From: Yousuk Seung Date: Mon, 27 Aug 2018 02:42:30 +0000 (-0700) Subject: q_netem: slotting with non-uniform distribution X-Git-Tag: v4.20.0~111^2 X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=588dd51e2c77791c916d3785313928ad6a0fc89c;p=thirdparty%2Fiproute2.git q_netem: slotting with non-uniform distribution Extend slotting with support for non-uniform distributions. This is similar to netem's non-uniform distribution delay feature. Syntax: slot distribution DISTRIBUTION DELAY JITTER [packets MAX_PACKETS] \ [bytes MAX_BYTES] The syntax and use of the distribution table is the same as in the non-uniform distribution delay feature. A file DISTRIBUTION must be present in TC_LIB_DIR (e.g. /usr/lib/tc) containing numbers scaled by NETEM_DIST_SCALE. A random value x is selected from the table and it takes DELAY + ( x * JITTER ) as delay. Correlation between values is not supported. Examples: Normal distribution delay with mean = 800us and stdev = 100us. > tc qdisc add dev eth0 root netem slot distribution normal \ 800us 100us Optionally set the max slot size in bytes and/or packets. > tc qdisc add dev eth0 root netem slot distribution normal \ 800us 100us bytes 64k packets 42 Signed-off-by: Yousuk Seung Signed-off-by: Neal Cardwell Signed-off-by: Dave Taht Signed-off-by: David Ahern --- diff --git a/man/man8/tc-netem.8 b/man/man8/tc-netem.8 index 8d485b026..111109cf0 100644 --- a/man/man8/tc-netem.8 +++ b/man/man8/tc-netem.8 @@ -53,9 +53,13 @@ NetEm \- Network Emulator .IR RATE " [ " PACKETOVERHEAD " [ " CELLSIZE " [ " CELLOVERHEAD " ]]]]" .IR SLOT " := " -.BR slot -.IR MIN_DELAY " [ " MAX_DELAY " ] [" -.BR packets +.BR slot " { " +.IR MIN_DELAY " [ " MAX_DELAY " ] |" +.br +.RB " " distribution " { "uniform " | " normal " | " pareto " | " paretonormal " | " +.IR FILE " } " DELAY " " JITTER " } " +.br +.RB " [ " packets .IR PACKETS " ] [ " .BR bytes .IR BYTES " ]" @@ -172,9 +176,13 @@ an artificial packet compression (bursts). Another influence factor are network adapter buffers which can also add artificial delay. .SS slot -defer delivering accumulated packets to within a slot, with each available slot -configured with a minimum delay to acquire, and an optional maximum delay. Slot -delays can be specified in nanoseconds, microseconds, milliseconds or seconds +defer delivering accumulated packets to within a slot. Each available slot can be +configured with a minimum delay to acquire, and an optional maximum delay. +Alternatively it can be configured with the distribution similar to +.BR distribution +for +.BR delay +option. Slot delays can be specified in nanoseconds, microseconds, milliseconds or seconds (e.g. 800us). Values for the optional parameters .I BYTES will limit the number of bytes delivered per slot, and/or diff --git a/tc/q_netem.c b/tc/q_netem.c index 824018b2d..6e0e8a8cb 100644 --- a/tc/q_netem.c +++ b/tc/q_netem.c @@ -43,7 +43,9 @@ static void explain(void) " [ rate RATE [PACKETOVERHEAD] [CELLSIZE] [CELLOVERHEAD]]\n" \ " [ slot MIN_DELAY [MAX_DELAY] [packets MAX_PACKETS]" \ " [bytes MAX_BYTES]]\n" \ - ); +" [ slot distribution" \ +" {uniform|normal|pareto|paretonormal|custom} DELAY JITTER" \ +" [packets MAX_PACKETS] [bytes MAX_BYTES]]\n"); } static