btf: CO-RE relocation is very slow on bpf-next #1081
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@lmb I think this is essentially the issue I was seeing awhile ago. |
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Some digging into why there are these duplicate types: The types really are different as well: We end up at All of these fields either point at |
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The only difference in |
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And this is out of the same vmlinux.h? Could you follow the ids of run_array further to see where some of the properties differ? Was this with latest pahole? |
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I'll do that. Not sure which pahole, the vmlinux is pulled from an Here is the BTF blob: vmlinux-bpf-next-6.4.0-rc3-g60548b825b08.gz |
We end up at |
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A loop? 🤯 |
No, the script I had bailed out after the first diff, so it gave misleading results. I rewrote the thing in Go, now it gives me a real diff: This says that |
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The problem is in ubuntu It doesn't just create duplicate BTF, it also creates really large types. For example, in ubuntu BTF there are 150983 types reachable from |
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This should now be much better on |
brb
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Most notably to fix [1] which caused pwru's slow loading on Ubuntu. [1]: cilium/ebpf#1081 Signed-off-by: Martynas Pumputis <m@lambda.lt>
brb
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Most notably to fix [1] which caused pwru's slow loading on Ubuntu. [1]: cilium/ebpf#1081 Signed-off-by: Martynas Pumputis <m@lambda.lt>
brb
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Most notably to fix [1] which caused pwru's slow loading on Ubuntu. [1]: cilium/ebpf#1081 Signed-off-by: Martynas Pumputis <m@lambda.lt>
tpapagian
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It doesn't seem to be part of any renovate PR. This also includes a fix for newer kernels: cilium/ebpf#1081 Signed-off-by: Anastasios Papagiannis <tasos.papagiannnis@gmail.com>
tpapagian
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It doesn't seem to be part of any renovate PR. This also includes a fix for newer kernels: cilium/ebpf#1081 Signed-off-by: Anastasios Papagiannis <tasos.papagiannnis@gmail.com>
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Using CO-RE to relocate against some common types like
struct net,struct sk_buffand so on takes a looong time.This was originally reported against pwru: cilium/pwru#189
The library spends a lot of time copying types to remove qualifiers:
The problem is exacerbated by the fact that some common types seem to be present a bunch of times in the kernel BTF:
Current CO-RE code will make a copy of every one of these types.
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