[Xen-devel] [PATCH 07/16] Bump EVTCHNS_PER_BUCKET to 512

[Wei Liu <wei.liu2@xxxxxxxxxx>]

For 64 bit build and 3-level event channel and the original value of
EVTCHNS_PER_BUCKET (128), the space needed to accommodate d->evtchn
would be 4 pages (PAGE_SIZE = 4096). Given that not every domain needs
3-level event channel, this leads to waste of memory. Also we've
restricted d->evtchn to one page, if we move to 3-level event channel,
Xen cannot build.

Having EVTCHN_PER_BUCKETS to be 512 can occupy exact one page.

Signed-off-by: Wei Liu <wei.liu2@xxxxxxxxxx>
---
 xen/include/public/xen.h |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/xen/include/public/xen.h b/xen/include/public/xen.h
index 6132682..4a354e1 100644
--- a/xen/include/public/xen.h
+++ b/xen/include/public/xen.h
@@ -557,7 +557,7 @@ DEFINE_XEN_GUEST_HANDLE(multicall_entry_t);
  *  1024 if a long is 32 bits; 4096 if a long is 64 bits.
  */
 #define NR_EVENT_CHANNELS (sizeof(unsigned long) * sizeof(unsigned long) * 64)
-#define EVTCHNS_PER_BUCKET 128
+#define EVTCHNS_PER_BUCKET 512
 #define NR_EVTCHN_BUCKETS  (NR_EVENT_CHANNELS / EVTCHNS_PER_BUCKET)
 
 struct vcpu_time_info {
-- 
1.7.10.4


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