Messages in this thread | | | Subject | Re: [PATCH v1 4/5] mm: ptdump: Support hugepd table entries | From | Christophe Leroy <> | Date | Fri, 16 Apr 2021 07:25:36 +0200 |
| |
Hi Daniel,
Le 16/04/2021 à 01:29, Daniel Axtens a écrit : > Hi Christophe, > >> Which hugepd, page table entries can be at any level >> and can be of any size. >> >> Add support for them. >> >> Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> >> --- >> mm/ptdump.c | 17 +++++++++++++++-- >> 1 file changed, 15 insertions(+), 2 deletions(-) >> >> diff --git a/mm/ptdump.c b/mm/ptdump.c >> index 61cd16afb1c8..6efdb8c15a7d 100644 >> --- a/mm/ptdump.c >> +++ b/mm/ptdump.c >> @@ -112,11 +112,24 @@ static int ptdump_pte_entry(pte_t *pte, unsigned long addr, >> { >> struct ptdump_state *st = walk->private; >> pte_t val = ptep_get(pte); >> + unsigned long page_size = next - addr; >> + int level; >> + >> + if (page_size >= PGDIR_SIZE) >> + level = 0; >> + else if (page_size >= P4D_SIZE) >> + level = 1; >> + else if (page_size >= PUD_SIZE) >> + level = 2; >> + else if (page_size >= PMD_SIZE) >> + level = 3; >> + else >> + level = 4; >> >> if (st->effective_prot) >> - st->effective_prot(st, 4, pte_val(val)); >> + st->effective_prot(st, level, pte_val(val)); >> >> - st->note_page(st, addr, 4, pte_val(val), PAGE_SIZE); >> + st->note_page(st, addr, level, pte_val(val), page_size); > > It seems to me that passing both level and page_size is a bit redundant, > but I guess it does reduce the impact on each arch's code?
Exactly, as shown above, the level can be re-calculated based on the page size, but it would be a unnecessary impact on all architectures and would duplicate the re-calculation of the level whereas in most cases we get it for free from the caller.
> > Kind regards, > Daniel > >> >> return 0; >> } >> -- >> 2.25.0
| |