1246558 - downloading files & cpu utilisation

Status: RESOLVED INCOMPLETE

(Firefox :: Downloads Panel, defect)

Description

[abro163]

User Agent: Mozilla/5.0 (Windows NT 5.1; rv:35.0) Gecko/20100101 Firefox/35.0
Build ID: 20150108202552

Steps to reproduce:

Download a file at high speed eg linux iso http://ftp.citylink.co.nz/ubuntu-releases/12.04.5/  , when downloading at 3.5MB/s cpu usage sits at 70-90% on my athlon 64 3000+, winxp  also can be reproduced on my other dual core pc win 7,  IE 8 and chrome dont do this both sit around 30%


Actual results:

too much cpu time for downloading a file, also causes youtube to drop frames and stutter while buffering from the network


Expected results:

less cpu utilization

Comment 1

[abro163]

Also I tried firefox portable 44, same problem so it looks like it hasnt been fixed in newer versions

Comment 2

[YF (Yang)]

Bug 902733?

Comment 3

[abro163]

The download window is clear and i tried removing the download icon from the toolbar, but same result

Comment 4

[Cosmin Muntean [:cmuntean], Ecosystem QA]

Hi Abro163,

I have tested this issue on latest Firefox (44.0.1) release and latest Nightly (47.0a1) build an could not reproduce it. I have downloaded (with ~2.5 - 3.5MB/s) a large file and watched videos on YouTube but the CPU usage remained between 0-10%. The videos from YouTube worked properly during the download. Still I have tested this with an Intel i5 3rd generation processor and 8GB of RAM. In my opinion there is a high chance that this issue could be related to your hardware.

Firefox: 47.0a1, Build ID: 20160209030347
User Agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:47.0) Gecko/20100101 Firefox/47.0
Firefox: 44.0.1, Build ID: 20160205155049
User Agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:44.0) Gecko/20100101 Firefox/44.0

Also, can you please test this on the latest Firefox (44.0) release and on latest Nightly build (47.0a1, https://nightly.mozilla.org/) and tell me if this still reproduces for you ? When doing this please use a new fresh Firefox profile, maybe also in safe mode (https://support.mozilla.org/en-US/kb/troubleshoot-and-diagnose-firefox-problems). 

Thanks,
Cosmin.

Comment 5

[abro163]

Ok, i just downloaded nightly, same story.. it maxes out one core on my e6500 @ 2.93 ghz

If you are seeing 10% usage of a 5 core thats 50% of a single core right.. still too much

Comment 6

[Cosmin Muntean [:cmuntean], Ecosystem QA]

Hi Abro,

That is not very accurate. The Intel i5 3rd generation processors have only 4 cores but Firefox still uses only one of the cores. That means only 10% on a single core which is not much when playing YouTube videos and downloading large files.

Can you please make a copy of the about:support page (just write in address bar about:support) from Firefox and attach it here in order to have some information regarding your browser ?

Also, have you tried to test this with a new clean Firefox profile and safe mode ? There is a chance that it's something related to your settings or extensions installed that could produce this problem. 
Using a new profile will not affect your current one, you can have multiple Firefox profiles. So if you can please help us out to better understand this issue, so we can help you with it.


Thanks,
Cosmin

Comment 7

[abro163]

Attachment: ff.JPG

Comment 8

[abro163]

Attachment: aboutsupport.txt

Comment 9

[abro163]

i made a new profile and tried it, you can see the result in the screen shot

Comment 10

[Cosmin Muntean [:cmuntean], Ecosystem QA]

Hi,

I have looked over this bug 902733 and it seems to be a very similar problem. Karl can you confirm this please?

If it is not a duplicate, I will assign a component to involve the development team on this. Maybe someone with more experience could share an opinion.

Thanks,
Cosmin.

Comment 11

[Karl Tomlinson (:karlt)]

Comment 3 implies it is somewhat different from what I was seeing, but it sounds related.

Comment 12

[Martin Stránský [:stransky] (ni? me)]

Tested on trunk, debug build. When download is running on background, there are two extra CPU eaters:

11.22% libxul.so: mozilla::net::DigestOutputStream::Write()
10.53% libfreebl3.so: 95.58% SHA256_Compress

Comment 13

[Martin Stránský [:stransky] (ni? me)]

Maybe a regression from Bug 829832 ?

Comment 14

[Martin Stránský [:stransky] (ni? me)]

Or Bug 928536 which seem to enable the signatures on download.

Comment 15

[Wayne Mery (:wsmwk)]

mak, would you expect this problem to be gone?
(reporter is gone)

Comment 16

[Marco Bonardo [:mak]]

Regardless of it existing yet or not, we'd need a profile on a recent build. Since keeping this around is not as useful as having a recent report with a profile, we can close it as incomplete for now.