The configuration write-back process which runs several times during startup - does a huge slew of system-calls quite un-necessarily. We should buffer that to improve startup performance.
Michael Meeks committed a patch related to this issue. It has been pushed to "master": http://cgit.freedesktop.org/libreoffice/core/commit/?id=e1d78e123b74d37f95b4075b93202b023b4320e9 tdf#92764 - make configmgr write less noisy. It will be available in 5.1.0. The patch should be included in the daily builds available at http://dev-builds.libreoffice.org/daily/ in the next 24-48 hours. More information about daily builds can be found at: http://wiki.documentfoundation.org/Testing_Daily_Builds Affected users are encouraged to test the fix and report feedback.
Also interesting that the configuration is now non-deterministically ordered, so each time we write it it convolves - which is a bit unpleasant for diffing; we should prolly sort the data on save =)