Subject: Re: bug#66744: 30.0.50; Emacs crashes when re-dumping into the same dump file another Emacs instance is using

From: Gerd Möllmann <[email-masked]>
Date: Thu, 26 Oct 2023 18:32:23 +0200

Eli Zaretskii <[email-masked]> writes:

>> Cc: [email-masked]
>> From: Gerd Möllmann <[email-masked]>
>> Date: Thu, 26 Oct 2023 17:45:49 +0200
>> 
>> The linux man page for mmap says, according to Google,
>> 
>>   MAP_PRIVATE
>>        ...
>>       It is unspecified whether changes made to the file
>>       after the mmap() call are visible in the mapped region.
>> 
>> So, if the changes made to the dump file in step 3 are visible in the
>> mmaped dump file that Emacs from step 2 uses, that would be a bit
>> suboptimal :-).
>
> Emacs on GNU/Linux doesn't use mmap, we stopped doing this many years
> ago.

Ok, but I must admit that I don't see how that is done in pdumper.c.