Hi all,
commit a6d60245 "Track which levels of the page tables have been cleared"
added cleared_(ptes|pmds|puds|p4ds) in struct mmu_gather, and the values
of them are set in some places. For example:
In include/asm-generic/tlb.h, pte_free_tlb() set the tlb->cleared_pmds:
---8<---
#ifndef pte_free_tlb
#define pte_free_tlb(tlb, ptep, address) \
do { \
__tlb_adjust_range(tlb, address, PAGE_SIZE); \
tlb->freed_tables = 1; \
tlb->cleared_pmds = 1; \
__pte_free_tlb(tlb, ptep, address); \
} while (0)
#endif
---8<---
However, in arch/s390/include/asm/tlb.h, pte_free_tlb() set the tlb->cleared_ptes:
---8<---
static inline void pte_free_tlb(struct mmu_gather *tlb, pgtable_t pte,
unsigned long address)
{
__tlb_adjust_range(tlb, address, PAGE_SIZE);
tlb->mm->context.flush_mm = 1;
tlb->freed_tables = 1;
tlb->cleared_ptes = 1;
/*
* page_table_free_rcu takes care of the allocation bit masks
* of the 2K table fragments in the 4K page table page,
* then calls tlb_remove_table.
*/
page_table_free_rcu(tlb, (unsigned long *) pte, address);
}
---8<---
In my view, the cleared_(ptes|pmds|puds) and (pte|pmd|pud)_free_tlb
correspond one-to-one. So we should set cleared_ptes in pte_free_tlb(),
then use it when needed.
I'm very confused about this. Which is wrong? Or is there something
I understand wrong?
Thanks,
Zhenyu
