Richard Oudkerk added the comment: Using truncate() to zero extend is not really portable: it is only guaranteed on XSI-compliant POSIX systems.
Also, the FreeBSD man page for mmap() has the following warning: WARNING! Extending a file with ftruncate(2), thus creating a big hole, and then filling the hole by modifying a shared mmap() can lead to severe file fragmentation. In order to avoid such fragmentation you should always pre-allocate the file's backing store by write()ing zero's into the newly extended area prior to modifying the area via your mmap(). The fragmentation problem is especially sensitive to MAP_NOSYNC pages, because pages may be flushed to disk in a totally random order. ---------- _______________________________________ Python tracker <rep...@bugs.python.org> <http://bugs.python.org/issue21116> _______________________________________ _______________________________________________ Python-bugs-list mailing list Unsubscribe: https://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
