Oops. Missed one line in the last patch....
Roger.
--
** R.E.Wolff@BitWizard.nl ** http://www.BitWizard.nl/ ** +31-15-2600998 **
*-- BitWizard writes Linux device drivers for any device you may have! --*
* The Worlds Ecosystem is a stable system. Stable systems may experience *
* excursions from the stable situation. We are currently in such an *
* excursion: The stable situation does not include humans. ***************
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diff -ur rsync-2.5.6.orig/io.c rsync-2.5.6/io.c
--- rsync-2.5.6.orig/io.c Thu Apr 11 04:11:50 2002
+++ rsync-2.5.6/io.c Tue Jun 17 23:43:49 2003
@@ -416,10 +416,19 @@
* use a bit less bandwidth than specified, because it doesn't make up
* for slow periods. But arguably this is a feature. In addition, we
* ought to take the time used to write the data into account.
+ *
+ * During some phases of big transfers (file XXX is uptodate) this is
+ * called with a small bytes_written every time. As the kernel has to
+ * round small waits up to guarantee that we actually wait at least
+ * the requested number of microseconds, this can become grossly
+ * inaccurate. We therefore keep a cumulating number of microseconds
+ * to wait, and only actually perform the sleep when the rouding
+ * becomes insignificant. (less than 10%) -- REW.
**/
static void sleep_for_bwlimit(int bytes_written)
{
struct timeval tv;
+ static int time_to_sleep = 0;
if (!bwlimit)
return;
@@ -427,9 +436,13 @@
assert(bytes_written > 0);
assert(bwlimit > 0);
- tv.tv_usec = bytes_written * 1000 / bwlimit;
- tv.tv_sec = tv.tv_usec / 1000000;
- tv.tv_usec = tv.tv_usec % 1000000;
+ time_to_sleep += bytes_written * 1000 / bwlimit;
+
+ if (time_to_sleep < 100000) return;
+
+ tv.tv_sec = time_to_sleep / 1000000;
+ tv.tv_usec = time_to_sleep % 1000000;
+ time_to_sleep = 0;
select(0, NULL, NULL, NULL, &tv);
}
On 17 Jun 2003, Rogier Wolff <R.E.Wolff@BitWizard.nl> wrote:> > Oops. Missed one line in the last patch....Thankyou. That looks good. If we're going to make this more accurate it might be worthwhile to actually look at how long we really did sleep for, and use that to adjust time_to_sleep rather than resetting to zero. Also I'd prefer the variable be called micros_to_sleep or us_to_sleep. Small point I know.> diff -ur rsync-2.5.6.orig/io.c rsync-2.5.6/io.c > +++ rsync-2.5.6/io.c Tue Jun 17 23:43:49 2003 > @@ -416,10 +416,19 @@ > * use a bit less bandwidth than specified, because it doesn't make up > * for slow periods. But arguably this is a feature. In addition, we > * ought to take the time used to write the data into account. > + * > + * During some phases of big transfers (file XXX is uptodate) this is > + * called with a small bytes_written every time. As the kernel has to > + * round small waits up to guarantee that we actually wait at least > + * the requested number of microseconds, this can become grossly > + * inaccurate. We therefore keep a cumulating number of microseconds > + * to wait, and only actually perform the sleep when the rouding > + * becomes insignificant. (less than 10%) -- REW. > **/ > static void sleep_for_bwlimit(int bytes_written) > { > struct timeval tv; > + static int time_to_sleep = 0; > > if (!bwlimit) > return; > @@ -427,9 +436,13 @@ > assert(bytes_written > 0); > assert(bwlimit > 0); > > - tv.tv_usec = bytes_written * 1000 / bwlimit; > - tv.tv_sec = tv.tv_usec / 1000000; > - tv.tv_usec = tv.tv_usec % 1000000; > + time_to_sleep += bytes_written * 1000 / bwlimit; > + > + if (time_to_sleep < 100000) return; > + > + tv.tv_sec = time_to_sleep / 1000000; > + tv.tv_usec = time_to_sleep % 1000000; > + time_to_sleep = 0; > > select(0, NULL, NULL, NULL, &tv); > }-- Martin