The Design and Implementation of the Anykernel and Rump Kernels

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232 The results are presented in Figure 4.19. Rump kernels perform second best in the test after User Mode Linux. However, the figures are not directly comparable due to different hosts. All virtualization technologies perform significantly worse than the native case. This performance drop is because pinging a local address allows the system to route the packet through the loopback address. Since a virtualized OS does not have a local address configured on the host, the packet must be transmitted to the virtual OS instance and back. 4.6.7 Web Servers A web server performance test provides a macro benchmark of the performance of the TCP/IP stack in a rump kernel. We tested by adapting the thttpd [7] web server as a local client for a rump kernel. We used ApacheBench to measure the total execution time for 10,000 requests of an 80 byte root document on the web server. ApacheBench is always running against the host kernel TCP/IP stack, while the web server was run both against the host stack and the virtual stack. The rump kernel uses the virt interface, so as to access the host network. The results are displayed in Figure 4.20. With concurrency of 4 and above, the difference is about 0.1s in total time. The figure translates to a 0.01ms (3%) difference per request. We attribute this difference to the fact that in addition to the normal interface path, the rump kernel setup must deliver packets through the tap and bridge drivers. We did not attempt to optimize the host for Ethernet access to be available from userspace more directly. While the above is most likely an obvious result, there are more delicate implications. Running ApacheBench put 10,000 connections in TIME_WAIT on the server. This
233 ping rtt (us) 120 100 80 60 40 20 0 117 28 32 27 11 native rump Xen UML qemu Figure 4.19: RTT of ping with various virtualization technologies. The test measures how fast the virtualized kernel responds to an ICMP ping sent from the host. The UML test is not fully comparable, as it was run with Linux as the host operating system. 8 7 thttpd, rump TCP/IP thttpd, native TCP/IP total time (s) 6 5 4 3 2 20 40 60 80 100 120 concurrent requests Figure 4.20: Speed of 10,000 HTTP GET requests over LAN.
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Department of Computer Science and
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9 Preface Meet the new boss Same as
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11 Then there is my dear Xi, who, s
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14 2.3.3 InterruptsandPreemption...
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16 4.1.1 Implementation Effort ....
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18 Appendix C Patches to the 5.99.4
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20 ISA LGPL LRU LWP MD MI MMU NIC O
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23 List of Figures 2.1 Rumpkernelhi
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25 4.14 Time to execute 5M system c
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29 1 Introduction In its classic ro
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31 and application-level drivers. T
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33 We define an anykernel to be an
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35 Our implementation supports rump
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37 The project was done in small in
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39 2 The Anykernel and Rump Kernels
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41 building on top of the entities
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43 Drivers in a rump kernel remain
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45 Figure 2.1: Rump k
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47 in Section 3.2.3. Whenever discu
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49 int rumpns_bpfopen(dev_t, int, i
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51 Figure 2.4:
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53 while the application logic stil
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55 We must solve the lack of a rump
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57 2.3.1 Kernel threads Up until no
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59 void * pool_cache_get_paddr(pool
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61 2.3.4 An Example We present an e
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63 Figure 2.6: Prov
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65 The straightforward use of exist
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68 We identified three obstacles fo
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70 for loadable kernel modules (dis
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72 e.g. the routine for mapping a p
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74 3.2.1 C Symbol Namespaces In the
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76 the double underscore namespace
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78 since the representation might n
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80 The following rumpuser interface
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82 The entry point rump_schedule()
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84 3.3.1 CPU Scheduling Recall from
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86 The fastpath is taken in cases w
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88 Releasing a CPU requires the fol
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90 10 8 seconds 6 4 2 0 1CPU 2CPU n
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92 Hardware interrupt handlers are
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94 Due to the design choice that a
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96 in. Therefore, we should critica
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98 Pager window create+access time
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100 A rump kernel can be configured
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102 Since all pages managed by the
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104 not in control of thread schedu
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106 synchronization part of the alg
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108 /* * Run a cross call to cycle
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110 kernel needs to do is make sure
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112 The kernel with uniprocessor lo
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114 the header file while open() c
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116 The same wrapper works both for
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118 5. Some calling conventions (e.
