On Wed, Mar 1, 2017 at 11:40 PM, Weedy <weedy2...@gmail.com> wrote: > On 28 February 2017 at 05:40, Martin Tippmann <m...@i3o.de> wrote: >> On Mon, Feb 27, 2017 at 9:17 PM, Stijn Segers >> <francesco.borrom...@inventati.org> wrote: >>> Okay, so I tracked it down to cake being the culprit. When I disable the >>> Cake SQM instance, no more of those traces, and no more sudden reboots. >>> >>> If I can help debug this, let me know - I enabled a Cake SQM instance on an >>> APU2 and so far that seems to run fine. >> >> cake: Maybe it's related - I'm seeing high cpu usage with cake on >> TP-Link 841N routers even with none, moderate traffic after a while. I >> don't see hanging tasks in the logs but the system feels sluggish even >> it's idle. > > > I have a WR842ND v2, I'm also seeing high CPU suddenly with only > default fq-codel on 4.4.50.
with fq_codel everything is fine for me (on WR841Nv7/8/11), even cake is fine on a MAC1200R. We have a few a few WR842N in our community mesh network but these are also remote and in use at the moment. Just to be sure: Is the build newer than January 27? We've seen high sys without these fixes: https://git.lede-project.org/?p=source.git;a=commit;h=82d580e8b5c43f4dd228f2bb5927ca3e47752a34 https://git.lede-project.org/?p=source.git;a=commit;h=b94177e10fc72f9309eae7459c3570e5c080e960 > Are you able to git bisect? This particular device is installed in a > remote location so I can't deal with it for a while. Never done that but I guess it's possible. At the moment I'm not even sure how to reliable reproduce the cake issue. Filling /tmp might trigger it. I've discovered after routers got slow after uploading the a new sysupgrade image to /tmp. I wanted to play with trace-cmd (ftrace) after discovering that you can use trace-cmd to record what's going on in the kernel remotly using the -N option (http://man7.org/linux/man-pages/man1/trace-cmd-record.1.html) but this is pretty much all new to me. The idea was to get a grasp where that high sys is coming from. Had no time to play with this and I'm not sure if trace-cmd record is even the right tool for this or works on my 32mb ram/4mb flash device. http://www.brendangregg.com/linuxperf.html has a lot of stuff that looks useful. I don't have much time until the weekend, if I manage to get the traces running I'll post them in the bugticket. regards Martin _______________________________________________ Lede-dev mailing list Lede-dev@lists.infradead.org http://lists.infradead.org/mailman/listinfo/lede-dev
