1 TOP 2 Version 3.8beta1 3 4 William LeFebvre 5 with much help from others 6 7 Frequently Asked Questions and their Answers 8 9 10 11 GENERAL 12 13 1. What is top? 14 15 Top provies the user with a regularly updated display showing 16 information about the system and its top cpu-using processes. Think 17 of it as a full-screen "ps" output that gets updated at regular 18 intervals. 19 20 2. Where do I get the latest version of top? 21 22 The official site for top is "ftp.unixtop.org" in the directory 23 "/pub/top". Top is also a SourceForge project, and the most recent 24 releases are available on any of the SourceForge mirrors. The 25 SourceForge project page is at 26 http://sourceforge.net/projects/unixtop. 27 28 3. Is there a web page for top? 29 30 Yes. Point your browser at http://www.unixtop.org. It includes all 31 documentation, a nice interactive display which describes the various 32 components of the output of top, web-based retrieval of the package, 33 year 2000 information, and other neat stuff. 34 35 4. Is there a mailing list or on-line bulletin board for top? 36 37 There is a mailing list used for general announcements regarding top, 38 including new releases. This mailing list is available to sourceforge 39 members and can be accessed from the unixtop sourceforge project 40 page. Visit SourceForge and search for the project "unixtop", then 41 click on "mailing lists". There are also on-line forums available 42 through SourceForge where members can post questions and comments. 43 44 5. What about Year 2000 compliance? 45 46 Top did not experience any problems with the transition to the year 47 2000. A full statement concerning top and the year 2000 can be found 48 in the file "Y2K" included with the distribution. 49 50 6. Will there be another major release of top? Will there be a top 51 version 4? 52 53 I have some great ideas for the next major release of top, and I very 54 much want to make those ideas a reality. What I don't have much of 55 these days is free time. But I will keep poking at it and I hope to 56 have top version 4.0 ready by the fall of 2006. 57 58 7. Does top really support multi-processor systems? 59 60 On platforms that support multiple processors, top is able to detect 61 and correctly summarize the information about those processors. What 62 top does not do is break down the cpu states summary (the third line 63 of the display) by cpu. Instead it collects the cpu state information 64 from all processors and combines them in to a single line. Some 65 vendors include a modified version of top that presents this 66 information for each cpu. Top 3.7 may have this functionality but it 67 is not present in the standard top 3.6 release. 68 69 8. Is top under CVS control? Can I access the sources via SourceForge 70 CVS or Subversion? 71 72 I maintain top using subversion, not CVS. Although I utilize my own 73 private subversion repository, it is regularly mirrored in to the 74 SourceForge Subversion repository. You can access the SourceForge 75 repository here: https://svn.unixtop.org/unixtop/top-3. 76 77 78 COMPILING 79 80 9. We just upgraded our operating system to a new version and top broke. 81 What should we do? 82 83 Recompile it. Top is very sensitive to changes in internal kernel 84 data structures. It is not uncommon for a new version of the 85 operating system to include changes to kernel data structures. 86 87 88 RUNNING 89 90 10. I just finished compiling top and it works fine for root, but when I 91 try to run it as a regular user it either complains about files it 92 can't open or it doesn't display all the information it should. Did I 93 do something wrong? 94 95 Well, you're just not done. On many operating systems today, access 96 to many of the kernel memory devices and other system files is 97 restricted to either root or a particular group. The configure script 98 figures this out (usually) and makes sure that the "install" rule in 99 the Makefile will install top so that anyone can run it successfully. 100 However, you have to *install* it first. Do this with the command 101 "make install". 102 103 11. Top is (not) displaying idle processes and I don't (do) want it to. 104 105 This default has only changed about a dozen times, and I finally got 106 tired of people whining about it. Go read the manual page for the 107 current version and pay special attention to the description of the 108 "TOP" environment variable. 109 110 12. We have so much memory in our machine that the memory status display 111 (the fourth line) ends up being longer than 80 characters. This 112 completely messes up top's output. Is there a patch? 113 114 Most modules have been changed to use new memory formatting functions 115 which will display large values in terms of megabytes instead of 116 kilobytes. This should fix all occurences of this problem. Also note 117 that newer versions of top can use columns beyond 79, and understand 118 window resizes. So you can always make your window wider. 119 120 13. I tried to compile top with gcc and it doesn't work. I get 121 compilation errors in the include files, or I get an executable that 122 dumps core, or top displays incorrect numbers in some of the 123 displays. What's wrong? 