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Member "atop-2.8.1/README" (7 Jan 2023, 4338 Bytes) of package /linux/misc/atop-2.8.1.tar.gz:

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    1 COPYRIGHT NOTICE
    2 ----------------
    3 For all files that are not marked differently:
    4 
    5 Copyright Gerlof Langeveld 2007-2022 and licensed under the GPL v2 (or any later version).
    6 
    7 
    8 DEPENDENCIES
    9 ------------
   10 
   11 Install the following packages to be able to build atop (package name
   12 can be different depending on the Linux distro):
   13 
   14 * zlib-devel    or libz-dev or zlib1g-dev
   15 * ncurses-devel or libncurses5-dev/libncursesw5-dev
   16 
   17 
   18 Install the following packages to be able to execute atop (package name
   19 can be different depending on the Linux distro):
   20 
   21 * zlib    or zlib1g
   22 * ncurses or libncurses5/libncursesw5
   23 
   24 
   25 INSTALLING AND USING ATOP
   26 -------------------------
   27 
   28 For interactive use, it is sufficient to install ATOP with the command
   29 (as root):
   30 
   31 	make install		(systemd based)
   32 
   33 		or
   34 
   35 	make sysvinstall	(System V init based)
   36 
   37 For automatic logging in compressed binary format, see the
   38 description in the manual-page.
   39 
   40 The kernel module 'netatop' can be downloaded and installed separately
   41 from www.atoptool.nl/downloadnetatop.php
   42 This module is optional and can be used to gather network statistics
   43 per process/thread as described in www.atoptool.nl/netatop.php
   44 
   45 
   46 PROCESS ACCOUNTING WITH PSACCT/ACCT PACKAGE
   47 -------------------------------------------
   48 
   49 Preferably, process accounting should be handled by the atopacctd daemon
   50 which is implicitly installed when installing atop. This daemon takes
   51 care that process accounting is only active when at least one atop
   52 process is running. Besides, when process accounting is activated,
   53 atopacctd takes care that the disk utilization is minimal.
   54 See the man page of atopacctd for further details.
   55 
   56 When the psacct or acct package is installed in parallel with the
   57 atop package and you want to enable/start the (ps)acct service for
   58 permanent process accounting, the atopacct.service refuses to activate
   59 the atopacctd daemon to avoid clashes.
   60 When the (ps)acct service is enabled, atop automatically uses the
   61 process accounting file that is used by this package.
   62 See also the section PROCESS ACCOUNTING in the man page of atop.
   63 
   64 
   65 KERNEL ISSUES WITH PROCESS ACCOUNTING
   66 -------------------------------------
   67 
   68 Newer upstream kernels (e.g. 4.8 and 4.9) have two issuess
   69 with process accounting:
   70 
   71 1) Sometimes process accounting does not work at all¹. Atopacctd tries to
   72 work around this issue, by retrying to initialize process accounting
   73 several times.
   74 
   75 2) When using the NETLINK inface, the command TASKSTATS_CMD_GET
   76 consequently returns -EINVAL². Atopacctd needs NETLINK to be able to
   77 be triggered that some process in the system has finished. In this way,
   78 atopacctd can be in a blocking state as long as no processes terminate.
   79 When atopacctd detects that NETLINK fails, it switches into a polling
   80 mode to periodically try if it can read process accounting records as
   81 a workaround. This issue has to do with cpumasks and you can work-around
   82 it by building a kernel that has CONFIG_NR_CPUS configured to exactly
   83 the amount of CPUs (logical CPUs) in the system the kernel runs on. You
   84 can find this kernel option under "Processor type and features" -->
   85 "Maximum number of CPUs".
   86 
   87 
   88 [1] Bug 190271 - process accounting sometimes does not work
   89 https://bugzilla.kernel.org/show_bug.cgi?id=190271
   90 
   91 [2] Bug 190711 - Process accounting: Using the NETLINK interface,
   92 the command TASKSTATS_CMD_GET returns -EINVAL
   93 https://bugzilla.kernel.org/show_bug.cgi?id=190711
   94 
   95 Linux kernel mailing list thread:
   96 
   97 [REGRESSION] Two issues that prevent process accounting (taskstats) from
   98 working correctly
   99 https://lkml.org/lkml/2016/12/19/182
  100 
  101 
  102 SERVICE ACTIVATION AFTER INSTALLATION
  103 -------------------------------------
  104 
  105 After the package has been installed, be sure that the related services
  106 are activated.
  107 To support handling of terminated processes using process accounting,
  108 enable the atopacct service:
  109 
  110 	systemctl enable --now atopacct
  111 
  112 Notice that this service should not be enabled when the package
  113 psacct or acct (depends on the Linux distribution) has been installed
  114 and enabled. In that case atop uses the daily process accounting file
  115 created via that package.
  116 
  117 To support maintaining daily log files to keep track of long-term analysis
  118 information, enable the atop service and the related timer:
  119 
  120 	systemctl enable --now atop
  121 	systemctl enable --now atop-rotate.timer
  122 
  123 
  124 
  125 
  126 Gerlof Langeveld
  127 gerlof.langeveld@atoptool.nl