[Bug 3186] Surprisingly large unshared memory usage
bugzilla-daemon at dp3.samba.org
bugzilla-daemon at dp3.samba.org
Wed Nov 23 06:42:00 GMT 2005
https://bugzilla.samba.org/show_bug.cgi?id=3186
------- Comment #2 from vanes002 at umn.edu 2005-11-22 23:41 MST -------
What version are you using? You have 2.6.7 selected in the bug report, but
that's still in development.
The copy-on-write optimization wasn't done until v2.6.1 (Apr 2004):
- The generator is now better about not modifying the file list
during the transfer in order to avoid a copy-on-write memory
bifurcation (on systems where fork() uses shared memory).
Previously, rsync's shared memory would slowly become unshared,
resulting in real memory usage nearly doubling on the receiving
side by the end of the transfer. Now, as long as permissions
are being preserved, the shared memory should remain that way
for the entire transfer.
You use the -p option, so you meet the "permissions being preserved" condition.
The file_struct data and other chunks of data are allocated out of the free
memory pool. If lots of those allocated chunks are returned to the pool, pool
management involves memory being modified, so that would require new writes.
Wayne - does rsync free up anything substantial at any time after the fork that
might trigger this?
--
Configure bugmail: https://bugzilla.samba.org/userprefs.cgi?tab=email
------- You are receiving this mail because: -------
You are the QA contact for the bug, or are watching the QA contact.
More information about the rsync
mailing list