Does anyone know where I can get a description of the different kernel objects whose memory caches reported by slabtop on Linux?
For example what is filp
, radix_tree_node
, etc?
Linux – what are the different caches reported by slabtop
linux
linux
Does anyone know where I can get a description of the different kernel objects whose memory caches reported by slabtop on Linux?
For example what is filp
, radix_tree_node
, etc?
Best Answer
Background
The slab's reported in
excerpt - How /proc/slabinfo is not quite telling you what it looks likeslabtop
are difficult to quantify to a particular kernel module because they're getting merged down into singular types which overlap based on their similarity to others in terms of the objects they're holding.This article goes on to discuss that because of the above merging, often times there's slab cache types that don't show up at all in
/proc/slabinfo
. You can see some of this effect by looking here:/sys/kernel/slab
. This directory shows which slab caches are getting merged with others in the form of symbolic links.The image on the left shows the links (light blue) from the directory
/sys/kernel/slab
which are getting merged into other slabs. The image on the right shows all the caches which are merging into:t-0000256
slab.Tracking slabs
If we continue to look through the
/sys/kernel/slab
directory:Here's the
filp
you were inquiring about. To see more about it you might want to try installing theslabinfo
CLI.slabinfo
I did not have this CLI available to triage this further on CentOS 7.x but you may want to investigate it. Compiling this CLI gives you access to
reference: Slab allocators in the Linux Kernel: SLAB, SLOB, SLUBslabinfo -a
which shows the aliases that the slabs associate with under/sys/kernel/slab
. I believe it's these alias that you're looking for which will help to associate which slabs are which in theslabtop
.References