memory a matematika okolo MemAvailable

Dobry den, kdyz chci zjistit kolik mam volne ram, kterou muzu pouzit pro spusteni novych procesu, aniz by system zacal swapovat, koukam se na hodnotu available.

Kdyz vezmu tyto informace:

free -k
              total        used        free      shared  buff/cache   available
Mem:        1874348      185836     1300484        8644      388028     1532920
Swap:        421884           0      421884

A spocitam:

1874348(total) - 185836(used) = 1688512

Co je to vlastne za cislo? Ocekaval bych ze dostanu "available", ale nadbyva me v nem nejakych 150Mb...

Predem dekuji

Linux zacne strankovat drive nez po vycerpani "available", zavisi to na nastaveni swapiness ( https://eklitzke.org/swappiness ) a mnohych dalsich faktorech (mnozstvi inactive a active neanonymni pameti, jak nove spustene aplky zatizi unreclaimable slab, kolik pameti budou sharovat,...). Je to celkove pomerne komplexni zalezitost a fundovana odpoved by vydala na dizertacni praci.

15.1.2020 14:55 chtel_bych_se_zeptat
Rozbalit Rozbalit vše Re: memory a matematika okolo MemAvailable

Ahoj, jasne urcite mas pravdu. To moje tvrzeni bylo velice obecne - cituju z odkazu od kolegy nahore:

+MemAvailable: An estimate of how much memory is available for starting new
+              applications, without swapping. Calculated from MemFree,
+              SReclaimable, the size of the file LRU lists, and the low
+              watermarks in each zone.
+              The estimate takes into account that the system needs some
+              page cache to function well, and that not all reclaimable
+              slab will be reclaimable, due to items being in use. The
+              impact of those factors will vary from system to system.

Nahodou odkaz na takovu dizertacni praci nemas? Nebo nejaky pekny zdroj v cestine?

Dotaz: memory a matematika okolo MemAvailable

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