Since "enabled=always" is the kernel default value, anything that uses a stock kernel (example: Arch family) or has to build its own (Gentoo) will probably have it enabled by default.
I just checked, and my Gentoo and Manjaro systems have it set to "enabled=always".
Anyway, recently they added new "defer" mode for defragmentation so THP doesn't try to defragment (the main cause of the slow down) upon allocation and instead it is triggering it in background (via kswapd and kcompactd). This is now set to be the default. I think it is available in RedHat/CentOS 7.3+
The best out of both worlds though (although then it requires more manual work) is pre-allocating HugaPages in advance and then let application use them (if the application supports it) or through libhugetlbfs (if it doesn't).
Edit: changed hugetlbfs to libhugetlbfs, so it's easier to find how to do it with man libhugetlbfs
I can confirm that neither my Ubuntu nor Debian servers have is in "always", they're either "madvise" or "never".
# CONFIG_TRANSPARENT_HUGEPAGE_ALWAYS is not set
CONFIG_TRANSPARENT_HUGEPAGE_MADVISE=y
CONFIG_TRANSPARENT_HUGEPAGE_ALWAYS=y
# CONFIG_TRANSPARENT_HUGEPAGE_MADVISE is not set
Edit: The linux kernel source says the default is always (in mm/Kconfig), and that's been true since 2011.
The debian package changelog says the change occurred in 4.13.4-1:
* thp: Enable TRANSPARENT_HUGEPAGE_ALWAYS instead of
TRANSPARENT_HUGEPAGE_MADVISE
As advised by Andrea Arcangeli - since commit 444eb2a449ef "mm: thp: set THP defrag by default to madvise and add a stall-free defrag option" this will generally be best for performance.
https://anonscm.debian.org/cgit/kernel/linux.git/commit/debi...
Edit 2: The mentioned commit (444eb2a449ef) dates back to 4.6, so presumably, at least some performance issues with transparent huge pages may be gone since that version of the kernel.
$ cat /sys/kernel/mm/transparent_hugepage/enabled
[always] madvise never
I can also confirm that my Ubuntu 16.04.3 LTS (GNU/Linux 4.4.0-101-generic x86_64) droplet has the same setting.
It is in the process of being fixed (it should be set to madvise).
Makes me think that your setting is a default and his was set by Digital Ocean.
Perhaps there are issues with 'madvise' in kernels prior to 4.11, so they chose 'always' rather than 'never'.
It baffles me that THP became enabled by default (is it? I think it’s only a default on RHEL distros?). It really screws up many expectations that applications might assume about memory behavior (like the page size). In the majority of cases, THP is a bad, bad idea and anyone with perf or devops experience will agree with this I think.
Do you want to impose GC like pause characteristics to all processes on your box? And possibly double, triple, or 10x your memory usage? Enable THP then.