x86/mm/cpa: Add missing comment in populate_pdg()

[linux-beck.git] / arch / x86 / mm / pageattr.c

diff --git a/arch/x86/mm/pageattr.c b/arch/x86/mm/pageattr.c
index 2bc6ea153f763793ddda06af489adcc3656b5249..47870a534877c59e0580c74f54095d6db0ccfc83 100644 (file)
--- 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;