From mboxrd@z Thu Jan  1 00:00:00 1970
From: Olaf Hering <olaf@aepfle.de>
Subject: Re: [PATCH] mem_event: use wait queue when ring is full
Date: Mon, 5 Dec 2011 12:33:16 +0100
Message-ID: <20111205113316.GA29024@aepfle.de>
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On Mon, Dec 05, Olaf Hering wrote:

> Wakeup will take the number of free slots into account.

This is not entirely tree unless this additional change is applied:

diff -r cd163bcd0f06 xen/arch/x86/mm/mem_event.c
--- a/xen/arch/x86/mm/mem_event.c
+++ b/xen/arch/x86/mm/mem_event.c
@@ -235,6 +235,7 @@ void mem_event_wake_requesters(struct me
     mem_event_ring_lock(med);
 
     free_req = RING_FREE_REQUESTS(&med->front_ring);
+    free_req -= med->foreign_producers;
     if ( free_req )
         wake_up_nr(&med->wq, free_req);
 

And perhaps the wake_up should be done outside the ring lock?

Olaf