From 7ebc013ae76b7f8bcb8d32718a373726e1c92262 Mon Sep 17 00:00:00 2001
From: Rostislav Lisovy <lisovy@gmail.com>
Date: Tue, 30 Aug 2011 15:23:13 +0200
Subject: [PATCH] Added some more information to qdisc review.

---
 doc/canprio/qdiscs_review.txt | 49 +++++++++++++++++++++++++++--------
 1 file changed, 38 insertions(+), 11 deletions(-)

diff --git a/doc/canprio/qdiscs_review.txt b/doc/canprio/qdiscs_review.txt
index 5d3dec3..e19eb01 100644
--- a/doc/canprio/qdiscs_review.txt
+++ b/doc/canprio/qdiscs_review.txt
@@ -5,31 +5,55 @@
 Classification
 ==============
 * u32
-  -- pros: Seems to be quite versatile
-  -- cons: Difficult to write rules (i.e. exact byte values)
+  -- pros: Seems to be quite versatile.
+  -- cons: Difficult to write rules (i.e. exact byte values).
            Possibly problems with different endianess?
 
 * Canprio (!)
-  -- pros: CAN specific filter
+  -- pros: CAN specific filter.
 
 
 Priority queues
 ===============
 * Prio (!)
-  -- pros: Classfull
-           
+  -- pros: Classfull.
+
+* pfifo_fast
+  -- cons: Classless (contains so called Bands).
+           Packets are classified accordint their TOS bits or assigned (from 
+             socket() syscall?) priority.
 
 Throttling
 ==========
 * TBF (!)
-  -- pros: Classfull
-           Peakrate management
+  -- pros: Classfull.
+           Peakrate management.
 
 * HTB (!)
+  -- more info: http://luxik.cdi.cz/~devik/qos/htb/
+  -- pros: Creates hierarchy of restriction rules.
+           Diferentiates between "guaranteed flow rate" and "maximum flow" 
+             (i.e. "ceiling" -- "This limits how much bandwidth class can 
+             borrow").
 
 * SFB
   -- more info: http://www.pps.jussieu.fr/~jch/software/sfb/README
-  -- ???
+  -- cons: Doesn't treat every flow the same.
+
+  -- Abstract of paper describing general SFB algorithm:
+       This paper describes and evaluates Stochastic Fair Blue (SFB), a
+       novel technique for enforcing fairneas among a large number of
+       flows. SFB scalably detects and rate-timits non-responsive flows
+       through the use of a marking probability derived from the BLUE
+       queue management algorithm and a Bloom filter. Using analysis
+       and simulation, SFB is shown to effectively handle non-responsive
+       flows using an extremely small amount of state information.
+
+  -- README says:
+       Since sfb penalises inelastic flows rather severely, you may want to
+       put another qdisc above sfb to bypass sfb for such flows.  And of
+       course if you're rate-limiting (e.g. using cbq, tbf or htb) you'll
+       want to do that above sfb.
 
 Round-robin dequeuing
 =====================
@@ -37,8 +61,11 @@ Round-robin dequeuing
   -- cons: Apparently works only for Intel NICs with hardware support of
              multiple queues.
 
+* mq
+  -- cons: Only for NICs with more than 1 TX queues.
+
 * drr
-  -- cons: Seems to be classful although all classes have to be of type "drr"
+  -- cons: Seems to be classful although all classes have to be of type "drr".
            Manpage says:
               Like SFQ, DRR is only useful when it owns the queue --  it  is  a  pure
               scheduler  and  does  not delay packets.  Attaching non-work-conserving
@@ -48,8 +75,8 @@ Round-robin dequeuing
               queue.
 
 * CBQ
-  -- cons: Too complex (everybody discourages from using it)
+  -- cons: Too complex (everybody discourages from using it).
            Uses Weighted Round Robin for dequeuing -- this behaves in the same 
-              way as "prio" qdisc (i.e. not useful for us)
+              way as "prio" qdisc (i.e. not useful for us).
 
 
-- 
2.39.2