Hi! ...
These should actually be 64-bit and therefore enable innodb_log_file_mmap. Is your configuration check tripping because of the following?
static constexpr const char *innodb_log_file_mmap_description= "Whether ib_logfile0" # ifdef HAVE_PMEM " resides in persistent memory or" # endif " should initially be memory-mapped";
It is not "my configuration check", it is standard output from mariadbd --verbose --help.
On systems where it isn't available, shouldn't the option still show up (but as permanently disabled)?
In my opinion, a smaller footprint is better. To name another example: On Microsoft Windows, WITH_WSREP will not be defined.
That is not the same situation. It is a completely different scenario if the software is missing some options because a feature was not compiled into it, or the software is too old to have some feature. What I now discovered is the **first and only system variable** that may disappear based on what the architecture is. I agree that most of the time less is more, but in the case of configuration options / system variables, it is extremely confusing to users if an option occasionally exists and occasionally not in the same version of MariaDB build with the same dependencies. Can you please help me write a patch (apparently for a_innodb.cc) to make the variable will always be visible?