fcicq

--- a/block/blk-throttle.c	2016-08-09 15:48:03.242986929 +0800
+++ b/block/blk-throttle.c	2016-08-09 15:53:33.060446303 +0800
@@ -735,7 +735,8 @@
 	}
 
 	/* Calc approx time to dispatch */
-	extra_bytes = tg->bytes_disp[rw] + bio->bi_iter.bi_size - bytes_allowed;
+	/* fcicq: iops limit not checked and allow smaller request, use the correct wait time here */
+	extra_bytes = tg->bytes_disp[rw] + max(bio->bi_iter.bi_size, 32768U) - bytes_allowed;
 	jiffy_wait = div64_u64(extra_bytes * HZ, tg->bps[rw]);

fcicq

00000000  f9 be b4 fe (magic bytes of namecoin)
          a6 02 00 00 (message hash)
(namecoin block, merged)
          01 01 01 00 (version)
          36 90 9a c0
00000010  7a 16 73 da f6 5f a7 d8  28 88 2e 66 c9 e8 9f 85
00000020  46 cd d5 0a 9f b1 00 00  00 00 00 00 (prev block)
          0f 5c 65 49
00000030  bc d6 08 ab 7c 4e ac 59  3e 5b d5 a7 3b 2d 43 2e
00000040  b6 35 18 70 8f 77 8f c7  dc df af 88 (merkle root)

hellerbarde

Latency numbers every programmer should know

L1 cache reference ......................... 0.5 ns
Branch mispredict ............................ 5 ns
L2 cache reference ........................... 7 ns
Mutex lock/unlock ........................... 25 ns
Main memory reference ...................... 100 ns             
Compress 1K bytes with Zippy ............. 3,000 ns  =   3 µs
Send 2K bytes over 1 Gbps network ....... 20,000 ns  =  20 µs
SSD random read ........................ 150,000 ns  = 150 µs

Read 1 MB sequentially from memory ..... 250,000 ns = 250 µs

rednaxelafx

  1   b   java.lang.String::charAt (33 bytes)
  2   b   java.lang.Math::max (11 bytes)
  3   b   java.util.jar.Manifest$FastInputStream::readLine (167 bytes)
  4   b   sun.nio.cs.UTF_8$Decoder::decodeArrayLoop (553 bytes)
  5   b   java.util.Properties$LineReader::readLine (383 bytes)
  6   b   java.lang.String::hashCode (60 bytes)
  7   b   java.lang.String::indexOf (151 bytes)
  8   b   sun.nio.cs.ext.DoubleByteDecoder::decodeSingle (10 bytes)
  9   b   java.lang.String::lastIndexOf (156 bytes)
 10   b   java.lang.String::replace (142 bytes)