Hi Rachel,
On 18/11/2015 5:50 AM, Rachel Protacio wrote:
Hi,
Please review the following small logging enhancement.
Summary: The former -XX:+TraceVMOperation flag is updated to the unified
logging framework and is now replaced with -Xlog:vmoperation in product
mode.
Open webrev: http://cr.openjdk.java.net/~rprotacio/8143157/
Bug: https://bugs.openjdk.java.net/browse/JDK-8143157
Testing: Passes jtreg, JPRT, RBT quick tests, and refworkload
performance tests.
Meta-question: the logging framework is safe to be called when at a
safepoint isn't it?
---
src/share/vm/runtime/vm_operations.cpp
void VM_Operation::evaluate() {
ResourceMark rm;
! outputStream* debugstream = LogHandle(vmoperation)::debug_stream();
! if (log_is_enabled(Debug, vmoperation)) {
! debugstream->print("[");
! print_on_error(debugstream);
! debugstream->cr();
}
doit();
! if (log_is_enabled(Debug, vmoperation)) {
! print_on_error(debugstream);
! debugstream->print_cr("]");
}
}
Why are you calling print_on_error twice?
Why is the only logging level for this tag the "debug" level? I think I
may be missing part of the way UL works here - can you enable logging
both by explicit tag (ie vmoperation) and the level (ie debug)?
And I know I sound like a broken record but I'm concerned about the
overhead of the logging actions when it is not enabled ie:
outputStream* debugstream = LogHandle(vmoperation)::debug_stream();
always gets executed - and we evaluate is_enabled twice.
---
test/runtime/logging/VMOperationTestMain.java
Can you add a comment explaining what the logic is attempting to do
please. I'm curious how many times the loop executes before you get a
safepoint-based GC (and how it varies for different GC's).
Style nit: while( -> while (
A compatability request has been accepted with regard to this change.
I'll record my objections again to the conversion of develop flags to
product. <sigh>
Thanks,
David
Thank you very much,
Rachel
