Re: PHP performance on Xen domU with mulitple vcpu

[Taylor R Campbell <riastradh%NetBSD.org@localhost>]

> Date: Sun, 6 Apr 2025 00:03:25 +0000
> From: Emmanuel Dreyfus <manu%netbsd.org@localhost>
> 
> I was not able to load dtrace:
> kobj_checksyms, 1013: [dtrace]: linker error: symbol `dtrace_smap_enable' not found

Try the attached patch?

(It would be good to have dtrace working, though it might not help in
this case -- all of the dtrace probes, except sdt:xen:hardclock:jump,
have corresponding event counters which would have gone up if the
probes would have fired.)

--- a/sys/arch/amd64/amd64/cpufunc.S
+++ b/sys/arch/amd64/amd64/cpufunc.S
@@ -83,7 +83,17 @@
 END(xen_mb)
 #endif	/* XEN */
 
-#ifndef XENPV
+#ifdef XENPV
+#ifdef KDTRACE_HOOKS
+ENTRY(dtrace_smap_enable)
+	ret
+END(dtrace_smap_enable)
+
+ENTRY(dtrace_smap_disable)
+	ret
+END(dtrace_smap_disable)
+#endif
+#else
 ENTRY(invlpg)
 #ifdef SVS
 	movb	_C_LABEL(svs_pcid),%al