Re: [RFC PATCH] mm, oom: distinguish blockable mode for mmu notifiers
From: Christian KÃnig
Date: Mon Jul 02 2018 - 08:14:11 EST
Am 02.07.2018 um 13:54 schrieb Michal Hocko:
On Mon 02-07-18 11:14:58, Christian KÃnig wrote:
Am 27.06.2018 um 09:44 schrieb Michal Hocko:
This is the v2 of RFC based on the feedback I've received so far. The
code even compiles as a bonus ;) I haven't runtime tested it yet, mostly
because I have no idea how.
Any further feedback is highly appreciated of course.
That sounds like it should work and at least the amdgpu changes now look
good to me on first glance.
Can you split that up further in the usual way? E.g. adding the blockable
flag in one patch and fixing all implementations of the MMU notifier in
follow up patches.
But such a code would be broken, no? Ignoring the blockable state will
simply lead to lockups until the fixup parts get applied.
Well to still be bisect-able you only need to get the interface change
in first with fixing the function signature of the implementations.
Then add all the new code to the implementations and last start to
actually use the new interface.
That is a pattern we use regularly and I think it's good practice to do
this.
Is the split up really worth it? I was thinking about that but had hard
times to end up with something that would be bisectable. Well, except
for returning -EBUSY until all notifiers are implemented. Which I found
confusing.
It at least makes reviewing changes much easier, cause as driver
maintainer I can concentrate on the stuff only related to me.
Additional to that when you cause some unrelated side effect in a driver
we can much easier pinpoint the actual change later on when the patch is
smaller.
This way I'm pretty sure Felix and I can give an rb on the amdgpu/amdkfd
changes.
If you are worried to give r-b only for those then this can be done even
for larger patches. Just make your Reviewd-by more specific
R-b: name # For BLA BLA
Yeah, possible alternative but more work for me when I review it :)
Regards,
Christian.