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[Gcl-devel] Re: address@hidden: Re: interrupts in 64-bit GCL]
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From: |
Matt Kaufmann |
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Subject: |
[Gcl-devel] Re: address@hidden: Re: interrupts in 64-bit GCL] |
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Date: |
Wed, 25 Feb 2009 19:54:01 -0600 |
Hi --
You can just make your own directory, grab ACL2 from the web as
follows
wget http://www.cs.utexas.edu/users/moore/acl2/v3-4/distrib/acl2.tar.gz
and then, after extracting with "tar xfz acl2.tar.gz", type
make LISP=<path_to_gcl>
in your source directory.
Actually, if you want to build ACL2 *exactly* as I did, create this
script to use for <path_to_gcl> above, where "..." is the appropriate
path:
#!/bin/sh
.../gcl-2.6.8pre/bin/gcl -eval "(defparameter user::*fast-acl2-gcl-build* t)" $*
Then you should be able to do the experiment I sent you before. By
the way, what I used for "..." just above was /lusr/opt.
-- Matt
Cc: address@hidden, address@hidden
From: Camm Maguire <address@hidden>
Date: Wed, 25 Feb 2009 20:43:26 -0500
X-SpamAssassin-Status: No, hits=-2.5 required=5.0
X-UTCS-Spam-Status: No, hits=-280 required=165
Greetings, and thanks! And the acl2 source location, and any special
build instructions?
Take care,
Matt Kaufmann <address@hidden> writes:
> Forwarding to gcl-devel:
>
> From: "David A. Kotz" <address@hidden>
> Subject: Re: interrupts in 64-bit GCL
> To: Matt Kaufmann <address@hidden>
> CC: address@hidden, address@hidden, address@hidden
> Date: Wed, 25 Feb 2009 14:10:58 -0600
>
> ./configure --prefix=/lusr/opt/gcl-2.6.8pre \
> --disable-statsysbfd --enable-locbfd \
> --enable-ihssize=2097110 \
> --enable-vssize=2097110 \
> --enable-maxpage=524288 \
> --enable-holediv=100 \
> --enable-debug
>
>
>
>
> Matt Kaufmann wrote:
>> Great! Thank you. Dave, if you send me your build instructions, I'll
>> forward them along since you're (I'm guessing) not on the gcl-devel
>> list, which only allows posts from members.
>>
>> Thanks --
>> -- Matt
>> Cc: address@hidden, address@hidden, address@hidden
>> From: Camm Maguire <address@hidden>
>> Date: Wed, 25 Feb 2009 15:03:41 -0500
>> X-SpamAssassin-Status: No, hits=-2.6 required=5.0
>> X-UTCS-Spam-Status: No, hits=-282 required=165
>>
>> Greetings! OK, suprisingly enough I think I might have indirectly
>> deduced what is going on. It is verifiably independent of SGC, but
>> appears related to 64bit only by the enhanced time window possible in
>> which to receive SIGINT.
>>
>> In short, could you please send me (and post to gcl-devel) the
>> instructions for rebuilding your source again against a patched gcl
>> tree for testing.
>>
>> This does bring up the legacy gcl signal handling code, which is quite
>> clever given the age in which it was developed, but has since been
>> made somewhat obsolete by recent system developments, at least on
>> Linux.
>>
>> The GCL strategy is to maintain global variables tracking pending and
>> blcked signals, and to loop over alarm(1) until the unblocking code
>> snippet is executed. (i.e. BEGIN_NO_INTERRUPT and END_NO_INTERRUPT,
>> which essentially set signals_allowed to 0 and restores the previous
>> value respectively). Nowadays, bracketing the code needing protection
>> directly with sigprocmask is more typical. Heaven knows what
>> portability issues are involved in making this change.
>>
>> The bug appears to be that critical GC code is not protected against
>> interrupts and subsequent possible longjumps. Specifically,
>> add_page_to_freelist is apparently allowing partially initialized
>> freelists to escape. An immediate fix would be at hand in this case,
>> but more systematically we need to review the areas this protection is
>> required and come up with a decent centralization policy. I don't
>> think there is any reason to clock signals other that object creation,
>> gc, and anything modifying tm_table. Other thoughts most welcome.
