Re: Improve logging when using Huge Pages

Thanks!

At Wed, 8 Sep 2021 07:52:35 +0000, "Shinoda, Noriyoshi (PN Japan FSIP)" <noriyoshi(dot)shinoda(at)hpe(dot)com> wrote in
> Hello,
>
> Thank you everyone for comments.
> I have attached a patch that simply changed the message like the advice from Horiguchi-san.
>
> > Even with the patch, there are still some cases where huge pages is disabled silently. We should report something even in these cases?
> > For example, in the platform where huge pages is not supported, it's silently disabled when huge_pages=try.
>
> The area where this patch is written is inside the "#ifdef MAP_HUGETLB #endif" block.
> For this reason, I think it is excluded from binaries created in an environment that does not have the MAP_HUGETLB macro.

Ah, right.

> > One big concern about the patch is that log message is always reported when shared memory fails to be allocated with huge pages enabled when huge_pages=try. Since
> > huge_pages=try is the default setting, many users would see this new log message whenever they start the server. Those who don't need huge pages but just use the default
> > setting might think that such log messages would be noisy.
>
> This patch is meant to let the admin know that HugePages isn't being used, so I'm sure you're right. I have no idea what to do so far.

It seems *to me* sufficient. I'm not sure what cases CreateFileMapping
return ERROR_NO_SYSTEM_RESOURCES when non-huge page can be allocated
successfully, though, but that doesn't matter much, maybe.

regards.

--
Kyotaro Horiguchi
NTT Open Source Software Center