Re: Improve logging when using Huge Pages

On Wed, Oct 27, 2021 at 3:40 PM Shinoda, Noriyoshi (PN Japan FSIP)
<noriyoshi(dot)shinoda(at)hpe(dot)com> wrote:
>
> Hi,
> Thank you for your comment.
> The attached patch stops message splitting.
> This patch also limits the timing of message output when huge_pages = try and HugePages is not used.
>

I've looked at the patch. Here are comments:

if (huge_pages == HUGE_PAGES_TRY && ptr == MAP_FAILED)
elog(DEBUG1, "mmap(%zu) with MAP_HUGETLB
failed, huge pages disabled: %m",
allocsize);
+ else
+ with_hugepages = true;

ISTM the name with_hugepages could lead to confusion since it can be
true even if mmap failed and huge_pages == HUGE_PAGES_ON.

Also, with the patch, the log message is emitted also during initdb
and starting up in single user mode:

selecting default max_connections ... 100
selecting default shared_buffers ... 128MB
selecting default time zone ... Asia/Tokyo
creating configuration files ... ok
running bootstrap script ... 2021-10-29 15:45:51.408 JST [55101] LOG:
Anonymous shared memory was allocated without huge pages.
ok
performing post-bootstrap initialization ... 2021-10-29 15:45:53.326
JST [55104] LOG: Anonymous shared memory was allocated without huge
pages.
ok
syncing data to disk ... ok

Which is noisy. Perhaps it's better to log it only when
IsPostmasterEnvironment is true.

Regards,

--
Masahiko Sawada
EDB: https://www.enterprisedb.com/