Linus Torvalds wrote:
On Fri, 6 Oct 2006, Jeff Garzik wrote:
Here is the raw, un-split-up first pass of the irq argument removal patch
(500K): http://gtf.org/garzik/misc/patch.irq-remove
So I'm not at all as sure about this as about the "regs" stuff.
The "regs" value has always been controversial. It's pretty much always
existed (due to the keyboard hander and the magic debugging keysequences),
and anybody who looks at 0.01 will quickly realize that the keyboard
driver was one of the very first drivers (I think it's even written in
assembly at that point: originally _all_ of what was to become Linux was
pure asm, the whole "oh, cool, I could write this part in C" came later).
But it's been pretty much a special case since day #1, purely for that
"press a key to see where the h*ck we hung" case.
Chuckle :)
In contrast, the irq argument itself is really no different from the
cookie we pass in on registration - it's just passing it back to the
driver that requested the thing. So unlike "regs", there's not really
anything strange about it, and there's nothing really "wrong" with having
it there.
It doesn't have the colorful history of pt_regs, but the 'irq' argument
is dead weight. I'd say the wrongness stems from its utter uselessness.
Out of ~1100 irq handlers, the irq parameter is used in ~50. The vast
majority of those 50 uses are debug printks, or abused as a "did I call
myself?" internal driver flag. The number of "real" uses is under 15,
and those are all ancient ISA or platform drivers that pre-date my ~10
year history with Linux.
So, I don't see any convincing argument to keep it. And if we are going
to kill it, given the pt_regs churn, this is probably the best
opportunity we'll have in years.
Another weak-but-still-present argument in favor of killing it is that
this change would IMO future-proof irq handlers, against more exotic irq
handling methods that may come down the pipe.
Jeff
-
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/
[Index of Archives]
[Kernel Newbies]
[Netfilter]
[Bugtraq]
[Photo]
[Stuff]
[Gimp]
[Yosemite News]
[MIPS Linux]
[ARM Linux]
[Linux Security]
[Linux RAID]
[Video 4 Linux]
[Linux for the blind]
[Linux Resources]
