Re: [PATCH bpf-next v3 1/2] arm64: stacktrace: Implement arch_bpf_stack_walk() for the BPF JIT

From: Alexei Starovoitov
Date: Tue Feb 27 2024 - 16:58:21 EST


On Tue, Feb 27, 2024 at 10:10 AM Catalin Marinas
<catalin.marinas@xxxxxxx> wrote:
>
> On Tue, Feb 27, 2024 at 06:01:56PM +0000, Catalin Marinas wrote:
> > On Thu, Feb 22, 2024 at 06:04:35PM -0800, Alexei Starovoitov wrote:
> > > On Thu, Feb 22, 2024 at 11:28 AM Catalin Marinas
> > > <catalin.marinas@xxxxxxx> wrote:
> > > > On Thu, Feb 01, 2024 at 12:52:24PM +0000, Puranjay Mohan wrote:
> > > > > This will be used by bpf_throw() to unwind till the program marked as
> > > > > exception boundary and run the callback with the stack of the main
> > > > > program.
> > > > >
> > > > > This is required for supporting BPF exceptions on ARM64.
> > > > >
> > > > > Signed-off-by: Puranjay Mohan <puranjay12@xxxxxxxxx>
> > > > > ---
> > > > > arch/arm64/kernel/stacktrace.c | 26 ++++++++++++++++++++++++++
> > > > > 1 file changed, 26 insertions(+)
> > [...]
> > > > I guess you want this to be merged via the bpf tree?
> > >
> > > We typically take bpf jit patches through bpf-next, since
> > > we do cross arch jits refactoring from time to time,
> > > but nothing like this is pending for this merge window,
> > > so if you want it to go through arm64 tree that's fine with us.
> >
> > I don't have any preference. I can add it on top of the other arm64
> > patches if there are no dependencies on it from your side.
>
> Actually, it depends on patches in bpf-next AFAICT (it doesn't apply
> cleanly on top of vanilla -rc3). So please take the patches through the
> bpf tree.

Ok. Took it into bpf-next.

Please take a look at these Puranjay's patchset:

https://patchwork.kernel.org/project/netdevbpf/cover/20240221145106.105995-1-puranjay12@xxxxxxxxx/

It's a pretty nice performance improvement.