[src/trunk]: src/sys/arch/sparc/sparc in pgt_page_alloc(), wait and retry the...

[chs <chs%NetBSD.org@localhost>]

details:   https://anonhg.NetBSD.org/src/rev/db3008ab87b5
branches:  trunk
changeset: 949372:db3008ab87b5
user:      chs <chs%NetBSD.org@localhost>
date:      Mon Jan 11 06:12:43 2021 +0000

description:
in pgt_page_alloc(), wait and retry the page allocation if PR_WAITOK.
fixes PR 55895.

diffstat:

 sys/arch/sparc/sparc/pmap.c |  15 +++++++++++----
 1 files changed, 11 insertions(+), 4 deletions(-)

diffs (41 lines):

diff -r e195ada871cf -r db3008ab87b5 sys/arch/sparc/sparc/pmap.c
--- a/sys/arch/sparc/sparc/pmap.c       Mon Jan 11 02:18:40 2021 +0000
+++ b/sys/arch/sparc/sparc/pmap.c       Mon Jan 11 06:12:43 2021 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: pmap.c,v 1.369 2020/12/09 11:35:44 uwe Exp $ */
+/*     $NetBSD: pmap.c,v 1.370 2021/01/11 06:12:43 chs Exp $ */
 
 /*
  * Copyright (c) 1996
@@ -56,7 +56,7 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: pmap.c,v 1.369 2020/12/09 11:35:44 uwe Exp $");
+__KERNEL_RCSID(0, "$NetBSD: pmap.c,v 1.370 2021/01/11 06:12:43 chs Exp $");
 
 #include "opt_ddb.h"
 #include "opt_kgdb.h"
@@ -907,13 +907,20 @@
        paddr_t pa;
 
        /* Allocate a page of physical memory */
-       if ((pg = uvm_pagealloc(NULL, 0, NULL, 0)) == NULL)
-               return (NULL);
+       while ((pg = uvm_pagealloc(NULL, 0, NULL, 0)) == NULL &&
+              (flags & PR_WAITOK) != 0) {
+               uvm_wait("pgtpg");
+       }
+       if (pg == NULL) {
+               KASSERT((flags & PR_WAITOK) == 0);
+               return NULL;
+       }
 
        /* Allocate virtual memory */
        va = uvm_km_alloc(kernel_map, PAGE_SIZE, 0, UVM_KMF_VAONLY |
                ((flags & PR_WAITOK) ? 0 : UVM_KMF_NOWAIT | UVM_KMF_TRYLOCK));
        if (va == 0) {
+               KASSERT((flags & PR_WAITOK) == 0);
                uvm_pagefree(pg);
                return (NULL);
        }