RFR(S): 8203669: PPC64: Fix jtreg RTM tests after "8203305: Improve TM detection for enabling RTM on Linux / POWER9"

Wed May 30 09:34:54 UTC 2018

Hi Gustavo, 

looks good now.

Unfortunately some of our test runs failed altogether again, 
but let's advance with this for now.

Best regards,
  Goetz.

> -----Original Message-----
> From: Gustavo Romero [mailto:gromero at linux.vnet.ibm.com]
> Sent: Montag, 28. Mai 2018 16:32
> To: Doerr, Martin <martin.doerr at sap.com>; hotspot-compiler-
> dev at openjdk.java.net; ppc-aix-port-dev at openjdk.java.net
> Cc: Lindenmaier, Goetz <goetz.lindenmaier at sap.com>
> Subject: Re: RFR(S): 8203669: PPC64: Fix jtreg RTM tests after "8203305:
> Improve TM detection for enabling RTM on Linux / POWER9"
> 
> Hi Martin,
> 
> On 05/28/2018 06:43 AM, Doerr, Martin wrote:
> > Hi Gustavo,
> >
> > thanks for fixing AIX. Looks correct.
> >
> > I think the tests don't fail because of the warning. I was just wondering why
> we're spending time for something we don't want to support. I think you can
> remove the warning with this change if you like.
> 
> Got it. The warning message is removed and now the JVM behaves as
> on x86 regarding UseRTMLocking:
> 
> http://cr.openjdk.java.net/~gromero/POWER9/8203669/v3/
> 
> 
> Best regards,
> Gustavo
> 
> > Maybe the tests don't fit for PPC64. We have too many other things to do
> in jdk11 time frame. Maybe it'd be better to switch them off for PPC64.
> >
> > Best regards,
> > Martin
> >
> >
> > -----Original Message-----
> > From: Gustavo Romero [mailto:gromero at linux.vnet.ibm.com]
> > Sent: Freitag, 25. Mai 2018 22:44
> > To: Doerr, Martin <martin.doerr at sap.com>; hotspot-compiler-
> dev at openjdk.java.net; ppc-aix-port-dev at openjdk.java.net
> > Cc: Lindenmaier, Goetz <goetz.lindenmaier at sap.com>
> > Subject: Re: RFR(S): 8203669: PPC64: Fix jtreg RTM tests after "8203305:
> Improve TM detection for enabling RTM on Linux / POWER9"
> >
> > Hi Martin,
> >
> > On 05/25/2018 10:29 AM, Doerr, Martin wrote:
> >> Hi Gustavo,
> >>
> >> after talking with Götz, we found a couple of problems.
> >>
> >> vm_version_ppc.cpp:
> >> AIX 7.2 on Power7 would report "rtm" in the feature string which is not
> true.
> >> The check for Power8 is missing here. However, PowerArchitecturePPC64
> can't be used here because it's not initialized at this point. "has_lqarx()" could
> be used.
> >
> > I see. In the end "rtm" for AIX is being reported if AIX version matches and
> is
> > not taking the CPU version into account. On Linux that seems not an issue
> > because if we find any HTM support on AUXV it's pretty sure that the CPU
> > supports it so reporting "rtm" after only checking AUXV is correct. So I kept
> > code unchanged for Linux. As has_lqarx() checks '_features' and not
> 'features' I
> > decided for moving the code below '_features = features' attribution.
> >
> > Would that version work on AIX?
> >
> > http://cr.openjdk.java.net/~gromero/POWER9/8203669/v2/
> >
> >
> >> Some tests complain:
> >> OpenJDK 64-Bit Server VM warning: UseRTMLocking is only available as
> experimental option on this platform.
> >
> > hmm right. Do you mean on Linux as well? That change was supposed to
> not cause
> > that kind of test complain... Can you share some logs on that?
> >
> > On POWER8 LE (just like before 8203305 when in) I see only 10 test failing:
> >
> > FAILED: compiler/rtm/locking/TestRTMAbortThreshold.java
> > FAILED: compiler/rtm/locking/TestRTMAfterNonRTMDeopt.java
> > FAILED: compiler/rtm/locking/TestRTMDeoptOnHighAbortRatio.java
> > FAILED: compiler/rtm/locking/TestRTMDeoptOnLowAbortRatio.java
> > FAILED: compiler/rtm/locking/TestRTMLockingCalculationDelay.java
> > FAILED: compiler/rtm/locking/TestRTMLockingThreshold.java
> > FAILED: compiler/rtm/locking/TestRTMRetryCount.java
> > FAILED: compiler/rtm/locking/TestRTMSpinLoopCount.java
> > FAILED: compiler/rtm/locking/TestUseRTMXendForLockBusy.java
> > FAILED: compiler/rtm/print/TestPrintPreciseRTMLockingStatistics.java
> >
> > and none is because of RTM being an experimental feature. Here are the
> reasons
> > (not in the same order of the above list):
> >
> > gromero at gromero16:~/hg/jdk11/jdk$ egrep -E "TEST.*failed:" rtm.log
> > TEST RESULT: Failed. Execution failed: `main' threw exception:
> java.lang.RuntimeException: Expected that method with rtm lock elision was
> deoptimized after 1 lock attempts: expected 10000 to equal 1
> > TEST RESULT: Failed. Execution failed: `main' threw exception:
> java.lang.RuntimeException: Total aborts count (2001) should be less or equal
> to 1001: expected that 2001 <= 1001
> > TEST RESULT: Failed. Execution failed: `main' threw exception:
> java.lang.RuntimeException: VM output should contain two RTM locking
> statistics entries.: expected 1 to equal 2
