Regression: jemalloc >= 4.0 use munmap() even when configured with --disable-munmap

[Daniel Mewes]

Thank you for your great work on jemalloc first of all.

In jemalloc 3.0, this patch added the `--disable-munmap` option and
disabled the use of `munmap` on Linux by default:
https://github.com/jemalloc/jemalloc/commit/59ae2766af88bad07ac721c4ee427b171e897bcb

It looks like jemalloc starting with version 4.0 makes use of `munmap` even
when `--disable-munmap` is specified. From what I can tell, `chunk_map.c`
honors the `config_munmap` flag, but the function `page_unmap` in `pages.c`
ignores it (this code appears to be new in jemalloc 4?).

We are using jemalloc for RethinkDB and would like to upgrade to version
4.1 because we think that it fixes some bugs that our users have run into.
However it causes a regression for
https://github.com/rethinkdb/rethinkdb/issues/3516 :
"<jemalloc>: Error in munmap(): Cannot allocate memory"


- Daniel
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://jemalloc.net/mailman/jemalloc-discuss/attachments/20160422/8b6876fb/attachment.html>