>>
>> Take care,
>>
>>
>>
>> Matt Kaufmann <address@hidden> writes:
>>
>> > Hi --
>> >
>> > I was able to reproduce the error after building ACL2 a new debug
copy
>> > of 64-bit gcl that the sysadmins built. Same instructions as before,
>> > except for a slight change in the ACL2 executable directory. Quoting
>> > from below, but updating the executable path (and fixing a misleading
>> > comment):
>> >
>> > Start up ACL2 built on GCL, as follows:
>> >
>> > /projects/acl2/v3-4-linux-64/fast-linux-gcl-saved_acl2
>> >
>> > Then issue these commands:
>> >
>> > ; Just to slow down the output from the thm form below:
>> > (trace$ rewrite)
>> >
>> > ; ACL2 disables the debugger by default; this restores it:
>> > (set-debugger-enable t)
>> >
>> > ; This goes pretty fast but you'll have time to interrupt it:
>> > (thm (equal (append (append x x) x) (append x x x)))
>> >
>> > [Now quickly interrupt with control-c, and then :q from the
break.
>> > If the form above completes, just try it again. Eventually I
think
>> > you'll see a Lisp "fatal error" or even a "Segmentation fault".]
>> >
>> > It seems to take me about 3 to 5 THM calls to get the error, which
>> > looks like this:
>> >
>> > ACL2 !>(thm (equal (append (append x x) x) (append x x x)))
>> > [SGC off]
>> > Error: Caught fatal error [memory may be damaged]
>> > Fast links are on: do (si::use-fast-links nil) for debugging
>> > Error signalled by ACL2_*1*_ACL2::THM-FN.
>> > Broken at COND. Type :H for Help.
>> > ACL2[RAW LISP]>>
>> >
>> > -- Matt
>> > Date: Mon, 23 Feb 2009 17:12:04 -0600
>> > From: "David A. Kotz" <address@hidden>
>> > CC: address@hidden, address@hidden, address@hidden
>> >
>> > I've replaced both of our 64bit flavors and the 32bit with
debug-enabled
>> > versions. The 64s are in place now, and the 32 should rdist
around
>> > tonight. I want to keep all of them in sync, even if we're only
>> > investigating a problem in one.
>> >
>> > - dave
>> >
>> >
>> > Matt Kaufmann wrote:
>> > > Thanks, Dave! I really appreciate it.
>> > >
>> > > When I get the word from you, or when I see
>> > > /lusr/opt/gcl-2.6.8pre/bin/gcl updated on lhug-0, I'll rebuild
ACL2 on
>> > > top of it and try to reproduce the problem.
>> > >
>> > > Thanks again --
>> > > -- Matt
>> > > Date: Mon, 23 Feb 2009 10:13:54 -0600
>> > > From: "David A. Kotz" <address@hidden>
>> > > CC: Matt Kaufmann <address@hidden>, address@hidden,
>> > > address@hidden
>> > >
>> > > I'll rebuild it with the debug flag.
>> > >
>> > > - dave
>> > >
>> > >
>> > > Camm Maguire wrote:
>> > > > Thanks! Please let me know if you run into troubles here.
>> > > >
>> > > > Take care,
>> > > >
>> > > > Matt Kaufmann <address@hidden> writes:
>> > > >
>> > > >> Howdy --
>> > > >>
>> > > >> Thanks for the reply.
>> > > >>
>> > > >> If address@hidden is willing to do (1), or to send me the
exact configure
>> > > >> and make commands and source directory used so that I can
do it
>> > > >> myself, then I'll try to reproduce the error by building
ACL2 on top
>> > > >> of it. I'm assuming that --enable-debug is given to the
configure
>> > > >> command, not to make.
>> > > >>
>> > > >> Then if if I can't reproduce the problem, I'll let you
and address@hidden
>> > > >> know and we can explore (2). In that case, if
address@hidden is willing to
>> > > >> do it, great; then I'll try to reproduce the problem.
But if I'm to
>> > > >> do the build, I'd need explicit instructions on how to
"make sure -g
>> > > >> is included in the gcc calls"; maybe I need to do some
setq in Lisp?
>> > > >> Also I didn't understand the comment about makedefs. But
I guess we
>> > > >> can ignore (2) if (1) works.
