On Mon, Jan 22, 2018 at 03:54:26PM +1300, Thomas Munro wrote: > On Fri, Jan 12, 2018 at 1:12 PM, Thomas Munro > <thomas.mu...@enterprisedb.com> wrote: > > On Tue, Jan 9, 2018 at 6:24 AM, Catalin Iacob <iacobcata...@gmail.com> > > wrote: > > I don't know enough about this to make such a strong recommendation > > myself, which is why I was only trying to report that bad performance > > had been observed on some version, not that you shouldn't do it. Any > > other views on this stronger statement? > > Now that the Windows huge pages patch has landed, here is a rebase. I > took your alternative and tweaked it a tiny bit more. Thoughts?
+ <para> + Note that, besides explicitly requesting huge pages via + <varname>huge_pages</varname>, => I would just say: "Note that, besides huge pages requested explicitly, ..." + In Linux this automatic use is => ON Linux comma? + called "transparent huge pages" and is not enabled by default in + popular distributions as of the time of writing, but since transparent => really ? I don't know if I've ever seen it not enabled. In any case, that's a strong statement to make (to be disabled in ALL popular distributions). I checked all our servers, including centos6 and ubuntu t-LTS and x-LTS. On a limited few where it was disabled, I'd explicitly done so. On a server on which I just installed ubuntu-x LTS, with 4.13.0-26-generic: pryzbyj@gta-ubuntu:~$ cat /sys/kernel/mm/transparent_hugepage/enabled always [madvise] never https://github.com/torvalds/linux/commit/13ece886d99cd668483113f7238e419d5331af26 => the compile time default is to disable, but (if enabled at compile time), the runtime default is "always". On centos7 Linux template0 3.10.0-693.11.6.el7.x86_64 #1 SMP Thu Jan 4 01:06:37 UTC 2018 x86_64 x86_64 x86_64 GNU/Linux $ cat /sys/kernel/mm/transparent_hugepage/enabled [always] madvise never $ grep TRANS /boot/config-3.10.0-693.11.6.el7.x86_64 CONFIG_HAVE_ARCH_TRANSPARENT_HUGEPAGE=y CONFIG_TRANSPARENT_HUGEPAGE=y CONFIG_TRANSPARENT_HUGEPAGE_ALWAYS=y # CONFIG_TRANSPARENT_HUGEPAGE_MADVISE is not set https://blog.nelhage.com/post/transparent-hugepages/ => It is enabled (”enabled=always”) by default in most Linux distributions. Justin