PVE/AutoBalloon.pm

   1 package PVE::AutoBalloon;
   2
   3 use warnings;
   4 use strict;
   5
   6 sub compute_alg1 {
   7     my ($vmstatus, $goal, $maxchange, $debug) =  @_;
   8
   9     my $log = sub { print @_ if $debug; };
  10
  11     my $change_func = sub {
  12         my ($res, $idlist, $bytes) = @_;
  13
  14         my $rest = $bytes;
  15         my $repeat = 1;
  16         my $done_hash = {};
  17         my $progress = 1;
  18
  19         while ($rest && $repeat && $progress) {
  20             $repeat = 0;
  21             $progress = 0;
  22
  23             my $shares_total = 0;
  24             my $alloc_old = 0;
  25
  26             foreach my $vmid (@$idlist) {
  27                 next if defined($done_hash->{$vmid});
  28                 my $d = $vmstatus->{$vmid};
  29                 my $balloon = defined($res->{$vmid}) ? $res->{$vmid} : $d->{balloon};
  30                 $alloc_old += $balloon - $d->{balloon_min};
  31                 $shares_total += $d->{shares} || 1000;
  32             }
  33
  34             my $changes = 0;
  35
  36             my $alloc_new = $alloc_old + $rest;
  37
  38             &$log("shares_total: $shares_total $alloc_new\n");
  39
  40             foreach my $vmid (@$idlist) {
  41                 next if defined($done_hash->{$vmid});
  42                 my $d = $vmstatus->{$vmid};
  43                 my $shares = $d->{shares} || 1000;
  44                 my $desired = $d->{balloon_min} + int(($alloc_new/$shares_total)*$shares);
  45
  46                 if ($desired > $d->{maxmem}) {
  47                     $desired = $d->{maxmem};
  48                     $repeat = 1;
  49                 } elsif ($desired < $d->{balloon_min}) {
  50                     $desired = $d->{balloon_min};
  51                     $repeat = 1;
  52                 }
  53
  54                 my ($new, $balloon);
  55                 if (($bytes > 0) && ($desired - $d->{balloon}) > 0) { # grow
  56                     $new = $d->{balloon} + $maxchange;
  57                     $balloon = $new > $desired ? $desired : $new;
  58                 } elsif (($desired - $d->{balloon}) < 0) { # shrink
  59                     $new = $d->{balloon} - $maxchange;
  60                     $balloon = $new > $desired ? $new : $desired;
  61                 } else {
  62                     $done_hash->{$vmid} = 1;
  63                     next;
  64                 }
  65
  66                 my $diff = $balloon - $d->{balloon};
  67                 if ($diff != 0) {
  68                     my $oldballoon = defined($res->{$vmid}) ? $res->{$vmid} : $d->{balloon};
  69                     $res->{$vmid} = $balloon;
  70                     my $change = $balloon - $oldballoon;
  71                     if ($change != 0) {
  72                         $changes += $change;
  73                         my $absdiff = $diff > 0 ? $diff : -$diff;
  74                         $progress += $absdiff;
  75                         $repeat = 1;
  76                     }
  77                     &$log("change request for $vmid ($balloon, $diff, $desired, $new, $changes, $progress)\n");
  78                 }
  79             }
  80
  81             $rest -= $changes;
  82         }
  83
  84         return $rest;
  85     };
  86
  87
  88     my $idlist = []; # list of VMs with working balloon river
  89     my $idlist1 = []; # list of VMs with memory pressure
  90     my $idlist2 = []; # list of VMs with enough free memory
  91
  92     foreach my $vmid (keys %$vmstatus) {
  93         my $d = $vmstatus->{$vmid};
  94         next if !$d->{balloon}; # skip if balloon driver not running
  95         next if !$d->{balloon_min}; # skip if balloon value not set in config
  96
  97         push @$idlist, $vmid;
  98
  99         if ($d->{freemem} &&
 100             ($d->{freemem} > $d->{balloon_min}*0.25) &&
 101             ($d->{balloon} >= $d->{balloon_min})) {
 102             push @$idlist2, $vmid;
 103             &$log("idlist2 $vmid $d->{balloon}, $d->{balloon_min}, $d->{freemem}\n");
 104         } else {
 105             push @$idlist1, $vmid;
 106             &$log("idlist1 $vmid $d->{balloon}, $d->{balloon_min}, $d->{freemem}\n");
 107         }
 108     }
 109
 110     my $res = {};
 111
 112     if ($goal > 10*1024*1024) {
 113         &$log("grow request start $goal\n");
 114         # priorize VMs with memory pressure
 115         my $rest = &$change_func($res, $idlist1, $goal);
 116         if ($rest >= $goal) { # no progress ==> consider all VMs
 117             &$log("grow request loop $rest\n");
 118             $rest = &$change_func($res, $idlist, $rest);
 119         }
 120         &$log("grow request end $rest\n");
 121
 122     } elsif ($goal < -10*1024*1024) {
 123         &$log("shrink request $goal\n");
 124         # priorize VMs with enough free memory
 125         my $rest = &$change_func($res, $idlist2, $goal);
 126         if ($rest <= $goal) { # no progress ==> consider all VMs
 127             &$log("shrink request loop $rest\n");
 128             $rest = &$change_func($res, $idlist, $rest);
 129         }
 130         &$log("shrink request end $rest\n");
 131    } else {
 132         &$log("do nothing\n");
 133         # do nothing - requested change to small
 134     }
 135
 136     foreach my $vmid (@$idlist) {
 137         next if !$res->{$vmid};
 138         my $d = $vmstatus->{$vmid};
 139         my $diff = int($res->{$vmid} - $d->{balloon});
 140         my $absdiff = $diff < 0 ? -$diff : $diff;
 141         &$log("BALLOON $vmid to $res->{$vmid} ($diff)\n");
 142     }
 143     return $res;
 144 }
 145
 146 1;