124 125 Gnu CC likes very much to use its own include files. Not being a gcc 126 expert, I can't explain why it does this. But I can tell you that if 127 you upgrade your operating system (say from Solaris 2.6 to Solaris 128 2.7) after installing gcc, then the include files that gcc uses will 129 be incorrect, especially those found in the "sys" directory. Your 130 choices are: (1) rebuild and reinstall the "standard" include files 131 for gcc (look for scripts in the distribution called "fixincludes" 132 and "fixinc.svr4"), (2) compile machine.c with 133 "CFLAGS=-I/usr/include" then make the rest of the object files 134 normally, or (3) use a different compiler. 135 136 14. The cpu state percentages are all wrong, indicating that my machine 137 is using 95% system time when it is clearly idle. What's wrong? 138 139 This can happen if you compiled with gcc using the wrong include 140 files. See the previous question. 141 142 143 FREEBSD PROBLEMS 144 145 15. This version of top does not show individual threads with the "t" or 146 "H" commands. Instead it says "command not available." Why? 147 148 Previous versions of top attempted to support the display of 149 individual threads under FreeBSD through the use of the "t" command. 150 However, the FreeBSD kernel does not supply sufficient or correct 151 information on the individual threads within a process. So the data 152 that was being displayed was incorrect and misleading. Therefore, top 153 version 3.8 disables the use of this command to prevent the display 154 of incorrect information. FreeBSD 8.0 will correctly report 155 per-thread information and top version 3.8 supports the use of the 156 "t" command for version 8.0. 157 158 16. The "f" command (to display full command lines for the processes) 159 does not work and instead says "command not available". Why? 160 161 The current version of top is able to use sysctl to retrieve almost 162 all of the information it needs without having to open /dev/kmem. The 163 one piece of information not available via sysctl is the full command 164 line of each argument. If you run top as a regular user and it cannot 165 open /dev/kmem (in other words, it is not installed set-gid to the 166 kmem group) then it will disable the "f" command. Make sure the top 167 binary is installed with a group ownership of "kmem" and with the 168 set-gid bit on if you want the "f" command to work properly. 169 170 171 MACOSX PROBLEMS 172 173 17. I tried to configure top on my Mac OSX system and I got an error 174 claiming "macosx not supported". What up? 175 176 Since I don't have full time root access to a Mac OSX system I cannot 177 provide effective support for the platform. MacOSX uses Mach, and it 178 is very difficult to extract accurate system and process information 179 from the system. It takes a lot of trial and error, along with root 180 access. I have included the most up-to-date version of the macosx 181 module in the distribution, but I do not claim that it works. If you 182 want to try to use it, you can configure with "./configure 183 --with-module=macosx". 184 185 186 SUNOS PROBLEMS 187 188 18. I tried compiling top under SunOS version 4.1.x and it got compile 189 time errors or run time errors. Is there a patch? 190 191 If you try compiling top in a "System V environment" under SunOS 192 (that is, /usr/5bin is before /usr/bin on your path) then the 193 compilation may fail. This is mostly due to the fact that top thinks 194 its being compiled on a System V machine when it really isn't. The 195 only solution is to put /usr/bin and /usr/ucb before /usr/5bin on 196 your path and try again. 197 198 199 SOLARIS PROBLEMS 200 201 202 NOTE: the most common source of problems with top under Solaris is 203 the result of compiling it with the wrong front end. Make sure that 204 /usr/ucb is not on your path before attempting to compile top under 205 Solaris. 206 207 19. Is there somewhere I can get a pre-compiled package? 208 209 Yes. Although I don't provide pre-compiled binaries, you can get a 210 Sun-style package from www.sunfreeware.com. 211 212 20. Under Solaris 2, when I type "make", the system says "language 213 optional software package not installed." What's going on? 214 215 You tried to compile with /usr/ucb/cc. Make sure /usr/ucb is not on 216 your path. Furthermore, you do not have a Sun compiler installed on 217 your system. You need a compiler to make top. Either Sun's C compiler 218 or the Gnu C compiler will work fine. 219 220 21. Under Solaris 2, when I run top as root it only shows root processes, 221 or it only shows processes with a PID less than 1000. It refuses to 222 show anything else. What do I do? 223 224 You probably compiled it with /usr/ucb/cc instead of the real C 225 compiler. /usr/ucb/cc is a cc front end that compiles programs in BSD 226 source-level compatability mode. You do not want that. Make sure that 227 /usr/ucb is not on your path and try compiling top again. 228 229 22. Under Solaris 2, I compiled top using what I am sure is the correct 230 compiler but when I try to run it it complains about missing dynamic 231 libraries. What is wrong? 232 233 Check to see if you have LD_LIBRARY_PATH defined in your shell. If 234 you do, make sure that /usr/ucblib is not on the path anywhere. Then 235 try compiling top again. 