* [PATCH iproute2-next 0/2] Support RED ECN nodrop mode
@ 2020-03-18 12:18 Petr Machata
2020-03-18 12:18 ` [PATCH iproute2-next 1/2] uapi: pkt_sched: Update headers for RED nodrop Petr Machata
2020-03-18 12:18 ` [PATCH iproute2-next 2/2] tc: q_red: Support 'nodrop' flag Petr Machata
0 siblings, 2 replies; 5+ messages in thread
From: Petr Machata @ 2020-03-18 12:18 UTC (permalink / raw)
To: netdev; +Cc: Petr Machata, David Ahern
The kernel supports a new RED mode, "ECN nodrop". In the nodrop mode,
non-ECT packets are always queued, instead of being subject to early
dropping.
This patchset adds support for the RED ECN nodrop mode to iproute2. In
patch #1, kernel headers are synced. #2 adds support for the new mode and
describes it in the man page.
Petr Machata (2):
uapi: pkt_sched: Update headers for RED nodrop
tc: q_red: Support 'nodrop' flag
include/uapi/linux/pkt_sched.h | 17 +++++++++++++++++
man/man8/tc-red.8 | 6 +++++-
tc/q_red.c | 22 +++++++++++++++++-----
tc/tc_red.c | 5 +++++
4 files changed, 44 insertions(+), 6 deletions(-)
--
2.20.1
^ permalink raw reply [flat|nested] 5+ messages in thread
* [PATCH iproute2-next 1/2] uapi: pkt_sched: Update headers for RED nodrop
2020-03-18 12:18 [PATCH iproute2-next 0/2] Support RED ECN nodrop mode Petr Machata
@ 2020-03-18 12:18 ` Petr Machata
2020-03-18 12:18 ` [PATCH iproute2-next 2/2] tc: q_red: Support 'nodrop' flag Petr Machata
1 sibling, 0 replies; 5+ messages in thread
From: Petr Machata @ 2020-03-18 12:18 UTC (permalink / raw)
To: netdev; +Cc: Petr Machata, David Ahern
Add the new defines and a comment.
Signed-off-by: Petr Machata <petrm@mellanox.com>
---
include/uapi/linux/pkt_sched.h | 17 +++++++++++++++++
1 file changed, 17 insertions(+)
diff --git a/include/uapi/linux/pkt_sched.h b/include/uapi/linux/pkt_sched.h
index bbe791b2..ea39287d 100644
--- a/include/uapi/linux/pkt_sched.h
+++ b/include/uapi/linux/pkt_sched.h
@@ -256,6 +256,7 @@ enum {
TCA_RED_PARMS,
TCA_RED_STAB,
TCA_RED_MAX_P,
+ TCA_RED_FLAGS, /* bitfield32 */
__TCA_RED_MAX,
};
@@ -268,12 +269,28 @@ struct tc_red_qopt {
unsigned char Wlog; /* log(W) */
unsigned char Plog; /* log(P_max/(qth_max-qth_min)) */
unsigned char Scell_log; /* cell size for idle damping */
+
+ /* This field can be used for flags that a RED-like qdisc has
+ * historically supported. E.g. when configuring RED, it can be used for
+ * ECN, HARDDROP and ADAPTATIVE. For SFQ it can be used for ECN,
+ * HARDDROP. Etc. Because this field has not been validated, and is
+ * copied back on dump, any bits besides those to which a given qdisc
+ * has assigned a historical meaning need to be considered for free use
+ * by userspace tools.
+ *
+ * Any further flags need to be passed differently, e.g. through an
+ * attribute (such as TCA_RED_FLAGS above). Such attribute should allow
+ * passing both recent and historic flags in one value.
+ */
unsigned char flags;
#define TC_RED_ECN 1
#define TC_RED_HARDDROP 2
#define TC_RED_ADAPTATIVE 4
+#define TC_RED_NODROP 8
};
+#define TC_RED_HISTORIC_FLAGS (TC_RED_ECN | TC_RED_HARDDROP | TC_RED_ADAPTATIVE)
+
struct tc_red_xstats {
__u32 early; /* Early drops */
__u32 pdrop; /* Drops due to queue limits */
--
2.20.1
^ permalink raw reply related [flat|nested] 5+ messages in thread
* [PATCH iproute2-next 2/2] tc: q_red: Support 'nodrop' flag
2020-03-18 12:18 [PATCH iproute2-next 0/2] Support RED ECN nodrop mode Petr Machata
2020-03-18 12:18 ` [PATCH iproute2-next 1/2] uapi: pkt_sched: Update headers for RED nodrop Petr Machata
@ 2020-03-18 12:18 ` Petr Machata
2020-03-22 21:43 ` David Ahern
1 sibling, 1 reply; 5+ messages in thread
From: Petr Machata @ 2020-03-18 12:18 UTC (permalink / raw)
To: netdev; +Cc: Petr Machata, David Ahern
Recognize the new configuration option of the RED Qdisc, "nodrop". Add
support for passing flags through TCA_RED_FLAGS, and always use it for
passing RED flags.
