Re: [PATCH v2 1/2] contigmem: support including mapped buffers in core dump

[Bruce Richardson <bruce.richardson@intel.com>]

On Mon, Oct 28, 2024 at 04:26:06PM +0300, Dmitry Kozlyuk wrote:
> 2024-10-26 06:43 (UTC-0500), Lewis Donzis:
> > Is the extra control necessary, i.e., why not just always do this and let
> > the EAL option control whether the pages get dumped?
> 
> I've been evaluating your suggestion and see no downsides,
> except contigmem default behavior change, but does it have non-DPDK users?
> If no one objects, I'll prepare v3 doing the following:
> 1) everything from v2,
> 2) except always mark contigmem buffers as dumpable,
> 3) add --dump-mapped back and make DPDK disable dumping by default.
> As a result, in order to include mapped memory in coredump:
> * FreeBSD will require only "--dump-mapped";
> * Linux will require both "coredump_filter" setup and "--dump-mapped".

That all seems very reasonable, but it is late in the release cycle at this
point. Do you think it would be good to just take the v2 as is for 24.11,
and then change things thereafter to have more dynamic/runtime control of
the dump-setting in 25.03? 

From compatibility viewpoint, I don't think there are any non-DPDK users,
so if behaviour with EAL doesn't change, I don't think having the kernel
module default be different matters as we go from one release to the next.

/Bruce