Yeah, it took a while for me to come up with a reasonable test. It
possibly could use some tuning. I first required it match 5 out of 5
lines, and do so in 30 seconds. Then I realized that a fixed time wasn't
a good idea, nor matching every line. It failed frequently, mostly on
slower machines but sometimes even on fast machines due to bad luck. So
I figured out how to get the target to terminate when the main test was
done so a timer wasn't needed, and also relaxed the requirement for
matching every line so the test wouldn't need to run as long, eventually
settling on 5 out of 10 lines instead of 5 out of 5. A port without the
8231634 fix will at most match 2 lines (start and end of loop) although
I think I only ever saw it match the line at the start of the loop.
thanks,
Chris
On 4/28/20 1:02 PM, [email protected] wrote:
Hi Chris,
LGTM++
The test is interesting.
Thanks,
Serguei
On 4/28/20 12:16, Chris Plummer wrote:
Thanks Alex!
Can I get one more review please?
Chris
On 4/27/20 6:52 PM, Alex Menkov wrote:
Hi Chris,
The fix looks good.
--alex
On 04/27/2020 12:17, Chris Plummer wrote:
Ping! Please help review if you can.
thanks,
Chris
On 4/24/20 12:44 AM, Chris Plummer wrote:
Hello,
Please review the following:
https://bugs.openjdk.java.net/browse/JDK-8243500
http://cr.openjdk.java.net/~cjplummer/8243500/webrev.00/index.html
A couple years ago JDK-8214226 fixed an issue on Linux-x64 with SA
stack dumps not properly displaying the correct line number for
the topmost frame if it was interpreted. The issue was that SA was
always relying on frame->bcp when in fact the BCP is kept in R13,
and only flushed to frame->bcp when needed as a scratch register.
So this means that SA was in most cases grabbing a stale value
from frame->bcp.
The fix for JDK-8214226 was mostly made in X86Frame.java to
support using the BCP register for the topmost frame instead using
frame->bcp. This fix actually had a bug in it that was causing the
"illegal bci" failures we've been seeing. There is already a
separate webrev and RFR out for that:
https://bugs.openjdk.java.net/browse/JDK-8231634
http://cr.openjdk.java.net/~cjplummer/8231634/webrev.00/index.html
What this RFR addresses is the fact that part of the fix for
JDK-8214226 was in LinuxAMD64JavaThreadPDAccess.java, but the same
changes were never made to WindowsAMD64JavaThreadPDAccess.java or
BsdAMD64JavaThreadPDAccess.java. This fix addresses those two
ports. Here's the CR and changeset for reference:
https://bugs.openjdk.java.net/browse/JDK-8214226
http://hg.openjdk.java.net/jdk/jdk/rev/9a73a4e4011f
The changes for the fix are pretty trivial. The more complicated
part is the test I added that will reproduce the issue 100% of the
time on platforms where SA does not properly check the BCP
register. For this reason I've used @requires to limit running
this test on just those platforms I know have the support in
place. The test has pretty good comments on how it works, so I
won't go into details here.
thanks,
Chris