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120 int rump_pub_lwproc_rfork(int a
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122 By convention, file system devi
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124 ule directory tree from /stand
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126 After these steps have been per
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128 Host Dynamic Linker Using the h
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130 for (i = 0; i < SYS_NSYSENT; i+
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132 into a rump kernel and the driv
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134 sys/arch/x86/include/cpu.h: #de
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136 3.8.4 Rump Component Init Routi
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138 RUMP_COMPONENT(RUMP_COMPONENT_N
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140 We have three distinct cases we
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142 # ifconfig tap0 create # ifconf
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144 Unprivileged use of host’s ne
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146 DOMAIN_DEFINE(sockindomain); co
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148 issue another write before the
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150 using an interface called USBDI
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152 The kernel device configuration
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154 # $NetBSD: UMASS.ioconf,v 1.4 2
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156 USB Host Controller Hub0 (root)
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158 Figure 3.30: File s
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160 in-kernel mount: /dev/sd0e /m/u
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162 structure being created by rump
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164 3.12.1 Client-Kernel Locators B
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166 A tmpfs server listening on INA
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168 Request Arguments Response Desc
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170 Host syscall rump syscall 1. op
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172 A client’s initial connection
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174 their system calls to a rump ke
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176 stdin/stdout, the new file desc
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178 Supporting fork() Recall, the f
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180 As with fork, most of the kerne
Page 184 and 185: 182 Anecdotal analysis For several
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Page 188 and 189: 186 SLOC 8000 7000 6000 5000 4000 3
Page 190 and 191: 188 Total commits to the kernel 9,6
Page 192 and 193: 190 120 build time (minutes) 100 80
Page 194 and 195: 192 4.2.2 makefs For a source tree
Page 196 and 197: 194 not include later debugging [76
Page 198 and 199: 196 the necessary tools such as mak
Page 200 and 201: 198 proach of supplying alternate c
Page 202 and 203: 200 are not out-of-the-box compatib
Page 204 and 205: 202 golem> mount -t msdos -o rump /
Page 206 and 207: 204 Full OS By a full OS we mean a
Page 208 and 209: 206 • Rapid prototyping: One of t
Page 210 and 211: 208 4.5.3 Testing: Case Studies We
Page 212 and 213: 210 static void scsitest_request(st
Page 214 and 215: 212 waits for the timeout and check
Page 216 and 217: 214 • We noticed that even in sup
Page 218 and 219: 216 which were discovered during wr
Page 220 and 221: 218 version swap no swap NetBSD 5.1
Page 222 and 223: 220 It needs to be stressed that Ta
Page 224 and 225: 222 Network clusters Bootstrapping
Page 226 and 227: 224 8 7 Standard components Self-co
Page 228 and 229: 226 Rump kernel calls, as expected,
Page 230 and 231: 228 Traditional FFS We measure the
Page 232 and 233: 230 80 70 60 seconds 50 40 30 20 10
Page 236 and 237: 234 behavior is required by the act
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Page 240 and 241: 238 Rialto [29] is an operating sys
Page 242 and 243: 240 One argument for partitioned op
Page 244 and 245: 242 View OS The View OS [37] approa
Page 246 and 247: 244 OSKit Instead of making system
Page 248 and 249: 246 discussing the type incompatibi
Page 250 and 251: 248 difference to the abovementione
Page 252 and 253: 250 At runtime, a rump kernel can a
Page 254 and 255: 252 For testing and development we
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Page 258 and 259: 256 Art of Virtualization. In: Proc
Page 260 and 261: 258 [30] Adam Dunkels. 2001. Design
Page 262 and 263: 260 [47] Galen C. Hunt and James R.
Page 264 and 265: 262 [67] Steven McCanne and Van Jac
Page 266 and 267: 264 [87] NetBSD Project. URL http:/
Page 268 and 269: 266 of the 6th Workshop on Programm
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Page 272 and 273: A-2 RUMP.DHCPCLIENT(1) NetBSD Gener
Page 274 and 275: A-4 RUMP.HALT(1) NetBSD General Com
Page 276 and 277: A-6 RUMP_SERVER(1) NetBSD General C
Page 278 and 279: A-8 RUMP_SERVER(1) NetBSD General C
Page 280 and 281: A-10 SHMIF_DUMPBUS(1) NetBSD Genera
Page 282 and 283: A-12 P2K(3) NetBSD Library Function
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A-14 P2K(3) NetBSD Library Function
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A-16 RUMP(3) NetBSD Library Functio
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A-18 RUMP(3) NetBSD Library Functio
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A-20 RUMP_ETFS(3) NetBSD Library Fu
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A-22 RUMP_ETFS(3) NetBSD Library Fu
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A-24 RUMP_LWPROC(3) NetBSD Library
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A-26 RUMP_LWPROC(3) NetBSD Library
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A-28 RUMPCLIENT(3) NetBSD Library F
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A-30 RUMPCLIENT(3) NetBSD Library F
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A-32 RUMPHIJACK(3) NetBSD Library F
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A-38 UKFS(3) NetBSD Library Functio
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A-48 SHMIF(4) NetBSD Kernel Interfa
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A-50 RUMP_SP(7) NetBSD Miscellaneou
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A-52 RUMP_SP(7) NetBSD Miscellaneou
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B-2 TCP connections use standard TC
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B-4 rump clients. This means that j
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B-6 ponents. That can be done simpl
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B-8 Our goal is to add another part
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B-10 golem> export RUMP_SERVER=unix
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B-12 golem> rump.dd if=/dev/rcgd0d
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B-14 demogorgon# cgdconfig cgd0 /de
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B-16 rump_server -lrumpnet -lrumpne
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B-18 golem> rump.ifconfig virt0 cre
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B-20 Congratulations, that’s it.
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B-22 purely in userspace, it does n
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B-24 We then proceed to create a mo
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B-26 Then, the only thing left is t
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B-28 -d key=/dk,hostpath=${NFSX}/ff
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B-30 configuration. golem> sh rumpn
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B-32
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C-2 This is a quick fix for making
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C-4 This fixes the conditionally co
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Aalto-DD 171/2012 9HSTFMG*aejbgi+ I
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