Arch Linux

El Lobo

Banned

Registered: 2012-10-06

Posts: 13

ionice breaks desktop?

Hi,

since I use my desktop system quite multitaskingly, sometimes I try to reduce the I/O load of certain tasks by setting them to class "idle" with ionice. E.g. a running rsync or tar or filesystem scans.

This worked perfectly, no issues ever. Since I started to use ArchLinux, and I have switched to systemd with control groups, apparently something has changed. Under unknown circumstances, the whole system gets stuck. And "stuck" means, I can't even start a new console shell - I can switch to a console and log in, but a shell prompt never appears.

Instead, I get funny log messages, like "kernel: [14160.660031] INFO: task flush-254:0:607 blocked for more than 120 seconds." This is somewhat beyond my understanding, since a "blocked" flush (why the hell it is blocked??) should lead to other processes unable to write - and an idle condition. But, apparently, this never happens.

Obviously, I have never understood what I was doing. Can please someone give me a hint?

WonderWoofy

Member

From: Los Gatos, CA

Registered: 2012-05-19

Posts: 8,414

Re: ionice breaks desktop?

I have no idea about ionice.  But maybe you should try graysky's linux-ck repo.  The ck patchset (or possibly just the bfq patch/scheduler) reduces i/o in favor of maintaining a usable desktop.  It works pretty great, though now I have a SSD, so it doens't matter much.  Still I use it because the cpu scheduler is apparently faster.

El Lobo

Banned

Registered: 2012-10-06

Posts: 13

Re: ionice breaks desktop?

I have no idea about ionice.  But maybe you should try graysky's linux-ck repo.  The ck patchset (or possibly just the bfq patch/scheduler) reduces i/o in favor of maintaining a usable desktop.  It works pretty great, though now I have a SSD, so it doens't matter much.  Still I use it because the cpu scheduler is apparently faster.

I had been a long time user of Con Kolivas' schedulers. After all, I stopped expecting much from a kernel scheduler, because it has to guess which task is interactive, and which is not. But it can't guess which one I am staring at... so...