RFR(s): 8205581: PPC64: RTM: Fix abort on native calls

[Gustavo Romero]

Hi,

Could I get a second review for that change please?

Best regards,
Gustavo

On 06/26/2018 09:54 AM, Doerr, Martin wrote:
> Hi Gustavo,
> 
> thanks for the update. Looks good to me.
> 
> Best regards,
> Martin
> 
> 
> -----Original Message-----
> From: Gustavo Romero [mailto:gromero at linux.vnet.ibm.com]
> Sent: Dienstag, 26. Juni 2018 14:41
> To: Doerr, Martin <martin.doerr at sap.com>; Lindenmaier, Goetz <goetz.lindenmaier at sap.com>; hotspot-compiler-dev at openjdk.java.net
> Cc: ppc-aix-port-dev at openjdk.java.net
> Subject: Re: RFR(s): 8205581: PPC64: RTM: Fix abort on native calls
> 
> Hi Martin,
> 
> Thanks for the quick review!
> 
> On 06/25/2018 01:37 PM, Doerr, Martin wrote:
>> I wonder why you placed the tabort so late in generate_native_wrapper. I'd put it at the Verified Entry Point.
> 
> Actually for no particular reason.
> 
> So previously:
> 
> 2247 [Verified Entry Point]
> 2248   0x00007fff9c816520: mfcr    r22
> 2249   0x00007fff9c816524: std     r22,8(r1)
> 2250   0x00007fff9c816528: mflr    r22
> 2251   0x00007fff9c81652c: std     r22,16(r1)
> 2252   0x00007fff9c816530: addis   r11,r1,-2
> 2253   0x00007fff9c816534: std     r0,0(r11)
> 2254   0x00007fff9c816538: mr      r21,r1
> 2255   0x00007fff9c81653c: stdu    r1,-176(r1)
> 2256   0x00007fff9c816540: std     r3,96(r1)
> 2257   0x00007fff9c816544: addi    r4,r1,96
> 2258   0x00007fff9c816548: cmpdi   r3,0
> 2259   0x00007fff9c81654c: bne-    0x00007fff9c816554
> 2260   0x00007fff9c816550: li      r4,0
> 2261   0x00007fff9c816554: addi    r3,r16,824        ; ImmutableOopMap{[96]=Oop }
> 2262   0x00007fff9c816558: addis   r28,r29,7
> 2263   0x00007fff9c81655c: addi    r28,r28,25944     ;   {internal_word}
> 2264   0x00007fff9c816560: tabort. r0 <==
> ...
> 
> Now:
> 
> 2169 [Verified Entry Point]
> 2170   0x00007fff78816320: tabort. r0 <==
> 2171   0x00007fff78816324: mfcr    r22
> 2172   0x00007fff78816328: std     r22,8(r1)
> 2173   0x00007fff7881632c: mflr    r22
> 2174   0x00007fff78816330: std     r22,16(r1)
> 2175   0x00007fff78816334: addis   r11,r1,-2
> 2176   0x00007fff78816338: std     r0,0(r11)
> 2177   0x00007fff7881633c: mr      r21,r1
> 2178   0x00007fff78816340: stdu    r1,-176(r1)
> 2179   0x00007fff78816344: std     r3,96(r1)
> 2180   0x00007fff78816348: addi    r4,r1,96
> 2181   0x00007fff7881634c: cmpdi   r3,0
> 2182   0x00007fff78816350: bne-    0x00007fff78816358
> 2183   0x00007fff78816354: li      r4,0
> 2184   0x00007fff78816358: addi    r3,r16,824        ; ImmutableOopMap{[96]=Oop }
> 2185   0x00007fff7881635c: addis   r28,r29,7
> 2186   0x00007fff78816360: addi    r28,r28,25436     ;   {internal_word}
> ...
> 
> Yep, it's better to abort sooner.
> 
> new webrev: http://cr.openjdk.java.net/~gromero/8205581/v2/
> 
> 
> Best regards,
> Gustavo
> 
>> Besides that, it looks good to me.
>>
>> Thanks,
>> Martin
>>
>>
>> -----Original Message-----
>> From: Gustavo Romero [mailto:gromero at linux.vnet.ibm.com]
>> Sent: Montag, 25. Juni 2018 10:21
>> To: Lindenmaier, Goetz <goetz.lindenmaier at sap.com>; Doerr, Martin <martin.doerr at sap.com>; hotspot-compiler-dev at openjdk.java.net
>> Cc: ppc-aix-port-dev at openjdk.java.net
>> Subject: RFR(s): 8205581: PPC64: RTM: Fix abort on native calls
>>
>> Hi,
>>
>> Could the following change be reviewed please?
>>
>> bug   : https://bugs.openjdk.java.net/browse/JDK-8205581
>> webrev: http://cr.openjdk.java.net/~gromero/8205581/v1/
>>
>> It forces a transactional state to abort before calling native methods, before
>> calling runtime, and on uncommon trap checking, mostly because transaction will
>> be aborted soon or latter in either case, similarly to what happens on Intel.
>> The abort instruction (tabort) is only emitted if UseRTMLocking is "true" and
>> any 'tabort' instruction is treated as a 'nop' instruction if TM state is
>> non-transactional.
>>
>> It fixes the following tests:
>>
>> +Passed: compiler/rtm/print/TestPrintPreciseRTMLockingStatistics.java
>> +Passed: compiler/rtm/locking/TestRTMDeoptOnHighAbortRatio.java
>>
>>
>> Thank you and best regards,
>> Gustavo
>>
>