[sisyphus] Re: Утекает память с новым ядром

[Konstantin A. Lepikhov]

<цитата от="Michael Shigorin">
> On Tue, Feb 01, 2005 at 04:03:25PM +0300, Konstantin A. Lepikhov wrote:
>> Это не утечка а новое поведение - все
>> данные хранятся в
>> оперативной памяти для ускорения
>> дисковых операций и меньшего
>> обращения к swap.
>
> Ох.  То кэш в своп заталкивают, то
> наоборот -- своп изгоняют...
> Воистину неисповедимы тараканы пишущих
> VM :(
from FAQ на con.kolivas.org:

Mapped watermark??
This readjusts the way memory is evicted by lightly removing cached ram
once the ram just under full capacity, if less than the "mapped watermark"
percent of ram is mapped ram (ie applications). The normal system is to
aggresively start scanning ram once it is completely full. The benefits of
this are:
1. Allocating memory while ram is being lightly scanned is faster and
cheaper than when it is being heavily scanned.
2. There is usually some free ram which tends to speed up application
startup times.
3. Swapping is an unusual event instead of a common one if you have enough
ram for your workload.
4. It is rare for your applications to be swapped out by file cache pressure.
Disadvantage: Less file cache.

The mapped watermark is configurable so a server for example might be
happy to have a lower mapped percentage. The default is 66 and a server
might like 33

echo 33 > /proc/sys/vm/mapped

This removes the swappiness knob entirely and deprecates all my previous
vm hacks (autoregulated swappiness, hard swappiness, kiflush).


-- 
WBR et al.