Nuutti Kotivuori wrote:
Patrick McHardy wrote:
I've completed the port and tested it yesterday, unfortunately it's
not useable in the real world as is. There is a strong bias against
non-ECN flows because their packets are simply dropped instead of
marked. At high load (50 ECN vs. 1 non-ECN flow) and a marking
probability of about 10% the non-ECN flow simply stalls.
I can send you the patch if you're interested ..
Thank you, I am really interested.
Patch is attached. Use the original tc patch.
I will try how it behaves for me in various circumstances.
What you say, though, is probably true - and the situation is even
more accentuated when considering that different TCP stacks react to
ECN and packet drops differently - a single drop percent will not be
enough.
OTOH, with only ECN flows it works great, not a single packet
drop after a couple of minutes, without BLUE there were multiple
thousands.
Which ofcourse brings us to SFB - with Stochastic Fair Blue, the drop
percentage for the non-ECN flow should be significantly lower and the
connections should transfer more or less fairly.
I'm going to check this out, don't know anything about it.
Regards
Patrick
-- Naked
# This is a BitKeeper generated diff -Nru style patch.
#
# ChangeSet
# 2004/03/06 16:57:42+01:00 [EMAIL PROTECTED]
# Add BLUE scheduler
#
# net/sched/sch_blue.c
# 2004/03/06 16:57:35+01:00 [EMAIL PROTECTED] +453 -0
#
# net/sched/sch_blue.c
# 2004/03/06 16:57:35+01:00 [EMAIL PROTECTED] +0 -0
# BitKeeper file /home/kaber/src/blue/linux-2.6/net/sched/sch_blue.c
#
# net/sched/Makefile
# 2004/03/06 16:57:35+01:00 [EMAIL PROTECTED] +1 -0
# Add BLUE scheduler
#
# net/sched/Kconfig
# 2004/03/06 16:57:35+01:00 [EMAIL PROTECTED] +19 -0
# Add BLUE scheduler
#
# include/linux/pkt_sched.h
# 2004/03/06 16:57:35+01:00 [EMAIL PROTECTED] +31 -0
# Add BLUE scheduler
#
diff -Nru a/include/linux/pkt_sched.h b/include/linux/pkt_sched.h
--- a/include/linux/pkt_sched.h Sat Mar 6 16:58:06 2004
+++ b/include/linux/pkt_sched.h Sat Mar 6 16:58:06 2004
@@ -321,6 +321,37 @@
TCA_HFSC_MAX = TCA_HFSC_USC
};
+/* BLUE section */
+
+enum
+{
+ TCA_BLUE_UNSPEC,
+ TCA_BLUE_PARMS,
+};
+
+struct tc_blue_qopt
+{
+ __u32 limit; /* Limit on queue length, bytes */
+ __s32 freeze_time; /* Minimum time between Pmark updates, usec! */
+ __s32 pmark_init; /* Initial Pmark */
+ __s32 pmark_inc; /* Pmark increment step */
+ __s32 pmark_dec; /* Pmark decrement step */
+ __s32 pmark_max; /* Pmark never exceeds this maximum */
+ __u32 flags;
+};
+
+/* Flags: */
+#define TC_BLUE_ECN 1 /* Do ECN marking, if ECT is set in the packet */
+
+struct tc_blue_xstats
+{
+ __s32 pmark; /* Current Pmark */
+ __u32 marked; /* Marked packets */
+ __u32 early_drops; /* Early drops */
+ __u32 limit_drops; /* Drops due to queue limits */
+ __u32 other_drops; /* Drops due to drop() calls */
+};
+
/* CBQ section */
#define TC_CBQ_MAXPRIO 8
diff -Nru a/net/sched/Kconfig b/net/sched/Kconfig
--- a/net/sched/Kconfig Sat Mar 6 16:58:06 2004
+++ b/net/sched/Kconfig Sat Mar 6 16:58:06 2004
@@ -101,6 +101,25 @@
To compile this code as a module, choose M here: the
module will be called sch_red.
+config NET_SCH_BLUE
+ tristate "BLUE queue"
+ depends on NET_SCHED
+ help
+ Say Y here if you want to use the BLUE queue management algorithm
+ for some of your network devices. BLUE is similar to RED as it
+ randomly ECN-marks or drops packets, but uses a different approach
+ to select the packets to be marked/dropped, which is intended to
+ perform better under high load.
+
+ For details and references about BLUE see:
+
+ - http://thefengs.com/wuchang/blue/
+ - http://www.sch.bme.hu/~bartoki/projects/thesis/
+ - The top of net/sched/sch_blue.c
+
+ To compile this code as a module, choose M here: the
+ module will be called sch_blue.
+
config NET_SCH_SFQ
tristate "SFQ queue"
depends on NET_SCHED
diff -Nru a/net/sched/Makefile b/net/sched/Makefile
--- a/net/sched/Makefile Sat Mar 6 16:58:06 2004
+++ b/net/sched/Makefile Sat Mar 6 16:58:06 2004
@@ -15,6 +15,7 @@
obj-$(CONFIG_NET_SCH_HFSC) += sch_hfsc.o
obj-$(CONFIG_NET_SCH_RED) += sch_red.o
obj-$(CONFIG_NET_SCH_GRED) += sch_gred.o
+obj-$(CONFIG_NET_SCH_BLUE) += sch_blue.o
obj-$(CONFIG_NET_SCH_INGRESS) += sch_ingress.o
obj-$(CONFIG_NET_SCH_DSMARK) += sch_dsmark.o
obj-$(CONFIG_NET_SCH_SFQ) += sch_sfq.o
diff -Nru a/net/sched/sch_blue.c b/net/sched/sch_blue.c
--- /dev/null Wed Dec 31 16:00:00 1969
+++ b/net/sched/sch_blue.c Sat Mar 6 16:58:06 2004
@@ -0,0 +1,453 @@
+/*
+ * net/sched/sch_blue.c BLUE queue.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version
+ * 2 of the License, or (at your option) any later version.
+ *
+ * Author: Bartok Istvan, <[EMAIL PROTECTED]> <[EMAIL PROTECTED]>
+ * Credits: Based on sch_red.c written by Alexey Kuznetsov