>> > > >>
>> > > >> -- Matt
>> > > >> Cc: address@hidden, address@hidden
>> > > >> From: Camm Maguire <address@hidden>
>> > > >> Date: Fri, 20 Feb 2009 20:58:49 -0500
>> > > >> X-SpamAssassin-Status: No, hits=-2.6 required=5.0
>> > > >> X-UTCS-Spam-Status: No, hits=-282 required=165
>> > > >>
>> > > >> Greetings! I suspect a missing signal block around
some code that
>> > > >> needs protecting. I've reprodced under gdb, but there
are no
>> > > >> debugging symbols in the image. [ Question for list
-- have computers
>> > > >> now become so fast that -g should be included by
default in all gcl
>> > > >> images? It used to slow down the compiler, don't know
about now. It
>> > > >> does make the image quite a bit bigger. ]
>> > > >>
>> > > >> Ideally, you or someone else at the site might be so
kind as to
>> > > >> rebuild atop
>> > > >>
>> > > >> 1) a gcl build with --enable-debug. If this does not
reproduce, then
>> > > >> in addition
>> > > >> 2) rebuild atop a standard gcl with the CFLAGS
environment variable
>> > > >> set to -g before configure and make. Please make sure
-g is included
>> > > >> in the gcc calls. Otherwise, makedefs can be modified
after configure
>> > > >> and before make to include -g wherever one sees -O3 or
-O
>> > > >>
>> > > >> Would this be too much trouble?
>> > > >>
>> > > >> Take care,
>> > > >>
>> > > >> Matt Kaufmann <address@hidden> writes:
>> > > >>
>> > > >> > Hi --
>> > > >> >
>> > > >> > The sysadmins here at UT CS have built GCL 2.6.8pre
from CVS as you
>> > > >> > suggested. It's working great on 32-bit linux, but
I've run into an
>> > > >> > issue for 64-bit linux.
>> > > >> >
>> > > >> > You can re-create the issue on a UT CS 64-bit linux
machine as
>> > > >> > follows.
>> > > >> >
>> > > >> > Start up ACL2 built on GCL, as follows:
>> > > >> >
>> > > >> > /projects/acl2/v3-4-linux/fast-linux-gcl-saved_acl2
>> > > >> >
>> > > >> > Then issue these commands:
>> > > >> >
>> > > >> > ; Just to slow down the output from the next form:
>> > > >> > (trace$ rewrite)
>> > > >> >
>> > > >> > ; ACL2 disables the debugger by default; this
restores it:
>> > > >> > (set-debugger-enable t)
>> > > >> >
>> > > >> > ; This goes pretty fast but you'll have time to
interrupt it:
>> > > >> > (thm (equal (append (append x x) x) (append x x
x)))
>> > > >> >
>> > > >> > [Now quickly interrupt with control-c, and then :q
from the break.
>> > > >> > If the form above completes, just try it again.
Eventually I think
>> > > >> > you'll see a Lisp "fatal error" or even a
"Segmentation fault".]
>> > > >> >
>> > > >> > By the way, I built
/projects/acl2/v3-4-linux/fast-linux-gcl as
>> > > >> > follows, on lhug-0 (a 64-bit linux machine):
>> > > >> >
>> > > >> > rm -f TAGS ; mv make-fast-gcl.log
make-fast-gcl.old.log ; (time nice make PREFIX=fast-linux-gcl-
LISP=my-fast-gcl) >& make-fast-gcl.log&
>> > > >> >
>> > > >> > where "my-fast-gcl" is a script containing:
>> > > >> >
>> > > >> > #!/bin/sh
>> > > >> > /lusr/opt/gcl-2.6.8pre/bin/gcl -eval "(defparameter
user::*fast-acl2-gcl-build* t)" $*
>> > > >> >
>> > > >> > Also by the way, if you instead run the following on
a 32-bit UT CS
>> > > >> > linux machine
>> > > >> >
>> > > >> > /projects/acl2/v3-4-linux/gcl-saved_acl2
>> > > >> >
>> > > >> > then you won't see the interrupt problem described
above (or at least,
>> > > >> > I didn't, and I tried).
>> > > >> >
>> > > >> > Thanks --
>> > > >> > -- Matt
>> > > >> >
>> > > >> >
>> > > >> >
>> > > >> >
>> > > >>
>> > > >> --
>> > > >> Camm Maguire
address@hidden
>> > > >>
==========================================================================
>> > > >> "The earth is but one country, and mankind its
citizens." -- Baha'u'llah
>> > > >>
>> > > >>
>> > > >>
>> > > >>
>> > > >
>> >
>> >
>> >
>> >
>>
>> --
>> Camm Maguire address@hidden
>>
==========================================================================
>> "The earth is but one country, and mankind its citizens." --
Baha'u'llah
> ----------
>
--
Camm Maguire address@hidden
==========================================================================
"The earth is but one country, and mankind its citizens." -- Baha'u'llah