Tutorial: advanced BTF example #49
Conversation
Signed-off-by: Jesper Dangaard Brouer <brouer@redhat.com>
Signed-off-by: Jesper Dangaard Brouer <brouer@redhat.com>
Signed-off-by: Jesper Dangaard Brouer <brouer@redhat.com>
Signed-off-by: Jesper Dangaard Brouer <brouer@redhat.com>
Signed-off-by: Jesper Dangaard Brouer <brouer@redhat.com>
Signed-off-by: Jesper Dangaard Brouer <brouer@redhat.com>
When loading with libbpf I'm getting some BTF loading errors. Adding this doesn't solve the problem, but is looks like I should add it anyhow. Signed-off-by: Jesper Dangaard Brouer <brouer@redhat.com>
This is still getting rejected when loading BTF. Last error is: [12] Invalid kind:13 Signed-off-by: Jesper Dangaard Brouer <brouer@redhat.com>
Signed-off-by: Jesper Dangaard Brouer <brouer@redhat.com>
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Jesper Dangaard Brouer <notifications@github.com> writes:
It didn't merge this branch with BTF examples as it failed...
It believe it now actually works, as it was a issue in libbpf that
caused the BTF code to get rejected on load. You can view, comment on,
or merge this pull request online at:
So no issue on the kernel side? We are currently recommending people to
use 4.20 or higher when running the tutorial...
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BTF in the kernel tree have moved away from In kernel v5.5 it will be placed in: tools/testing/selftests/bpf/bpf_legacy.h
We should instead have a tutorial that uses the new BTF method... but AFAIK it depends on LLVM version 9, which is not adopted by many distros ...yet. |
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Yeah, the lack of LLVM9 is a problem; we also want to use the new BTF syntax for map pinning. Should we just tell people to install it? :) |
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@tohojo, with LLVM9 you also won't need pahole for BTF generation, so that's a double win: you can get rid of a good chunk of sample Makefile ;) |
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In lack of places to put this, let me link a really advanced example by @chaudron We unfortunately have to wait for a LLVM release to use this in the tutorial... |
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My plan is to drop this PR, and create a new one based on LLVM9 and use the new ELF-maps style as an example. I also want to detect the LLVM version, to give users a more clear expectations when compiling the example. |
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Jesper Dangaard Brouer <notifications@github.com> writes:
My plan is to drop this PR, and create a new one based on LLVM9 and
use the new ELF-maps style as an example. I also want to detect the
LLVM version, to give users a more clear expectations when compiling
the example.
SGTM
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It didn't merge this branch with BTF examples as it failed...
It believe it now actually works, as it was a issue in libbpf that caused the BTF code to get rejected on load.