This patch changes out the page_table_lock for the pud_page ptl in the
THP fault path; pretty self-explanatory. I got lazy and commented out
the spinlock assertion in follow_trans_huge_pmd instead of digging up
the pud_page ptl in this function. This is just a proof of concept, so
I didn't feel that it was too important to keep around for now.
---
mm/huge_memory.c | 4 ++--
mm/memory.c | 6 +++---
2 files changed, 5 insertions(+), 5 deletions(-)
diff --git a/mm/huge_memory.c b/mm/huge_memory.c
index a92012a..d3b34e2f 100644
--- a/mm/huge_memory.c
+++ b/mm/huge_memory.c
@@ -1240,10 +1240,10 @@ struct page *follow_trans_huge_pmd(struct vm_area_struct *vma,
pmd_t *pmd,
unsigned int flags)
{
- struct mm_struct *mm = vma->vm_mm;
+// struct mm_struct *mm = vma->vm_mm;
struct page *page = NULL;
- assert_spin_locked(&mm->page_table_lock);
+// assert_spin_locked(&mm->page_table_lock);
if (flags & FOLL_WRITE && !pmd_write(*pmd))
goto out;
diff --git a/mm/memory.c b/mm/memory.c
index af84bc0..5b4e910 100644
--- a/mm/memory.c
+++ b/mm/memory.c
@@ -1527,15 +1527,15 @@ struct page *follow_page_mask(struct vm_area_struct *vma,
split_huge_page_pmd(vma, address, pmd);
goto split_fallthrough;
}
- spin_lock(&mm->page_table_lock);
+ spin_lock(&pud_page(*pud)->ptl);
if (likely(pmd_trans_huge(*pmd))) {
if (unlikely(pmd_trans_splitting(*pmd))) {
- spin_unlock(&mm->page_table_lock);
+ spin_unlock(&pud_page(*pud)->ptl);
wait_split_huge_page(vma->anon_vma, pmd);
} else {
page = follow_trans_huge_pmd(vma, address,
pmd, flags);
- spin_unlock(&mm->page_table_lock);
+ spin_unlock(&pud_page(*pud)->ptl);
*page_mask = HPAGE_PMD_NR - 1;
goto out;
}
--
1.7.12.4
--
To unsubscribe, send a message with 'unsubscribe linux-mm' in
the body to majordomo@xxxxxxxxx. For more info on Linux MM,
see: http://www.linux-mm.org/ .
Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>