RFR(M): 8170655: [posix] Fix minimum stack size computations
Lindenmaier, Goetz
goetz.lindenmaier at sap.com
Tue Dec 13 16:16:12 UTC 2016
Hi,
I rebased 8170655 to the recent changes in hotspot:
http://cr.openjdk.java.net/~goetz/wr16/8169373-ppc-stackFix/webrev.09/
The patch is still in our test patch queue for the nightly tests, and there
were no failures I can attribute to this change.
Best regards,
Goetz.
> -----Original Message-----
> From: Daniel D. Daugherty [mailto:daniel.daugherty at oracle.com]
> Sent: Dienstag, 13. Dezember 2016 16:45
> To: Lindenmaier, Goetz <goetz.lindenmaier at sap.com>; David Holmes
> <david.holmes at oracle.com>; Coleen Phillimore
> <coleen.phillimore at oracle.com>; hotspot-runtime-dev at openjdk.java.net
> Subject: Re: RFR(M): 8170655: [posix] Fix minimum stack size computations
>
> The current set of RBT test results looks bad. I suspect a mismatch
> between current test suite version(s) and the baseline that I used.
> I created the repo for 8169373 back on 2016.12.02 and the last
> changeset in hotspot at that time was dated 2016.11.30... so the
> baseline on which I applied your changes is almost 2 weeks out of
> date (pre-dates the latest Jigsaw refresh)...
>
> > Should I rebase the changes to the latest repo version?
>
> If you don't mind rebasing both patches (8169373 and 8170655) to the
> current JDK9-hs, that would be appreciated. Thanks!
>
> Dan
>
>
>
> On 12/13/16 8:17 AM, Daniel D. Daugherty wrote:
> > Both 8169373 and 8170655 are bug fixes so they do not have to be
> > in by the extended Feature Complete deadline. If they did, I would
> > be going through more Tums than I already am... :-)
> >
> > Dan
> >
> >
> >
> > On 12/13/16 8:02 AM, Lindenmaier, Goetz wrote:
> >> Hi Dan,
> >>
> >> that sounds bad ... thanks for your update! Yes, I also have the
> >> Feature
> >> Complete deadline in mind, that's why I would like to see the changes
> >> committed :) But obviously I currently can't help.
> >>
> >> Thanks,
> >> Goetz.
> >>
> >>
> >>
> >>> -----Original Message-----
> >>> From: Daniel D. Daugherty [mailto:daniel.daugherty at oracle.com]
> >>> Sent: Dienstag, 13. Dezember 2016 15:56
> >>> To: David Holmes <david.holmes at oracle.com>; Lindenmaier, Goetz
> >>> <goetz.lindenmaier at sap.com>; Coleen Phillimore
> >>> <coleen.phillimore at oracle.com>; hotspot-runtime-dev at openjdk.java.net
> >>> Subject: Re: RFR(M): 8170655: [posix] Fix minimum stack size
> >>> computations
> >>>
> >>> Hi Goetz,
> >>>
> >>> JDK9-hs is still closed for the run up to extended Feature Complete.
> >>> Should be open again sometime soon.
> >>>
> >>> I kicked off a "full RBT" run on 8169373 last Monday. It ran for four
> >>> days before it collided with a maintenance window on the Aurora DB.
> >>> I kicked off a "full RBT" run on 8170655 last Tuesday. It ran for three
> >>> days before it collided with the same brick wall.
> >>>
> >>> Neither RBT run is complete; in fact there are entire platforms with
> >>> zero results so they are pretty much useless. Normally RBT runs don't
> >>> take more than a couple of days, but our internal test systems are a
> >>> bit swamped due to the upcoming extended Feature Complete deadline.
> >>>
> >>> I did start another "full RBT" run on 8169373 on Sunday, but it is
> >>> not complete either. I was hoping to have all the testing done by
> >>> the time JDK9-hs reopened, but it looks like that is not going to
> >>> happen.
> >>>
> >>> Dan
> >>>
> >>>
> >>> On 12/13/16 1:41 AM, David Holmes wrote:
> >>>> On 13/12/2016 6:16 PM, Lindenmaier, Goetz wrote:
> >>>>> Hi Dan,
> >>>>>
> >>>>> what's the status of my changes? I think hs is open again, at least
> >>>>> I see changes popping up ... just a gentle reminder :)
> >>>> Actually it is closed (again?) other than for selective changes as we
> >>>> had to pull down the big jigsaw update from dev, and merge in with AOT
> >>>> push, and a couple of other approved changes, and need things to
> >>>> stabilise so we can push up to dev.
> >>>>
> >>>> David
> >>>>
> >>>>> Should I rebase the changes to the latest repo version?
> >>>>>
> >>>>> Best regards,
> >>>>> Goetz.
