RFR(XS): 8204652: [aix] fix thread stack allocation, too big stack sizes not recognized

[Thomas Stüfe]

Hi,

yes, that is better. However, there are many more thread types (see
ThreadType in os.hpp) so your message now misrepresents a number of
thread types as VM thread.

I would either remove the thr_type printout, or just print the
numerical value of the enum.

If you just remove the printout, I do not need to see a new webrev.

Best Regards, Thomas


On Mon, Jun 11, 2018 at 11:47 AM, Lindenmaier, Goetz
<goetz.lindenmaier at sap.com> wrote:
> Hi,
>
> Is this better?
> http://cr.openjdk.java.net/~goetz/wr18/8204652-aixHugeStacksCrash/02/
>
> It reports now:
> bin/java -XX:CompilerThreadStackSize=80000000000000
> [1.989s][warning][os,thread] The compiler thread stack size specified is invalid: 80000000000000k
> Error occurred during initialization of VM
> java.lang.OutOfMemoryError: unable to create native thread: possibly out of memory or process/resource limits reached
>
> Best,
>   Goetz.
>
>> -----Original Message-----
>> From: David Holmes [mailto:david.holmes at oracle.com]
>> Sent: Montag, 11. Juni 2018 10:36
>> To: Lindenmaier, Goetz <goetz.lindenmaier at sap.com>; Thomas Stüfe
>> <thomas.stuefe at gmail.com>
>> Cc: hotspot-runtime-dev at openjdk.java.net
>> Subject: Re: RFR(XS): 8204652: [aix] fix thread stack allocation, too big stack
>> sizes not recognized
>>
>> On 11/06/2018 6:07 PM, Lindenmaier, Goetz wrote:
>> > Hi,
>> >
>> > Yes, reporting the pthread_create is a bit misleading. But it is the same
>> > as reported on linux x86_64:
>> >
>> > bin/java -XX:CompilerThreadStackSize=8000000000000
>> > [0.271s][warning][os,thread] Failed to start thread - pthread_create failed
>> (EAGAIN) for attributes: stacksize: 8000000000000k, guardsize: 0k, detached.
>> > Error occurred during initialization of VM
>> > java.lang.OutOfMemoryError: unable to create native thread: possibly out
>> of memory or process/resource limits reached
>>
>> But on linux you _do_ call pthread_create and it did fail!
>>
>> > As we know linux is bad at implementing the pthread functionality here:
>> > It accepts setting the big value as stack size, and only when you call create
>> > you get the failure.
>>
>> Does POSIX require otherwise?
>>
>> > So it's not true that the VM starts with any other value, it also crashes on
>> > linux.  And you get the same output as on linux. So I realy don't want to
>> > start implementing any clever tracing, or even implement other stack
>> > handling (setting defaults) as on linux.  I would just like to keep it as is.
>> > Currently we get a SIGSEGV which is hard to debug on aix.
>>
>> The point is the error should be reported accurately in the logging
>> information. It's not coming from pthread_create in your AIX case so
>> don't report that it is.
>>
>> David
>>
>> > Best,
>> >    Goetz
>> >
>> >> -----Original Message-----
>> >> From: Thomas Stüfe [mailto:thomas.stuefe at gmail.com]
>> >> Sent: Montag, 11. Juni 2018 06:26
>> >> To: Lindenmaier, Goetz <goetz.lindenmaier at sap.com>
>> >> Cc: hotspot-runtime-dev at openjdk.java.net
>> >> Subject: Re: RFR(XS): 8204652: [aix] fix thread stack allocation, too big
>> stack
>> >> sizes not recognized
>> >>
>> >> Hi Goetz,
>> >>
>> >> On Sun, Jun 10, 2018 at 9:11 PM, Lindenmaier, Goetz
>> >> <goetz.lindenmaier at sap.com> wrote:
>> >>> Hi Thomas,
>> >>>
>> >>> The stack is started with 192k.  See the output:
>> >>>
>> >>
>> >> Ah you are right. With 64K pages this would not be enough to establish
>> >> red/yellow zones and still have breathing space left.
>> >>
