High CPU Utilization and freezes on 4.2.2 and 4.2.3

[igorekvaluev]

Please provide the following information

qBittorrent version and Operating System

4.2.2 and 4.2.3
Windows 10 Pro x64

If on linux, libtorrent-rasterbar and Qt version

(type here)

What is the problem

High 9900k utilization, freezes pc and mouse, high power usage and memory usage

What is the expected behavior

Last seen 9% cpu utilization

Steps to reproduce

Download a few torrents and try on windows 10 and ssd

Extra info(if any)

4.2.1

4.2.2 and 4.2.3 at screenshot 5%, but it was 9%

[Ryrynz]

Provide comparisons with against 4.1.9 I'm actually seeing less memory usage vs 4.1.9 and no freezes at all.

[FranciscoPombal]

Are you using an HDD or an SSD? For performance issue reports it is critical to post long term trends as well, not just a static screenshot of a fixed moment in time.

[Ryrynz]

Yeah, in one screenshot you're barely writing anything to the disk ~1.3MB/s and in the other you're writing to the disk at 28.1MB/s which explains the higher CPU utilization and memory allocation. As Francisco said you need to do proper comparisons otherwise you're wasting everyone's time.

[lucky1luc]

Just my 2 cents worth. How can a non tech person know what is required? i reported the same issue with 4.2.2 on the forum with the question if anybody had similar problems, and never got any reply. I installed 4.2.3 and for me the problem disappeared (although come to think of it, I did change my network settings before installing 4.2.3).

With 4.2.2 I saw high CPU usage as well, but mostly network connection issues after that. I took almost half an hour for qbittorrent to become responsive again. qbittorrent did a complete resume data check on all torrents when starting up, and it tried to connect to my proxy at several ip adresses (unsuccesfully). So at one point I had big disk I/O (checking resume data), at another I had almost no disk usage and almost no cpu usage (because of network connection issues - timeouts)

I, for one, am not so keen to share qbittorrent logs and/or process explorer output, because of privacy issues. Please explain how to get the necessary data in a way that any non tech person can understand. I can edit out torrents and ip adresses if that becomes necessary.

Another cents worth, I have the feeling that the several threads are not any longer running in parallel, but consecutively at startup. (but this is a suspicion, not backed by any data)

[igorekvaluev]

I will not install 4.2.2 or 4.2.3 again for tests. I have many torrents in qbit. I use it on SSD. 4.2.1 don't have such problems. When I saw 4.2.3 notification I was glad and thought that problems could be fixed after 4.2.2, but the same high cpu usage and freezes.
And you can don't have problems if you have about 10 torrents or less, this is my opinion.

[FranciscoPombal]

Well I have hundreds of torrents and I cannot reproduce this. Without more information, nothing can be done.

[igorekvaluev]

What is "more information"?

[FranciscoPombal]

@lucky1luc

The problem with performance/connectivity-related issues is that first it must be determined if the issue really lies with qBIttorrent/libtorrent or some quirk/misconfiguration of the user's setup; even if the problem only starts occurring from one version of qBittorrent to another, the problem may still lie with the user, in some circumstances. Most performance-related issue reports don't pass this stage, i.e., they are not confirmed/reproducible, and the user/user's setup is assumed to be at fault for the problem ("works on my machine!").

If it has been determined that the issue is in fact due to qBittorrent/libtorrent, enough data has to be collected in order to try to debug the issue and come up with a fix. This requires some effort on the users' part, and the more tech-savvy the user is the better. Some of these issues take more time to solve than others, but I'd say all of the confirmed/reproducible performance connectivity issues end up being resolved.

Some things that are expected when diagnosing performance issues (not all may be needed, but the more, the merrier):

• Testing if the issue is reproducible with a clean install of qBittorrent
• Providing proper and detailed steps to reproduce the problem
• Logs with potentially sensitive information redacted
• Settings files with potentially sensitive information redacted
• If you don't know how to use more advanced profiling tools, a screenshot of the speedgraph/task manager graphs over a decent period of time, process explorer data, etc.
• On Windows, disable anti-virus/firewall programs/etc and see if you can reproduce with them disabled
• Some minimal investigation/documented efforts to track down the cause by the user (e.g. "I tried with anti-virus disabled, did not work")
• Some willingness to test with different/patched versions to see if the problem is fixed
• It is expected that the user makes a reasonable effort to provide as much data as possible without having to be asked for it every time (reading the https://github.com/qbittorrent/qBittorrent/blob/master/CONTRIBUTING.md is a pre-requisite for this), otherwise it's a waste of everyone's time.

In short, a lot of things that the OP of this issue report has not provided thus far.

Here are some good examples where things are done right:

• Resolved issues: api/v2/sync/maindata is much more slower than api/v2/torrents/info #10999, 4.2.2 download/upload stalled for all torrents using only TCP with VPN (µTP works) #12253
• Currently under investigation: 4.2.x high RAM memory usage due to HTTPS tracker announces for some users #12326, Fluctuating speeds with certain torrents (or it seems like that at the speedgraph). #12336 (this one looks like it's about to get fixed soon, read the latest comments)

With the right attitude, you can gain a lot from this process. I've seen some people starting to use use profiling tools like valgrind memcheck for the first time due to issue reports on this tracker. That's valuable learning experience.

[igorekvaluev]

I have no antivirus. Also I have no time test again.

