unnecessary polls of cdrom block device from udisks daemon

[David Zeuthen]

Hey,

On Fri, Apr 6, 2012 at 5:15 AM, Aaron Lu <aaron.lu at amd.com> wrote:
> Hi,
>
> I'm doing some development on Linux scsi cdrom driver(sr module)
> recently and found that the udisks daemon will periodically open the
> ODD block device /dev/sr0. I guess the reason is to check events, since
> on block open, the check_events function will be called.
>
> But since the udev will also enable in kernel polling by change the
> kernel parameter /sys/module/block/parameters/events_dfl_poll_msecs to 2
> seconds, so the polls done by udisks daemon by a open system call for
> the scsi cdrom block device should be unnecessary.

Maybe you are just using an old version of udisks? As of udisks 1.0.3
(released mid 2011), we no longer poll if the kernel does, this is the
commit

http://cgit.freedesktop.org/udisks/commit/?h=udisks1&id=2d0272eb3be71f6ee3f52c55a3d608764b675fb0

For udisks2, we never poll, we assume the kernel is always polling.

Thanks,
David