>> >>> bash-4.4$ ~/oJ/vms/aix_j-1/bin/java -
>> >> XX:CompilerThreadStackSize=8000000000000
>> >>> [1.482s][warning][os,thread] The compiler thread stack size specified is
>> >> invalid: 8000000000000k
>> >>> [1.483s][warning][os,thread] Failed to start thread - pthread_create
>> failed
>> >> (22=EINVAL) for attributes: stacksize: 192k, guardsize: 4k, detached.
>> >>> Error occurred during initialization of VM
>> >>> java.lang.OutOfMemoryError: unable to create native thread: possibly
>> out
>> >> of memory or process/resource limits reached
>> >>>
>> >>> I think the output is not that bad ...
>> >>
>> >> See my mail to David: I think the output is misleading, since
>> >> pthread_create() did not even run. So, "pthread_create failed" is
>> >> wrong.
>> >>
>> >> Best Regards, Thomas
>> >>
>> >>>
>> >>> Best,
>> >>>    Goetz.
>> >>>
>> >>>> -----Original Message-----
>> >>>> From: Thomas Stüfe <thomas.stuefe at gmail.com>
>> >>>> Sent: Sunday, June 10, 2018 7:33 PM
>> >>>> To: Lindenmaier, Goetz <goetz.lindenmaier at sap.com>
>> >>>> Cc: hotspot-runtime-dev at openjdk.java.net
>> >>>> Subject: Re: RFR(XS): 8204652: [aix] fix thread stack allocation, too big
>> >> stack
>> >>>> sizes not recognized
>> >>>>
>> >>>> Hi Goetz,
>> >>>>
>> >>>> I see what you intent to do, but I think we need to think about error
>> >>>> handling a bit more. The pattern here (which was broken you try to fix
>> >>>> it with this patch) is that we try, sequentially:
>> >>>>
>> >>>> - pthread_attr_setstacksize()
>> >>>>
>> >>>> - if ok-so-far pthread_attr_setguardsize
>> >>>>
>> >>>> - if ok-so-far pthread_ceate
>> >>>>
>> >>>> - logging and error handling
>> >>>>
>> >>>>
>> >>>> Problem with that is that in the end, we log information about a
>> >>>> failing thread creation, printing errno as if pthread_create() failed,
>> >>>> but that errno may have come actually from one of the preceeding OS
>> >>>> calls. So the error message would be misleading.
>> >>>>
>> >>>> I think it would be better to handle errors of each system call explicitly:
>> >>>>
>> >>>> pthread_attr_setstacksize()
>> >>>> if failed
>> >>>>     - log out "pthread_attr_setsize failed" and errno
>> >>>>     - [ also: optionally decide what to do: failing thread creation?
>> >>>> retry with a default stack size? ]
>> >>>>     - return false
>> >>>>
>> >>>> pthread_attr_setguardsize()
>> >>>> if failed
>> >>>>     - log out "pthread_attr_setguardsize failed" and errno
>> >>>>     - decide what to do - ignore? assert? fail thread creation? Should
>> >>>> we even care?
>> >>>>     - return false
>> >>>>
>> >>>> and then call pthread_create with the existing error handling as follow
>> up.
>> >>>>
>> >>>> What do you think?`
>> >>>>
>> >>>> (Also, if pthread_attr_setstacksize() fails, should the thread not be
>> >>>> created with the pthread default stack size, which should be ~2MB?
>> Why
>> >>>> is that stack tiny?)
>> >>>>
>> >>>> Best Regards, Thomas
>> >>>>
>> >>>>
>> >>>> On Sun, Jun 10, 2018 at 5:33 PM, Lindenmaier, Goetz
>> >>>> <goetz.lindenmaier at sap.com> wrote:
>> >>>>> Hi,
>> >>>>>
>> >>>>> This fixes a crash in thread creation with too big stack sizes
>> >>>>> http://cr.openjdk.java.net/~goetz/wr18/8204652-
>> >> aixHugeStacksCrash/01/
>> >>>>> Please review.
>> >>>>>
>> >>>>> For Java and Compiler threads the return code of
>> >>>> pthread_attr_setstacksize
>> >>>>>   is overwritten. If pthread_attr_setstacksize does not succeed, a tiny
>> >>>>>   stack size with not enough space for the yellow/red pages is
>> allocated.
>> >>>>>   VM crashes with SIGSEGV right away.
>> >>>>>
>> >>>>> Best regards,
>> >>>>>    Goetz