From cb1f76532cf3f37ca48dd54b9b2e1cb0f77bba85 Mon Sep 17 00:00:00 2001
From: Alexander Motin <mav@FreeBSD.org>
Date: Wed, 30 Jan 2008 21:24:10 +0000
Subject: [PATCH] Implement GET_STACK_USAGE() macro to get the current kernel
 thread stack usage. This implemntation made for growing down stack
 organization like i386/amd64 platforms have, but prefers different machine
 dependent version if it is present.

---
 sys/sys/proc.h | 14 ++++++++++++++
 1 file changed, 14 insertions(+)

diff --git a/sys/sys/proc.h b/sys/sys/proc.h
index 13a5d1be06e..98973397edc 100644
--- a/sys/sys/proc.h
+++ b/sys/sys/proc.h
@@ -784,6 +784,20 @@ MALLOC_DECLARE(M_ZOMBIE);
 	curthread->td_pflags &= ~TDP_NOSLEEPING;			\
 } while (0)
 
+/*
+ * Get the current kernel thread stack usage.
+ * Prefer machine dependent version if present.
+ */
+#ifndef GET_STACK_USAGE
+#define GET_STACK_USAGE(total, used) do {				\
+	struct thread	*td = curthread;				\
+	(total) = td->td_kstack_pages * PAGE_SIZE;			\
+	(used) = (char *)td->td_kstack +				\
+	    td->td_kstack_pages * PAGE_SIZE -				\
+	    (char *)&td;						\
+} while (0)
+#endif /* GET_STACK_USAGE */
+
 #define	PIDHASH(pid)	(&pidhashtbl[(pid) & pidhash])
 extern LIST_HEAD(pidhashhead, proc) *pidhashtbl;
 extern u_long pidhash;