Re: mmap vs fs cache

Kirill A. Shutemov
2013-03-08T08:40:20Z

On Thu, Mar 07, 2013 at 11:46:39PM -0800, Howard Chu wrote:
> You're misreading the information then. slapd is doing no caching of
> its own, its RSS and SHR memory size are both the same. All it is
> using is the mmap, nothing else. The RSS == SHR == FS cache, up to
> 16GB. RSS is always == SHR, but above 16GB they grow more slowly
> than the FS cache.

It only means, that some pages got unmapped from your process. It can
happned, for instance, due page migration. There's nothing worry about: it
will be mapped back on next page fault to the page and it's only minor
page fault since the page is in pagecache anyway.

--
Kirill A. Shutemov