> >>>>>
> >>>>>> -----Original Message-----
> >>>>>> From: Daniel D. Daugherty [mailto:daniel.daugherty at oracle.com]
> >>>>>> Sent: Dienstag, 6. Dezember 2016 22:15
> >>>>>> To: Lindenmaier, Goetz <goetz.lindenmaier at sap.com>; Coleen
> >>>>>> Phillimore
> >>>>>> <coleen.phillimore at oracle.com>; hotspot-runtime-
> dev at openjdk.java.net
> >>>>>> Subject: Re: RFR(M): 8170655: [posix] Fix minimum stack size
> >>>>>> computations
> >>>>>>
> >>>>>> On 12/6/16 1:31 PM, Lindenmaier, Goetz wrote:
> >>>>>>> Hi Dan,
> >>>>>>>
> >>>>>>> I fixed the comment. I will post a new webrev once the other
> >>>>>>> change is pushed so that I can make a real change.
> >>>>>> I'll resync my repo to the webrev.02 version and restart my
> >>>>>> testing on this fix. I'm hoping we have only comment changes
> >>>>>> after the webrev.02 version...
> >>>>>>
> >>>>>> Also gotta check the test results on 8169373.
> >>>>>>
> >>>>>>
> >>>>>>>> Meta question: Now _java_thread_min_stack_allowed is
> >>>>>>>> specific to an
> >>>>>>>> OS/CPU platform (as are the other two). That OS/CPU
> >>>>>>>> platform
> >>>>>>>> enumeration
> >>>>>>>> doesn't take into account whether C1 or C2 is in play. We
> >>>>>>>> used to add
> >>>>>>>> just a little more space via the COMPILER2_PRESENT() macro,
> >>>>>>>> but now
> >>>>>> we
> >>>>>>>> don't. Yes, I know that you've done a bunch of testing and
> >>>>>>>> I'm running
> >>>>>>>> our usual batch of tests also, but this subtle change is
> >>>>>>>> bothering
> >>>>>>> Yep, I could have made sizing with C1, then C2, then
> >>>>>>> TieredCompilation,
> >>>>>>> but I don't think that would make a change.
> >>>>>>> This extra size was meant for the compiler thread. 83251780 moved
> >>>>>>> it to the
> >>>>>>> Java threads. I think it was there because C2 used to have
> >>>>>>> recursive
> >>>>>> algorithms.
> >>>>>>> But it only would have had an effect in rare situations because the
> >>>>>>> other MAX
> >>>>>>> should mostly be used on systems with large pages, where the
> >>>>>>> alignement
> >>>>>>> would bring more than these 4K. The compiler gained the alignment
> >>>>>>> of the
> >>>>>>> vm_default_page_size() region plus the space gained by bigger
> >>>>>> StackShadowPages
> >>>>>>> which were huge at some point (20+ pages * 64K ...). Remember the
> >>>>>> compiler does
> >>>>>>> no stack banging and thus could use the shadow region.
> >>>>>>>
> >>>>>>> The original code looked like this:
> >>>>>>>
> >>>>>>>
> >>>
> http://hg.openjdk.java.net/jdk8/jdk8/hotspot/file/87ee5ee27509/src/os/linux/v
> >>>
> >>>>>> m/os_linux.cpp
> >>>>>>> os::Linux::min_stack_allowed =
> >>>>>>> MAX2(os::Linux::min_stack_allowed,
> >>>>>>> (size_t)(StackYellowPages+StackRedPages+StackShadowPages) *
> >>>>>> Linux::page_size() +
> >>>>>>> (2*BytesPerWord COMPILER2_PRESENT(+1)) *
> >>>>>> Linux::vm_default_page_size());
> >>>>>>
> >>>>>> I'm good with this explanation. Coleen?
> >>>>>>
> >>>>>> Dan
> >>>>>>
> >>>>>>
> >>>>>>> Best regards,
> >>>>>>> Goetz.
> >>>>>>>
> >>>>>>>> -----Original Message-----
> >>>>>>>> From: Daniel D. Daugherty [mailto:daniel.daugherty at oracle.com]
> >>>>>>>> Sent: Tuesday, December 06, 2016 8:32 PM
> >>>>>>>> To: Lindenmaier, Goetz <goetz.lindenmaier at sap.com>; Coleen
> >>> Phillimore
> >>>>>>>> <coleen.phillimore at oracle.com>; hotspot-runtime-
> >>> dev at openjdk.java.net
> >>>>>>>> Subject: Re: RFR(M): 8170655: [posix] Fix minimum stack size
> >>>>>>>> computations
> >>>>>>>>
> >>>>>>>> On 12/6/16 2:35 AM, Lindenmaier, Goetz wrote:
> >>>>>>>>> Hi Coleen,
> >>>>>>>>>
> >>>>>>>>> thanks for looking at this change!
> >>>>>>>>>
> >>>>>>>>> New webrev:
> >>>>>>>>> http://cr.openjdk.java.net/~goetz/wr16/8170655-
> >>>>>>>> compilerGuardFix/webrev.02/
> >>>>>>>>
> >>>>>>>> src/cpu/ppc/vm/globals_ppc.hpp
> >>>>>>>> No comments.
> >>>>>>>>
> >>>>>>>> src/cpu/x86/vm/globals_x86.hpp
> >>>>>>>> No comments.
