Re: computing drop-able caches

[Daniel Walker]

On 02/10/2016 10:13 AM, Dave Hansen wrote:
> On 02/10/2016 10:04 AM, Daniel Walker wrote:
> > > [Linux_0:/]$ echo 3 > /proc/sys/vm/drop_caches
> > > [Linux_0:/]$ cat /proc/meminfo
> > > MemTotal:        3977836 kB
> > > MemFree:         1095012 kB
> > > MemAvailable:    1434148 kB
> > I suspect MemAvailable takes into account more than just the droppable
> > caches. For instance, reclaimable slab is included, but I don't think
> > drop_caches drops that part.
> There's a bit for page cache and a bit for slab, see:
>
> 	https://kernel.org/doc/Documentation/sysctl/vm.txt

Ok, then this looks like a defect then. I would think MemAvailable would 
always be smaller then MemFree (after echo 3 > 
/proc/sys/vm/drop_caches).. Unless there is something else be accounted 
for that we aren't aware of.

Daniel