On Wed, 21 Mar 2001, Linus Torvalds wrote:
> diff -u --recursive --new-file pre6/linux/mm/memory.c linux/mm/memory.c
> --- pre6/linux/mm/memory.c Tue Mar 20 23:13:03 2001
> +++ linux/mm/memory.c Wed Mar 21 22:21:27 2001
> @@ -1031,18 +1031,20 @@
> struct vm_area_struct * vma, unsigned long address,
> pte_t * page_table, swp_entry_t entry, int write_access)
> {
> - struct page *page = lookup_swap_cache(entry);
> + struct page *page;
> pte_t pte;
>
> + spin_unlock(&mm->page_table_lock);
> + page = lookup_swap_cache(entry);
> if (!page) {
> - spin_unlock(&mm->page_table_lock);
> lock_kernel();
> swapin_readahead(entry);
> page = read_swap_cache(entry);
> unlock_kernel();
> - spin_lock(&mm->page_table_lock);
> - if (!page)
> + if (!page) {
> + spin_lock(&mm->page_table_lock);
> return -1;
> + }
>
> flush_page_to_ram(page);
> flush_icache_page(vma, page);
Are you sure flush_page_to_ram()/flush_icache_page() without
page_table_lock held is ok for all archs?
Looking at arch/mips/mm/r2300.c:
static void r3k_flush_cache_page(struct vm_area_struct *vma,
unsigned long page)
{
struct mm_struct *mm = vma->vm_mm;
...
if ((physpage = get_phys_page(page, vma->vm_mm))) <--------
r3k_flush_icache_range(physpage, PAGE_SIZE);
...
}
static inline unsigned long get_phys_page (unsigned long addr,
struct mm_struct *mm)
{
pgd_t *pgd;
pmd_t *pmd;
pte_t *pte;
unsigned long physpage;
pgd = pgd_offset(mm, addr);
pmd = pmd_offset(pgd, addr);
pte = pte_offset(pmd, addr);
if((physpage = pte_val(*pte)) & _PAGE_VALID)
return KSEG1ADDR(physpage & PAGE_MASK);
else
return 0;
...
}
-
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This archive was generated by hypermail 2b29 : Fri Mar 23 2001 - 21:00:16 EST