[ISSUE] Linux Kernel CONFIG_DEBUG_INFO_BTF by default

[ISSUE] Linux Kernel CONFIG_DEBUG_INFO_BTF by default

[DanPartelly]

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New issue by DanPartelly on void-packages repository

https://github.com/void-linux/void-packages/issues/23723

Description:
Please consider changing the default kernel config to include BTF deduplicated type information. The flag is CONFIG_DEBUG_INFO_BTF .  The flag allow the kernel to make available type information to BPF programs, allowing those to introspect kernel structures without resorting to llvm/clang to parse kernel headers as was done in past by iovisor bcc tool for example.  This was iffy at times and broke many times.   BTF allows a lot of introspection into running kernel, making the setting usefull to all kind of ppl from developer to ops and sytem admins.  given this usefulness more and more distros are enabling it by default.  It is a relative recent addition, so the config flag should only be upaded for latest kernel serie (5.7)  and up. 

Note that when using this config, pahole utility becomes a build dependency. 

BTF type info is de-duplicated and greatly reduced in size compared to dwarf.  A primer into its usefulness can be read at:
https://facebookmicrosites.github.io/bpf/blog/2018/11/14/btf-enhancement.html

Re: Linux Kernel CONFIG_DEBUG_INFO_BTF by default

[luhann]

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New comment by luhann on void-packages repository

https://github.com/void-linux/void-packages/issues/23723#issuecomment-662398282

Comment:
Currently there is a PR to implement this change for 5.7 on x86_64. See  #23534.

Re: Linux Kernel CONFIG_DEBUG_INFO_BTF by default

[leahneukirchen]

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New comment by leahneukirchen on void-packages repository

https://github.com/void-linux/void-packages/issues/23723#issuecomment-672823038

Comment:
Enabled for our platforms in Linux 5.8 now.

Re: [ISSUE] [CLOSED] Linux Kernel CONFIG_DEBUG_INFO_BTF by default

[leahneukirchen]

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Closed issue by DanPartelly on void-packages repository

https://github.com/void-linux/void-packages/issues/23723

Description:
Please consider changing the default kernel config to include BTF deduplicated type information. The flag is CONFIG_DEBUG_INFO_BTF .  The flag allow the kernel to make available type information to BPF programs, allowing those to introspect kernel structures without resorting to llvm/clang to parse kernel headers as was done in past by iovisor bcc tool for example.  This was iffy at times and broke many times.   BTF allows a lot of introspection into running kernel, making the setting usefull to all kind of ppl from developer to ops and sytem admins.  given this usefulness more and more distros are enabling it by default.  It is a relative recent addition, so the config flag should only be upaded for latest kernel serie (5.7)  and up. 

Note that when using this config, pahole utility becomes a build dependency. 

BTF type info is de-duplicated and greatly reduced in size compared to dwarf.  A primer into its usefulness can be read at:
https://facebookmicrosites.github.io/bpf/blog/2018/11/14/btf-enhancement.html