Re: [PATCH dwarves v2 4/4] btf_encoder: add global_var feature to encode globals

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



On Tue, Oct 1, 2024 at 8:10 AM Arnaldo Carvalho de Melo <acme@xxxxxxxxxx> wrote:
>
> On Fri, Sep 20, 2024 at 01:19:01AM -0700, Stephen Brennan wrote:
> > Currently the "var" feature only encodes percpu variables. Add the
> > ability to encode all global variables.
> >
> > This also drops the use of the symbol table to find variable names and
> > compare them against DWARF names. We simply rely on the DWARF
> > information to give us all the variables.
>
> I applied the three first patches to the next branch that soon will move
> to master, but the last patch I think does too many things and ends up
> being too big.
>
> For instance, you could have done the btf_encoder->skip_encoding_vars
> transformation into a bitfield in a separate, prep patch, also you
> mentions "this also drops the use of the symbol table", can this be made
> a separate, prep patch?
>
> There was a conflict with some new options I added (--padding,
> --padding_ge) and I fixed that up and made the series available in the
> btf_global_vars branch, can you please go from there and split the last
> patch into smaller chunks?
>
> Thanks for your work on this! I noticed that this is not the default,
> i.e. one has to explicitely opt in to have the global variables encoded
> in BTF, so that would be interesting to have spelled out in the chunked
> out patch that introduces the feature, etc.

We probably shouldn't enable this option in kernel build until we work
out details of loading vmlinux BTF(s) through the kernel module.

>
> Also since we have it as a feature and can ask for global variables
> using --btf_features=global_var, I don't think we need
> --encode_btf_global_vars, right?
>
> That will also make the patch smaller, and even if it was required, that
> would be something to have in a separate patch.
>
> - Arnaldo
>
> > Signed-off-by: Stephen Brennan <stephen.s.brennan@xxxxxxxxxx>
> > Tested-by: Alan Maguire <alan.maguire@xxxxxxxxxx>
> > ---
> >  btf_encoder.c      | 347 +++++++++++++++++++++------------------------
> >  btf_encoder.h      |   8 ++
> >  dwarves.h          |   1 +
> >  man-pages/pahole.1 |   8 +-
> >  pahole.c           |  11 +-
> >  5 files changed, 183 insertions(+), 192 deletions(-)
> >

[...]





[Index of Archives]     [Linux USB Devel]     [Linux Audio Users]     [Yosemite News]     [Linux Kernel]     [Linux SCSI]

  Powered by Linux