Cory Petkovsek wrote: > What does 'select' mean? What about unix_stream_data_wait, wait4, > read_chan, nanosleep. That is what is the process waiting on. > Selecting what? polling what? > > unix_stream_data_wait? Where can I learn about which data stream it is > waiting on? Will lsof tell me? (I guess I can look there.)
If there's a specific process you want info on, try strace. Strace will print all the system calls a process uses. If a process is hanging, waiting on something, select will just print one syscall. For example, I have an xterm process, PID 1785. > > ps l 1785 > F UID PID PPID PRI NI VSZ RSS WCHAN STAT TTY TIME COMMAND > 000 13935 1785 1738 9 0 5292 3052 do_sel S ? 0:00 xterm > > strace -p 1785 > select(5, [3 4], [], NULL, NULL <unfinished ...> > > ls -l /proc/1785/fd > total 0 > lr-x------ 1 bmiller engr 64 Oct 7 16:47 0 -> /dev/null > l-wx------ 1 bmiller engr 64 Oct 7 16:47 1 -> /dev/null > l-wx------ 1 bmiller engr 64 Oct 7 16:47 2 -> /dev/null > lrwx------ 1 bmiller engr 64 Oct 7 16:47 3 -> socket:[2537] > lrwx------ 1 bmiller engr 64 Oct 7 16:47 4 -> /dev/ptmx I see that it's currently selecting for read on descriptor 3, a socket, and descriptor 4, /dev/ptmx. (I happen to know that descriptor 3 is its connection to the X server.) I haven't figured out how to map the socket numbers in /proc/*/fd into anything meaningful. Does that help you? -- Bob Miller K<bob> kbobsoft software consulting http://kbobsoft.com [EMAIL PROTECTED] _______________________________________________ EuG-LUG mailing list [EMAIL PROTECTED] http://mailman.efn.org/cgi-bin/listinfo/eug-lug