> >>>>>>>>
> >>>>>>>> src/os/posix/vm/os_posix.cpp
> >>>>>>>> L1112: // It dependes on word size, platform calling
> >>>>>>>> conventions, C
> >>>>>>>> frame layout and
> >>>>>>>> Typo: 'dependes' -> 'depends'
> >>>>>>>>
> >>>>>>>> If you put "It" at the end of the sentence on the
> >>>>>>>> previous
> >>>>>>>> line, then the formatting will look better. :-)
> >>>>>>>>
> >>>>>>>> Meta question: Now _java_thread_min_stack_allowed is
> >>>>>>>> specific to an
> >>>>>>>> OS/CPU platform (as are the other two). That OS/CPU
> >>>>>>>> platform
> >>>>>>>> enumeration
> >>>>>>>> doesn't take into account whether C1 or C2 is in play. We
> >>>>>>>> used to add
> >>>>>>>> just a little more space via the COMPILER2_PRESENT() macro,
> >>>>>>>> but now
> >>>>>> we
> >>>>>>>> don't. Yes, I know that you've done a bunch of testing and
> >>>>>>>> I'm running
> >>>>>>>> our usual batch of tests also, but this subtle change is
> >>>>>>>> bothering
> >>>>>>>> me...
> >>>>>>>>
> >>>>>>>> src/os/posix/vm/os_posix.hpp
> >>>>>>>> No comments.
> >>>>>>>>
> >>>>>>>> src/os_cpu/aix_ppc/vm/os_aix_ppc.cpp
> >>>>>>>> No comments.
> >>>>>>>>
> >>>>>>>> src/os_cpu/bsd_x86/vm/os_bsd_x86.cpp
> >>>>>>>> No comments.
> >>>>>>>>
> >>>>>>>> src/os_cpu/linux_aarch64/vm/os_linux_aarch64.cpp
> >>>>>>>> No comments.
> >>>>>>>>
> >>>>>>>> src/os_cpu/linux_ppc/vm/os_linux_ppc.cpp
> >>>>>>>> No comments.
> >>>>>>>>
> >>>>>>>> src/os_cpu/linux_s390/vm/os_linux_s390.cpp
> >>>>>>>> No comments.
> >>>>>>>>
> >>>>>>>> src/os_cpu/linux_sparc/vm/os_linux_sparc.cpp
> >>>>>>>> No comments.
> >>>>>>>>
> >>>>>>>> src/os_cpu/linux_x86/vm/os_linux_x86.cpp
> >>>>>>>> No comments.
> >>>>>>>>
> >>>>>>>> src/os_cpu/solaris_sparc/vm/os_solaris_sparc.cpp
> >>>>>>>> No comments.
> >>>>>>>>
> >>>>>>>> src/os_cpu/solaris_x86/vm/os_solaris_x86.cpp
> >>>>>>>> No comments.
> >>>>>>>>
> >>>>>>>> src/share/vm/runtime/os.hpp
> >>>>>>>> No comments.
> >>>>>>>>
> >>>>>>>> Dan
> >>>>>>>>
> >>>>>>>>
> >>>>>>>>> See my comments inline.
> >>>>>>>>>
> >>>>>>>>>> -----Original Message-----
> >>>>>>>>>> From: hotspot-runtime-dev [mailto:hotspot-runtime-dev-
> >>>>>>>>>> bounces at openjdk.java.net] On Behalf Of Coleen Phillimore
> >>>>>>>>>> Sent: Dienstag, 6. Dezember 2016 01:00
> >>>>>>>>>> To: hotspot-runtime-dev at openjdk.java.net
> >>>>>>>>>> Subject: Re: RFR(M): 8170655: [posix] Fix minimum stack size
> >>>>>>>> computations
> >>>>>>>>>>
> >>>>>>>>>> On 12/5/16 6:27 PM, Daniel D. Daugherty wrote:
> >>>>>>>>>>> On 12/3/16 11:17 AM, Lindenmaier, Goetz wrote:
> >>>>>>>>>>>> Hi,
> >>>>>>>>>>>>
> >>>>>>>>>>>>
> >>>>>>>>>>>>
> >>>>>>>>>>>> I would like to fix two issues of minimum stack size
> >>>>>>>>>>>> computation:
> >>>>>>>>>>>>
> >>>>>>>>>>>> http://cr.openjdk.java.net/~goetz/wr16/8170655-
> >>>>>>>>>> compilerGuardFix/webrev.01/
> >>>>>>>>>>>> Please review and sponsor.
> >>>>>>>>>>> I'm sponsoring the related bug:
> >>>>>>>>>>>
> >>>>>>>>>>> 8169373 Work around linux NPTL stack guard error
> >>>>>>>>>>> https://bugs.openjdk.java.net/browse/JDK-8169373
> >>>>>>>>>>>
> >>>>>>>>>>> so I guess I should sponsor this one also... For obvious
> >>>>>>>>>>> reasons, this
> >>>>>>>>>>> fix will also need a "full RBT" run...
