On 2023-09-26 15:29, Arnd Bergmann wrote:
On Tue, Sep 26, 2023, at 20:47, Deucher, Alexander wrote:
From: Arnd Bergmann <arnd@xxxxxxxxxx>
Subject: Re: [PATCH 2/2] drm/amdkfd: drop struct kfd_cu_info
On Tue, Sep 26, 2023, at 18:39, Alex Deucher wrote:
I think this was an abstraction back from when kfd supported both
radeon and amdgpu. Since we just support amdgpu now, there is no more
need for this and we can use the amdgpu structures directly.
This also avoids having the kfd_cu_info structures on the stack when
inlining which can blow up the stack.
Cc: Arnd Bergmann <arnd@xxxxxxxxxx>
Signed-off-by: Alex Deucher <alexander.deucher@xxxxxxx>
Nice cleanup!
Acked-by: Arnd Bergmann <arnd@xxxxxxxx>
I guess you could fold patch 1/2 into this as it removes all the added code from
that anyway.
I left it as a separate patch as I didn't get a chance to see when the
stack warning appeared and figured it might be a good way to mitigate
that on stable kernels if necessary without pulling in the whole
rework, but if not, I can just squash it into the second patch.
Makes sense. FWIW, I had never seen the warning before updating
to linux-next this week from an older snapshot from last month.
My guess is that one of the recent changes made gcc take
different inlining decisions so we end up with two copies
of the cu_info in the same stack frame, even though the
fundamental problem was there already.
I've seen this type of problem before because our data structures keep
growing. When we need to support more GPUs, or bigger GPUs with more
CUs, the arrays in those structures grow, and start blowing up the stack
in functions that didn't have a problem before.
Regards,
Felix
Arnd