void explain1(const char *arg) @@ -159,6 +161,7 @@ static int netem_parse_opt(struct qdisc_util *qu, int argc, char **argv, struct nlmsghdr *n, const char *dev) { int dist_size = 0; + int slot_dist_size = 0; struct rtattr *tail; struct tc_netem_qopt opt = { .limit = 1000 }; struct tc_netem_corr cor = {}; @@ -169,6 +172,7 @@ static int netem_parse_opt(struct qdisc_util *qu, int argc, char **argv, struct tc_netem_rate rate = {}; struct tc_netem_slot slot = {}; __s16 *dist_data = NULL; + __s16 *slot_dist_data = NULL; __u16 loss_type = NETEM_LOSS_UNSPEC; int present[__TCA_NETEM_MAX] = {}; __u64 rate64 = 0; @@ -417,21 +421,55 @@ static int netem_parse_opt(struct qdisc_util *qu, int argc, char **argv, } } } else if (matches(*argv, "slot") == 0) { - NEXT_ARG(); - present[TCA_NETEM_SLOT] = 1; - if (get_time64(&slot.min_delay, *argv)) { - explain1("slot min_delay"); - return -1; - } if (NEXT_IS_NUMBER()) { NEXT_ARG(); - if (get_time64(&slot.max_delay, *argv) || - slot.max_delay < slot.min_delay) { - explain1("slot max_delay"); + present[TCA_NETEM_SLOT] = 1; + if (get_time64(&slot.min_delay, *argv)) { + explain1("slot min_delay"); return -1; } + if (NEXT_IS_NUMBER()) { + NEXT_ARG(); + if (get_time64(&slot.max_delay, *argv) || + slot.max_delay < slot.min_delay) { + explain1("slot max_delay"); + return -1; + } + } else { + slot.max_delay = slot.min_delay; + } } else { - slot.max_delay = slot.min_delay; + NEXT_ARG(); + if (strcmp(*argv, "distribution") == 0) { + present[TCA_NETEM_SLOT] = 1; + NEXT_ARG(); + slot_dist_data = calloc(sizeof(slot_dist_data[0]), MAX_DIST); + if (!slot_dist_data) + return -1; + slot_dist_size = get_distribution(*argv, slot_dist_data, MAX_DIST); + if (slot_dist_size <= 0) { + free(slot_dist_data); + return -1; + } + NEXT_ARG(); + if (get_time64(&slot.dist_delay, *argv)) { + explain1("slot delay"); + return -1; + } + NEXT_ARG(); + if (get_time64(&slot.dist_jitter, *argv)) { + explain1("slot jitter"); + return -1; + } + if (slot.dist_jitter <= 0) { + fprintf(stderr, "Non-positive jitter\n"); + return -1; + } + } else { + fprintf(stderr, "Unknown slot parameter: %s\n", + *argv); + return -1; + } } if (NEXT_ARG_OK() && matches(*(argv+1), "packets") == 0) { @@ -559,6 +597,14 @@ static int netem_parse_opt(struct qdisc_util *qu, int argc, char **argv, return -1; free(dist_data); } + + if (slot_dist_data) { + if (addattr_l(n, MAX_DIST * sizeof(slot_dist_data[0]), + TCA_NETEM_SLOT_DIST, + slot_dist_data, slot_dist_size * sizeof(slot_dist_data[0])) < 0) + return -1; + free(slot_dist_data); + } tail->rta_len = (void *) NLMSG_TAIL(n) - (void *) tail; return 0; } @@ -713,8 +759,13 @@ static int netem_print_opt(struct qdisc_util *qu, FILE *f, struct rtattr *opt) } if (slot) { - fprintf(f, " slot %s", sprint_time64(slot->min_delay, b1)); - fprintf(f, " %s", sprint_time64(slot->max_delay, b1)); + if (slot->dist_jitter > 0) { + fprintf(f, " slot distribution %s", sprint_time64(slot->dist_delay, b1)); + fprintf(f, " %s", sprint_time64(slot->dist_jitter, b1)); + } else { + fprintf(f, " slot %s", sprint_time64(slot->min_delay, b1)); + fprintf(f, " %s", sprint_time64(slot->max_delay, b1)); + } if (slot->max_packets) fprintf(f, " packets %d", slot->max_packets); if (slot->max_bytes)