Re: [kvm-devel] [PATCH 3 of 9] Moves all mmu notifier methods outside the PT lock (first and not last

[Christoph Lameter]

Not sure why this patch is not merged into 2 of 9. Same comment as last 
round.




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[kvm-devel] [PATCH 3 of 9] Moves all mmu notifier methods outside the PT lock (first and not last

[Andrea Arcangeli]

# HG changeset patch
# User Andrea Arcangeli <[EMAIL PROTECTED]>
# Date 1207666463 -7200
# Node ID 33de2e17d0f5670515833bf8d3d2ea19e2a85b09
# Parent  baceb322b45ed43280654dac6c964c9d3d8a936f
Moves all mmu notifier methods outside the PT lock (first and not last
step to make them sleep capable).

Signed-off-by: Andrea Arcangeli <[EMAIL PROTECTED]>

diff --git a/include/linux/mmu_notifier.h b/include/linux/mmu_notifier.h
--- a/include/linux/mmu_notifier.h
+++ b/include/linux/mmu_notifier.h
@@ -117,27 +117,6 @@
INIT_HLIST_HEAD(&mm->mmu_notifier_list);
 }
 
-#define ptep_clear_flush_notify(__vma, __address, __ptep)  \
-({ \
-   pte_t __pte;\
-   struct vm_area_struct *___vma = __vma;  \
-   unsigned long ___address = __address;   \
-   __pte = ptep_clear_flush(___vma, ___address, __ptep);   \
-   mmu_notifier_invalidate_page(___vma->vm_mm, ___address);\
-   __pte;  \
-})
-
-#define ptep_clear_flush_young_notify(__vma, __address, __ptep)
\
-({ \
-   int __young;\
-   struct vm_area_struct *___vma = __vma;  \
-   unsigned long ___address = __address;   \
-   __young = ptep_clear_flush_young(___vma, ___address, __ptep);   \
-   __young |= mmu_notifier_clear_flush_young(___vma->vm_mm,\
- ___address);  \
-   __young;\
-})
-
 #else /* CONFIG_MMU_NOTIFIER */
 
 static inline void mmu_notifier_release(struct mm_struct *mm)
@@ -169,9 +148,6 @@
 {
 }
 
-#define ptep_clear_flush_young_notify ptep_clear_flush_young
-#define ptep_clear_flush_notify ptep_clear_flush
-
 #endif /* CONFIG_MMU_NOTIFIER */
 
 #endif /* _LINUX_MMU_NOTIFIER_H */
diff --git a/mm/filemap_xip.c b/mm/filemap_xip.c
--- a/mm/filemap_xip.c
+++ b/mm/filemap_xip.c
@@ -194,11 +194,13 @@
if (pte) {
/* Nuke the page table entry. */
flush_cache_page(vma, address, pte_pfn(*pte));
-   pteval = ptep_clear_flush_notify(vma, address, pte);
+   pteval = ptep_clear_flush(vma, address, pte);
page_remove_rmap(page, vma);
dec_mm_counter(mm, file_rss);
BUG_ON(pte_dirty(pteval));
pte_unmap_unlock(pte, ptl);
+   /* must invalidate_page _before_ freeing the page */
+   mmu_notifier_invalidate_page(mm, address);
page_cache_release(page);
}
}
diff --git a/mm/memory.c b/mm/memory.c
--- a/mm/memory.c
+++ b/mm/memory.c
@@ -1626,9 +1626,10 @@
 */
page_table = pte_offset_map_lock(mm, pmd, address,
 &ptl);
-   page_cache_release(old_page);
+   new_page = NULL;
if (!pte_same(*page_table, orig_pte))
goto unlock;
+   page_cache_release(old_page);
 
page_mkwrite = 1;
}
@@ -1644,6 +1645,7 @@
if (ptep_set_access_flags(vma, address, page_table, entry,1))
update_mmu_cache(vma, address, entry);
ret |= VM_FAULT_WRITE;
+   old_page = new_page = NULL;
goto unlock;
}
 
@@ -1688,7 +1690,7 @@
 * seen in the presence of one thread doing SMC and another
 * thread doing COW.
 */
-   ptep_clear_flush_notify(vma, address, page_table);
+   ptep_clear_flush(vma, address, page_table);
set_pte_at(mm, address, page_table, entry);
update_mmu_cache(vma, address, entry);
lru_cache_add_active(new_page);
@@ -1700,12 +1702,18 @@
} else
mem_cgroup_uncharge_page(new_page);
 
-   if (new_page)
+unlock:
+   pte_unmap_unlock(page_table, ptl);
+
+   if (new_page) {
+   if (new_page == old_page)
+   /* cow happened, notify before releasing old_page */
+   mmu_notifier_invalidate_page(mm, address);
page_cache_release(new_page);
+   }
if (old_page)
page_cache_release(old_page);
-unlock:
-   pte_unmap_unlock(page_table, ptl);
+
if (dirty_page) {
if (vma->vm_file)
file_update_time(vma->vm_file);
d