Browser freezes/lags with every page load (+ sometimes randomly), CPU pegged at 100%

[crypdick]

• Did you search for similar issues before submitting this one?
  Yes

• Describe the issue you encountered:
  Every time I open a new tab or nav to a new page, the browser becomes momentarily unresponsive : no scrolling, typing, or clicking. The freeze typically starts immediately after the page is fully loaded, but it froze ~5 times as I was writing this report (minutes after it had finished loading). Freezing even happens when I open a new tab (to the default dashboard) or when opening the Brave preferences window!

I have a system resource monitor on my panel and every single time this happens I see exactly one of my CPU cores get pegged at 100%. I have plenty of RAM. There are various brave-related processes (brave, brave --type=renderer [...]) but there doesn't seem to be a single one which gets pegged; they take turns going to 100% when I open a page.

I tried running brave --v in terminal and checked dmesg, nothing interesting.

• Platform (Win7, 8, 10? macOS? Linux distro?):
  Linux mint 4.4.0-77-generic 64-bit

• Brave Version (revision SHA):
  Unsure about the SHA, I just downloaded brave_0.15.2_amd64.deb from the website an hour ago (4/14/17).

• Steps to reproduce:

  1. Load any website or open any tab
  2. wait for it to load

• Actual result:
  Browser lags for 1-1.5 seconds

• Expected result:
  No CPUs pegged, or at least distribute the load across multiple cores so that that the browser does not become unresponsive.

• Will the steps above reproduce in a fresh profile? If not what other info can be added?
  All shields are up, all "advanced" shields are enabled, ads and 3rd party cookies are blocked.

• Is this an issue in the currently released version?
  Yes.

• Can this issue be consistently reproduced?
  Every time.

[andutoo]

Does the freeze/lag happen when you move around / zoom on google maps and when you switch between the sections in about:preferences?

Update:
I thought I had tried clearing my browsing data already, but I hadn't ticked any of the boxes before clicking the clear button. After I had cleared my browsing data and the browser restarted, I was free of the freezing.

OS: Win10 64 bit

[crypdick]

@andutoo Clearing my browser data fixed the problem. Thanks! The browser was unusable before.

[bsclifton]

Duplicate history can cause a lot of problems- for example, using Google Maps (notice the URL changes a lot). We have an issue captured to fix that with #3848