Module Name: src
Committed By: pooka
Date: Tue Nov 18 16:57:52 UTC 2014
Modified Files:
src/sys/rump/librump/rumpkern: emul.c
Log Message:
delay() can't use rumpuser_clock_sleep(), because that may unschedule().
Instead, busyloop with calls to rumpuser_clock_gettime(). Fixing delay()
properly should addressed in hypercall rev.18 by introducing a nowrap
variant/flag for rumpuser_clock_sleep().
To generate a diff of this commit:
cvs rdiff -u -r1.167 -r1.168 src/sys/rump/librump/rumpkern/emul.c
Please note that diffs are not public domain; they are subject to the
copyright notices on the relevant files.
Modified files:
Index: src/sys/rump/librump/rumpkern/emul.c
diff -u src/sys/rump/librump/rumpkern/emul.c:1.167 src/sys/rump/librump/rumpkern/emul.c:1.168
--- src/sys/rump/librump/rumpkern/emul.c:1.167 Tue Nov 18 13:05:33 2014
+++ src/sys/rump/librump/rumpkern/emul.c Tue Nov 18 16:57:52 2014
@@ -1,4 +1,4 @@
-/* $NetBSD: emul.c,v 1.167 2014/11/18 13:05:33 pooka Exp $ */
+/* $NetBSD: emul.c,v 1.168 2014/11/18 16:57:52 pooka Exp $ */
/*
* Copyright (c) 2007-2011 Antti Kantee. All Rights Reserved.
@@ -26,7 +26,7 @@
*/
#include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: emul.c,v 1.167 2014/11/18 13:05:33 pooka Exp $");
+__KERNEL_RCSID(0, "$NetBSD: emul.c,v 1.168 2014/11/18 16:57:52 pooka Exp $");
#include <sys/param.h>
#include <sys/null.h>
@@ -234,11 +234,27 @@ module_init_md(void)
/*
* Try to emulate all the MD definitions of DELAY() / delay().
* Would be nice to fix the #defines in MD headers, but this quicker.
+ *
+ * XXX: we'd need a rumpuser_clock_sleep_nowrap() here. Since we
+ * don't have it in the current hypercall revision, busyloop.
+ * Note that rather than calibrate a loop delay and work with that,
+ * get call gettime (which does not block) in a loop to make sure
+ * we didn't get virtual ghosttime. That might be slightly inaccurate
+ * for very small delays ...
+ *
+ * The other option would be to run a thread in the hypervisor which
+ * sleeps for us and we can wait for it using rumpuser_cv_wait_nowrap()
+ * Probably too fussy. Better just wait for hypercall rev 18 ;)
*/
static void
rump_delay(unsigned int us)
{
- uint64_t sec, nsec;
+ struct timespec target, tmp;
+ uint64_t sec, sec_ini, sec_now;
+ long nsec, nsec_ini, nsec_now;
+ int loops;
+
+ rumpuser_clock_gettime(RUMPUSER_CLOCK_ABSMONO, &sec_ini, &nsec_ini);
#ifdef __mac68k__
sec = us / 1000;
@@ -248,10 +264,27 @@ rump_delay(unsigned int us)
nsec = (us % 1000000) * 1000;
#endif
+ target.tv_sec = sec_ini;
+ tmp.tv_sec = sec;
+ target.tv_nsec = nsec_ini;
+ tmp.tv_nsec = nsec;
+ timespecadd(&target, &tmp, &target);
+
if (__predict_false(sec != 0))
printf("WARNING: over 1s delay\n");
- rumpuser_clock_sleep(RUMPUSER_CLOCK_RELWALL, sec, nsec);
+ for (loops = 0; loops < 1000*1000*100; loops++) {
+ struct timespec cur;
+
+ rumpuser_clock_gettime(RUMPUSER_CLOCK_ABSMONO,
+ &sec_now, &nsec_now);
+ cur.tv_sec = sec_now;
+ cur.tv_nsec = nsec_now;
+ if (timespeccmp(&cur, &target, >=)) {
+ return;
+ }
+ }
+ printf("WARNING: DELAY ESCAPED\n");
}
void (*delay_func)(unsigned int) = rump_delay;
__strong_alias(delay,rump_delay);
