(2014/06/25 0:12), Toshi Kani wrote:
On Tue, 2014-06-24 at 09:31 +0900, Yasuaki Ishimatsu wrote:
(2014/06/21 3:30), Toshi Kani wrote:
On Wed, 2014-06-18 at 15:38 +0900, Yasuaki Ishimatsu wrote:
:
@@ -186,7 +186,12 @@ void sync_global_pgds(unsigned long start, unsigned long end)
const pgd_t *pgd_ref = pgd_offset_k(address);
struct page *page;
- if (pgd_none(*pgd_ref))
+ /*
+ * When it is called after memory hot remove, pgd_none()
+ * returns true. In this case (removed == 1), we must clear
+ * the PGD entries in the local PGD level page.
+ */
+ if (pgd_none(*pgd_ref) && !removed)
continue;
spin_lock(&pgd_lock);
@@ -199,12 +204,18 @@ void sync_global_pgds(unsigned long start, unsigned long end)
pgt_lock = &pgd_page_get_mm(page)->page_table_lock;
spin_lock(pgt_lock);
- if (pgd_none(*pgd))
- set_pgd(pgd, *pgd_ref);
- else
+ if (!pgd_none(*pgd_ref) && !pgd_none(*pgd))
BUG_ON(pgd_page_vaddr(*pgd)
!= pgd_page_vaddr(*pgd_ref));
+ if (removed) {
Shouldn't this condition be "else if"?
The first if sentence checks whether PGDs hit to BUG_ON. And the second
if sentence checks whether the function was called after hot-removing memory.
I think that the first if sentence and the second if sentence check different
things. So I think the condition should be "if" sentence.
When the 1st if sentence is true, you have no additional operation and
the 2nd if sentence is redundant. But I agree that the two ifs can be
logically separated. So:
Acked-by: Toshi Kani <toshi.kani@xxxxxx>
Thank you for your review.
Thanks,
Yasuaki Ishimatsu
Thanks,
-Toshi
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