Signed-off-by: Petr Machata <petrm@mellanox.com>
---
man/man8/tc-red.8 | 6 +++++-
tc/q_red.c | 22 +++++++++++++++++-----
tc/tc_red.c | 5 +++++
3 files changed, 27 insertions(+), 6 deletions(-)
diff --git a/man/man8/tc-red.8 b/man/man8/tc-red.8
index dd1ab74c..b5aaa986 100644
--- a/man/man8/tc-red.8
+++ b/man/man8/tc-red.8
@@ -13,7 +13,7 @@ bytes
bytes
.B [ burst
packets
-.B ] [ ecn ] [ harddrop] [ bandwidth
+.B ] [ ecn ] [ harddrop ] [ nodrop ] [ bandwidth
rate
.B ] [ probability
chance
@@ -123,6 +123,10 @@ If average flow queue size is above
.B max
bytes, this parameter forces a drop instead of ecn marking.
.TP
+nodrop
+With this parameter, traffic that should be marked, but is not ECN-capable, is
+enqueued. Without the parameter it is early-dropped.
+.TP
adaptive
(Added in linux-3.3) Sets RED in adaptive mode as described in http://icir.org/floyd/papers/adaptiveRed.pdf
.nf
diff --git a/tc/q_red.c b/tc/q_red.c
index 6256420f..ee81803e 100644
--- a/tc/q_red.c
+++ b/tc/q_red.c
@@ -30,12 +30,17 @@ static void explain(void)
fprintf(stderr,
"Usage: ... red limit BYTES [min BYTES] [max BYTES] avpkt BYTES [burst PACKETS]\n"
" [adaptive] [probability PROBABILITY] [bandwidth KBPS]\n"
- " [ecn] [harddrop]\n");
+ " [ecn] [harddrop] [nodrop]\n");
}
+#define RED_SUPPORTED_FLAGS (TC_RED_HISTORIC_FLAGS | TC_RED_NODROP)
+
static int red_parse_opt(struct qdisc_util *qu, int argc, char **argv,
struct nlmsghdr *n, const char *dev)
{
+ struct nla_bitfield32 flags_bf = {
+ .selector = RED_SUPPORTED_FLAGS,
+ };
struct tc_red_qopt opt = {};
unsigned int burst = 0;
unsigned int avpkt = 0;
@@ -95,13 +100,15 @@ static int red_parse_opt(struct qdisc_util *qu, int argc, char **argv,
return -1;
}
} else if (strcmp(*argv, "ecn") == 0) {
- opt.flags |= TC_RED_ECN;
+ flags_bf.value |= TC_RED_ECN;
} else if (strcmp(*argv, "harddrop") == 0) {
- opt.flags |= TC_RED_HARDDROP;
+ flags_bf.value |= TC_RED_HARDDROP;
+ } else if (strcmp(*argv, "nodrop") == 0) {
+ flags_bf.value |= TC_RED_NODROP;
} else if (strcmp(*argv, "adaptative") == 0) {
- opt.flags |= TC_RED_ADAPTATIVE;
+ flags_bf.value |= TC_RED_ADAPTATIVE;
} else if (strcmp(*argv, "adaptive") == 0) {
- opt.flags |= TC_RED_ADAPTATIVE;
+ flags_bf.value |= TC_RED_ADAPTATIVE;
} else if (strcmp(*argv, "help") == 0) {
explain();
return -1;
@@ -154,6 +161,7 @@ static int red_parse_opt(struct qdisc_util *qu, int argc, char **argv,
addattr_l(n, 1024, TCA_RED_STAB, sbuf, 256);
max_P = probability * pow(2, 32);
addattr_l(n, 1024, TCA_RED_MAX_P, &max_P, sizeof(max_P));
+ addattr_l(n, 1024, TCA_RED_FLAGS, &flags_bf, sizeof(flags_bf));
addattr_nest_end(n, tail);
return 0;
}
@@ -183,6 +191,10 @@ static int red_print_opt(struct qdisc_util *qu, FILE *f, struct rtattr *opt)
RTA_PAYLOAD(tb[TCA_RED_MAX_P]) >= sizeof(__u32))
max_P = rta_getattr_u32(tb[TCA_RED_MAX_P]);
+ if (tb[TCA_RED_FLAGS] &&
+ RTA_PAYLOAD(tb[TCA_RED_FLAGS]) >= sizeof(__u32))
+ qopt->flags = rta_getattr_u32(tb[TCA_RED_FLAGS]);
+
print_uint(PRINT_JSON, "limit", NULL, qopt->limit);
print_string(PRINT_FP, NULL, "limit %s ", sprint_size(qopt->limit, b1));
print_uint(PRINT_JSON, "min", NULL, qopt->qth_min);
diff --git a/tc/tc_red.c b/tc/tc_red.c
index 681ca297..88f5ff35 100644
--- a/tc/tc_red.c
+++ b/tc/tc_red.c
@@ -116,4 +116,9 @@ void tc_red_print_flags(__u32 flags)
print_bool(PRINT_ANY, "adaptive", "adaptive ", true);
