[PATCH] [22/31] CPA: Only queue actually unused page table pages for freeing

Andi Kleen
2008-01-14T22:24:42Z

With the separate data structure added for flush earlier it is only
needed to call save_page() now on pte pages that have been already reverted.

Also move all freeing checks into the caller.

Signed-off-by: Andi Kleen <ak@suse.de>

---
arch/x86/mm/pageattr_32.c | 4 +---
arch/x86/mm/pageattr_64.c | 7 +++----
2 files changed, 4 insertions(+), 7 deletions(-)

Index: linux/arch/x86/mm/pageattr_32.c
===================================================================
--- linux.orig/arch/x86/mm/pageattr_32.c
+++ linux/arch/x86/mm/pageattr_32.c
@@ -270,9 +270,9 @@ __change_page_attr(struct page *page, pg
* replace it with a largepage.
*/

- save_page(kpte_page);
if (!PageReserved(kpte_page)) {
if (cpu_has_pse && (page_private(kpte_page) == 0)) {
+ save_page(kpte_page);
paravirt_release_pt(page_to_pfn(kpte_page));
revert_page(kpte_page, address);
}
@@ -333,8 +333,6 @@ void global_flush_tlb(void)
list_for_each_entry_safe(pg, next, &free_pages, lru) {
list_del(&pg->lru);
ClearPageDeferred(pg);
- if (PageReserved(pg) || !cpu_has_pse || page_private(pg) != 0)
- continue;
ClearPagePrivate(pg);
__free_page(pg);
}
Index: linux/arch/x86/mm/pageattr_64.c
===================================================================
--- linux.orig/arch/x86/mm/pageattr_64.c
+++ linux/arch/x86/mm/pageattr_64.c
@@ -246,9 +246,10 @@ __change_page_attr(unsigned long address
/* on x86-64 the direct mapping set at boot is not using 4k pages */
BUG_ON(PageReserved(kpte_page));

- save_page(kpte_page);
- if (page_private(kpte_page) == 0)
+ if (page_private(kpte_page) == 0) {
+ save_page(kpte_page);
revert_page(address, ref_prot);
+ }
return 0;
}

@@ -336,8 +337,6 @@ void global_flush_tlb(void)
list_for_each_entry_safe(pg, next, &free_pages, lru) {
list_del(&pg->lru);
ClearPageDeferred(pg);
- if (page_private(pg) != 0)
- continue;
ClearPagePrivate(pg);
__free_page(pg);
}