1692635 - session store interval

Status: RESOLVED WORKSFORME

(Firefox :: Session Restore, defect)

Description

[u669021]

User Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:85.0) Gecko/20100101 Firefox/85.0

Steps to reproduce:

open any resource intensive website such as facebook, reddit, etc

on windows 10 pro x64
16gb ram, i7

Actual results:

excessive session stores, (every 15 seconds by default per browser.sessionstore.interval), cause excessive disk writes as well as ram usage, one tab can consume from 300mb to even 1gb if left open long enough.

Expected results:

tab should stay at ~30mb

I corrected this issue by setting browser.sessionstore.interval to a much larger interval ( 30 minutes in my case 1800000)
tabs are now no longer more than 30mb

Comment 1

[BugBot [:suhaib / :marco/ :calixte]]

The Bugbug bot thinks this bug should belong to the 'Core::Performance' component, and is moving the bug to that component. Please revert this change in case you think the bot is wrong.

Comment 2

[Kim Moir [:kmoir] ET]

Hi contact: Could you attach a profile to this bug. Here are the steps to https://developer.mozilla.org/en-US/docs/Mozilla/Performance/Profiling_with_the_Built-in_Profiler

Comment 3

[Olli Pettay [:smaug][[e-mail]]]

A profile would be indeed very useful here.
And also memory report from about:memory (click measure there, possibly with 'verbose') when memory usage is high.

30MB sounds very very small number for a tab containing things like Facebook or Reddit.

Comment 4

[Randell Jesup [:jesup] (needinfo me)]

A memory report taken after N minutes with interval at 15s, and a memory report taken after the same amount of time with interval set to 30 minutes would help a lot in diagnosing this. I agree that having facebook or reddit use only 30MB would be very unexpected.
Was the browser idle during this time, or were you actively scrolling/clicking/interacting with the page?
Thanks!

Comment 5

[u669021]

Attachment: 2021-04-20-23-12-43-perfmon.png

top disk reads by process...

Comment 6

[u669021]

Attachment: 2021-04-20-23-13-54-perfmon.png

top disk writes by process

Comment 7

[u669021]

I could not get performance profile recording to work.

browser is idle, will cause excessive disk writes, can be seen with process explorer and resource monitor in windows.

I hardly used the laptop the entire day, only minor browsing, and total disk write was 9.5GB, and read was 4.7GB! This means firefox has been killing SSDs for a long time..as this bug existed ever since 2016 at least

I've attached 2 screen shots from resource monitor showing the files that firefox is reading and writing to/from from within the user profile folder.

Comment 8

[u669021]

Attachment: 2021-04-20-23-21-28-perfmon.png

immediately after increasing the time interval

Comment 9

[u669021]

the 3 files in the last screen shot are the heavy writers, but B/sec reduced significantly, immediately after reducing the firefox store interval

Comment 10

[Daniel Bodea [:danibodea]]

I have attempted to reproduce this issue in multiple tries with extensive time left opened after scrolling several high usage websites, but no success. Tested in Windows 10 with Release v85.0 and v 88.0.1.

1. I would like to ask you to attempt to reproduce it in safe mode (https://support.mozilla.org/en-US/kb/troubleshoot-extensions-themes-to-fix-problems). If it does not reproduce, it will prove that there is some user data in the profile you use that might influence the browser's high usage.

2. I would like to ask you to load the "about:support" page in a new tab and attach the information to this bug. This way we could try to rule out add-ons one by one to see if one of those is the culprit.

3. I have to say that a memory report with a browsing session in which this issue reproduces would be the easiest way for developers to determine what causes this rising memory usage, so if I can help you obtain it, that would be best.

This being said, I will try to write you a list of steps to do it:
a. Open https://profiler.firefox.com/
b. Click "Enable Firefox Profiler Menu Button"
c. From the opened pop-up/drop/down of the installed addon button in the menubar, click the "Start recording" button.
d. Do whatever you o in a normal browsing session and reproduce the issue. If the Usage is becoming to heavy and the firefox might be too slow to use, try to limit the browsing time and stop the capture prematurely: by clicking the "Capture" button from the same pop-up you started it.
e. When the profile is displayed, click the "Upload Local Profile" button from the upper right corner of the web content area, select all boxes to be sure and then click "Upload".
f. Then copy-paste the permalink displayed (in this form https://share.firefox.dev/33OVRGH) to this bug. (Link is displayed when clicking the "Permalink" button from the upper-right corner of the web content area.

Thank you for your report! Please provide us the necessary information to be able to investigate this issue.

Comment 11

[Daniel Bodea [:danibodea]]

Please reopen if it still reproduces and there's new information to back it up (requested above).
Thank you for your contribution!