So commenting out all the lines in /etc/syslog.conf and then rebooting seems to have done the trick. I now see ~7.8MB/s read times. Yay!
Muchas gracias! On Wed, Apr 28, 2010 at 8:00 AM, Jason Manley <[email protected]> wrote: > Syslog flushes all logs to disk as they happen (synchronous writes). So it > is very slow. > > I believe tcpborphserver (ROACH's KATCP server) should not be logging > anything anymore. > > The logs you're seeing are likely from the kernel itself, as BORPH logs > every bus transaction. A kernel recompile is required to remove this > entirely. But you can configure what is logged to disk by syslog in > /etc/syslog.conf. Perhaps try to disable the logging of these messages. > > You should be getting around 7MegaBytes/s across that bus. Even over a > network. This is just dumping data, and does not count bus overhead incurred > by reading small quantities of data from different BRAMs etc. > > If you try to dump the whole DRAM using tcpborphserver's "bulkread" command, > you should achieve something close to 3.5MB/s across the network using the > Python KATCP and the wrapper in corr. > > Jason > > On 28 Apr 2010, at 08:11, Aaron Parsons wrote: > >> I'm currently only able to read ~100kB/s from shared BRAMs on the >> ROACH. I assume the ROACH can do better than this. >> >> I've profiled my code and am certain that the bottleneck is in reading >> BRAM files. When I looked closer, I found a bunch of logging showing >> up in /proc/kmsg for every file transaction. Acting on the theory >> that this logging was slowing everything down, I killed syslogd and >> klogd (/etc/init.d/klogd stop, etc). Yet I still get lines in >> /proc/kmsg from "proc_borph". I can't find any processes that I >> recognize as potentiall logging daemons, and I haven't found anything >> with lsof that indicates what may be writing to /proc/kmsg. I'm left >> thinking that maybe this logging is compiled into the kernel. >> >> Does anyone know what is cause such lousy file I/O performance on the >> ROACH? If it is indeed a problem with excessive logging, how do I >> stop it? >> >> -- >> Aaron Parsons >> >> 510-406-4322 (cell) >> Campbell Hall 523, UCB >> > > -- Aaron Parsons 510-406-4322 (cell) Campbell Hall 523, UCB
