[Date Prev][Date Next] [Thread Prev][Thread Next] [Date Index] [Thread Index]

Fortran I/O problems

Hello all,

	just to continue the Fortran saga: it looks suspiciously like
the I/O library in f2c and g77 both don't do buffered I/O any longer.
This differs from the standard behaviour on other platforms where the
WRITE statement produces buffered I/O. Could this be a side-effect of
the 5.4.x library? The problem is shown by jobs which have I/O, even
to a local disk which never attain 90% CPU usage on the machine.
Watching the data with tail -f shows that data is written continuosly,
without any buffering of any sort.

	Please note that the machines are 166MHz pentiums with 430HX
motherboards and fast EIDE disks and 64Mb of RAM, i.e. the stuff
should be buffered by Linux in any case. The boxes are running
Linux 2.0.25.

	I have a situation where the processor is idle 56% of the
time, system usage is at about 1% and jobs only get 40%ish. The same
jobs on other boxes (Suns running SunOS or Solaris, DEC alphas with
OSF) constantly stay at 90+% cpu usage. A typical vmstat line is:

 procs                  memory    swap        io    system         cpu
 r b w  swpd  free  buff cache  si  so   bi   bo   in   cs  us  sy  id
1 0 0  3544   992   304  5340   0   0    0    1  152  121  40   2  59

	Not very impressive...

	Any information/help would be greatly appreciated.



Arrigo Triulzi <arrigo@ic.ac.uk>, http://www.ma.ic.ac.uk/~agbt
Mathematics Dept. Imperial College of Science & Technology - London - UK

This message was distributed manually by Bruce@debian.org after the list
initially failed to distribute it.

Reply to: