PERFORCE change 126860 for review
John Birrell
jb at FreeBSD.org
Thu Sep 27 03:15:48 PDT 2007
http://perforce.freebsd.org/chv.cgi?CH=126860
Change 126860 by jb at jb_freebsd1 on 2007/09/27 10:14:48
Hi-ho, hi-ho, it's obfuscate we go.
In mi_startup, get the traditional size of 'struct thread',
including the 'struct td_sched' using sched_sizeof_thread().
That's the offset to the start of the DTrace-specific thread
data.
The overall size of that is saved in kdtrace_thread_size
which is used in each call to uma_zcreate() when a thread
is allocated.
Affected files ...
.. //depot/projects/dtrace/src/sys/kern/init_main.c#14 edit
Differences ...
==== //depot/projects/dtrace/src/sys/kern/init_main.c#14 (text+ko) ====
@@ -60,6 +60,7 @@
#include <sys/syscallsubr.h>
#include <sys/sysctl.h>
#include <sys/proc.h>
+#include <sys/kdtrace.h>
#include <sys/resourcevar.h>
#include <sys/systm.h>
#include <sys/signalvar.h>
@@ -98,6 +99,15 @@
struct vmspace vmspace0;
struct proc *initproc;
+/* DTrace data for the primary thread in proc0. */
+char kdtrace_thread0[KDTRACE_THREAD_SIZE];
+
+/* Offset from 'struct thread *' to the opaque DTrace fields. */
+int kdtrace_thread_offset;
+
+/* Overall per-thread allocation size. */
+int kdtrace_thread_size;
+
int boothowto = 0; /* initialized so that it can be patched */
SYSCTL_INT(_debug, OID_AUTO, boothowto, CTLFLAG_RD, &boothowto, 0, "");
int bootverbose;
@@ -177,6 +187,18 @@
int verbose;
#endif
+ /* Get the size of 'struct thread' plus 'struct td_sched' */
+ kdtrace_thread_offset = sched_sizeof_thread();
+
+ /*
+ * Allow for the DTrace-specific thread data after
+ * struct td_sched. This space is allocated opaquely to
+ * avoid license issues. The value of KDTRACE_THREAD_SIZE
+ * set in sys/proc.h must be larger than that required by
+ * the DTrace kernel modules.
+ */
+ kdtrace_thread_size = kdtrace_thread_offset + KDTRACE_THREAD_SIZE;
+
if (sysinit == NULL) {
sysinit = SET_BEGIN(sysinit_set);
sysinit_end = SET_LIMIT(sysinit_set);
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