On Sun, Dec 10, 2006 at 12:25:08AM -0700, Grant Grundler wrote: > On Tue, Dec 05, 2006 at 11:26:51PM -0800, Greg KH wrote: > ... > > I do have a few minor comments: > ... > > > Please mark the initialization and cleanup functions where appropriate > > > (the corresponding macros are defined in <linux/init.h>): > > > > > > __init Initialization code. Thrown away after the driver > > > initializes. > > > __exit Exit code. Ignored for non-modular drivers. > > > __devinit Device initialization code. Identical to __init if > > > the kernel is not compiled with CONFIG_HOTPLUG, normal > > > function otherwise. > > > __devexit The same for __exit. > > > > > > Tips on marks: > > > o The module_init()/module_exit() functions (and all initialization > > > functions called _only_ from these) should be marked > > > __init/__exit. > > > > > > o The struct pci_driver shouldn't be marked with any of these tags. > > > > > > o The ID table array should be marked __devinitdata. > > > > > > o The probe() and remove() functions (and all initialization > > > functions called only from these) should be marked __devinit > > > and __devexit. > > > > > > o If the driver is not a hotplug driver then use only > > > __init/__exit and __initdata/__exitdata. > > > > No, don't say this, pci drivers are not "hotplug drivers", > > agreed - removed that bullet item. > > > and since CONFIG_HOTPLUG is really hard to turn off these days, > > don't confuse people with the devinit stuff. Everyone gets it wrong... > > While revisiting this bit, I started thinking: > > o While I agree HOTPLUG is essential to desktop and server, > I don't think that's true for "embedded" (e.g. routers/switches).
Agreed, but those are the minority. > o drivers should use __dev* exactly because HOTPLUG is defined. Yes, they should, but it is confusing as to why it should be used in places, and __init used in others. If you want to detail the differences better than the current documentation does, please do. > o Why does everyone get __dev* wrong? Bad API? Missing or bad Documentation? > [ This is not a free-for-all...I'd like a clear answer from > Greg what would help driver writers get this right. ] They get it wrong usually because they cut-and-paste from others. The proof of that is seeing __dev* used in pci hotplug controller drivers :) I'm just pointing out that about every 6 months I have to sweep the tree and fix up all of the improper usages. And the whole __devexit_p() stuff is usually used incorrectly too. > o Prefer a seperate patch to clean this up? > Take what I have for now and sort out the __devinit handling in > another round? > > o Note what I have is essentially the original text - just reformatted > to be a bit more readable. > > o Hrm...what did greg mean with "it"? All of the markers? > Or just the __dev* markers? Just the __dev stuff. > > > o Pointers to functions marked as __devexit must be created using > > > __devexit_p(function_name). That will generate the function > > > name or NULL if the __devexit function will be discarded. > > > > I really recommend just not using any of these for almost all PCI > > drivers, as the space savings just really isn't there... > > It's a bit too late for that, no? > And even if it's more of a PITA than it's worth, we do save something: > > # hppa64-linux-gnu-readelf -S vmlinux > ... > [26] .init.text PROGBITS 0000000040598000 00457000 > 0000000000022280 0000000000000000 AX 0 0 8 > [27] .init.data PROGBITS 00000000405ba280 00479280 > 000000000001faf0 0000000000000000 WA 0 0 8 > ... > > Reality is they are used in _alot_ of drivers. > I checked 2.6.19: > grundler <514>find -name \*.c | xargs fgrep __devinit | wc > 2723 16812 235863 > > I'd prefer to keep the short references here if you > don't mind too much. At least until you can get some > consensus that __init and __exit should go away > or get replaced by easier-to-get-right markers. Ok, just describe them properly and we should be fine. thanks, greg k-h - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
