I'm not looking for fairies :-) I was just curious exactly how mmap interacts with the OS in order to understand performance metrics better.
On Sat, Feb 6, 2016 at 5:46 PM, Howard Chu hyc@symas.com wrote:
Kristoffer Sjögren wrote:
Thanks Howard. What's the best documentation on mmap you know, aside from read kernel source code?
Not sure what you're asking. Read the mmap(2) manpage and its related pages. If you're thinking there's something fancy hidden in there for you to take advantage of, I don't think you should be using mmap in the first place.
On Fri, Feb 5, 2016 at 10:33 PM, Howard Chu hyc@symas.com wrote:
Kristoffer Sjögren wrote:
Hi
Our application do lots of caching using vmtouch, up to a point where there isn't a lot of memory left on the machine. We would like to use LMDB on the same machine to store around 40GiB data of a few hundred million entries.
How can we best understand the interaction and behavior of the OS cache and sharing of memory between processes? Is LMDB doing something to help the OS?
Nope, LMDB does nothing special with its mmap.
-- -- Howard Chu CTO, Symas Corp. http://www.symas.com Director, Highland Sun http://highlandsun.com/hyc/ Chief Architect, OpenLDAP http://www.openldap.org/project/
-- -- Howard Chu CTO, Symas Corp. http://www.symas.com Director, Highland Sun http://highlandsun.com/hyc/ Chief Architect, OpenLDAP http://www.openldap.org/project/