🚀 go-pugleaf

In <1992Dec24.013446.26848@donau.et.tudelft.nl> reinoud@dutecai.et.tudelft.nl (R. Lamberts) writes:


| OK guys, don't laugh. I still have 8 meg and IRIX 4.0.1,
| and was getting sick of the slow disk write bug. If you
| are in the same situation (8 meg / 4.0.1), this crazy
| fix may be of interest to you.
| 
| It appears that doing a file system sync 20 times a second
| increases disk write speed enormously, without giving too
| much overhead. So compile something like this:
| 
| main()
| {
|   do
|   {
|     sync();
|     sginap(5);
|   }
|   while (1);
| }
| 
| (Please don't whine about this not being the best example
| of software engineering. ;-)
| 
| If you use applications that write to disk at very high
| rates, you may try to decrease the sginap argument, but
| that results in a noticeable system load. Most tools
| run at maximum write speed with the code shown above.
| 
| Run this thingy in the background and you'll actually start
| enjoying large cp or file un-tar actions...

The best fix is to get 4.0.5.  This bug was introduced in the last days
of 4.0.1, and fixed in 4.0.2 (after I found it (I wasn't the one who
introduced this one!) and all later releases.  The code has changed
enough since then that I don't want to invest the time to see  just
what else might help; certainly dropping BDFLUSHR to 1 would have
similar effects, without using up another process slot and causing
more context switches.  I seem to recall that increasing NBUF would help
prevent the situation from arising, but I may be remembering wrong.

Doing it ever 50 msecs (as your program does) seems just a *bit*
excessive though!
--
Let no one tell me that silence gives consent,  |   Dave Olson
because whoever is silent dissents.             |   Silicon Graphics, Inc.
    Maria Isabel Barreno                        |   olson@sgi.com