On Thu, Oct 24, 2013 at 1:00 PM, Andres Freund <and...@2ndquadrant.com> wrote: > On 2013-10-24 16:06:19 +0300, Heikki Linnakangas wrote: >> On 24.10.2013 09:03, Abhijit Menon-Sen wrote: >> >One open question is what to do about rounding up the size. It should >> >not be necessary, but for the fairly recent bug described at the link >> >in the comment (https://bugzilla.kernel.org/show_bug.cgi?id=56881). I >> >tried it without the rounding-up, and it fails on Ubuntu's 3.5.0-28 >> >kernel (mmap returns EINVAL). >> >> Let's get rid of the rounding. It's clearly a kernel bug, and it shouldn't >> be our business to add workarounds for any kernel bug out there. And the >> worst that will happen if you're running a buggy kernel version is that you >> fall back to not using huge pages (assuming huge_tlb_pages=try). > > But it's a range of relatively popular kernels, that will stay around > for a good while. So I am hesitant to just not do anything about it. The > directory scanning code isn't that bad imo. > > Either way: > I think we should log when we tried to use hugepages but fell back to > plain mmap, currently it's hard to see whether they are used.
Logging it might be a good idea, but suppose the systems been running for 6 months and you don't have the startup logs. Might be a good way to have an easy way to discover later what happened back then. -- Robert Haas EnterpriseDB: http://www.enterprisedb.com The Enterprise PostgreSQL Company -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
