upstream: Fix calculation of initial bandwidth limits. Account for

written bytes before the initial timer check so that the first buffer written
is accounted.  Set the threshold after which the timer is checked such that
the limit starts being computed as soon as possible, ie after the second
buffer is written.  This prevents an initial burst of traffic and provides a
more accurate bandwidth limit.  bz#2927, ok djm.

OpenBSD-Commit-ID: ff3ef76e4e43040ec198c2718d5682c36b255cb6
This commit is contained in:
dtucker@openbsd.org 2018-12-07 04:36:09 +00:00 committed by Damien Miller
parent a6a0788cbb
commit 434b587afe
2 changed files with 8 additions and 7 deletions

9
misc.c
View File

@ -1,4 +1,4 @@
/* $OpenBSD: misc.c,v 1.134 2018/11/16 03:26:01 djm Exp $ */
/* $OpenBSD: misc.c,v 1.135 2018/12/07 04:36:09 dtucker Exp $ */
/*
* Copyright (c) 2000 Markus Friedl. All rights reserved.
* Copyright (c) 2005,2006 Damien Miller. All rights reserved.
@ -1335,11 +1335,11 @@ bandwidth_limit_init(struct bwlimit *bw, u_int64_t kbps, size_t buflen)
{
bw->buflen = buflen;
bw->rate = kbps;
bw->thresh = bw->rate;
bw->thresh = buflen;
bw->lamt = 0;
timerclear(&bw->bwstart);
timerclear(&bw->bwend);
}
}
/* Callback from read/write loop to insert bandwidth-limiting delays */
void
@ -1348,12 +1348,11 @@ bandwidth_limit(struct bwlimit *bw, size_t read_len)
u_int64_t waitlen;
struct timespec ts, rm;
bw->lamt += read_len;
if (!timerisset(&bw->bwstart)) {
monotime_tv(&bw->bwstart);
return;
}
bw->lamt += read_len;
if (bw->lamt < bw->thresh)
return;

6
misc.h
View File

@ -1,4 +1,4 @@
/* $OpenBSD: misc.h,v 1.76 2018/11/16 03:26:01 djm Exp $ */
/* $OpenBSD: misc.h,v 1.77 2018/12/07 04:36:09 dtucker Exp $ */
/*
* Author: Tatu Ylonen <ylo@cs.hut.fi>
@ -135,7 +135,9 @@ void put_u32_le(void *, u_int32_t)
struct bwlimit {
size_t buflen;
u_int64_t rate, thresh, lamt;
u_int64_t rate; /* desired rate in kbit/s */
u_int64_t thresh; /* threshold after which we'll check timers */
u_int64_t lamt; /* amount written in last timer interval */
struct timeval bwstart, bwend;
};