Hi James, ...my board does not use systemd as far as I know...the whole mimic is original gentoo stage3 stuff and Gentoo defaults to openrc/udev and not systemd (or am I wrong?)
Cheers Meino James <wirel...@tampabay.rr.com> [14-12-06 21:16]: > <meino.cramer <at> gmx.de> writes: > > > > > (1) Then pursue quantifying with tools just what is causing the > > > writes, strategies for minimization and monitoring as needed. > > > > So folks are going down path (1) with you, that is fine. > > Prong (1) includes all issues related to systemd. Probably embedded > experience with systemd is rare, just guessing. Certainly I have none > of that experience. So post to those iotop responses and remind > folks you are using systemd on an embedded (gentoo) micro. > > root 563 1 0 15:37 ? 00:00:00 /lib/systemd/systemd-udevd --daemon > > > > > > > (2) First minimize those write to your non-mechanical memory. > > > > I have dozens of tricks to minimize a gentoo system. But it is quite > > > a bit of work, just so you know. It's not a do this and it great. It > > > more like, try this, study the result and then alter the strategy. > > > > > > hth, > > > James > > > > > > > Hi, > > > > thank you very for all help I received regarding my question. > > > > The system is already down to a limit. The by default running > > processes are: > > > > root 1 0 0 15:36 ? 00:00:00 init [3] > > root 2 0 0 15:36 ? 00:00:00 [kthreadd] > > root 3 2 0 15:36 ? 00:00:01 [ksoftirqd/0] > > root 5 2 0 15:36 ? 00:00:00 [kworker/0:0H] > > root 7 2 0 15:36 ? 00:00:00 [khelper] > > root 8 2 0 15:36 ? 00:00:00 [kdevtmpfs] > > root 160 2 0 15:36 ? 00:00:00 [writeback] > > root 162 2 0 15:36 ? 00:00:00 [crypto] > > root 164 2 0 15:36 ? 00:00:00 [bioset] > > root 166 2 0 15:36 ? 00:00:00 [kblockd] > > root 168 2 0 15:36 ? 00:00:00 [cfg80211] > > root 169 2 0 15:36 ? 00:00:00 [kworker/0:1] > > root 280 2 0 15:36 ? 00:00:00 [kswapd0] > > root 296 2 0 15:36 ? 00:00:00 [fsnotify_mark] > > root 372 2 0 15:36 ? 00:00:00 [ipv6_addrconf] > > root 398 2 0 15:36 ? 00:00:00 [deferwq] > > root 406 2 0 15:36 ? 00:00:12 [mmcqd/0] > > root 412 2 0 15:36 ? 00:00:00 [kworker/0:2] > > root 415 2 0 15:36 ? 00:00:00 [jbd2/mmcblk0p2-] > > root 416 2 0 15:36 ? 00:00:00 [ext4-rsv-conver] > > root 563 1 0 15:37 ? 00:00:00 /lib/systemd/systemd-udevd > --daemon > > root 952 1 0 15:37 ? 00:00:00 /usr/sbin/ifplugd > > --iface=usb0 > > root 1380 1 0 15:37 ? 00:00:00 /usr/sbin/sshd > > root 1399 1 0 15:37 tty1 00:00:00 /sbin/agetty 38400 tty1 > > linux > > root 1400 1 0 15:37 tty2 00:00:00 /sbin/agetty 38400 tty2 > > linux > > root 1401 1 0 15:37 tty3 00:00:00 /sbin/agetty 38400 tty3 > > linux > > root 1402 1 0 15:37 tty4 00:00:00 /sbin/agetty 38400 tty4 > > linux > > root 1403 1 0 15:37 tty5 00:00:00 /sbin/agetty 38400 tty5 > > linux > > root 1404 1 0 15:37 tty6 00:00:00 /sbin/agetty 38400 tty6 > > linux > > root 1405 1 0 15:37 ttyS0 00:00:00 /sbin/agetty -L 9600 ttyS0 > vt100 > > root 1406 1380 0 15:37 ? 00:00:02 sshd: root <at> pts/0 > > root 1412 1406 0 15:37 pts/0 00:00:00 screen -R -d > > root 1414 1412 0 15:37 ? 00:00:01 SCREEN -R -d > > root 1415 1414 0 15:37 pts/1 00:00:05 -/bin/zsh > > root 1434 2 0 15:38 ? 00:00:00 [kworker/0:1H] > > root 1866 2 0 15:43 ? 00:00:00 [kworker/u2:0] > > root 8556 2 0 16:49 ? 00:00:00 [kworker/u2:2] > > I'd research "kworker" > > http://askubuntu.com/questions/33640/kworker-what-is-it-and-why-is-it-hogging-so-much-cpu > > > > The count of getty processes may be decreaseable...but the rest is ok, > > I think. > > Those are static and just sitting incase you need a getty, so not a problem > > > When I do a ftop I get no process, which have an open file handle for > > writes...sometimes screen writes to utmp but thats it. > > With a traditional (non systemd) approach, init scripts just fire > up things at boot time and such. With systemd, I have no idea > what's going on. It's a curious situation and maybe systemd has > no issue in your excessive writes; pure speculation on my part. > But an embedded system just sitting idle should use very little > resource and sit quietly, in my experiences. > > > > I suspect the swapfile I mounted as swapdevice for being guilty. > > I will deactivate that and we will see then. > > good thing to examine. > > > When looking at /proc/diskstats: Will I see writes to FIFOs on the > > disk as writes to the disk??? > > If YES...it would explain it... > > > Also good to look at. > > I usually use ext2 or one of the newer files systems, just for solid state > memory. Here is a good link to get your research your fs options. > > http://free-electrons.com/blog/managing-flash-storage-with-linux/ > > Since you have (2) boards, have you considered installing the second one > differently (different file system, no systemd etc etc to compare the > 2 results? If you can put different install-varients on different usb/sd/? > media, then you can just power down and change them out while comparing > resource utilization; just a thought, but something I do routinely. > > > Also, you need to get a custom/stripped kernel building methodology > establish so you can try to reduce the kernel size by eliminating things > you do not use, testing scheduler options and a host of things. > > Your entire toolchain needs to be documented and keep track of what > you change and the results of which test you run, when and such. > > Also, when compiling a kernel for a minimize system I find that using > (CFLAGS="-Os"" yields faster and small executables) and is an excellent > way to reduce resource loading on a minimized or embedded system. > > It's going to be a long journey, so keep meticulous records of what you > try, the results and your conclusions for the best path forward. > > > I'm out for a while. > hth, > James > > > > > > > > >