> >>>>>>>>>> Thank you, Dan for sponsoring this.
> >>>>>>>>>>> http://cr.openjdk.java.net/~goetz/wr16/8170655-
> >>>>>>>>>> compilerGuardFix/webrev.01/
> >>>>>>>>>>> src/cpu/ppc/vm/globals_ppc.hpp
> >>>>>>>>>>> No comments.
> >>>>>>>>>>>
> >>>>>>>>>>> src/cpu/x86/vm/globals_x86.hpp
> >>>>>>>>>>> No comments.
> >>>>>>>>>>>
> >>>>>>>>>>> src/os/posix/vm/os_posix.cpp
> >>>>>>>>>>> My brain read right past where you took out "MAX2" and
> >>>>>>>>>>> changed
> >>>>>> the
> >>>>>>>>>>> math to "cur = cur + guard_size + shadow_size". I think
> >>>>>>>>>>> I've been
> >>>>>>>>>>> staring at that particular line of code for way too long
> >>>>>>>>>>> (in a couple
> >>>>>>>>>>> of different bug fixes)...
> >>>>>>>>>>>
> >>>>>>>>>>> I think with your fix that Solaris specific block on
> >>>>>>>>>>> L1132 - L1148 can go away (see JDK-8161093). Hopefully
> >>>>>>>>>>> Coleen will chime in on just this part.
> >>>>>>>>>> Yes, I think with refactoring, this is dead code. I think you
> >>>>>>>>>> should
> >>>>>>>>>> remove it, and make 8161093 a duplicate so it can be closed with
> >>>>>>>>>> this fix.
> >>>>>>>>> I removed the code and closed the bug as duplicate.
> >>>>>>>>>
> >>>>>>>>>> The changes in this file (adding the guard_size and shadow_size)
> >>>>>>>>>> are a
> >>>>>>>>>> lot cleaner than the max of some random number of pages
> someone
> >>>>>>>>>> calculated a long time ago.
> >>>>>>>>> Thanks!
> >>>>>>>>>
> >>>>>>>>>> There's a comment above this function that should be
> >>>>>>>>>> rewritten also
> >>>>>>>> though:
> >>>>>>>>>> // Check minimum allowable stack sizes for thread creation
> >>>>>>>>>> and to
> >>>>>>>> initialize
> >>>>>>>>>> // the java system classes, including StackOverflowError -
> >>>>>>>>>> depends on
> >>>>>>>> page
> >>>>>>>>>> // size. Add two 4K pages for compiler2 recursion in main
> >>>>>>>>>> thread.
> >>>>>>>>>> // Add in 4*BytesPerWord 4K pages to account for VM stack
> during
> >>>>>>>>>> // class initialization depending on 32 or 64 bit VM.
> >>>>>>>>> Dan saw this too. I wrote a summary of the text in the bug.
> >>>>>>>>>
> >>>>>>>>>> http://cr.openjdk.java.net/~goetz/wr16/8170655-
> >>>>>>>>>>
> >>>
> compilerGuardFix/webrev.01/src/os_cpu/linux_sparc/vm/os_linux_sparc.cpp
> >>>>>>>> .u
> >>>>>>>>>> diff.html
> >>>>>>>>>> This seems small. I don't think it should be reduced because I
> >>>>>>>>>> don't
> >>>>>>>>>> think we have a lot of testing for this platform.
> >>>>>>>>> I changed it to 64K. I can't test on this platform, so this
> >>>>>>>>> probably really is
> >>>>>>>> better.
> >>>>>>>>>> http://cr.openjdk.java.net/~goetz/wr16/8170655-
> >>>>>>>>>>
> >>>
> compilerGuardFix/webrev.01/src/os_cpu/linux_x86/vm/os_linux_x86.cpp.ud
> >>>>>>>> iff.
> >>>>>>>>>> html
> >>>>>>>>>> Why is DEBUG_ONLY( + 4) removed? We do run native JVM code
> >>> with
> >>>>>>>>>> debugging on in Java threads also, although the +4 seems
> >>>>>>>>>> arbitrary.
> >>>>>>>>> I checked startup and ran jvm98 and did not find any
> >>>>>>>>> differences in
> >>>>>>>> slowdebug/opt
> >>>>>>>>> variants. So I thought I should get rid of this. Also, this kind
> >>>>>>>>> of accounts for
> >>>>>>>> the
> >>>>>>>>> extra space of shadow pages in dbg builds, which now is no more
> >>>>>>>>> included
> >>>>>>>> in that
> >>>>>>>>> number.
> >>>>>>>>>
> >>>>>>>>>> If you're removing the concept of DEBUG_ONLY to these sizes, it
> >>>>>>>>>> still
> >>>>>>>>>> remains in this change:
> >>>>>>>>>> http://cr.openjdk.java.net/~goetz/wr16/8170655-
> >>>>>>>>>>
> >>>
> compilerGuardFix/webrev.01/src/os_cpu/linux_s390/vm/os_linux_s390.cpp.
