Re: [PATCH 1/5] MIPS: kdb: Remove old workaround for backtracing on other CPUs

From: Daniel Thompson
Date: Thu Nov 14 2019 - 05:51:32 EST


On Sat, Nov 09, 2019 at 11:16:40AM -0800, Douglas Anderson wrote:
> As of commit 2277b492582d ("kdb: Fix stack crawling on 'running' CPUs
> that aren't the master") we no longer need any special case for doing
> stack dumps on CPUs that are not the kdb master. Let's remove.
>
> Signed-off-by: Douglas Anderson <dianders@xxxxxxxxxxxx>
> ---
> I have no way to test this personally, so hopefully someone who uses
> kdb/kgdb on MIPS can.

I took this as a hint to add mips support to kgdbtest ;-)

Support is added and working well. Unfortunately lack of familiarity
with mips means I have not yet figured out which mips defconfig gives
us working SMP (and what the corresponding qemu invocation should be).

I think that means I still can't (quite) exercise this code fully.
The most appropriate test is bta on an SMP system, right?


> Ideally this patch should be Acked by MIPS folks and then land through
> the kdb/kgdb tree since the next patch in the series, ("kdb:
> kdb_current_regs should be private") depends on it.

An Acked-by from a MIPS maintainer would be very welcome. Perhaps
with a bit of extra work on the above I might be able to provide
a Tested-by:.

I didn't see anything that particularly bothered me in the patches but
given we're already at -rc7 I'm inclined to target this patchset for 5.6
rather than 5.5.


Daniel.