xenpaging: no poll timeout while page-out is in progress

The main loop calls xenpaging_wait_for_event_or_timeout() unconditionally
before doing any work. This function calls poll() with a timeout of 100ms. As
a result the page-out process is very slow due to the delay in poll().

Call poll() without timeout so that it returns immediately until the page-out
is done. Page-out is done when either the policy finds no more pages to
nominate or when the requested number of pages is reached.

The condition is cleared when a watch event arrives, so that processing the
new target is not delayed once again by poll().

v2:
- no poll timeout also when large number of evicts is pending

Signed-off-by: Olaf Hering <olaf@aepfle.de>
Committed-by: Ian Jackson <ian.jackson.citrix.com>

1 files changed, 1 insertions, 0 deletions

diff --git a/tools/xenpaging/xenpaging.h b/tools/xenpaging/xenpaging.h
index 545f2d3626..abc9f89ec4 100644
--- a/tools/xenpaging/xenpaging.h
+++ b/tools/xenpaging/xenpaging.h
@@ -55,6 +55,7 @@ struct xenpaging {
     int num_paged_out;
     int target_tot_pages;
     int policy_mru_size;
+    int use_poll_timeout;
     int debug;
     unsigned long pagein_queue[XENPAGING_PAGEIN_QUEUE_SIZE];
 };