> >>>>>>>> udi
> >>>>>>>>>> ff.html
> >>>>>>>>> On s390, I quickly ran into stack overflows with the debug build.
> >>>>>>>>> Therefore
> >>>>>>>>> I increased the sizes.
> >>>>>>>>>
> >>>>>>>>>> I assume that all these minimum stack sizes have been tested in
> >>>>>>>>>> your lab.
> >>>>>>>>> Yes, the change is running with our nighly tests on the platforms
> >>>>>>>>> we have
> >>>>>>>> available.
> >>>>>>>>> This includes jck tests and hotspot jtreg tests.
> >>>>>>>>>
> >>>>>>>>>> This seems like a good change but I hope this is the last of
> >>>>>>>>>> these until
> >>>>>>>>>> JDK10 opens.
> >>>>>>>>> :) Yes, stack changes kind of got my special hobby ... I
> >>>>>>>>> still have
> >>>>>>>> implementing
> >>>>>>>>> StackReservedPages support on s390 on my list, but that should be
> >>>>>>>> platform-only.
> >>>>>>>>> Also I'm not sure whether I'll find time for that.
> >>>>>>>>>
> >>>>>>>>> Best regards,
> >>>>>>>>> Goetz.
> >>>>>>>>>
> >>>>>>>>>
> >>>>>>>>>> Thanks,
> >>>>>>>>>> Coleen
> >>>>>>>>>>
> >>>>>>>>>>> L1154: _compiler_thread_min_stack_allowed =
> >>>>>>>>>>> _compiler_thread_min_stack_allowed +
> >>>>>>>>>>> Please add a comment above this line:
> >>>>>>>>>>>
> >>>>>>>>>>> // Reminder: a compiler thread is-a Java thread.
> >>>>>>>>>>>
> >>>>>>>>>>> src/os/posix/vm/os_posix.hpp
> >>>>>>>>>>> L48: // Set_minimum_stack_sizes() ...
> >>>>>>>>>>> Please change 'S' -> 's' since it is the function's
> >>>>>>>>>>> name.
> >>>>>>>>>>>
> >>>>>>>>>>> src/os_cpu/aix_ppc/vm/os_aix_ppc.cpp
> >>>>>>>>>>> L539: // HotSpotguard pages is added later.
> >>>>>>>>>>> Typo: space before 'guard'
> >>>>>>>>>>>
> >>>>>>>>>>> L542: size_t
> >>>>>>>>>>> os::Posix::_vm_internal_thread_min_stack_allowed = 64
> >>>>>>>>>>> * K;
> >>>>>>>>>>> VM internal thread size lowered from 128K to 64K
> >>>>>>>>>>> without any
> >>>>>>>>>>> changes to how _vm_internal_thread_min_stack_allowed
> >>>>>>>>>>> is set.
> >>>>>>>>>>> Any particular reason for this change?
> >>>>>>>>>>>
> >>>>>>>>>>> src/os_cpu/bsd_x86/vm/os_bsd_x86.cpp
> >>>>>>>>>>> No comments.
> >>>>>>>>>>>
> >>>>>>>>>>> src/os_cpu/linux_aarch64/vm/os_linux_aarch64.cpp
> >>>>>>>>>>> No comments.
> >>>>>>>>>>>
> >>>>>>>>>>> src/os_cpu/linux_ppc/vm/os_linux_ppc.cpp
> >>>>>>>>>>> L542: size_t
> >>>>>>>>>>> os::Posix::_vm_internal_thread_min_stack_allowed = 64
> >>>>>>>>>>> * K;
> >>>>>>>>>>> VM internal thread size lowered from 128K to 64K
> >>>>>>>>>>> without any
> >>>>>>>>>>> changes to how _vm_internal_thread_min_stack_allowed
> >>>>>>>>>>> is set.
> >>>>>>>>>>> Any particular reason for this change?
> >>>>>>>>>>>
> >>>>>>>>>>> src/os_cpu/linux_s390/vm/os_linux_s390.cpp
> >>>>>>>>>>> L478: size_t
> >>>>>>>>>>> os::Posix::_compiler_thread_min_stack_allowed = (52
> >>>>>>>>>>> DEBUG_ONLY(+32)) * K;
> >>>>>>>>>>> L479: size_t
> >>>>>>>>>>> os::Posix::_java_thread_min_stack_allowed = (32
> >>>>>>>>>>> DEBUG_ONLY(+8)) * K;
> >>>>>>>>>>> consistency - trying to put space around
> >>>>>>>>>>> operators so...
> >>>>>>>>>>>
> >>>>>>>>>>> '+32' -> '+ 32'
> >>>>>>>>>>> '+8' -> '+ 8'
> >>>>>>>>>>>
> >>>>>>>>>>> L480: size_t
> >>>>>>>>>>> os::Posix::_vm_internal_thread_min_stack_allowed = 32
> >>>>>>>>>>> * K;
> >>>>>>>>>>> VM internal thread size lowered from 128K to 32K
> >>>>>>>>>>> without any
> >>>>>>>>>>> changes to how _vm_internal_thread_min_stack_allowed
> >>>>>>>>>>> is set.
