On Fri, Oct 17, 2014 at 04:57:27PM +0800, Linhaifeng wrote: > > > On 2014/10/17 16:33, Daniel P. Berrange wrote: > > On Fri, Oct 17, 2014 at 04:27:17PM +0800, haifeng....@huawei.com wrote: > >> From: linhaifeng <haifeng....@huawei.com> > >> > >> The VM start with share hugepage should close the hugefile fd > >> when exit.Because the hugepage fd may be send to other process > >> e.g vhost-user If qemu not close the fd the other process can > >> not free the hugepage otherwise exit process,this is ugly,so > >> qemu should close all shared fd when exit. > >> > >> Signed-off-by: linhaifeng <haifeng....@huawei.com> > > > > Err, all file descriptors are closed automatically when a process > > exits. So manually calling close(fd) before exit can't have any > > functional effect on a resource leak. > > > > If QEMU has sent the FD to another process, that process has a > > completely separate copy of the FD. Closing the FD in QEMU will > > not close the FD in the other process. You need the other process > > to exit for the copy to be closed. > > > > Regards, > > Daniel > > > Hi,daniel > > QEMU send the fd by unix domain socket.unix domain socket just install the fd > to > other process and inc the f_count,if qemu not close the fd the f_count is not > dec. > Then the other process even close the fd the hugepage would not freed whise > the other process exit.
The kernel always closes all FDs when a process exits. So if this FD is not being correctly closed then it is a kernel bug. There should never be any reason for an application to do close(fd) before exiting. Regards, Daniel -- |: http://berrange.com -o- http://www.flickr.com/photos/dberrange/ :| |: http://libvirt.org -o- http://virt-manager.org :| |: http://autobuild.org -o- http://search.cpan.org/~danberr/ :| |: http://entangle-photo.org -o- http://live.gnome.org/gtk-vnc :|
