From: Paul E. McKenney Sent: 10/01/13 10:27 PM > To: Tibor Billes > Subject: Re: Unusually high system CPU usage with recent kernels > > On Sat, Sep 14, 2013 at 03:59:51PM +0200, Tibor Billes wrote: > > > From: Paul E. McKenney Sent: 09/13/13 02:19 AM > > > On Wed, Sep 11, 2013 at 08:46:04AM +0200, Tibor Billes wrote: > > > > > From: Paul E. McKenney Sent: 09/09/13 10:44 PM > > [ . . . ] > > > > > Sure. The attached tar file contains traces of good kernels. The first > > > > is with > > > > version 3.9.7 (no patch applied) which was the last stable kernel I > > > > tried and > > > > didn't have this issue. The second is version 3.11 with your fix > > > > applied. > > > > Judging by the size of the traces, 3.11.0+ is still doing more work than > > > > 3.9.7. > > > > > > Indeed, though quite a bit less than the problematic traces. > > > > > > Did you have all three patches applied to 3.11.0, or just the last one? > > > If the latter, could you please try it with all three? > > > > Only the last one was applied to 3.11.0. The attachement now contains the > > RCU trace with all thee applied. It seems to be smaller in size, but still > > not close to 3.9.7. > > > > > > > > I'm not sure about LKML policies about attaching not-so-small files > > > > > > to > > > > > > emails, so I've dropped LKML from the CC list. Please CC the mailing > > > > > > list in your reply. > > > > > > > > > > Done! > > > > > > > > > > Another approach is to post the traces on the web and send the URL to > > > > > LKML. But whatever works for you is fine by me. > > > > > > > > Sending directly to you won again :) Could you please CC the list in > > > > your > > > > reply? > > > > > > Done! ;-) > > > > Could you please CC the list in your reply again? :) > > This trace is quite strange -- there are a number of processes that sleep > and then wake up almost immediately, as in within a microsecond or so. > I don't know why they would be doing that, and I also cannot think of > what RCU might be doing to make them do that. > > I am unfortunately out of ideas on this one.
Okay. Thank you for all your help! :) Tibor -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
