In commit 21cbc2822aa1 ("x86/mm/cpa: Unbreak populate_pgd(): stop
trying to deallocate failed PUDs"), I intended to add this comment,
but I failed at using git.
Signed-off-by: Andy Lutomirski <l...@kernel.org>
---
arch/x86/mm/pageattr.c | 5 +++++
1 file changed, 5 insertions(+)
diff --git a/arch/x86/mm/pageattr.c b/arch/x86/mm/pageattr.c
index 2bc6ea153f76..47870a534877 100644
--- a/arch/x86/mm/pageattr.c
+++ b/arch/x86/mm/pageattr.c
@@ -1091,6 +1091,11 @@ static int populate_pgd(struct cpa_data *cpa, unsigned
long addr)
ret = populate_pud(cpa, addr, pgd_entry, pgprot);
if (ret < 0) {
+ /*
+ * Leave the PUD page in place in case some other CPU or thread
+ * already found it, but remove any useless entries we just
+ * added to it.
+ */
unmap_pud_range(pgd_entry, addr,
addr + (cpa->numpages << PAGE_SHIFT));
return ret;
--
2.7.4
