Hello Jiandi,
On 08/06/2016 07:54, Jiandi An wrote:
As the number of CPUs supported on the system grows, number of
GIC redistributors and mmio handlers increase. We need to increase
MAX_RDIST_COUNT and MAX_IO_HANDLER which makes size of struct domain
bigger than one page.
With this change, the memory footprint of a domain will increase by 4KB
even if they don't use GICv3.
What is the size of the domain structure with your patch?
I would much prefer to allocate separate memory for the vGIC
redistributors if it takes too much space.
Remove the BUILD_BUG_ON check for if size of struct domain is greater
than PAGE_SIZE. And allocate xenheap pages according to the order of
the size of struct domain.
Signed-off-by: Jiandi An <anjia...@codeaurora.org>
---
xen/arch/arm/domain.c | 5 +++--
xen/include/asm-arm/gic.h | 2 +-
xen/include/asm-arm/mmio.h | 2 +-
3 files changed, 5 insertions(+), 4 deletions(-)
diff --git a/xen/arch/arm/domain.c b/xen/arch/arm/domain.c
index 1365b4a..7f69236 100644
--- a/xen/arch/arm/domain.c
+++ b/xen/arch/arm/domain.c
@@ -438,8 +438,9 @@ void startup_cpu_idle_loop(void)
struct domain *alloc_domain_struct(void)
{
struct domain *d;
- BUILD_BUG_ON(sizeof(*d) > PAGE_SIZE);
- d = alloc_xenheap_pages(0, 0);
+ unsigned int order = get_order_from_bytes(sizeof(*d));
+
+ d = alloc_xenheap_pages(order, 0);
if ( d == NULL )
return NULL;
diff --git a/xen/include/asm-arm/gic.h b/xen/include/asm-arm/gic.h
index cd97bb2..8165de6 100644
--- a/xen/include/asm-arm/gic.h
+++ b/xen/include/asm-arm/gic.h
@@ -20,7 +20,7 @@
#define NR_GIC_LOCAL_IRQS NR_LOCAL_IRQS
#define NR_GIC_SGI 16
-#define MAX_RDIST_COUNT 4
+#define MAX_RDIST_COUNT 64
How many re-distributor regions does your platform have?
#define GICD_CTLR (0x000)
#define GICD_TYPER (0x004)
diff --git a/xen/include/asm-arm/mmio.h b/xen/include/asm-arm/mmio.h
index da1cc2e..798d373 100644
--- a/xen/include/asm-arm/mmio.h
+++ b/xen/include/asm-arm/mmio.h
@@ -23,7 +23,7 @@
#include <asm/processor.h>
#include <asm/regs.h>
-#define MAX_IO_HANDLER 16
+#define MAX_IO_HANDLER 32
The vGICv3 driver is allocating one I/O handler per redistributor
region. So if you bump MAX_RDIST_COUNT to 64, you at least need to bump
MAX_IO_HANDLER to 80.
However, I am bit concerned of the performance impact in long-term
because the lookup is linear.
Regards,
--
Julien Grall
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