else
print_bool(PRINT_ANY, "adaptive", NULL, false);
+
+ if (flags & TC_RED_NODROP)
+ print_bool(PRINT_ANY, "nodrop", "nodrop ", true);
+ else
+ print_bool(PRINT_ANY, "nodrop", NULL, false);
}
--
2.20.1
^ permalink raw reply related [flat|nested] 5+ messages in thread
* Re: [PATCH iproute2-next 2/2] tc: q_red: Support 'nodrop' flag
2020-03-18 12:18 ` [PATCH iproute2-next 2/2] tc: q_red: Support 'nodrop' flag Petr Machata
@ 2020-03-22 21:43 ` David Ahern
2020-03-23 10:20 ` Petr Machata
0 siblings, 1 reply; 5+ messages in thread
From: David Ahern @ 2020-03-22 21:43 UTC (permalink / raw)
To: Petr Machata, netdev; +Cc: David Ahern
On 3/18/20 6:18 AM, Petr Machata wrote:
> @@ -154,6 +161,7 @@ static int red_parse_opt(struct qdisc_util *qu, int argc, char **argv,
> addattr_l(n, 1024, TCA_RED_STAB, sbuf, 256);
> max_P = probability * pow(2, 32);
> addattr_l(n, 1024, TCA_RED_MAX_P, &max_P, sizeof(max_P));
> + addattr_l(n, 1024, TCA_RED_FLAGS, &flags_bf, sizeof(flags_bf));
the attr is a bitfield32 here ...
> addattr_nest_end(n, tail);
> return 0;
> }
> @@ -183,6 +191,10 @@ static int red_print_opt(struct qdisc_util *qu, FILE *f, struct rtattr *opt)
> RTA_PAYLOAD(tb[TCA_RED_MAX_P]) >= sizeof(__u32))
> max_P = rta_getattr_u32(tb[TCA_RED_MAX_P]);
>
> + if (tb[TCA_RED_FLAGS] &&
> + RTA_PAYLOAD(tb[TCA_RED_FLAGS]) >= sizeof(__u32))
> + qopt->flags = rta_getattr_u32(tb[TCA_RED_FLAGS]);
> +
but a u32 here. These should be consistent.
^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: [PATCH iproute2-next 2/2] tc: q_red: Support 'nodrop' flag
2020-03-22 21:43 ` David Ahern
@ 2020-03-23 10:20 ` Petr Machata
0 siblings, 0 replies; 5+ messages in thread
From: Petr Machata @ 2020-03-23 10:20 UTC (permalink / raw)
To: David Ahern; +Cc: netdev
David Ahern <dsahern@gmail.com> writes:
> On 3/18/20 6:18 AM, Petr Machata wrote:
>> @@ -154,6 +161,7 @@ static int red_parse_opt(struct qdisc_util *qu, int argc, char **argv,
>> addattr_l(n, 1024, TCA_RED_STAB, sbuf, 256);
>> max_P = probability * pow(2, 32);
>> addattr_l(n, 1024, TCA_RED_MAX_P, &max_P, sizeof(max_P));
>> + addattr_l(n, 1024, TCA_RED_FLAGS, &flags_bf, sizeof(flags_bf));
>
> the attr is a bitfield32 here ...
>
>> addattr_nest_end(n, tail);
>> return 0;
>> }
>> @@ -183,6 +191,10 @@ static int red_print_opt(struct qdisc_util *qu, FILE *f, struct rtattr *opt)
>> RTA_PAYLOAD(tb[TCA_RED_MAX_P]) >= sizeof(__u32))
>> max_P = rta_getattr_u32(tb[TCA_RED_MAX_P]);
>>
>> + if (tb[TCA_RED_FLAGS] &&
>> + RTA_PAYLOAD(tb[TCA_RED_FLAGS]) >= sizeof(__u32))
>> + qopt->flags = rta_getattr_u32(tb[TCA_RED_FLAGS]);
>> +
>
> but a u32 here. These should be consistent.
:-/ That's a leftover from previous ABI, thanks for catching it.
Will send a v2.
^ permalink raw reply [flat|nested] 5+ messages in thread
end of thread, other threads:[~2020-03-23 10:20 UTC | newest]
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2020-03-18 12:18 [PATCH iproute2-next 0/2] Support RED ECN nodrop mode Petr Machata
2020-03-18 12:18 ` [PATCH iproute2-next 1/2] uapi: pkt_sched: Update headers for RED nodrop Petr Machata
2020-03-18 12:18 ` [PATCH iproute2-next 2/2] tc: q_red: Support 'nodrop' flag Petr Machata
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2020-03-23 10:20 ` Petr Machata
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