RFR 8010280: jvm.cfg needs updating for non-server builds (original) (raw)

Mike Duigou mike.duigou at oracle.com
Mon Apr 15 16:25:24 UTC 2013

Hi David;

I remember reviewing the jvm.cfg config patch for JDK 7. I had hoped to see the "classic" and "green" flags go away and some of the other legacy flags like "-hotspot" reduced to WARN. What's the difference between removing an entry completely and retaining it with "ERROR"?

Additionally I don't like that aliases have differing definitions and some confusing ones like "-server ALIASED_TO -client". Is this necessary or just historically convenient?

Mike

On Apr 14 2013, at 17:18 , David Holmes wrote:

Some background.

The jvm.cfg file, for which there is a per-architecture committed file in the repository, controls which VM's (client, server, minimal) are known, which is the default, whether there are other aliases and whether ergonomic selection is used. Historically things were simple: - 64-bit platforms had server only - 32-bit platforms had client and server then we acknowledged that some platforms may be client only and we added some support (originally in the old build then converted to the new build) for dynamically creating a jvm.cfg for the case of building client only. Then the minimal VM was introduced and we potentially have three VMs to handle. To address this we initially added "-minimal KNOWN" to all the jvm.cfg files for platforms known to support the minimal VM - this was done under JDK-7198815 (and those changes are now reversed by this changeset.) The problem after minimal was introduced was that the logic for "building client only" didn't account for building minimal (only or combined with client) and we need support for not-building-server. And that is what this changeset does. This only affects 32-bit builds as there is no client nor minimal VM on 64-bit. The basic operation is as follows: - If building client+server then we use the committed jvm.cfg (which handles ergonomics if applicable), adding a "-minimal KNOWN" line if minimal is also selected; - Otherwise we dynamically generate a jvm.cfg for the set of VMs being built, using these simple rules: - if client or server are present they are default - if client and/or server is absent then the absent VM is aliased to the default VM in that config - if minimal is not selected then it is absent from the jvm.cfg (we do not add any aliases for minimal**). ** The alias mechanism is useful for deprecating legacy VM names, and has also made testing more convenient. However I think it is a flawed mechanism for testing and our internal test infrastructure is moving away from arbitrarily using -client/-server when actually running server/client. If you ask for the minimal VM and it is not available I think you should get an error not silent use of a different VM. (Note: this selection doesn't affect SE Embedded as it defines jvm.cfg files using it's own rules/preferences.) webrev: http://cr.openjdk.java.net/~dholmes/8010280/webrev/ Thanks, David

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