> >>>>>>>>>>> Any particular reason for this change?
> >>>>>>>>>>>
> >>>>>>>>>>> src/os_cpu/linux_sparc/vm/os_linux_sparc.cpp
> >>>>>>>>>>> No comments.
> >>>>>>>>>>>
> >>>>>>>>>>> src/os_cpu/linux_x86/vm/os_linux_x86.cpp
> >>>>>>>>>>> No comments.
> >>>>>>>>>>>
> >>>>>>>>>>> src/os_cpu/solaris_sparc/vm/os_solaris_sparc.cpp
> >>>>>>>>>>> No comments.
> >>>>>>>>>>>
> >>>>>>>>>>> src/os_cpu/solaris_x86/vm/os_solaris_x86.cpp
> >>>>>>>>>>> No comments.
> >>>>>>>>>>>
> >>>>>>>>>>> src/share/vm/runtime/os.hpp
> >>>>>>>>>>> L439: java_thread, // Java, CocdeCacheSweeper,
> >>>>>>>>>>> JVMTIAgent and Service threads.
> >>>>>>>>>>> Typo: 'CocdeCacheSweeper' -> 'CodeCacheSweeper'
> >>>>>>>>>>>
> >>>>>>>>>>>
> >>>>>>>>>>> Dan
> >>>>>>>>>>>
> >>>>>>>>>>>> This are the issues I excluded from the "8169373: Work around
> >>>>>>>>>>>> linux
> >>>>>>>>>>>> NPTL stack guard error."
> >>>>>>>>>>>>
> >>>>>>>>>>>>
> >>>>>>>>>>>>
> >>>>>>>>>>>> I wrote a lengthy explanation in the bug, trying to comment on
> >>>>>>>>>>>> what
> >>>>>>>> was
> >>>>>>>>>>>> said in the other thread. I'll repeat it here, I think that's
> >>>>>>>>>>>> better
> >>>>>>>>>>>> for discussion.
> >>>>>>>>>>>>
> >>>>>>>>>>>> Dan, thanks for improving the text, I use the improved variant
> >>>>>>>>>>>> here:
> >>>>>>>>>>>>
> >>>>>>>>>>>>
> >>>>>>>>>>>>
> >>>>>>>>>>>> HotSpot has three cmd line options to set stack sizes (besides
> >>>>>>>>>>>> -Xss):
> >>>>>>>>>>>>
> >>>>>>>>>>>> -XX:ThreadStackSize for threads executing Java code.
> >>>>>>>>>>>>
> >>>>>>>>>>>> -XX:CompilerThreadStackSize for threads used by the JIT
> >>>>>>>>>>>> compilers.
> >>>>>>>>>>>>
> >>>>>>>>>>>> -XX:VMThreadStackSize for threads executing VM internal
> >>>>>>>>>>>> tasks as
> >>>>>> gc.
> >>>>>>>>>>>>
> >>>>>>>>>>>>
> >>>>>>>>>>>> All these flags should not be set to a value that leads to a
> >>>>>>>>>>>> stack
> >>>>>>>>>>>> overflow before user code can be executed. As the VM executes
> >>>>>>>>>>>> a lot
> >>>>>>>>>>>> of code for initialization and also the JIT already compiles
> >>>>>>>>>>>> methods,
> >>>>>>>>>>>> considerable amounts of stack can be used during startup. We
> >>>>>>>>>>>> must try
> >>>>>>>>>>>> to avoid stack overflows before startup is complete as error
> >>>>>>>>>>>> handling
> >>>>>>>>>>>> might not be properly in place yet.
> >>>>>>>>>>>>
> >>>>>>>>>>>>
> >>>>>>>>>>>>
> >>>>>>>>>>>> Required minimum stack sizes depend on frame sizes and
> program
> >>>>>>>>>>>> execution paths. Frame sizes again depend on the C compiler
> >>>>>>>>>>>> used, the
> >>>>>>>>>>>> platform compiled for, and design decisions in interpreter, C1
> >>>>>>>>>>>> and C2.
> >>>>>>>>>>>>
> >>>>>>>>>>>>
> >>>>>>>>>>>>
> >>>>>>>>>>>> Required stack sizes also depend on option settings, e.g. with
> >>>>>>>>>>>> JVM/TI
> >>>>>>>>>>>> enabled, frames can get bigger. With inlining increased JIT
> >>>>>>>>>>>> compilers
> >>>>>>>>>>>> might do more optimizations leading to deeper call chains,
> >>>>>>>>>>>> etc.
> >>>>>>>>>>>>
> >>>>>>>>>>>>
> >>>>>>>>>>>>
> >>>>>>>>>>>> While the minimum stack sizes should reflect differences in
> >>>>>>>>>>>> Platform
> >>>>>>>>>>>> and compiler, they must not, and cannot, cover all possible
> >>>>>>>>>>>> option
> >>>>>>>>>>>> settings.
