On 2020-05-18 15:16, Erik Joelsson wrote:
Should we then add the big flags instead to have some control over
memory footprint, or are we trusting the default ergonomics to do the
right thing on every possible build system out there?
You make it sound like we shouldn't. :-) But seriously, I think we
should have some faith in our product to actually produce good default
values. If anything, the "small" flags were created to signal that the
default ergonomics didn't really apply, that we favored fastest possible
startup, at the expense of long-term performance.
Also, this is what we do for all other tools. There is no
"$(JAVA_TOOL_FLAGS_BIG)". Yes, I know, there is a $(JAVA_FLAGS_BIG), and
we could of course turn it into a "TOOLS" version, but so far we have
not done that. (The difference is that the "normal" version is supposed
to be passed to java, like -Xmx, and the "TOOLS" version is supposed to
be passed to tools like javac, so they are prefixed with -J like -J-Xmx.)
Are you happy with this, or do you want me to change the patch to
include a new JAVA_TOOL_FLAGS_BIG?
/Magnus
/Erik
On 2020-05-18 03:12, Magnus Ihse Bursie wrote:
The linking of the JDK image using the jlink tool takes a
considerable amount of time. However, the jlink tool is classified as
a "small java" tool in the build script. This should only be used on
quick small tools where a long startup time has a measurable
performance impact. Clearly this does not apply to jlink.
The effect of removing the small tool flags are most pronounced when
running a slowdebug build. Robbin Ehn, which made me aware of this,
reduced the running time of jlink from 36 to 21 seconds on his
machine by removing the "small" flags. On a release build, the effect
is much less noticeable, but it's still worth fixing.
Bug: https://bugs.openjdk.java.net/browse/JDK-8245168
Patch inline:
diff --git a/make/autoconf/spec.gmk.in b/make/autoconf/spec.gmk.in
--- a/make/autoconf/spec.gmk.in
+++ b/make/autoconf/spec.gmk.in
@@ -642,7 +642,7 @@
JAVAC=@FIXPATH@ $(JAVAC_CMD)
JAVADOC=@FIXPATH@ $(JAVADOC_CMD)
JAR=@FIXPATH@ $(JAR_CMD)
-JLINK = @FIXPATH@ $(JLINK_CMD) $(JAVA_TOOL_FLAGS_SMALL)
+JLINK = @FIXPATH@ $(JLINK_CMD)
JMOD = @FIXPATH@ $(JMOD_CMD) $(JAVA_TOOL_FLAGS_SMALL)
JARSIGNER=@FIXPATH@ $(JARSIGNER_CMD)
JJS=@FIXPATH@ $(JJS_CMD) $(JAVA_TOOL_FLAGS_SMALL)
/Magnus
