Attachment 144099 Details for Bug 220328 – current proposed patch - (verified to fix the issue on x86_64)

[patch] current proposed patch - (verified to fix the issue on x86_64)

page_mkclean-fixup.patch (text/plain), 1.54 KB, created by Peter Zijlstra on 2006-12-20 14:12:51 UTC

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Creator: Peter Zijlstra

Created: 2006-12-20 14:12:51 UTC

Size: 1.54 KB

patch

obsolete

>
>page_mkclean_one() fix
>
>it had several issues:
> - it failed to flush the cache
> - it failed to flush the tlb
> - it failed to do s390 (s390 guys, please verify this is now correct)
>
>Also, clear in a loop to ensure SMP safeness as suggested by Arjan.
>
>Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
>---
> mm/rmap.c |   23 +++++++++++++----------
> 1 file changed, 13 insertions(+), 10 deletions(-)
>
>Index: linux-2.6/mm/rmap.c
>===================================================================
>--- linux-2.6.orig/mm/rmap.c
>+++ linux-2.6/mm/rmap.c
>@@ -432,7 +432,7 @@ static int page_mkclean_one(struct page 
> {
> 	struct mm_struct *mm = vma->vm_mm;
> 	unsigned long address;
>-	pte_t *pte, entry;
>+	pte_t *pte;
> 	spinlock_t *ptl;
> 	int ret = 0;
> 
>@@ -444,17 +444,20 @@ static int page_mkclean_one(struct page 
> 	if (!pte)
> 		goto out;
> 
>-	if (!pte_dirty(*pte) && !pte_write(*pte))
>-		goto unlock;
>+	while (pte_dirty(*pte) || pte_write(*pte)) {
>+		pte_t entry;
> 
>-	entry = ptep_get_and_clear(mm, address, pte);
>-	entry = pte_mkclean(entry);
>-	entry = pte_wrprotect(entry);
>-	ptep_establish(vma, address, pte, entry);
>-	lazy_mmu_prot_update(entry);
>-	ret = 1;
>+		flush_cache_page(vma, address, pte_pfn(*pte));
>+		entry = ptep_get_and_clear(mm, address, pte);
>+		flush_tlb_page(vma, address);
>+		(void)page_test_and_clear_dirty(page); /* do the s390 thing */
>+		entry = pte_wrprotect(entry);
>+		entry = pte_mkclean(entry);
>+		set_pte_at(vma, address, pte, entry);
>+		lazy_mmu_prot_update(entry);
>+		ret = 1;
>+	}
> 
>-unlock:
> 	pte_unmap_unlock(pte, ptl);
> out:
> 	return ret;

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Attachments on bug 220328: 144099