On Tuesday, 12/07/2010 at 12:30 EST, Malcolm Beattie <[email protected]> wrote: > No, I'm opening a sysfs file--maybe I was unclear. The notification > mechanism I'm talking about it is via the sysfs driver model file > (/sys/.....) and not the special character device file (/dev/...). > The latter is, as both you and I have written, a non-blocking model. > > In the Linux driver model, device-related notifications can be sent > as uevents (broadcast over an AF_NETLINK socket, one of whose > listeners is udevd with its configurable rulesets undef /udev) or, > more recently, via a POLLPRI condition on a descriptor opened on > a sysfs file. Neither of these affects the open/read/write/close > behaviour of the special character device file in /dev. > Or I may have misunderstood your point?
I was saying that the sysfs entry is fine, providing more comprehensive event service, but that I/O model for VMUR is wrong (IMO). Thinking about it even more, I recant my statement about open() giving an error related to the presence of data or the lack thereof. Data presence or lack would be indicated by read() or select(). Alan Altmark z/VM and Linux on System z Consultant IBM System Lab Services and Training ibm.com/systems/services/labservices office: 607.429.3323 [email protected] IBM Endicott ---------------------------------------------------------------------- For LINUX-390 subscribe / signoff / archive access instructions, send email to [email protected] with the message: INFO LINUX-390 or visit http://www.marist.edu/htbin/wlvindex?LINUX-390 ---------------------------------------------------------------------- For more information on Linux on System z, visit http://wiki.linuxvm.org/
