[Vm-dev] new Cog VMs available [please read]
Eliot Miranda
eliot.miranda at gmail.com
Fri Sep 23 18:22:18 UTC 2011
Hi All,
yesterday's new VMs bore fruit and I found and fixed a bug that could
cause fatal VM crashes. Alas it was not the one I was looking for, simply
closely related. So I've uploaded new VMs to
http://www.mirandabanda.org/files/Cog/VM/VM.r2494/README.2494 and would ask
you, especially if you used yesterday's VM, to upgrade to today's VM and
hopefully I can nail the one I was after in the first place.
thanks for the great response!
Eliot
P.S. Here's the readme, and a reiteration of what I need from you
CogVM source as per VMMaker.oscog-eem.126. Fix cPICEndSize mis-computation
caused by using rounded-up closedPICSize. Compute cPICEndSize and /then/
round-up closedPICSize.
These VMs are not much changed from the 2487 VMs, BUT the 2487 VMs
introduced a bug while providing faster doesNotUnderstand: processing.
These 2494 VMs contain code to help identify that bug. If you're already
using a 2487 VM or newer /please/ upgrade to these 2494 VMs asap. I want to
see C stack backtraces from these VMs whenever they crash. Typically the
VMs produce a crash.dmp file somewhere in the file system (may be / on Mac
OS, may be in the directory containing the VM or the current directory on
other OSs, but it will be called crash.dmp, and on Mac OS info will be
printed to the console or to a crash report window). The C backtrace part
of things looks like
this on windows:
Stack backtrace:
[004193EA] ??? + 4297706 in CogCode
[00442337] ??? + 4465463 in CogCode
[00442685] ??? + 4466309 in CogCode
[00583018] ??? + 5779480 in CogCode
[0040124B] ??? + 4198987 in CogCode
[00401298] ??? + 4199064 in CogCode
[7C816FE7] RegisterWaitForInputIdle + 73 in kernel32.dll
[7C913BA7] RtlDosApplyFileIsolationRedirection_Ustr + 1824 in ntdll.dll
this on Mac
C stack backtrace:
0 nsvm 0x00038689 reportStackState + 105
1 nsvm 0x0003893e sigsegv + 110
2 libsystem_c.dylib 0x9b2e259b _sigtramp + 43
3 ??? 0xffffffff 0x0 + 4294967295
4 nsvm 0x0008b2a5 sufficientSpaceAfterGC +
69
5 nsvm 0x0008d11d primitiveNewWithArg + 221
6 ??? 0x068b9899 0x0 + 109811865
7 nsvm 0x00098d10
initStackPagesAndInterpret + 512
8 nsvm 0x0002c530 EventLoopEventHandler +
16
Etc. So please feel free to email me the crash.dmp's and/or the C
backtraces of any crashes you have with 2494 VMs. Hopefully I'll track down
this regression quickly.
For the curious, what's the bug? I don't know yet. The symptom is that very
rarely the inline cache linking machinery for MNU PICs relinks the call of
an MNU PIC to the address 0x00000013, which causes a crash when the call is
next executed, long after the bug bit. These VMs contain code that will
raise an error when the relinking attempt is made, which should reveal the
bug.
On Thu, Sep 22, 2011 at 10:37 AM, Eliot Miranda <eliot.miranda at gmail.com>wrote:
> ...in http://www.mirandabanda.org/files/Cog/VM/VM.r2493/. These VMs are
> not much changed from the 2487 VMs, BUT the 2487 VMs introduced a bug while
> providing faster doesNotUnderstand: processing. These 2493 VMs contain code
> to help identify that bug. If you're already using a 2487 VM or newer
> /please/ upgrade to these 2493 VMs asap. I want to see C stack backtraces
> from these VMs whenever they crash. Typically the VMs produce a crash.dmp
> file somewhere in the file system (may be / on Mac OS, may be in the
> directory containing the VM or the current directory on other OSs, but it
> will be called crash.dmp, and on Mac OS info will be printed to the console
> or to a crash report window). The C backtrace part of things looks like
>
> this on windows:
> Stack backtrace:
> [004193EA] ??? + 4297706 in CogCode
> [00442337] ??? + 4465463 in CogCode
> [00442685] ??? + 4466309 in CogCode
> [00583018] ??? + 5779480 in CogCode
> [0040124B] ??? + 4198987 in CogCode
> [00401298] ??? + 4199064 in CogCode
> [7C816FE7] RegisterWaitForInputIdle + 73 in kernel32.dll
> [7C913BA7] RtlDosApplyFileIsolationRedirection_Ustr + 1824 in ntdll.dll
>
> this on Mac
> C stack backtrace:
> 0 nsvm 0x00038689 reportStackState + 105
> 1 nsvm 0x0003893e sigsegv + 110
> 2 libsystem_c.dylib 0x9b2e259b _sigtramp + 43
> 3 ??? 0xffffffff 0x0 + 4294967295
> 4 nsvm 0x0008b2a5 sufficientSpaceAfterGC +
> 69
> 5 nsvm 0x0008d11d primitiveNewWithArg +
> 221
> 6 ??? 0x068b9899 0x0 + 109811865
> 7 nsvm 0x00098d10
> initStackPagesAndInterpret + 512
> 8 nsvm 0x0002c530 EventLoopEventHandler +
> 16
>
> Etc. So please feel free to email me the crash.dmp's and/or the C
> backtraces of any crashes you have with 2493 VMs. Hopefully I'll track down
> this regression quickly.
>
> For the curious, what's the bug? I don't know yet. The symptom is that
> very rarely the inline cache linking machinery for MNU PICs relinks the call
> of an MNU PIC to the address 0x00000013, which causes a crash when the call
> is next executed, long after the bug bit. These VMs contain code that will
> raise an error when the relinking attempt is made, which should reveal the
> bug.
>
> Here's the 2493 readme:
>
> CogVM binaries as per VMMaker.oscog-eem.125/r2493. Add callsite link/relocate
> checks to catch the call 0x00000013 MNU callsite relinking bug.
> Reduce the size of the simStack to something proportional to LargeContextSize.
>
> In the Newspeak VM, don't cd to the image's directory on win32. Fix off-by-one
> error in Win32OSProcessPlugin>primitiveGetCurrentWorkingDirectory so it doesn't
> include an erroneous trailing null.
>
> Fix the 1Gb allocation bug.
>
> --
> best,
> Eliot
>
>
--
best,
Eliot
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