This is the mail archive of the
java@gcc.gnu.org
mailing list for the Java project.
RE: gcj slower than JVM on RedHat/s390?
- From: "Boehm, Hans" <hans_boehm at hp dot com>
- To: "'Jeff Sturm'" <jsturm at one-point dot com>,Andy Faibishenko <AFAIBIS at transunion dot com>
- Cc: java at gcc dot gnu dot org
- Date: Wed, 2 Apr 2003 11:02:01 -0800
- Subject: RE: gcj slower than JVM on RedHat/s390?
Allocation of short-lived memory is also known to be slower in gcj than many other JVMs. (The allocation path is still suboptimal, the collector root set is too large, and the collector is not generational. On the positive side, real code usually allocates longer-lived objects, so we do relatively better.)
It would be interesting to see whether the statically linked executable is appreciably faster. Gcj sometimes gets hurt by the number of dynamic library calls into libgcj. But their cost is very platform dependent.
Hans
> -----Original Message-----
> From: Jeff Sturm [mailto:jsturm at one-point dot com]
> Sent: Wednesday, April 02, 2003 10:05 AM
> To: Andy Faibishenko
> Cc: java at gcc dot gnu dot org
> Subject: Re: gcj slower than JVM on RedHat/s390?
>
>
> On Wed, 2 Apr 2003, Andy Faibishenko wrote:
> > The doSomething() method performs a bunch of string
> comparisons and
> > assignments. Nothing tricky.
>
> String operations are suspected to be suboptimal in libgcj.
> I'm not aware
> of any serious attempts to profile and/or improve them, however.
>
> Jeff
>