[PATCH 2/2] arm64/mm: Improve comment in contpte_ptep_get_lockless()

Catalin Marinas catalin.marinas at arm.com
Mon Mar 4 09:37:40 PST 2024


On Mon, Mar 04, 2024 at 12:54:23PM +0000, Ryan Roberts wrote:
> On 01/03/2024 18:47, Catalin Marinas wrote:
> > On Mon, Feb 26, 2024 at 12:03:21PM +0000, Ryan Roberts wrote:
> >> Make clear the atmicity/consistency requirements of the API and how we
> >> achieve them.
> >>
> >> Link: https://lore.kernel.org/linux-mm/Zc-Tqqfksho3BHmU@arm.com/
> >> Signed-off-by: Ryan Roberts <ryan.roberts at arm.com>
> >> ---
> >>  arch/arm64/mm/contpte.c | 24 ++++++++++++++----------
> >>  1 file changed, 14 insertions(+), 10 deletions(-)
[...]
> > Throughout the callers of this function, I couldn't find one where it
> > matters. So I concluded that they don't need the dirty state. Normally
> > the dirty state is passed to the page flags, so not lost after the pte
> > has been cleaned.
> 
> I agree we can simplify the semantics. But I think its better done in a separate
> series (which I previously linked).
> 
> What's the bottom line here? Are you ok with this comment as a short term
> solution for now, or do you want something more radical (i.e. push to get the
> series that does these simplifications reviewed and in time for v6.9).
> 
> I still believe the current ptep_get_lockless() implementation is correct. So
> given I have a plan to simplify in the long run, I hope we can still get this
> series into v6.9 as planned.

Yes, I'm fine with this patch. Assuming Andrew picked them up:

Reviewed-by: Catalin Marinas <catalin.marinas at arm.com>

I'd like to get the simplification in as well at some point as I think
our ptep_get_lockless() is unnecessarily complex for most use-cases.

-- 
Catalin



More information about the linux-arm-kernel mailing list