Re: LOG: munmap(0x7fff80000000) failed: Invalid argument

I have another application that consumes all of the huge pages; they aren't
for pgsql. :) I've modified the configuration file from "try" to "off" and
munmap is no more. Mischief managed.

Thanks for your help.

On Tue, Oct 11, 2016 at 6:15 PM, Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us> wrote:

> Chris Richards <chris(at)infinite(dot)io> writes:
> > Oh the email spam :P
>
> No problem. I'm starting to think that this isn't actually a Postgres
> bug, but rather something funny with your kernel. The code in sysv_shmem
> is certainly as fragile as can be, but I'm darned if I can find an
> existing code path that would actually break it --- and the lack of other
> complaints is pointing towards something funny with your system, too.
>
> First off, does changing "huge_pages" in postgresql.conf alter the
> behavior? (It defaults to "try", see what happens with "on" or "off".)
>
> Second, I notice that you've got
>
> > Hugepagesize: 1048576 kB
>
> which is just enormous. PG is only going to request circa 140MB given
> the settings you mentioned. We've seen reports of kernel bugs that cause
> mmap() to fail for requests that aren't a multiple of the hugepage size,
> but I've not heard that mmap() might succeed and then munmap() fail.
> That seems like what's happening to you though.
>
> regards, tom lane
>