===================================================
There's no need in special enabling of PTE split page table lock: everything
-required is done by pgtable_pte_page_ctor() and pgtable_pte_page_dtor(), which
+required is done by pagetable_pte_ctor() and pagetable_pte_dtor(), which
must be called on PTE table allocation / freeing.
Make sure the architecture doesn't use slab allocator for page table
PMD split lock only makes sense if you have more than two page table
levels.
-PMD split lock enabling requires pgtable_pmd_page_ctor() call on PMD table
-allocation and pgtable_pmd_page_dtor() on freeing.
+PMD split lock enabling requires pagetable_pmd_ctor() call on PMD table
+allocation and pagetable_pmd_dtor() on freeing.
Allocation usually happens in pmd_alloc_one(), freeing in pmd_free() and
pmd_free_tlb(), but make sure you cover all PMD table allocation / freeing
With everything in place you can set CONFIG_ARCH_ENABLE_SPLIT_PMD_PTLOCK.
-NOTE: pgtable_pte_page_ctor() and pgtable_pmd_page_ctor() can fail -- it must
+NOTE: pagetable_pte_ctor() and pagetable_pmd_ctor() can fail -- it must
be handled properly.
page->ptl
split lock with enabled DEBUG_SPINLOCK or DEBUG_LOCK_ALLOC, but costs
one more cache line for indirect access;
-The spinlock_t allocated in pgtable_pte_page_ctor() for PTE table and in
-pgtable_pmd_page_ctor() for PMD table.
+The spinlock_t allocated in pagetable_pte_ctor() for PTE table and in
+pagetable_pmd_ctor() for PMD table.
Please, never access page->ptl directly -- use appropriate helper.
架构对分页表锁的支持
====================
-没有必要特别启用PTE分页表锁:所有需要的东西都由pgtable_pte_page_ctor()
-和pgtable_pte_page_dtor()完成,它们必须在PTE表分配/释放时被调用。
+没有必要特别启用PTE分页表锁:所有需要的东西都由pagetable_pte_ctor()
+和pagetable_pte_dtor()完成,它们必须在PTE表分配/释放时被调用。
确保架构不使用slab分配器来分配页表:slab使用page->slab_cache来分配其页
面。这个区域与page->ptl共享存储。
PMD分页锁只有在你有两个以上的页表级别时才有意义。
-启用PMD分页锁需要在PMD表分配时调用pgtable_pmd_page_ctor(),在释放时调
-用pgtable_pmd_page_dtor()。
+启用PMD分页锁需要在PMD表分配时调用pagetable_pmd_ctor(),在释放时调
+用pagetable_pmd_dtor()。
分配通常发生在pmd_alloc_one()中,释放发生在pmd_free()和pmd_free_tlb()
中,但要确保覆盖所有的PMD表分配/释放路径:即X86_PAE在pgd_alloc()中预先
一切就绪后,你可以设置CONFIG_ARCH_ENABLE_SPLIT_PMD_PTLOCK。
-注意:pgtable_pte_page_ctor()和pgtable_pmd_page_ctor()可能失败--必
+注意:pagetable_pte_ctor()和pagetable_pmd_ctor()可能失败--必
须正确处理。
page->ptl
的指针并动态分配它。这允许在启用DEBUG_SPINLOCK或DEBUG_LOCK_ALLOC的
情况下使用分页锁,但由于间接访问而多花了一个缓存行。
-PTE表的spinlock_t分配在pgtable_pte_page_ctor()中,PMD表的spinlock_t
-分配在pgtable_pmd_page_ctor()中。
+PTE表的spinlock_t分配在pagetable_pte_ctor()中,PMD表的spinlock_t
+分配在pagetable_pmd_ctor()中。
请不要直接访问page->ptl - -使用适当的辅助函数。
return true;
}
-static inline bool pgtable_pte_page_ctor(struct page *page)
-{
- return pagetable_pte_ctor(page_ptdesc(page));
-}
-
static inline void pagetable_pte_dtor(struct ptdesc *ptdesc)
{
struct folio *folio = ptdesc_folio(ptdesc);
lruvec_stat_sub_folio(folio, NR_PAGETABLE);
}
-static inline void pgtable_pte_page_dtor(struct page *page)
-{
- pagetable_pte_dtor(page_ptdesc(page));
-}
-
pte_t *__pte_offset_map(pmd_t *pmd, unsigned long addr, pmd_t *pmdvalp);
static inline pte_t *pte_offset_map(pmd_t *pmd, unsigned long addr)
{
return true;
}
-static inline bool pgtable_pmd_page_ctor(struct page *page)
-{
- return pagetable_pmd_ctor(page_ptdesc(page));
-}
-
static inline void pagetable_pmd_dtor(struct ptdesc *ptdesc)
{
struct folio *folio = ptdesc_folio(ptdesc);
lruvec_stat_sub_folio(folio, NR_PAGETABLE);
}
-static inline void pgtable_pmd_page_dtor(struct page *page)
-{
- pagetable_pmd_dtor(page_ptdesc(page));
-}
-
/*
* No scalability reason to split PUD locks yet, but follow the same pattern
* as the PMD locks to make it easier if we decide to. The VM should not be