RHEL 8: Premature swapping with swappiness=0 while there is still plenty of pagecache to be reclaimed
Issue
- Even if memory is under pressure with
swappiness=0, the inactive pagecache is swapped out instead of pagecache being reclaimed. - The system wide swappiness value specified at
/proc/sys/vm/swappinesshas little-to-no effect on the swap characteristics of a system with CgroupV1. This issue may lead to unexpected and inconsistent swap behaviour.
Environment
- Red Hat Enterprise Linux (RHEL) 8
- systems utilizing Cgroups v1
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