1124561 - HTTP2 causes high CPU and stalled navigation

Status: RESOLVED DUPLICATE of bug 1124717

(Core :: Networking: HTTP, defect)

Description

[Leman Bennett [Omega]]

Whatever happened over the last few days has caused some sites to trigger a network stall in which the browser will never be able to resolve any network activity. On top of that, the browser will generate high CPU usage. 

AMD CodeXL reports that these functions are involved:

Function, Samples, % of Hotspot Samples, Module
nsBufferedInputStream::ReadSegments(enum tag_nsresult (*)(class nsIInputStream *,void *,char const *,unsigned int,unsigned int,unsigned int *),void *,unsigned int,unsigned int *), 10888, 32.1892, xul.dll
mozilla::net::Http2Stream::OnReadSegment(char const *,unsigned int,unsigned int *), 7062, 20.878, xul.dll
mozilla::net::nsHttpTransaction::ReadRequestSegment(class nsIInputStream *,void *,char const *,unsigned int,unsigned int,unsigned int *), 6907, 20.4198, xul.dll
mozilla::TimeStampValue::CheckQPC(class mozilla::TimeStampValue const &), 3565, 10.5395, xul.dll
mozilla::net::Http2Session::TryToActivate(class mozilla::net::Http2Stream *), 2644, 7.8167, xul.dll

Turning off network.http.spdy.enabled.http2 in about:config fixed the issue.

Comment 1

[Patrick McManus [:mcmanus]]

Omega - what channel are you running?

Comment 2

[Leman Bennett [Omega]]

(In reply to Patrick McManus [:mcmanus] from comment #1)
> Omega - what channel are you running?

This is on Nightly.

Comment 3

[Leman Bennett [Omega]]

It happened again with Http2 off. I think this is related to SPDY in general.

Function, Samples, % of Hotspot Samples, Module
nsBufferedInputStream::ReadSegments(enum tag_nsresult (*)(class nsIInputStream *,void *,char const *,unsigned int,unsigned int,unsigned int *),void *,unsigned int,unsigned int *), 6783, 33.1947, xul.dll
mozilla::net::SpdyStream31::OnReadSegment(char const *,unsigned int,unsigned int *), 4099, 20.0597, xul.dll
mozilla::net::nsHttpTransaction::ReadRequestSegment(class nsIInputStream *,void *,char const *,unsigned int,unsigned int,unsigned int *), 2853, 13.962, xul.dll
mozilla::TimeStamp::IsNull(void), 1960, 9.59186, xul.dll
mozilla::TimeStampValue::CheckQPC(class mozilla::TimeStampValue const &), 1588, 7.77136, xul.dll

Comment 4

[Patrick McManus [:mcmanus]]

I know this may be difficult to answer, but do you think you were uploading anything before this happened?

Comment 5

[Leman Bennett [Omega]]

(In reply to Patrick McManus [:mcmanus] from comment #4)
> I know this may be difficult to answer, but do you think you were uploading
> anything before this happened?

Not to my knowledge. I had Google Play Music playing in another tab when it happened. Once I visited androidpolice.com navigating to another site gave me an endless load that didn't resolve.

After I turned off SPDY, I've had no issues since.

Comment 6

[Vladan Djeric (:vladan)]

I ran into the same issue (can't navigate, high CPU usage) with 32-bit Nightly 38 on Win7.
Stack: http://pastebin.mozilla.org/8365924