[src/netbsd-3-0]: src/sys/arch/xen/xen Apply patch (requested by jld in ticke...

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

details:   https://anonhg.NetBSD.org/src/rev/0875cacc56ad
branches:  netbsd-3-0
changeset: 579187:0875cacc56ad
user:      tron <tron%NetBSD.org@localhost>
date:      Thu Apr 06 12:43:34 2006 +0000

description:
Apply patch (requested by jld in ticket #1240):
Avoid panics under high system load. This fixes PR port-xen/33110.

diffstat:

 sys/arch/xen/xen/xbd.c |  19 ++++++++++++++-----
 1 files changed, 14 insertions(+), 5 deletions(-)

diffs (62 lines):

diff -r 4631800177ae -r 0875cacc56ad sys/arch/xen/xen/xbd.c
--- a/sys/arch/xen/xen/xbd.c    Sun Apr 02 18:08:44 2006 +0000
+++ b/sys/arch/xen/xen/xbd.c    Thu Apr 06 12:43:34 2006 +0000
@@ -1,4 +1,4 @@
-/* $NetBSD: xbd.c,v 1.14.2.5 2005/04/28 10:28:42 tron Exp $ */
+/* $NetBSD: xbd.c,v 1.14.2.5.2.1 2006/04/06 12:43:34 tron Exp $ */
 
 /*
  *
@@ -33,7 +33,7 @@
 
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: xbd.c,v 1.14.2.5 2005/04/28 10:28:42 tron Exp $");
+__KERNEL_RCSID(0, "$NetBSD: xbd.c,v 1.14.2.5.2.1 2006/04/06 12:43:34 tron Exp $");
 
 #include "xbd.h"
 #include "rnd.h"
@@ -1140,7 +1140,7 @@
        return dk_size(xs->sc_di, &xs->sc_dksc, dev);
 }
 
-static void
+static int
 map_align(struct xbdreq *xr)
 {
        int s;
@@ -1148,8 +1148,10 @@
        s = splvm();
        xr->xr_aligned = uvm_km_kmemalloc1(kmem_map, NULL,
            xr->xr_bqueue, XEN_BSIZE, UVM_UNKNOWN_OFFSET,
-           0/*  UVM_KMF_NOWAIT */);
+           UVM_KMF_NOWAIT);
        splx(s);
+       if (xr->xr_aligned == 0)
+               return 0;
        DPRINTF(XBDB_IO, ("map_align(%p): bp %p addr %p align 0x%08lx "
            "size 0x%04lx\n", xr, xr->xr_bp, xr->xr_bp->b_data,
            xr->xr_aligned, xr->xr_bqueue));
@@ -1157,6 +1159,7 @@
        if ((xr->xr_bp->b_flags & B_READ) == 0)
                memcpy((void *)xr->xr_aligned, xr->xr_bp->b_data,
                    xr->xr_bqueue);
+       return 1;
 }
 
 static void
@@ -1361,7 +1364,13 @@
        pxr->xr_sc = xs;
 
        if (pxr->xr_data & (XEN_BSIZE - 1))
-               map_align(pxr);
+               if (!map_align(pxr)) { /* No memory; try later. */
+                       DPRINTF(XBDB_IO, ("xbdstart: map_align failed\n"));
+                       ret = -1;
+                       disk_unbusy(&dksc->sc_dkdev, 0, bp->b_flags & B_READ);
+                       PUT_XBDREQ(pxr);
+                       goto out;
+               }
 
        fill_ring(pxr);