On 01/28/2016 05:55 PM, Johannes Weiner wrote:
On Thu, Jan 28, 2016 at 05:29:41PM -0800, Daniel Walker wrote:
On 01/28/2016 05:03 PM, Daniel Walker wrote:
[regarding MemAvaiable]
This new metric purportedly helps usrespace assess available memory. But,
its again based on heuristic, it takes 1/2 of page cache as reclaimable..
No, it takes the smaller value of cache/2 and the low watermark, which
is a fraction of memory. Actually, that does look a little weird. Rik?
We don't age cache without memory pressure, you don't know how much is
used until you start taking some away. Heuristics is all we can offer.
With a simple busybox root system I get this,
MemTotal: 16273996 kB
MemFree: 16137920 kB
MemAvailable: 16046132 kB
shouldn't MemAvailable be at least the same as MemFree ? I changed the
code somewhat so it subtracted the wmark_low only, or the pagecache/2
only, both are still under MemFree. This system has very little
drop-able caches.
Daniel
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