[FranciscoPombal]

What is "more information"?

Read my comment above and optionally https://github.com/FranciscoPombal/qBittorrent/blob/contrib/CONTRIBUTING.md#additional-steps-for-issues-about-performance

I have no antivirus. Also I have no time test again.

If you're not able to provide more info/test results, then there's nothing we can do, sorry.

[lucky1luc]

What is "more information"?

Read my comment above and optionally https://github.com/FranciscoPombal/qBittorrent/blob/contrib/CONTRIBUTING.md#additional-steps-for-issues-about-performance

I have no antivirus. Also I have no time test again.

If you're not able to provide more info/test results, then there's nothing we can do, sorry.

indeed, i will have to learn to use these tools then. I do want to point out that the documentation does not mention any of this. So, as a user with 300+ torrents seeding, and upgrading the torrent client and then not working anymore, you are basically f***. Nor is it very palatable to start with a fresh install. If that would fix everything, no one would ever upgrade again.

I do want to spend some time researching issues, but I cannot spend hours doing so.

[FranciscoPombal]

indeed, i will have to learn to use these tools then. I do want to point out that the documentation does not mention any of this. So, as a user with 300+ torrents seeding, and upgrading the torrent client and then not working anymore, you are basically f***. Nor is it very palatable to start with a fresh install. If that would fix everything, no one would ever upgrade again.

You can of course backup your config and BT_backup* folders before you do the clean install. That way, after testing, you can easily restore everything with little effort.

The point of testing with a clean install is just to rule out the possibility of a specific setting customization causing the problem or a faulty fastresume.

*this is where the .fastresume files are stored, which is how qBIttorrent "remembers" torrent states across restarts.

[eurobank]

I had some random freezes for 1-2 seconds latetly. No high cpu. Not at all sure my freezes are related to Qbit. I went back to 4.2.2 same issue.

Now i installed 4.2.1 and see how it goes. I use HDD for torrents.

[Ryrynz]

Now i installed 4.2.1 and see how it goes. I use HDD for torrents.

I would think if you had freezes to test you would be best using 4.1.9.1 to compare, however I have seen nothing but good performance from 4.2.3

[eurobank]

@Ryrynz

Actually no, i prefere to go back step by step. Until now with 4.2.1 i haven't any freeze but it is early to tell.

[A-UNDERSCORE-D]

Similar issue here. CPU spikes along with UI lockups. Torrents are going to a HDD for me, though it is a "fast" 7200RPM disk made in the last decade (meaning 2010-2020)

[Chocobo1]

For anyone facing the issue, this probably worth a try: go to Options -> Advanced -> Disk cache and change from auto to 64 MiB or 128 MiB.
Related issue: #12336 (comment)

[eurobank]

Ok some update on this.

After 2 days with 4.2.1 and not a single freeze problem, a few hours ago i installed 4.2.3 and the freezes are back.

So probably this is due to Qbitorrent.

[Ryrynz]

Ok some update on this.

After 2 days with 4.2.1 and not a single freeze problem, a few hours ago i installed 4.2.3 and the freezes are back.

So probably this is due to Qbitorrent.

Did you change your cache as chocobo said?

[eurobank]

@Ryrynz

My cache was already set to 16mb, so i didn't change anything. And for me, with max 2 torrents at very low speeds, i don't see any need for greater number.

Do you think i should try?

[FranciscoPombal]

@Ryrynz

My cache was already set to 16mb, so i didn't change anything. And for me, with max 2 torrents at very low speeds, i don't see any need for greater number.

Do you think i should try?

Yes.

[eurobank]

@Ryrynz

No luck, 4.2.3 freezes again. I'm going back to 4.2.1 and stay there waiting ....

[Ryrynz]

Given this happens with 4.2.2 as well this isn't entirely unexpected.
@FranciscoPombal is it possible for eurobank to test a version of qBT with an earlier version of libtorrent and or QT? 4.2.2 was a fairly big release so narrowing it down this way seems like the best way to start?

[FranciscoPombal]

@Ryrynz yes, that would be a good idea.

[githubsuckswhydoihaveamsaccountforfoss]

I had experienced the same issues except on Linux starting 4.2.1 and ending with 4.2.2. Since the 4.2.3 upgrade the freezing and pegging a single thread has stopped.

[eurobank]

Some update: While 4.2.1 is not so prone to freezes like 4.2.3, i have seen a couple of mild freezes even with 4.2.1.

Now, i would like to say that i'm not sure this comes from Qbit application. I have several other applications running like Comodo firewall or Primo Cache.

But this problem is definitely happens while Qbit is active.

[ghost]

I had the same GUI freezing issues ever since the transfer list update.

[FranciscoPombal]

This issue has been closed and locked for being too old, and thus either most likely resolved in recent versions or no longer applicable.
If you experience the reported problem or similar in the latest version, please open a new issue report with the requested information in the issue template.

A new issue report with relevant updated data gathered from the latest version is preferable to necroing an old report with a comment like "still happens in version x.y.z", even if you think the bug is the same, or suspect of a regression. Due to the changes made to the qBittorrent code and its dependencies over time, the exact cause of your problem could be totally different than the original one, despite the visible symptoms of the bug being similar. Thus, providing relevant updated information is crucial to find and fix the root cause of a recurrent problem or regression.

Thank you for your contributions.