236 237 23. Under Solaris 2, when I try to run top it complains that it can't 238 open the library "libucb.so.1". So I changed the LIBS line in 239 m_sunos5.c to include -R/usr/ucblib to make sure that the dynamic 240 linker will look there when top runs. I figured this was just an 241 oversight. Was I right? 242 243 No, you were not right. As distributed, top requires no alterations 244 for successful compilation and operations under any release of 245 Solaris 2. You probably compiled top with /usr/ucb/cc instead of the 246 real C compiler. See FAQ 22 for more details. 247 248 24. On my 64-bit system some processes show up with incorrect information 249 (such as zero memory). 250 251 If you are running a 64-bit system, then you need to make sure that 252 you are running the 64-bit top binary. Top's configure script 253 attempts to detect 64-bit systems, and will automatically generate 254 both 32-bit and 64-bit binaries on such systems. If you use or 255 install the 32-bit binary on a 64-bit system top will still run but 256 will not produce the correct results. This will also happen if you 257 configure your distribution on a 32-bit system then compile with that 258 configuration on a 64-bit system. You must configure and compile on 259 the same system. For Sparc systems the 32-bit binary will be created 260 in the subdirectory "sparcv7" and the 64-bit binary will be created 261 in the subdirectory "sparcv9". For Intel systems the directories will 262 be "i386" (32-bit) and "amd64" (64-bit). In all cases a copy of 263 /usr/lib/isaexec is made in the main directory and called "top". This 264 program will choose the correct binary to run from one of these 265 subdirectories. See isaexec(3c) for more details. 266 267 25. Can I install both 32-bit and 64-bit binaries on a central file 268 server and have machines which mount it automatically use the correct 269 one? 270 271 Yes. If you configure and compile on a 64-bit system, top's configure 272 script and makefile will automatically create both 32-bit and 64-bit 273 binaries. The "install" rule in the makefile will install these 274 binaries in subdirectories of /usr/local/bin appropriate to the 275 architecture (sparcv7/sparcv9 or i386/amd64) then create a copy of 276 /usr/lib/isaexec named "top" in /usr/local/bin to ensure that the 277 appropriate is run when a user types "top". If you make sure that you 278 configure and compile on a 64-bit system, then "make install" will do 279 the right thing. 280 281 26. This version of top show less available swap space than previous 282 versions. Why does it no longer match the output of the swap summary 283 produced with "swap -s"? 284 285 Starting with version 3.6 of top, the amount of swap space reported 286 by top has been changed to reflect only disk-based swap space. The 287 swap summary produced with "swap -s" also includes memory-based swap 288 space. This changed was made for several reasons. It makes the 289 display under Solaris more like those of other operating systems. The 290 display is more what users expect (except those used to previous 291 versions of top). Most importantly, "swap -s" gets its data via an 292 undocumented system interface. Now that top no longer displays that 293 data it can use publically documented and maintained system 294 interfaces to retrieve its data. 295 296 297 SVR4-DERIVED PROBLEMS 298 299 27. When I run top on my SVR4-derived operating system, it displays all 300 the system information at the top but does not display any process 301 information (or only displays process information for my own 302 processes). Yet when I run it as root, everything works fine. What's 303 wrong? 304 305 Your system probably uses the pseudo file system "/proc", which is by 306 default only accessible by root. Top needs to be installed setuid 307 root on such systems if it is going to function correctly for normal 308 users. 309 310 311 SVR42 PROBLEMS 312 313 28. The memory display doesn't work right. Why? 314 315 This is a known bug with the svr42 module. The problem has been 316 traced down to a potential bug in the "mem" driver. The author of the 317 svr42 module is working on a fix. 318 319 320 STILL STUCK 321 322 29. I'm still stuck. To whom do I report problems with top? 323 324 The most common problems are caused by top's sensitivity to internal 325 kernel data structures. So make sure that you are using the right 326 include files, and make sure that you test out top on the same 327 machine where you compiled it. Sun's BSD Source Compatability Mode is 328 also a common culprit. Make sure you aren't using either /usr/ucb/cc 329 or any of the libraries in /usr/ucblib. Finally, make sure you are 330 using the correct module. If there does not appear to be one 331 appropriate for your computer, then top probably will not work on 332 your system. 333 334 If after reading all of this file and checking everything you can you 335 are still stuck, then please use SourceForge to submit a support 336 request or a bug. Top is supported by the SourceForge project named 337 "unixtop". On SourceForge you will find defect tracking, a mailing 338 list, and on-line forums. You can also contact the author through 339 SourceForge. 340 341
Indexes created Sun Apr 12 00:22:20 UTC 2026