Subject: RE: Performance Problem: malloc() is calling madvise()
To: None <current-users@netbsd.org>
From: Bill Dorsey <dorsey@lila.lila.com>
List: current-users
Date: 05/19/2000 13:20:44
Hi,
The performance figures I gave earlier with my C++ application
may not have been realistic as I ran it on a very small
problem set (it takes a long time to run on the full problem
set). I reconfigured it to run on the full problem set but
set it to stop after completing only 1/32 of the work. This
allowed me to run it in a reasonable amount of time but get
realistic memory usage from it. Below is a table listing the
performance figures I get with libc.so from 1.4.2_Alpha and
from 1.4Y (on a DEC Personal Workstation):
Library Options Run time
libc.so.61 MALLOC_OPTIONS="" 38.229u 61.542s
libc.so.61 MALLOC_OPTIONS="h" 32.475u 0.048s
libc.so.40 MALLOC_OPTIONS="" 29.716u 0.043s
The changes in libc.so.61 (after setting MALLOC_OPTIONS to "h")
still impact my performance by -9% or so. I realize that this
may be offset by increased performance in other applications,
so this could be a non-issue. Still, it would be nice to know
that this was done cogently and not as the by-product of some
other change.
--
Bill Dorsey