Slow performance after 3.0.0

[justbispo]

Same report as #629 (comment)

After the 3.0.1 update, the commands became much slower. I haven't tried many commands, but I usually run ddcutil setvcp 12 - 5 and ddcutil setvcp 12 + 5, either manually or with a keybind, and ddcutil detect. On my system these commands take more than 5 seconds.

I've also reported in that comment that I had this error show up, even when I ran ddcutil setvcp 12 - 5 a few times:

> ddcutil setvcp 12 - 5
Setting value failed for feature x12, rc=DDCRC_RETRIES(-3007): maximum retries exceeded
   Try errors: DDCRC_RETRIES(EREMOTEIO(10))

But I haven't gotten this error after that.

ddcutil.txt

[rockowitz]

There's some excessive tracing that's happening in 3.0.1. I don't think that's what's slowing you down, but I'd like to take it out of the mix. So please rebuild from branch 3.0.2-dev.

Run sudo ddcutil interrogate or sudo ddcutil environment --verbose and again submit the output as an attachment.

Next, run ddcutil setvcp 12 - 5 --trace all --ts --tid or some other command the displays the slowdown. The output will likely be voluminous, but should help me identify where the slowdown is.

[justbispo]

interrogate.txt

setvcp_12_+_5.txt

[rockowitz]

I can see that the hangup is happening in the cross-instance-lock mechanism intended to keep ddcutil instances running in separate processes from clobbering each other. So please try two things:

ddcutil setvcp 12 + 5 --disable-flock

I expect that performance will return to normal.

Next, run the following to dig down into the function that's hanging and submit the output:

ddcutil setvcp 12 + 5 --trcfunc flock_lock_by_fd --ts --tid

Thanks.

[justbispo]

ddcutil setvcp 12 + 5 --disable-flock doesn't work, I get the error

No displays implementing DDC/CI found

flock_lock_by_fd.txt

[rockowitz]

Please rebuild with the latest 3.0.2-dev branch, install the following ddcutilrc file:, and restart plasma-powerdevil

[Global]
options: --syslog debug
options: --ts --tid
options: --trcfunc i2c_get_raw_edid_by_fd
options: --trcfunc i2c_check_bus 
options: --trcfunc i2c_edid_exists 
options: --trcfunc flock_lock_by_fd

[libddcutil]
options: --trace-to-syslog

The issue the following commands:

ddcutil setvcp 12 + 5
ddcutil setvcp 12 + 5 --f38 --f13

Send the jjournalctl output beginning with the powerdevil restart, along with the output of the two commands. Thank you.

[justbispo]

Oh I didn't mention in this post but did in #629 (comment) is that I'm using Sway, not Plasma. Not sure if the indications are different for this case.

[rockowitz]

Do you have anything running in the background that uses the libddcutil API as does PowerDevil? If so, please restart that instead of PowerDevil. If not, just run the two setvcp commands and submit their output. Do install the ddcutilrc file - the [global] options are still applicable.

[justbispo]

setvcp_1.txt
setvcp_2.txt

The commands are working faster than before 3.0, almost instantly, even without ddcutilrc.