Re: Solaris dldump

[Po Lu <luangruo@yahoo.com>]

ali_gnu2@emvision.com writes:

> On 8/17/24 6:10 PM, Po Lu wrote:
>> Hello Ali!
>> I think you underestimate the number of programs using dldump.  I've
>> seen both Perl 5 and GNU Make hacked to save state with dldump, on
>> Oracle Solaris, producing binaries that don't depend on the presence of
>> a state file and probably start faster as well.  Meanwhile
>> pdumper-dumped binaries appear to crash in an x86 Solaris 10 zone,
>> though I don't really use this configuration and I'm not interested in
>> trying the portable dumper on sparc:
>> core 'core' of 7021:        ../../src/bootstrap-emacs -batch
>> --no-site-file --no-site-lisp -f batc
>>   00007fffaf433dc2 ???????? ()
>>   00007fffaf5eb3d7 ???????? ()
>>   00007fffaf5ec590 ???????? ()
>>   00007fffae3f351a _lwp_kill () + a
>>   00007fffae3981b9 raise () + 19
>>   00000000008baf90 terminate_due_to_signal () + c0
>>   000000000090236e ???????? ()
>>   0000000000902334 deliver_thread_signal () + 74
>>   00000000009023b0 deliver_fatal_thread_signal () + 10
>>   00000000009024ef handle_sigsegv () + 4f
>>   00007fffae3edd16 __sighndlr () + 6
>>   00007fffae3e25e2 call_user_handler () + 252
>>   00007fffae3e280e sigacthandler () + ee
>>   00007fffaf5ea82d ???????? ()
>>   ffffffffffffffff ???????? ()
>>   00000000009c77e7 lisp_align_malloc () + 4d7
>>   00000000009c9dd2 make_float () + 42
>>   00000000009d2e9d init_alloc () + d
>>   00000000008bd373 main () + bb3
>>   00000000006d15ab ???????? ()
>> 
>
> Hello!
>
>    Is that stack from the s10 zone?

Yes.

> You're probably right that I don't know who is using
> dldump(), outside of emacs, but not to worry, it's not
> going away. It's a committed interface, so hard to remove,
> and at the same time, isn't causing any problems. Nonetheless,
> it's not our favored way to deploy emacs, and I wouldn't want
> anyone to think we prefer its use, or require it.
>
> We use pdumper on newer Solaris 11.4, both x86 and sparc,
> with no reported issues. I wasn't aware of the Solaris 10
> zone problems (haven't seen any reports). If you end up
> looking at it

I plan to, but not till Emacs 30 is released.

> and think that the s10 zone is somehow at fault, please feel free to
> contact me offline. However, given that s10 is 20 years old, it
> wouldn't be unreasonable to drop it off the support tail. From
> discussions with Rainer Orth, who maintains gcc for Solaris, I believe
> that s10 support for gcc has ended, or is very close to ending. My
> personal opinion is that anyone happy to use a 20 year old OS should
> have no problem using an older gcc, or emacs, so it's not really the
> end of the road for those folks.

I'm fine with using an older C compiler (whether GCC or no), but we have
plenty of precedent in these quarters for remaining on decades-old
operating systems.  Not least when the operating system is to be
supported for two more years.

> I expect that we're both benefiting from your work anyway.
> Isn't emacs still largely C (not C++)? I wouldn't expect
> exception handling to be needed, so maybe it's OK.

C, but several libraries draw in C++ dependencies and others create
threads: HarfBuzz and librsvg for example.