Ubuntu Mainline Build Status isn’t been updated in a month. Is there a problem? It’s missing the 6.12 kernels.
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What’s the status of this @jjohansen ? Will the final parts land in 6.12?
Thanks!
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There is a data center move still in progress and our services are not yet fully restored. We do not have an ETA for when mainline builds will resume.
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Hi everyone,
I am experiencing a significant performance degradation after upgrading my kernel from version 6.6 to 6.8 and would appreciate any insights or suggestions.
Problem Description:
I am running a simulation application where most of the threads are using real-time scheduling (SCHED_RR), and the threads of a model are using SCHED_DEADLINE. After upgrading the kernel, I noticed that the execution time of my model has increased from 4.5ms to 6ms
What I Have Done So Far:
- I found this bug report and reverted the offending commit efa7df3e3bb5da8e6abbe37727417f32a37fba47
mentioned in the post. Unfortunately, this did not resolve the issue. - I performed a git bisect and identified two offending commits related to scheduling (RT and deadline).
612f769edd06a6e42f7cd72425488e68ddaeef0a
5fe7765997b139e2d922b58359dea181efe618f9
After reverting these two commits, the model execution time improved to around 5 ms. - I revert two more commits, and the execution time is back to 4.7ms
63ba8422f876e32ee564ea95da9a7313b13ff0a1 [deadline server]
efa7df3e3bb5da8e6abbe37727417f32a37fba47
Questions:
- Has anyone else experienced similar performance degradation after upgrading to kernel 6.8?
- Can anyone explain why these two commits are causing the problem? I am not very familiar with the kernel code and would appreciate any insights.
- Are there any additional settings or configurations I need to apply when using kernel 6.8 to avoid similar issues?
Additional Details:
- CPU: AMD Ryzen Threadripper 3970X
- Operating System: Ubuntu 24.04
I cannot post a new topic, so I am asking here in hopes of getting some attention to this problem. Thanks again for any insights or suggestions.
@woshilcb neither 6.6 nor 6.7 are supported Ubuntu kernel versions? I am unsure what your expectations are here? Performance tuning is also highly dependent on the overall platform and not something we would be able to easily determine a root cause? Does the 6.8 kernel exhibit the same issues? Is it the generic or lowlatency kernel? Or you mention RT so is it the realtime kernel?
Hello @brettgrand , the degradation happens in 6.8 but not 6.6. Both 6.7 and 6.8 demonstrate the same poor behavior. I mention RT because most of the threads are using SCHED_RR scheduling policy and the kernel is a generic kernel. I notice this problem after I upgrade to ubuntu 24.04, and when I roll back the kernel to 6.6 this problem is gone. I am using the same binary and nothing else is changed, (or should I configure something for the new kernel?) .
Can you reproduce this regression with a mainline kernel from Index of /mainline? If so you, should report it to upstream https://www.kernel.org/.
Hello @juergh , yes, it can be reproduced, and I will write an email to the upstream. Just post it here to see if there is a similar problem to other users.
The 6.12 builds are only available for s390 on Index of /mainline/v6.12, I want to use it for testing the sched-ext with Ubuntu on x86.
…and if you scroll up, you’ll understand why that is…
Hi,
I’m running Ubuntu 24.04.1 LTS (GNU/Linux 6.8.0-51-generic x86_64) as a guest system in Proxmox VE 8.3.2. I have connected a WD SATA-HDD via passthrough directly to the Ubuntu guest system. It is mountable and works flawlessly.
However, I want it to spin down to “standby” state if it is not in use. So, I ran the “hdparm” command to check the current power mode status. The status of the SATA-HDD had been “idle” or “active” at this point:
root@xyz:~# hdparm -C /dev/sdb
/dev/sdb:
SG_IO: bad/missing sense data, sb: 70 00 05 00 00 00 00 0a 00 00 00 00 20 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 drive state is: standby
As you can see, “hdparm” threw an error and returned the wrong power mode state “standby”. I doublechecked by touching the SATA-HDD. It was spinning and the head was moving.
After, I did some googling and found a post in the Majaro (sorry!) forum exactly matching this issue:
Ata: libata-scsi: Sense data errors breaking hdparm with WD drives
The post also points out the solution - a kernel fix as part of the linux6.10.6-1 point release:
Revert “ata: libata-scsi: Honor the D_SENSE bit for CK_COND=1 and no error”
Now my question - Is there any chance to add this fix also to one of the next point releases of Ubuntu 24.04.1 LTS’s “Linux 6.8.0-5x” kernel?
I would really like to avoid introducing a “custom” kernel into my 100%-standard Ubuntu LTS system.
Thanks in advance for your replies!
You should file an LP bug report for this here.
Thanks for your suggestion, @juergh!
I just filed a bug report. I hope I have done it correctly…
Bug #2092222 “ata: libata-scsi: Honor the D_SENSE bit for CK_CON…” : Bugs : linux package : Ubuntu
Hi, Could someone say when 6.12 will be available for 24.10?
If you want to live on the edge, you can install the latest and greatest from the bootstrap PPA:
In the mainline I see v6.13-rc1 and 6.13-rc3 (empty) 6.13-rc2 is missing. From some sites seems that 6.13-rc7 is available. what is the real situation?
Mainline builder woes due to datacenter move, OS upgrades, ancient code, unreliable infrastructure, low priority, …
We are aware of the issues but unfortunately it has no priority (for management). I don’t like it but it is what it is.
Would be handy if users could install the 6.13 kernel which has been released since 19th and test it out to find any bugs or regressions.
Thank you for providing this space!
I’m using plain Ubuntu for music production with the low-latency kernel, and all is going well. Lately I’ve seen people saying that nowadays you don’t need the low-latency variant anymore, that the default kernel is good.
I have no intention of touching my setup unless I have to, but I’m curious about pros and cons (if any) of using one variant or the other for music production.
Hi @icaria36,
See the following links:
https://ubuntustudio.org/2024/07/updates-for-july-2024/
Ubuntu Studio is already tuned for you, so you don’t need to do any special tricks. If you don’t like the desktop environment it provides, you can use Ubuntu Desktop or any officially recognized flavor and use this:
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