From 9b0ed89172efec1d9f214d173ad6046f10f6b742 Mon Sep 17 00:00:00 2001 From: Stephen Hemminger Date: Tue, 14 Nov 2017 11:27:02 -0800 Subject: [PATCH] netem: remove unnecessary 64 bit modulus Fix compilation on 32 bit platforms (where doing modulus operation with 64 bit requires extra glibc functions) by truncation. The jitter for table distribution is limited to a 32 bit value because random numbers are scaled as 32 bit value. Also fix some whitespace. Fixes: 99803171ef04 ("netem: add uapi to express delay and jitter in nanoseconds") Reported-by: Randy Dunlap Signed-off-by: Stephen Hemminger Signed-off-by: David S. Miller --- net/sched/sch_netem.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) diff --git a/net/sched/sch_netem.c b/net/sched/sch_netem.c index 644323d6081c..dd70924cbcdf 100644 --- a/net/sched/sch_netem.c +++ b/net/sched/sch_netem.c @@ -312,9 +312,9 @@ static bool loss_event(struct netem_sched_data *q) * std deviation sigma. Uses table lookup to approximate the desired * distribution, and a uniformly-distributed pseudo-random source. */ -static s64 tabledist(s64 mu, s64 sigma, +static s64 tabledist(s64 mu, s32 sigma, struct crndstate *state, - const struct disttable *dist) + const struct disttable *dist) { s64 x; long t; @@ -327,7 +327,7 @@ static s64 tabledist(s64 mu, s64 sigma, /* default uniform distribution */ if (dist == NULL) - return (rnd % (2*sigma)) - sigma + mu; + return (rnd % (2 * sigma)) - sigma + mu; t = dist->table[rnd % dist->size]; x = (sigma % NETEM_DIST_SCALE) * t;