mozilla.org/showlog.cgi?log=Firefox/1122316800.4419.gz
indicates that almost all the new leaks are under JS_Malloc; I don't see any JS
engine changes in that time, so I can only assume that other things (which are
holding references to the JS stuff somehow) started leaking...

Comment 1

[Boris Zbarsky [:bzbarsky]]

To be exact, the single largest number change has the stack:

    40335 JS_malloc
      27859 js_NewScript
        27811 js_NewScriptFromCG
          27811 js_EmitFunctionBody
            27811 js_EmitTree
              27811 js_EmitTree
                27811 js_EmitTree
                  27586 js_EmitTree
                    27586
/builds/tinderbox/Firefox-gcc3.4/Linux_2.4.7-10_Depend/mozilla/obj/dist/bin/libmozjs.so+8CD40
                      27586 js_CompileTokenStream
                        27586
/builds/tinderbox/Firefox-gcc3.4/Linux_2.4.7-10_Depend/mozilla/obj/dist/bin/libmozjs.so+1D270
                          27586 JS_CompileFileHandleForPrincipals
                            27586 mozJSComponentLoader::GlobalForLocation(char
const*, nsIFile*)
                              27586 mozJSComponentLoader::ModuleForLocation(char
const*, nsIFile*)
                                27586
mozJSComponentLoader::AttemptRegistration(nsIFile*, int)

and the second largest has the stack:

      7216 js_NewScope
        6864 js_GetMutableScope
          6336 js_AddNativeProperty
            6336 js_AddHiddenProperty
              5368
/builds/tinderbox/Firefox-gcc3.4/Linux_2.4.7-10_Depend/mozilla/obj/dist/bin/libmozjs.so+8C744
                4488
/builds/tinderbox/Firefox-gcc3.4/Linux_2.4.7-10_Depend/mozilla/obj/dist/bin/libmozjs.so+8CAFC
                  4400
/builds/tinderbox/Firefox-gcc3.4/Linux_2.4.7-10_Depend/mozilla/obj/dist/bin/libmozjs.so+93D55
                    4400
/builds/tinderbox/Firefox-gcc3.4/Linux_2.4.7-10_Depend/mozilla/obj/dist/bin/libmozjs.so+91C26
                      4400
/builds/tinderbox/Firefox-gcc3.4/Linux_2.4.7-10_Depend/mozilla/obj/dist/bin/libmozjs.so+9181C
                        4400
/builds/tinderbox/Firefox-gcc3.4/Linux_2.4.7-10_Depend/mozilla/obj/dist/bin/libmozjs.so+91201
                          4400
/builds/tinderbox/Firefox-gcc3.4/Linux_2.4.7-10_Depend/mozilla/obj/dist/bin/libmozjs.so+910FD
                            4400
/builds/tinderbox/Firefox-gcc3.4/Linux_2.4.7-10_Depend/mozilla/obj/dist/bin/libmozjs.so+91033
                              4400
/builds/tinderbox/Firefox-gcc3.4/Linux_2.4.7-10_Depend/mozilla/obj/dist/bin/libmozjs.so+90EF7
                                4400
/builds/tinderbox/Firefox-gcc3.4/Linux_2.4.7-10_Depend/mozilla/obj/dist/bin/libmozjs.so+90E11

Comment 2

[Mike Schroepfer]

Bz can you help us understand risk and necessity to fix?

Comment 3

[Boris Zbarsky [:bzbarsky]]

I have no idea what's going on here and probably won't be able to debug for at
least a week, possibly longer.

Comment 4

[Asa Dotzler [:asa]]

brendan or dbaron, can one of you look into this so we can get a better sense of
whether or not this is something we should and can get for 1.8b4?bbb

Comment 5

[Boris Zbarsky [:bzbarsky]]

I've not been able to get TraceMalloc working, so I really can't get anywhere on this... :(

Comment 6

[Matthias Versen [:Matti]]

Boris: Is this bug report still valid ?

Comment 7

[Boris Zbarsky [:bzbarsky]]

Who knows.  The OS this was running on is gone, the hardware it was running on is gone.