Slow VC++ builds from Linux fileserver
davecb at Canada.Sun.COM
Wed Sep 9 11:59:41 GMT 1998
To give some concrete figures, building a AppWizard generated project
under NT4 takes 33 seconds when the project files sit on the UltraSparc
and 165 seconds when they sit on Linux. When built under W95 (on a
slower machine - NT4 is 200 MHz PII w/ 128Mb, W95 is a 90MHz Pentium
with 64Mb), the build takes 54 secs when the project files sit on Linux
or UltraSparc (and 64 seconds when the files are hosted on a NT server,
for what it's worth). Yep, a P90/W95 outperforms 200PII/NT4 by a factor
As a table:
Server Client Time
------ ------ ----
UltraSparc NT4 33
Linux NT4 165
NT4 NT4 -
UltraSparc win95 54
Linux win95 54
NT4 win95 64
Hmmn: I'd break this down into several separable questions:
Let's assume that a compile requires opening and reading lots
of .c .h and a few .o files....
There's caching and throughput issues possible:
caching allows faster opening of directories to get
.h files, throughput just give throughput (:-))
If and only if the win95/ultra build really is
indistinguishable from the win95/linux, then the
machines are producing equivalent performance,
probably in both areas (theoretically one could have
high caching and low throughput, the other the opposite:
I'm ignoring that case)
There is a terrific difference that the above logic
suggests is client-specific.
The right way to diagnose it is to take packet dumps
with timestamps and grovel over the request-reply pairs
looking for a feature (;-))
The bogus way is to guess: I will now guess (:-))
It sounds like NT is issuing a sequence of SMBs that
win95 isn't, and some of them are ``slow''. The extra
performance of the Ultra pays off here, for reasons I
haven't got a clue about.
I'd try turning things off. First, turn off oplocks.
Your performance may then be horrible.!!! Then try
fake oplocks. Then try locking= no. Then share
This is in hopes of finding something the NT does
wrong that's an option. And it may.
Beware! Multiple users working on the same project WILL
mess things up with locking mechanisms turned off. Use
RCS during any beta-testing!
And, whether you succeed or fail, send us mail.
If you do take packet dumps, send the samba team
an ftp location or url.
David Collier-Brown, | Cherish your enemies. They're harder to
185 Ellerslie Ave., | come by than friends and more motivated.
Willowdale, Ontario | davecb at canada.sun.com, hobbes.ss.org
N2M 1Y3. 416-223-8968 | http://java.science.yorku.ca/~davecb
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