> > TEST RESULT: Failed. Execution failed: `main' threw exception:
> java.lang.RuntimeException: Expected to get only one deoptimization due to
> rtm state change: expected 0 to equal 1
> > TEST RESULT: Failed. Execution failed: `main' threw exception:
> java.lang.RuntimeException: Expected to get only one deoptimization due to
> rtm state change: expected 0 to equal 1
> > TEST RESULT: Failed. Execution failed: `main' threw exception:
> java.lang.RuntimeException: At least one deoptimization due to
> rtm_state_chage is expected: expected 0 > 0
> > TEST RESULT: Failed. Execution failed: `main' threw exception:
> java.lang.RuntimeException: RTM locking statistics should contain non zero
> total aborts count: expected 0 > 0
> > TEST RESULT: Failed. Execution failed: `main' threw exception:
> java.lang.RuntimeException: Two uncommon traps with reason
> rtm_state_change should be fired.: expected 0 to equal 2
> > TEST RESULT: Failed. Execution failed: `main' threw exception:
> java.lang.RuntimeException: It is expected to get 2 aborts: expected 3 to
> equal 2
> > TEST RESULT: Failed. Execution failed: `main' threw exception:
> java.lang.RuntimeException: VM output should contain exactly one rtm
> locking statistics entry for method compiler.testlibrary.rtm.BusyLock::test:
> expected 0 to equal 1
> >
> >
> >> I think the warnings or vm_exit stuff could be removed if you want to
> support it officially. X86 only uses it for certain older processors.
> >
> > Got it. I see the same failing RTM tests on my x86 machine (Skylake) with
> RTM
> > support. I intended to set it as non-experimental once I was able to get all
> > tests passing on PPC64. But ok, as you noted maybe on x86 it's just there
> on
> > because of the initial broken support for RTM on old processors.
> >
> > Would you like to address it in that bug or should I open another bug?
> >
> >
> >> We'll have to check other tests, too. We'll do that next week.
> >
> > Thank you so much. I wished I had a change to read/reply that email earlier
> but
> > the whole email system was down until now.
> >
> >
> > Best regards,
> > Gustavo
> >
> >> Best regards,
> >> Martin
> >>
> >>
> >> -----Original Message-----
> >> From: Doerr, Martin
> >> Sent: Donnerstag, 24. Mai 2018 11:19
> >> To: 'Gustavo Romero' <gromero at linux.vnet.ibm.com>; hotspot-
> compiler-dev at openjdk.java.net; ppc-aix-port-dev at openjdk.java.net
> >> Cc: Lindenmaier, Goetz <goetz.lindenmaier at sap.com>
> >> Subject: RE: RFR(S): 8203669: PPC64: Fix jtreg RTM tests after "8203305:
> Improve TM detection for enabling RTM on Linux / POWER9"
> >>
> >> Hi Gustavo,
> >>
> >> the fix looks good. I especially like that you use "rtm" like x86, now.
> >> I can sponsor it after we got a 2nd review.
> >>
> >> Best regards,
> >> Martin
> >>
> >>
> >> -----Original Message-----
> >> From: ppc-aix-port-dev [mailto:ppc-aix-port-dev-
> bounces at openjdk.java.net] On Behalf Of Gustavo Romero
> >> Sent: Mittwoch, 23. Mai 2018 15:49
> >> To: hotspot-compiler-dev at openjdk.java.net; ppc-aix-port-
> dev at openjdk.java.net
> >> Subject: RFR(S): 8203669: PPC64: Fix jtreg RTM tests after "8203305:
> Improve TM detection for enabling RTM on Linux / POWER9"
> >>
> >> Hi,
> >>
> >> Could the following small fix be reviewed please?
> >>
> >> It touches shared code.
> >>
> >> bug:    https://bugs.openjdk.java.net/browse/JDK-8203669
> >> webrev: http://cr.openjdk.java.net/~gromero/POWER9/8203669
> >>
> >> Since change "8203305: Improve TM detection for enabling RTM on Linux /
> POWER9"
> >> JVM on PPC64 is not advertising anymore the feature "tcheck" which
> indicated
> >> that RTM was supported by the JVM in case both CPU and OS supported
> hardware
> >> transactional memory.
> >>
> >> It happens that several tests under /test/hotspot/jtreg/compiler/rtm rely
> on the
> >> JVM to advertise if RTM is supported by the JVM on a given CPU/OS and
> so they
> >> were failing to be skipped (or not) on different PPC64/Linux
> combinations.
> >>
> >> That change fixes it by re-introducing a feature to inform that RTM is
> supported
> >> by the JVM when appropriated (given valid OS/CPU support) and now it
> does it by
> >> advertising that feature as on x86_64, reporting the feature as "rtm".
> >>
> >> It also incorporates a check for when OS does not support RTM but CPU
> does in
> >> test:
> >>
> >> TestUseRTMLockingOptionOnUnsupportedCPU.java.
> >>
> >> Just on PPC64 it might be the case that although CPU supports RTM (HTM)
> >> instructions the OS version might not support it, like on old kernels that do
> >> not abort transactions on syscalls. JVM correctly reports each case so the
> test
> >> was adapted to test them.
> >>
> >> That change also corrects a couple of nit typos elsewhere not related to
> >> "8203305".
> >>
> >>
> >> Thank you.
> >>
> >> Best regards,
> >> Gustavo
> >>
> >