[Xen-devel] [PATCH] VT-d: prevent watchdog timer from kicking in when initializing on systems with huge amounts of memory

["Jan Beulich" <JBeulich@xxxxxxxxxx>]

Process pending soft-IRQs every 4G worth of pages initialized for Dom0
to keep timekeeping happy and prevent the NMI watchdog (when enabled)
from kicking in.

Signed-off-by: Jan Beulich <jbeulich@xxxxxxxxxx>

--- 2010-05-04.orig/xen/drivers/passthrough/vtd/ia64/vtd.c      2010-02-12 
08:48:15.000000000 +0100
+++ 2010-05-04/xen/drivers/passthrough/vtd/ia64/vtd.c   2010-05-10 
10:35:54.000000000 +0200
@@ -19,6 +19,7 @@
  */
 
 #include <xen/sched.h>
+#include <xen/softirq.h>
 #include <xen/domain_page.h>
 #include <xen/iommu.h>
 #include <xen/numa.h>
@@ -110,6 +111,9 @@ static int do_dom0_iommu_mapping(unsigne
             iommu_map_page(d, (pfn*tmp+j), (pfn*tmp+j));
 
        page_addr += PAGE_SIZE;
+
+        if (!(pfn & (0xfffff >> (PAGE_SHIFT - PAGE_SHIFT_4K))))
+            process_pending_softirqs();
     }
     return 0;
 }
--- 2010-05-04.orig/xen/drivers/passthrough/vtd/x86/vtd.c       2010-02-12 
08:48:15.000000000 +0100
+++ 2010-05-04/xen/drivers/passthrough/vtd/x86/vtd.c    2010-05-10 
10:35:06.000000000 +0200
@@ -19,6 +19,7 @@
  */
 
 #include <xen/sched.h>
+#include <xen/softirq.h>
 #include <xen/domain_page.h>
 #include <asm/paging.h>
 #include <xen/iommu.h>
@@ -153,6 +154,9 @@ void iommu_set_dom0_mapping(struct domai
         tmp = 1 << (PAGE_SHIFT - PAGE_SHIFT_4K);
         for ( j = 0; j < tmp; j++ )
             iommu_map_page(d, (i*tmp+j), (i*tmp+j));
+
+        if (!(i & (0xfffff >> (PAGE_SHIFT - PAGE_SHIFT_4K))))
+            process_pending_softirqs();
     }
 }

Attachment: vtd-dom0-mapping-latency.patch
Description: Text document

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