"Adam J. Richter" wrote:
> If a programmer errs in favor of __devinit, the result is
> extra memory consumption under CONFIG_HOTPLUG. If a programmer
> errs in favor of __init, the result is a crash during hot p
> ug insertion. Avoiding crashes at the expensive of a pretty small
> amount of memory usage is the more "conservative" way to err.
You suggest avoiding correctness in order to protect against dumb
programmers. That path leads to Windows.
> >Otherwise, you rob CONFIG_HOTPLUG people of some memory that could
> >otherwise be freed at boot. And the number of CONFIG_HOTPLUG people is
> >not small, it includes not only the CardBus users but USB users too...
>
> We have been discussing this on linux-devel-usb. The
> latest patches submitted to Linus and in 2.4.0-test10-pre{3,4}
> support USB hot plugging regardless of whether CONFIG_HOTPLUG is
> specified.
>
> bash% find linux-2.4.0-test11-pre4/drivers/usb -type f | xargs egrep HOTPLUG
Read the code. test11-pre[34] was broken due to my recent
CONFIG_KMOD/CONFIG_HOTPLUG separation, and should have had
CONFIG_HOTPLUG. test11-pre5 has CONFIG_HOTPLUG. As it should.
> Having USB hot plugging without needing to build in PCI
> hot plugging is useful,
Of course. But CONFIG_HOTPLUG does not mean PCI hotplugging. It means
any hotplug support in the kernel. That is why __devinit exists and is
used in a generic fashion.
> After 2.4.0, [...] we may
> want to explore adding __usbdevinit{,data} defines in include/linux/init.h
> that would be controlled by a new CONFIG_USB_HOTPLUG option, as in
> the patches that I posted for this to linux-usb-devel.
This is not just a USB issue. Please discuss this on linux-kernel, so
we can have a coherent hotplug strategy for the entire kernel.
If we are going to create CONFIG_USB_HOTPLUG, we must -eliminate-
CONFIG_HOTPLUG, and create CONFIG_PCI_HOTPLUG, and
CONFIG_ANOTHERBUS_HOTPLUG and so on, for each hotplug bus.
Jeff
-- Jeff Garzik | Building 1024 | The chief enemy of creativity is "good" sense MandrakeSoft | -- Picasso - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org Please read the FAQ at http://www.tux.org/lkml/
This archive was generated by hypermail 2b29 : Wed Nov 15 2000 - 21:00:27 EST