On Tue, May 06, 2008 at 12:51:08AM -0700, Dave Leskovec wrote: > This patch changes the lxc tty forwarding process to use epoll instead of > poll. > This is done to avoid a cpu consuming loop when a user disconnects from the > container console. > > During some testing, we found that when the slave end of a tty is closed, > calls > to poll() on the master end will return immediately with POLLHUP until the > slave > end is opened again. The result of this is that if you connect to the > container > console using virsh and then ctrl-] out of it, the container tty process will > chew up the processor handling POLLHUP. This event can't be disabled > regardless > of what is set in the events field. > > This can be avoided by using epoll. When used in edge triggered mode, you see > the initial EPOLLHUP but will not see another one until someone connects and > then disconnects from the console again. This also drove some changes into > how > the regular input data is handled. Once an EPOLLIN is seen from an fd, > another > one will not be surfaced until all data has been read from the file (EAGAIN is > returned by read).
Sounds fine in principle but i have a couple of questions with the patch > +#include <stdbool.h> err ... what is that ? looks like a linux specific header, do we really need this ? epoll is linux specific I think but #include <sys/epoll.h> should be sufficient no ? [...] > > - close(vm->parentTty); > + //close(vm->parentTty); > close(vm->containerTtyFd); if we really don't need this anymore just remove it, if you have doubts then maybe this should be clarified. In any case let's stick to old style comments /* ... */ Daniel -- Red Hat Virtualization group http://redhat.com/virtualization/ Daniel Veillard | virtualization library http://libvirt.org/ [EMAIL PROTECTED] | libxml GNOME XML XSLT toolkit http://xmlsoft.org/ http://veillard.com/ | Rpmfind RPM search engine http://rpmfind.net/ -- Libvir-list mailing list Libvir-list@redhat.com https://www.redhat.com/mailman/listinfo/libvir-list
