kernel_optimize_test/lib
Eric Dumazet 8af2a218de sch_red: Adaptative RED AQM
Adaptative RED AQM for linux, based on paper from Sally FLoyd,
Ramakrishna Gummadi, and Scott Shenker, August 2001 :

http://icir.org/floyd/papers/adaptiveRed.pdf

Goal of Adaptative RED is to make max_p a dynamic value between 1% and
50% to reach the target average queue : (max_th - min_th) / 2

Every 500 ms:
 if (avg > target and max_p <= 0.5)
  increase max_p : max_p += alpha;
 else if (avg < target and max_p >= 0.01)
  decrease max_p : max_p *= beta;

target :[min_th + 0.4*(min_th - max_th),
          min_th + 0.6*(min_th - max_th)].
alpha : min(0.01, max_p / 4)
beta : 0.9
max_P is a Q0.32 fixed point number (unsigned, with 32 bits mantissa)

Changes against our RED implementation are :

max_p is no longer a negative power of two (1/(2^Plog)), but a Q0.32
fixed point number, to allow full range described in Adatative paper.

To deliver a random number, we now use a reciprocal divide (thats really
a multiply), but this operation is done once per marked/droped packet
when in RED_BETWEEN_TRESH window, so added cost (compared to previous
AND operation) is near zero.

dump operation gives current max_p value in a new TCA_RED_MAX_P
attribute.

Example on a 10Mbit link :

tc qdisc add dev $DEV parent 1:1 handle 10: est 1sec 8sec red \
   limit 400000 min 30000 max 90000 avpkt 1000 \
   burst 55 ecn adaptative bandwidth 10Mbit

# tc -s -d qdisc show dev eth3
...
qdisc red 10: parent 1:1 limit 400000b min 30000b max 90000b ecn
adaptative ewma 5 max_p=0.113335 Scell_log 15
 Sent 50414282 bytes 34504 pkt (dropped 35, overlimits 1392 requeues 0)
 rate 9749Kbit 831pps backlog 72056b 16p requeues 0
  marked 1357 early 35 pdrop 0 other 0

Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2011-12-08 19:52:43 -05:00
..
lzo
raid6 md: Add in export.h for files using EXPORT_SYMBOL 2011-10-31 19:31:19 -04:00
reed_solomon
xz
zlib_deflate
zlib_inflate
.gitignore
argv_split.c
atomic64_test.c
atomic64.c
audit.c
average.c
bcd.c
bch.c
bitmap.c lib/bitmap.c: quiet sparse noise about address space 2011-10-31 17:30:56 -07:00
bitrev.c
bsearch.c
btree.c
bug.c
bust_spinlocks.c
check_signature.c
checksum.c
cmdline.c
cordic.c
cpu_rmap.c
cpu-notifier-error-inject.c
cpumask.c
crc-ccitt.c
crc-itu-t.c
crc-t10dif.c
crc7.c
crc8.c
crc16.c
crc32.c
crc32defs.h
ctype.c
debug_locks.c
debugobjects.c
dec_and_lock.c
decompress_bunzip2.c
decompress_inflate.c
decompress_unlzma.c
decompress_unlzo.c
decompress_unxz.c
decompress.c
devres.c
div64.c
dma-debug.c lib: dma-debug needs export.h for EXPORT_SYMBOL 2011-10-31 19:32:23 -04:00
dump_stack.c
dynamic_debug.c
dynamic_queue_limits.c dql: Dynamic queue limits 2011-11-29 12:46:19 -05:00
extable.c
fault-inject.c fault-inject: export setup_fault_attr() 2011-10-26 16:32:11 -04:00
find_last_bit.c
find_next_bit.c
flex_array.c
gcd.c
gen_crc32table.c
genalloc.c
halfmd4.c
hexdump.c
hweight.c
idr.c ida: make ida_simple_get/put() IRQ safe 2011-11-02 16:07:00 -07:00
inflate.c
int_sqrt.c
iomap_copy.c
iomap.c
iommu-helper.c
ioremap.c
irq_regs.c
is_single_threaded.c
kasprintf.c
Kconfig dql: Dynamic queue limits 2011-11-29 12:46:19 -05:00
Kconfig.debug lib/Kconfig.debug: fix help message for DEFAULT_HUNG_TASK_TIMEOUT 2011-10-31 17:30:51 -07:00
Kconfig.kgdb
Kconfig.kmemcheck
klist.c
kobject_uevent.c
kobject.c
kref.c
kstrtox.c lib/kstrtox: common code between kstrto*() and simple_strto*() functions 2011-10-31 17:30:56 -07:00
kstrtox.h lib/kstrtox: common code between kstrto*() and simple_strto*() functions 2011-10-31 17:30:56 -07:00
lcm.c
libcrc32c.c
list_debug.c
list_sort.c
llist.c
locking-selftest-hardirq.h
locking-selftest-mutex.h
locking-selftest-rlock-hardirq.h
locking-selftest-rlock-softirq.h
locking-selftest-rlock.h
locking-selftest-rsem.h
locking-selftest-softirq.h
locking-selftest-spin-hardirq.h
locking-selftest-spin-softirq.h
locking-selftest-spin.h
locking-selftest-wlock-hardirq.h
locking-selftest-wlock-softirq.h
locking-selftest-wlock.h
locking-selftest-wsem.h
locking-selftest.c
lru_cache.c
Makefile dql: Dynamic queue limits 2011-11-29 12:46:19 -05:00
md5.c
nlattr.c netlink: validate NLA_MSECS length 2011-11-04 17:47:34 -04:00
parser.c
percpu_counter.c lib/percpu_counter.c: enclose hotplug only variables in hotplug ifdef 2011-10-31 17:30:56 -07:00
plist.c
prio_heap.c
prio_tree.c
proportions.c
radix-tree.c radix_tree: clean away saw_unset_tag leftovers 2011-10-31 17:30:45 -07:00
random32.c
ratelimit.c
rational.c
rbtree.c
reciprocal_div.c sch_red: Adaptative RED AQM 2011-12-08 19:52:43 -05:00
rwsem-spinlock.c
rwsem.c
scatterlist.c
sha1.c
show_mem.c
smp_processor_id.c
sort.c
spinlock_debug.c lib/spinlock_debug.c: print owner on spinlock lockup 2011-10-31 17:30:56 -07:00
string_helpers.c
string.c lib/string.c: fix strim() semantics for strings that have only blanks 2011-10-31 17:30:56 -07:00
swiotlb.c
syscall.c
test-kstrtox.c
textsearch.c
timerqueue.c
ts_bm.c
ts_fsm.c
ts_kmp.c
uuid.c
vsprintf.c net: introduce and use netdev_features_t for device features sets 2011-11-16 17:43:10 -05:00