I had a problems with spontaneous router reboots every 1-3 days since we changed an ISP. Almost every time before reboot the internet connection dropped. Once with some luck, I was able to read the router logs shortly before the reboot happened. I found this very interesting entry:
2018-03-04T02:55:04+01:00 warning kernel: [86429.609956] netifd: page allocation failure: order:5, mode:0x24000c0
This means that netifd process requested memory allocation (if I am not wrong order 5 means 128kB) but this request failed. As the system had lots of free memory:
Normal free:17796kB min:3504kB low:4380kB high:5256kB active_anon:26476kB inactive_anon:28948kB active_file:271888kB inactive_file:258968kB .…
the reason is NOT memory exhaustion. The only candidate here can be memory fragmentation. Flowing log entries proves this hypothesis:
2018-03-04T02:55:04+01:00 warning kernel: [86429.610316] Normal: 1176*4kB (UME) 576*8kB (UME) 412*16kB (UME) 50*32kB (UM) 6*64kB (UM) 0*128kB 0*256kB 0*512kB 0*1024kB 0*2048kB 0*4096kB = 17888kB 2018-03-04T02:55:04+01:00 warning kernel: [86429.610337] HighMem: 98*4kB (UM) 43*8kB (UM) 8*16kB (UM) 6*32kB (UM) 3*64kB (M) 5*128kB (M) 0*256kB 0*512kB 0*1024kB 0*2048kB 0*4096kB = 1888kB
I find out that there was similar issue on arch linux for ARM https://github.com/archlinuxarm/PKGBUILDs/pull/630 and the solution is to enable flowing kernel compile options:
I have recompiled and installed kernel with this options and my router is running stable for months!
Initially I have informed support about the issue (ticket #001486), and later as I found the solution I have requested kernel change with this options. But unfortunately I did not received any reply from Turris support to my request.
To everybody with self-rebooting Turris, this small patch can hopefully help you. Send an email to support with link to this post and request to this small kernel change.