On 24/11/16 01:36, Aneesh Kumar K.V wrote: > Balbir Singh <bsinghar...@gmail.com> writes: > >> On 23/11/16 22:53, Aneesh Kumar K.V wrote: >>> Balbir Singh <bsinghar...@gmail.com> writes: >>> >>>> On 23/11/16 22:09, Aneesh Kumar K.V wrote: >>>>> When we are updating pte, we just need to flush the tlb mapping for >>>>> that pte. Right now we do a full mm flush because we don't track page >>>>> size. Update the interface to track the page size and use that to >>>>> do the right tlb flush. >>>>> >>>> >>>> Could you also clarify the scope -- this seems to be _radix_ only. >>>> The problem statement is not very clear and why doesn't the >>>> flush_tlb_page() >>>> following ptep_set_access_flags() work? What else do we need to do? >>> >>> Yes it modifies only radix part. Don't understand the flush_tlb_page() >>> part of the comment above. We are modifying the tlbflush that we need to do >>> in the pte update >>> sequence for DD1. ie, we need to do the flush before we can set the pte >>> with new value. >>> >>> Also in this specific case, we can idealy drop that flush_tlb_page, >>> because relaxing an access really don't need a tlb flush from generic >>> architecture point of view. I left it there to make sure, we measure and >>> get the invalidate path correct before going ahead with that >>> optimization. >>> >> >> OK.. here is my untested solution. I've only compiled it. >> It breaks the 64/hash/radix abstractions, but it makes the >> changes much simpler >> >> Signed-off-by: Balbir Singh <bsinghar...@gmail.com> > > I find the below one more confusing and complicated, spreading the > details of DD1 around the code. I am not sure what extra i could have > done to simplify the code. We have done the arch pte updates such that > most of the update use the pte_update() interface and the one which relax > the access bits get to ptep_set_access_flag. All pte updated rules are > contained there. What you did below is that you moved the dd1 sequence > out to a place where page size is available. What I did in my patch is to > pass page size around. IMHO it is a matter of style. I also want to pass > page size around so that we keep huge_pte_update, pte_update, > ptep_set_access_flags all similar. >
Agreed and the reason I did it that way is that after a while we know the _dd1_ variants need not be supported/maintained at all. It is a matter of style and I was wondering if we need to change the API to pass address and page_size as a permanent solution. Balbir Singh.
