From 55920d31f1e3fea06702c74271dd56c4fc9b70ca Mon Sep 17 00:00:00 2001 From: Andy Lutomirski Date: Sat, 23 Jul 2016 09:59:28 -0700 Subject: [PATCH] x86/mm/cpa: Add missing comment in populate_pdg() 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 Cc: Borislav Petkov Cc: Linus Torvalds Cc: Peter Zijlstra Cc: Thomas Gleixner Link: http://lkml.kernel.org/r/242baf8612394f4e31216f96d13c4d2e9b90d1b7.1469293159.git.luto@kernel.org Signed-off-by: Ingo Molnar --- 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; -- 2.20.1