--- Begin Message ---
|
Subject: |
Re: BPF in linux-libre |
|
Date: |
Mon, 06 Jul 2020 15:26:11 +0200 |
|
User-agent: |
Gnus/5.13 (Gnus v5.13) Emacs/26.3 (gnu/linux) |
Hey John,
> I think I tidied up the description to match the Guix situation. What do
> you think now?
Yes it's fine, thanks for the updated serie! I pushed the first patch
and patches two and three squashed together.
> I could see it being a useful default. BPF seems like a nice technology
> but I am making these patches to experiment with it myself. Because I
> haven't used it much I can't really speak on the pros of making it
> default. Other than my gut feeling that seems like something that
> should be opted into rather than opting out of I have no strong feelings
> on including it by default. The only other downside I see is that
> putting in the default might make the linux definitions less composable.
> The way it is now, one can assemble a (mostly) bpf-capable system from
> the pieces in gnu/packages/linux.scm.
Ok, thanks for explaining. I don't have much experience with BPF
either. For now we can work with a separate linux-libre, and will see
about merging it into the default, when we'll have more perspective.
I'll take more time to review patches 4 and 5. However, while trying
some of the examples packaged by BCC, I have the following error:
--8<---------------cut here---------------start------------->8---
mathieu@meru:~/guix-master$
/gnu/store/rv51f9n1w9i92m9qsg9k3ilsy3hyhjf3-bcc-0.15.0/share/bcc/tools/execsnoop
Traceback (most recent call last):
File
"/gnu/store/rv51f9n1w9i92m9qsg9k3ilsy3hyhjf3-bcc-0.15.0/share/bcc/tools/execsnoop",
line 21, in <module>
from bcc import BPF
ModuleNotFoundError: No module named 'bcc'
--8<---------------cut here---------------end--------------->8---
I think an additional wrapping is necessary. Could you please have a
look? I'm also removing help-guix, and opening a proper guix-patches
ticket.
Thanks,
Mathieu
--- End Message ---
--- Begin Message ---
|
Subject: |
Re: [bug#42227] BPF in linux-libre |
|
Date: |
Fri, 31 Jul 2020 13:04:47 +0200 |
|
User-agent: |
Gnus/5.13 (Gnus v5.13) Emacs/26.3 (gnu/linux) |
Hey,
> That seems ok. I did find a few questions about debugfs on old irc logs
> and mailing lists. My only concern again is that I would prefer to opt
> in to such a thing. debugfs is much simpler than the bpf kernel flags
> though, so maybe it will be ok to remove in the future.
Yeah, but I saw that Ubuntu for instance is enabling it by default, so I
guess it could help to have the same behaviour in Guix System. Added it
with: 6bb07e91e1ab9367f636a3a5e9d52a9e0772aa89.
> But I cannot see anything guix does differently that would cause it to
> fail. My only feeling is perhaps our configure flags for binutils might
> be causing the issue.
>
> As is, however, bpftrace does work even with out HAVE_BFD_DISASM and I
> even used it to debug a few processes recently.
Gave it another try and I think if we could get "binutils" to produce a
dynamic version of libbfd.a, that would make the trick. Anyway, let's
proceed without BFD support for now. Pushed bpftrace as
c55acb073248392b1387017378f36a1d378fa7c4.
Closing the serie, thank you!
Mathieu
--- End Message ---