Rate limit uvn_flush error during pageout messages. They occur

when a memory mapped file cannot be written to disk, e.g. if the
file system is full.  Too much printf() during kernel relinking
slows down the system boot.
OK deraadt@

diff --git a/sys/uvm/uvm_vnode.c b/sys/uvm/uvm_vnode.c
index cb882f1..8824d62 100644 (file)
--- a/sys/uvm/uvm_vnode.c
+++ b/sys/uvm/uvm_vnode.c
@@ -1,4 +1,4 @@
-/*     $OpenBSD: uvm_vnode.c,v 1.123 2022/04/28 18:12:33 mpi Exp $     */
+/*     $OpenBSD: uvm_vnode.c,v 1.124 2022/05/03 21:20:35 bluhm Exp $   */
 /*     $NetBSD: uvm_vnode.c,v 1.36 2000/11/24 20:34:01 chs Exp $       */
 
 /*
@@ -748,7 +748,7 @@ ReTry:
                         */
 #ifdef DIAGNOSTIC
                        if (flags & PGO_SYNCIO)
-       panic("uvn_flush: PGO_SYNCIO return 'try again' error (impossible)");
+       panic("%s: PGO_SYNCIO return 'try again' error (impossible)", __func__);
 #endif
                        flags |= PGO_SYNCIO;
                        if (flags & PGO_FREE)
@@ -812,14 +812,20 @@ ReTry:
                        } else if (flags & PGO_FREE &&
                            result != VM_PAGER_PEND) {
                                if (result != VM_PAGER_OK) {
-                                       printf("uvn_flush: obj=%p, "
-                                          "offset=0x%llx.  error "
-                                          "during pageout.\n",
-                                           pp->uobject,
-                                           (long long)pp->offset);
-                                       printf("uvn_flush: WARNING: "
-                                           "changes to page may be "
-                                           "lost!\n");
+                                       static struct timeval lasttime;
+                                       static const struct timeval interval =
+                                           { 5, 0 };
+
+                                       if (ratecheck(&lasttime, &interval)) {
+                                               printf("%s: obj=%p, "
+                                                  "offset=0x%llx.  error "
+                                                  "during pageout.\n",
+                                                   __func__, pp->uobject,
+                                                   (long long)pp->offset);
+                                               printf("%s: WARNING: "
+                                                   "changes to page may be "
+                                                   "lost!\n", __func__);
+                                       }
                                        retval = FALSE;
                                }
                                pmap_page_protect(ptmp, PROT_NONE);