diff options
| -rwxr-xr-x | scripts/build-remote.pl.in | 11 |
1 files changed, 10 insertions, 1 deletions
diff --git a/scripts/build-remote.pl.in b/scripts/build-remote.pl.in index c805d6740ef3..6a6515756163 100755 --- a/scripts/build-remote.pl.in +++ b/scripts/build-remote.pl.in @@ -225,8 +225,17 @@ sub removeRoots { } -# Copy the derivation and its dependencies to the build machine. +# Copy the derivation and its dependencies to the build machine. This +# is guarded by an exclusive lock per machine to prevent multiple +# build-remote instances from copying to a machine simultaneously. +# That's undesirable because we may end up with N instances uploading +# the same missing path simultaneously, causing the effective network +# bandwidth and target disk speed to be divided by N. +my $uploadLock = "$currentLoad/$hostName.upload-lock"; +open MAINLOCK, ">>$uploadLock" or die; +flock(MAINLOCK, LOCK_EX) or die; Nix::CopyClosure::copyTo($hostName, [ @sshOpts ], [ $drvPath, @inputs ], "", "", 0, 0, $maybeSign ne ""); +close MAINLOCK; # Perform the build. |