> >>>>>>>>>>>>
> >>>>>>>>>>>>
> >>>>>>>>>>>>
> >>>>>>>>>>>> This change addresses two issues:
> >>>>>>>>>>>>
> >>>>>>>>>>>>
> >>>>>>>>>>>>
> >>>>>>>>>>>> 1. Fixed minimum stack size configuration
> >>>>>>>>>>>>
> >>>>>>>>>>>>
> >>>>>>>>>>>>
> >>>>>>>>>>>> Currently, the minimum Java thread size is given in a constant
> >>>>>>>>>>>> per
> >>>>>>>>>>>> os/cpu platform for each of the three stack kinds. This number
> >>>>>>>>>>>> includes the size required for guard pages.
> >>>>>>>>>>>>
> >>>>>>>>>>>>
> >>>>>>>>>>>>
> >>>>>>>>>>>> The guard pages are used for stack overflow detection. They
> >>>>>>>>>>>> make up 4
> >>>>>>>>>>>> zones on the stack: Red, Yellow, Reserved and Shadow pages.
> >>>>>>>>>>>> The Red,
> >>>>>>>>>>>> Yellow and Reserved pages are protected to detect stack
> >>>>>>>>>>>> overflows.
> >>>>>>>>>>>> The Shadow pages are just some extra space to allow methods
> >>>>>>>>>>>> that
> >>>>>>>>>>>> don't do a stack bang to execute.
> >>>>>>>>>>>>
> >>>>>>>>>>>>
> >>>>>>>>>>>>
> >>>>>>>>>>>> Unfortunately, the size required for guard pages is not
> >>>>>>>>>>>> fixed at
> >>>>>>>>>>>> compile time. It depends on the concrete system the VM is
> >>>>>>>>>>>> started on.
> >>>>>>>>>>>> Thus the minimum sizes given can be too small to hold the
> >>>>>>>>>>>> guard
> >>>>>>>>>>>> pages. This lead to errors in the past that were solved by
> >>>>>>>>>>>> introducing code that overruled the per-platform minimum
> stack
> >>>>>>>>>>>> size.
> >>>>>>>>>>>> This code nowadays is the MAX2() in os_posix.cpp:1114 and the
> >>>>>>>> SOLARIS
> >>>>>>>>>>>> special case further down. It uses the value (4 * BytesPerWord
> >>>>>>>>>>>> COMPILER2_PRESENT(+ 2)) * 4 * K) (os_posix.cpp:1117) as
> >>> minimum
> >>>>>>>>>>>> required space for frames. Thereby it effectively overrules
> >>>>>>>>>>>> the
> >>>>>>>>>>>> minimum stack size settings given in the os/cpu constants, and
> >>>>>>>>>>>> there
> >>>>>>>>>>>> is currently no way to specify this size per platform.
> >>>>>>>>>>>>
> >>>>>>>>>>>>
> >>>>>>>>>>>>
> >>>>>>>>>>>> This change proposes to fix this issue by specifying the space
> >>>>>>>>>>>> needed
> >>>>>>>>>>>> for stack frames in the os/cpu constants. During startup, this
> >>>>>>>>>>>> number
> >>>>>>>>>>>> is increased by the space required for the guard pages. Thus,
> >>>>>>>>>>>> this
> >>>>>>>>>>>> takes into account the page size of the concrete system the VM
> >>>>>>>>>>>> runs
> >>>>>>>>>>>> on, and also eventual changes to the guard pages by the flags
> >>>>>>>>>>>> StackRed/Yellow/Reserved/Shadow/Pages. This gives the
> >>> opportunity
> >>>>>>>> to
> >>>>>>>>>>>> reduce the minimum stack sizes on systems with small pages.
> >>>>>>>>>>>>
> >>>>>>>>>>>>
> >>>>>>>>>>>>
> >>>>>>>>>>>> Minimum stack size configuration is more simple with this
> >>>>>>>>>>>> change and
> >>>>>>>>>>>> valid for systems with any page size.
> >>>>>>>>>>>>
> >>>>>>>>>>>>
> >>>>>>>>>>>>
> >>>>>>>>>>>> 2. Stack guard pages not considered for compiler thread stacks
> >>>>>>>>>>>>
> >>>>>>>>>>>>
> >>>>>>>>>>>>
> >>>>>>>>>>>> Compiler threads are Java threads. The C++ class
> >>>>>>>>>>>> CompilerThread is a
> >>>>>>>>>>>> subclass of JavaThread. When a compiler thread is started,
> >>>>>>>>>>>> JavaThread::run() is executed which protects the red,
> >>>>>>>>>>>> yellow and
> >>>>>>>>>>>> reserved pages.
> >>>>>>>>>>>>
> >>>>>>>>>>>>
> >>>>>>>>>>>>
> >>>>>>>>>>>> Since 8140520 the minimum stack sizes for Compiler and VM
> >>>>>>>>>>>> internal
> >>>>>>>>>>>> threads no longer include the space for the guard pages.
