On Fri, 08 Feb 2019 20:55:47 +0100, Bruno Friedmann wrote:
On jeudi, 7 février 2019 09.57:20 h CET Richard Brown wrote:
On Thu, 7 Feb 2019 at 09:04, Wolfgang Rosenauer
wrote: Am 07.02.19 um 08:05 schrieb Mike Galbraith:
On Wed, 2019-02-06 at 16:34 +0100, Richard Brown wrote:
Hi all,
I was talking to Takashi lately about the saga that is bug 1112824
http://bugzilla.opensuse.org/show_bug.cgi?id=1112824
In that bug a kernel with CONFIG_PREEMPT_VOLUNTARY=y was provided, and a user reported that it did not improve the situation for them
However, as a heavy GNOME user, in my own testing, I have found the following results
CONFIG_PREEMPT_NONE (as seen in SLE/Leap) 'feels' slower, but is usable without the sort of stalls/hangs/inputs being dropped that are described in 1112824
CONFIG_PREEMPT (as in Tumbleweed right now) 'feels' faster than _NONE, mostly, but then interactive processes like many functions in GNOME randomly stall/hang with keyboard entries being dropped, as described in 1112824. IOW - I can reproduce the issues reported to a perceptible degree
CONFIG_PREEMPT_VOLUNTARY (as used in 'other distros) 'feels' just as fast as _PREEMPT, without the stalls in GNOME
I'm suffering at least on one of my machines from the performance hit introduced around October still. And I'm currently running a PREEMPT_VOLUNTARY kernel for testing. Still I do not see a noticeable difference fwiw. Someone called it microhangs and I have plenty of them. Just writing these lines is distracting when the system cannot follow in realtime while I'm typing not speaking about all the animation latencies and hangs. So I cannot provide much feedback about if this change is worth it for some or in general for some reasons. But it is certainly not changing my experience under TW/Gnome for the better :-(
Yes, like Takashi says in the bug, there is probably no silver bullet
VOLUNTARY improves things for me, it's aligned with what two other major distros do, it's what folks like Mike are using themselves, therefore I'd like everyone here to use this opportunity to consider changing it as our default also. I accept this might not fix the issue that triggered the bug..That bug has become a mess full of generic "meh things aren't as slow as they used to" complaints. Rather than dismiss them I think it's a good opportunity to snipe out what few things we can identify, consider, and improve compared to the status quo.
In the bug there are (strangely private) comments in the but suggesting that we should drop the IBRS handling we currently have and adopt EIBRS+retpolines like upstream
That sounds like another reasonable step forward I'd like to see us consider and hopefully adopt, but given I don't have the problem as severely as you do I'm not in a position to test out the theory or vouch for it's sanity, so I'm left leaving that as a line of investigation I hope will be pursued by wiser brains.
- Rich
Hi all, I'm a bit surprized, I didn't detect any of the hickup describe here during the last few month. I'm an happy (and loyal) plasma5 user :-) (If I activate the troll mode, I would recommend the changing desktop, but I will not, no time for that).
So isn't there a kind of "scientist" method to meseaure and track it down ?
Unfortunately the interactivity is one of the difficult things to measure quantitatively. Especially the desktop interactivity is majorly influenced by other factors like the hardware components, the file systems, usage patterns, and whatever. There are some unattended benchmarks, but it doesn't guarantee what you wanted to see.
If there's a bugzilla opened for this would you mind to be sure it is open for community review, access.
As Richard's original post mentioned, it started from bug 1112824. Take a look at it and enjoy, if not done yet :)
Starting to change openSUSE kernel means having that option activated and only one kernel-flavor, or will we have -desktop kernel like we add several years ago ?
I'm feeling that having an excellent openSUSE kernel also for server deploiement, container and so on is also vital.
If that option really matters and inevitably needed for majority of users, we can revive a new flavor, yes. But I strongly doubt it. The effect of CONFIG_PREEMPT is mostly likely a placebo for normal desktop usages. Only the very hard RT (like the realtime audio with a bad hardware combination) may see the clear difference. Unless we get a significant demand, we'd like to avoid creating another flavor for keeping the maintainability. thanks, Takashi -- To unsubscribe, e-mail: opensuse-kernel+unsubscribe@opensuse.org To contact the owner, e-mail: opensuse-kernel+owner@opensuse.org