Re: [ovirt-users] VDSM memory consumption

Daniel Helgenberger <daniel.helgenberger(a)m-box.de&gt; writes: > Hello Everyone, > > I did create the original BZ on this. In the mean time, lab system I > used is dismantled and the production system is yet to deploy. > > As I wrote in BZ1147148 [1], I experienced two different issues. One, > one big mem leak of about 15MiB/h and a smaller one, ~300KiB. These seem > unrelated. > > The larger leak was indeed related to SSL in some way; not necessarily > M2Crypto. However, after disabling SSL this was gone leaving the smaller > leak. > > [1] https://bugzilla.redhat.com/show_bug.cgi?id=1147148 I think there are, at least for the purpose of this discussion, 3 leaks: 1. the M2Crypto leak 2. a slower leak 3. a large leak that's not M2Crypto related that's part of sampling My efforts have been around finding the source of my larger leak, which I think is #3. I had disabled ssl so I knew that M2Crypto isn't/shouldn't be the problem as in bz1147148, and ssl is beside the point as it happens with a deactived host. It's part of sampling which always runs. What I've found is, after trying to get the smallest reproducer, that it's not the netlink.iter_links that I commented on in [1] that is the problem. But in the _get_intefaces_and_samples loop is the call to create an InterfaceSample and that has getLinkSpeed() which, for vlans, ends up calling ipwrapper.getLink, and that to netlink.get_link(name) netlink.get_link(name) *is* the source of my big leak. This is vdsm 4.16.10, so it is [2] and it's been changed in master for the removal of support for libnl v1 so it might not be a problem anymore. def get_link(name): """Returns the information dictionary of the name specified link.""" with _pool.socket() as sock: with _nl_link_cache(sock) as cache: link = _rtnl_link_get_by_name(cache, name) if not link: raise IOError(errno.ENODEV, '%s is not present in the system' % name) return _link_info(cache, link) The libnl documentation note at [3] says that for the rtnl_link_get_by_name function "Attention The reference counter of the returned link object will be incremented. Use rtnl_link_put() to release the reference." So I took that hint, and made a change that does the rtnl_link_put() in get_link(name) and it looks like it works for me. diff oldnetlink.py netlink.py 67d66 < return _link_info(cache, link) 68a68,70 > li = _link_info(cache, link) > _rtnl_link_put(link) > return li 333a336,337 > > _rtnl_link_put = _none_proto(('rtnl_link_put', LIBNL_ROUTE)) Hope that helps. And if someone else could confirm that would be great. [1] https://bugzilla.redhat.com/show_bug.cgi?id=1158108 [2] https://gerrit.ovirt.org/gitweb?p=vdsm.git;a=blob;f=lib/vdsm/netlink.py;h... [3] http://www.infradead.org/~tgr/libnl/doc/api/group__link.html#ga1d583e4f0b...