> >>>>>>>>>>>> This is
> >>>>>>>>>>>> correct for the VM internal threads, but not for the Compiler
> >>>>>>>>>>>> thread.
> >>>>>>>>>>>>
> >>>>>>>>>>>>
> >>>>>>>>>>>>
> >>>>>>>>>>>> For the HotSpot C1 and C2 compilers it would be fine to
> >>>>>>>>>>>> reserve space
> >>>>>>>>>>>> for the Red/Yellow/Reserved pages, as they don't stack bang
> >>>>>>>>>>>> with the
> >>>>>>>>>>>> shadow page size. But since introducing JVMCI, compilers
> >>>>>>>>>>>> written in
> >>>>>>>>>>>> Java can be running on the compiler threads. Therefore the
> >>>>>>>>>>>> shadow
> >>>>>>>>>>>> pages are needed, too.
> >>>>>>>>>>>>
> >>>>>>>>>>>>
> >>>>>>>>>>>>
> >>>>>>>>>>>> As for the Java thread, this change uses a os/cpu constant for
> >>>>>>>>>>>> the
> >>>>>>>>>>>> required minimum space for compiler frames and then adds the
> >>> zone
> >>>>>>>>>>>> sizes to the minimum stack sizes during startup.
> >>>>>>>>>>>>
> >>>>>>>>>>>>
> >>>>>>>>>>>>
> >>>>>>>>>>>> New sizing:
> >>>>>>>>>>>>
> >>>>>>>>>>>>
> >>>>>>>>>>>>
> >>>>>>>>>>>> The constants of the os/cpu minimum thread sizes are reduced
> >>>>>>>>>>>> by the
> >>>>>>>>>>>> default guard page sizes and then verified by starting the
> >>>>>>>>>>>> VM to
> >>>>>>>>>>>> assure the stack still suffices to get through startup.
> >>>>>>>>>>>> Hotspot jtreg
> >>>>>>>>>>>> tests are passing. The overall sizes required (after adding
> >>>>>>>>>>>> guard
> >>>>>>>>>>>> pages) on the systems I have available get a bit smaller.
> >>>>>>>>>>>> In most
> >>>>>>>>>>>> cases the sizes even suffice to run simple programs as
> >>>>>>>>>>>> SpecJvm98. The
> >>>>>>>>>>>> table below gives the systems I tested and the required sizes
> >>>>>>>>>>>> reported when started with too small stacks.
> >>>>>>>>>>>>
> >>>>>>>>>>>>
> >>>>>>>>>>>>
> >>>>>>>>>>>> <pre>
> >>>>>>>>>>>>
> >>>>>>>>>>>> Thread kind: Java Compiler VM
> >>>>>>>>>>>>
> >>>>>>>>>>>> old new old new old new
> >>>>>>>>>>>>
> >>>>>>>>>>>>
> >>>>>>>>>>>>
> >>>>>>>>>>>> bsd x86_64 dbg: 240 232 64 64 64 64
> >>>>>>>>>>>>
> >>>>>>>>>>>> opt: 240 232 64 64 64 64
> >>>>>>>>>>>>
> >>>>>>>>>>>>
> >>>>>>>>>>>>
> >>>>>>>>>>>> linux x86_64 dbg: 240 144 64 152 64 64
> >>>>>>>>>>>>
> >>>>>>>>>>>> opt: 232 136 64 144 64 64
> >>>>>>>>>>>>
> >>>>>>>>>>>>
> >>>>>>>>>>>>
> >>>>>>>>>>>> solaris sparc dbg:
> >>>>>>>>>>>>
> >>>>>>>>>>>> opt: 240 192 128 128 128 128
> >>>>>>>>>>>>
> >>>>>>>>>>>>
> >>>>>>>>>>>>
> >>>>>>>>>>>> aix ppc64 dbg: 512 512 384 512 128 128
> >>>>>>>>>>>>
> >>>>>>>>>>>> opt: 512 512 384 512 128 128
> >>>>>>>>>>>>
> >>>>>>>>>>>> linux ppc64 dbg: 512 384 128 384 128 64
> >>>>>>>>>>>>
> >>>>>>>>>>>> opt: 512 384 128 384 128 64
> >>>>>>>>>>>>
> >>>>>>>>>>>> linux ppc64le dbg: 512 384 128 384 128 64
> >>>>>>>>>>>>
> >>>>>>>>>>>> opt: 512 384 128 384 128 64
> >>>>>>>>>>>>
> >>>>>>>>>>>>
> >>>>>>>>>>>>
> >>>>>>>>>>>> linux s390 dbg: 236 140 128 184 128 32
> >>>>>>>>>>>>
> >>>>>>>>>>>> opt: 236 124 128 144 128 32
> >>>>>>>>>>>>
> >>>>>>>>>>>> </pre>
> >>>>>>>>>>>>
> >>>>>>>>>>>>
> >>>>>>>>>>>>
> >>>>>>>>>>>>
> >>>>>>>>>>>>
> >>>>>>>>>>>>
> >
> >
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