maemo.org - Talk - BFS for the power kernel

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- - BFS for the power kernel (https://talk.maemo.org/showthread.php?t=58780)

Re: BFS for the power kernel

I'm afraid the distortion on calls still may be an ongoing problem - iDont has had at least one, and I did this afternoon too. However this may have been related to my running the "closer-to-original" version of the 330-to-350 patch (I've reverted to the old version), or running the timer at 100 Hz (I've now raised it to 300 again, as both iDont and myself agree it's a worthwhile compromise and doesn't appear to reduce battery life), or even from testing the BFQ v2 scheduler that I've successfully backported?

Regarding BTRFS, I'd love to backport it, but I am nowhere near a good enough kernel "hacker" to even attempt it. The BFQ and -ck patchsets were relatively easy to backport (especially with BFQ as I had a "reference" 2.6.28 version to work from), and the ext4 fixes had already been backported by someone else (I just had to figure which ones had and hadn't already been applied)..

PS I do have some weird problem with fcam-drivers, and I too have Catorise installed, but I haven't yet had chance to really dig into the issue properly.

Re: BFS for the power kernel

I guess it's fine to raise the timer to 300Hz, as is recommended in the official BFS FAQ:

On a side note, are you going to push an updated BFS-6 package with the new kernel timer frequency?

Quote:

Notebook / mobile device: 300 Hz Tickless Full preemption CPU frequency scaling, ondemand default

Re: BFS for the power kernel

Quote:

Originally Posted by Tigerite (Post 1021702)

Slightly off-topic, would anyone be interested in seeing the BFQ I/O scheduler in the BFS kernel? I'm working on backporting the latest BFQ-v2, although there is a version specifically for 2.6.28 out there which I can use if all else fails.

Yes, BFQ performs very nice alongside with BFS, both my desktop and my wife's netbook run Debian with liquorix kernel, I noticed great improvement in memory load operations (Netbeans IDE runs fine on the netbook).

It must give a performance boost for N900 :)

Re: BFS for the power kernel

Quote:

Originally Posted by Tigerite (Post 1022253)

PS I do have some weird problem with fcam-drivers, and I too have Catorise installed, but I haven't yet had chance to really dig into the issue properly.

Sometimes I see black screen when launching Camera / BlessN900. I use Camera Lens Launcher (so the camera app launches after the cover is already opened), that can be related.

When I close the cover and open it again, the image becomes displayed.

Nothing in dmesg, some messages in syslog, but they're related to the UI.

Re: BFS for the power kernel

eagerly awaiting the 300 hz version of the kernel, I feel my N900 is much more responsive under load conditions but indeed I also have the voice distortion issue. I'm still using the 100 hz, as that was the last one DEBianized and delivered here.

Anyway, great work guys, I would also love to see the BFQ IO scheduler as well. In our resource-constraint little gem, it can make a difference !!

If this stabilizes further, it sure deserves to be put in extras-dev.

Re: BFS for the power kernel

Quote:

Originally Posted by Bad_Habit (Post 1023038)

this happens to me without the BFS patch, seems like a bug in fcam, may not be related with the BFS kernel modification.

Re: BFS for the power kernel

I'll post a compiled deb later on today with Hz set to 300, and the latest BFQ (v2 r1) included. I would have done so sooner, but I've been trying to figure out how to get swap prefetch working with the nuances of Nokia's remapped swap (presumably a basic form of FASS). I also wanted to be sure BFQ was rock-solid stable - so far so good on that front ;) however, I'm contemplating enabling the CGROUPS_BFQIO option (I've had it disabled so far), as although BFS does not use cgroups, other things - such as freezer and ohmd - do. Google comes up a blank when searching for a definitive answer, despite BFS+BFQ being quite common, especially in Android world. There does seem to be a significant improvement over CFQ even with it disabled (as bonnie++ benchmarks testify; the 1.96 version has latency figures too), but it'd be nice to know if the bfqio would push the boundaries further.

Talking of cgroups, did the people having problems with audio issues follow these instructions, thus causing /syspart to not be mounted and disabling the ohmd cgroup module plus associated resource distribution rules?

Code:

mv /usr/lib/ohm/libohm_cgroups.so /usr/lib/ohm/libohm_cgroups.so_

I originally had done this step, but have now reverted it, as according to Eero Tamminen,

Quote:

It handles also audio policies and tries to make sure that you get
your phone calls when the device is heavily loaded and some other
minor things.

.. and since then, haven't had a single distortion, not even a minor one. So could this be the fix?

Re: BFS for the power kernel

Quote:

Originally Posted by Tigerite (Post 1024838)

Code:

mv /usr/lib/ohm/libohm_cgroups.so /usr/lib/ohm/libohm_cgroups.so_

I originally had done this step, but have now reverted it, as according to Eero Tamminen,

.. and since then, haven't had a single distortion, not even a minor one. So could this be the fix?

I can't try this as the moment as I just have the broken USB port issue. I had cgroups disabled like this though and definately had the audio distortions. Will check it out as soon as I have a working n900 again.

Re: BFS for the power kernel

I did not have cgroups disabled when experiencing audio distortion.

Re: BFS for the power kernel

neither did I. One thing to notice, every time i had distortion, i put the phone down and called back right away. every time the 2nd call was crystal clear.
just my 5 cents ...