(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. Thanks, Yasuaki Ishimatsu
Thanks, -Toshi+ if (pgd_none(*pgd_ref) && !pgd_none(*pgd)) + pgd_clear(pgd); + } else { + if (pgd_none(*pgd)) + set_pgd(pgd, *pgd_ref); + } + spin_unlock(pgt_lock); }
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