xen/spinlock: Document the xen_nopvspin parameter.

Which disables in the ticketlock slowpath the Xen PV optimization's. Useful for diagnosing issues and comparing benchmarks in over-commit CPU scenarios. Signed-off-by: Konrad Rzeszutek Wilk <[email protected]>
ambv · Sep 25, 2013 · 15a3eac · 15a3eac
1 parent 0160676
commit 15a3eac
Showing 1 changed file with 4 additions and 0 deletions.
diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt
@@ -3412,6 +3412,10 @@ bytes respectively. Such letter suffixes can also be entirely omitted.
 				the unplug protocol
 			never -- do not unplug even if version check succeeds
 
+	xen_nopvspin	[X86,XEN]
+			Disables the ticketlock slowpath using Xen PV
+			optimizations.
+
 	xirc2ps_cs=	[NET,PCMCIA]
 			Format:
 			<irq>,<irq_mask>,<io>,<full_duplex>,<do_sound>,<lockup_hack>[,<irq2>[,<irq3>[,<irq4>]]]