When try to debug high memory usage, I was getting frequent crashes with the stack below: xul.dll!nsACString_internal::SizeOfIncludingThisIfUnshared(unsigned __int64 (const void *) * mallocSizeOf) Line 1006 C++ xul.dll!mozilla::ChannelMediaResource::SizeOfExcludingThis(unsigned __int64 (const void *) * aMallocSizeOf) Line 595 C++ xul.dll!mozilla::MediaSourceResource::SizeOfIncludingThis(unsigned __int64 (const void *) * aMallocSizeOf) Line 401 C++ xul.dll!mozilla::MediaMemoryTracker::CollectReports(nsIMemoryReporterCallback * aHandleReport, nsISupports * aData) Line 1752 C++ xul.dll!nsMemoryReporterManager::GetReportsForThisProcessExtended(nsIMemoryReporterCallback * aHandleReport, nsISupports * aHandleReportData, const nsAString_internal & aDMDDumpIdent) Line 1113 C++ xul.dll!nsMemoryReporterManager::StartGettingReports() Line 1055 C++ xul.dll!nsMemoryReporterManager::GetReportsExtended(nsIMemoryReporterCallback * aHandleReport, nsISupports * aHandleReportData, nsIFinishReportingCallback * aFinishReporting, nsISupports * aFinishReportingData, bool aMinimize, const nsAString_internal & aDMDDumpIdent) Line 1037 C++ xul.dll!nsMemoryReporterManager::GetReports(nsIMemoryReporterCallback * aHandleReport, nsISupports * aHandleReportData, nsIFinishReportingCallback * aFinishReporting, nsISupports * aFinishReportingData) Line 959 C++ mallocSizeOf 0x000007fed3042550 {xul.dll!CategoryManagerMallocSizeOf(const void *)} unsigned __int64 (const void *) * this 0x0000000038db0600 {mData=0x000007fed4aac2d0 "`è:Ôþ\a" mLength=3567846048 mFlags=2046 } nsACString_internal * mData 0x000007fed4aac2d0 "`è:Ôþ\a" char * 96 '`' char mLength 3567846048 unsigned int mFlags 2046 unsigned int

Ryan, do you have media.mediasource.enabled set to true in your prefs? I'm not sure how you'd end up with a MediaSourceResource otherwise, unless the stack is bogus... which I'm suspicious of, because MediaSourceResource is-a MediaResource, not a ChannelMediaResource.

media.mediasource.enabled;false

Ryan, what version of Firefox was this on? I'm assuming this is a 32-bit build on 64-bit Windows 7 right? I agree with Matthew, that stack looks bogus although I think I might know what's going on. We're doing a |blah.SizeOfIncludingThis| measurement where we should really be doing |blah.SizeOfExcludingThis|. http://mxr.mozilla.org/mozilla-central/source/content/media/MediaResource.h#425

Home-brew 64bit build on Win7.

This should hopefully fix the crash, Ryan do you mind testing this for me?

Comment on attachment 8414797 [details] [diff] [review] Use SizeOfExcludingThis for non-heap allocated member variable Working well!

Comment on attachment 8414797 [details] [diff] [review] Use SizeOfExcludingThis for non-heap allocated member variable Review of attachment 8414797 [details] [diff] [review]: ----------------------------------------------------------------- Bring on bug 1003479!

remote: https://hg.mozilla.org/integration/mozilla-inbound/rev/090bd7835f82

Backed out for Linux mochitest-other failures. https://hg.mozilla.org/integration/mozilla-inbound/rev/bbd77de6be4b https://tbpl.mozilla.org/php/getParsedLog.php?id=38885587&tree=Mozilla-Inbound https://tbpl.mozilla.org/php/getParsedLog.php?id=38885177&tree=Mozilla-Inbound

That backout should have been on bug 999473. Re-landed. https://hg.mozilla.org/integration/mozilla-inbound/rev/e0b5e968c38f