Maintain a per-CPU global "struct pt_regs *" variable which can be used instead
of passing regs around manually through all ~1800 interrupt handlers in the
Linux kernel.
The regs pointer is used in few places, but it potentially costs both stack
space and code to pass it around. On the FRV arch, removing the regs parameter
from all the genirq function results in a 20% speed up of the IRQ exit path
(ie: from leaving timer_interrupt() to leaving do_IRQ()).
Where appropriate, an arch may override the generic storage facility and do
something different with the variable. On FRV, for instance, the address is
maintained in GR28 at all times inside the kernel as part of general exception
handling.
Having looked over the code, it appears that the parameter may be handed down
through up to twenty or so layers of functions. Consider a USB character
device attached to a USB hub, attached to a USB controller that posts its
interrupts through a cascaded auxiliary interrupt controller. A character
device driver may want to pass regs to the sysrq handler through the input
layer which adds another few layers of parameter passing.
I've build this code with allyesconfig for x86_64 and i386. I've runtested the
main part of the code on FRV and i386, though I can't test most of the drivers.
I've also done partial conversion for powerpc and MIPS - these at least compile
with minimal configurations.
This will affect all archs. Mostly the changes should be relatively easy.
Take do_IRQ(), store the regs pointer at the beginning, saving the old one:
struct pt_regs *old_regs = set_irq_regs(regs);
And put the old one back at the end:
set_irq_regs(old_regs);
Don't pass regs through to generic_handle_irq() or __do_IRQ().
In timer_interrupt(), this sort of change will be necessary:
- update_process_times(user_mode(regs));
- profile_tick(CPU_PROFILING, regs);
+ update_process_times(user_mode(get_irq_regs()));
+ profile_tick(CPU_PROFILING);
I'd like to move update_process_times()'s use of get_irq_regs() into itself,
except that i386, alone of the archs, uses something other than user_mode().
Some notes on the interrupt handling in the drivers:
(*) input_dev() is now gone entirely. The regs pointer is no longer stored in
the input_dev struct.
(*) finish_unlinks() in drivers/usb/host/ohci-q.c needs checking. It does
something different depending on whether it's been supplied with a regs
pointer or not.
(*) Various IRQ handler function pointers have been moved to type
irq_handler_t.
Signed-Off-By: David Howells <dhowells@redhat.com>
(cherry picked from 1b16e7ac850969f38b375e511e3fa2f474a33867 commit)
As I promised last week, here is the first pass at removing all
unnecessary printk's that exist in network device drivers currently in
promiscuous mode. The duplicate messages are not needed so they have
been removed. Some of these drivers are quite old and might not need an
update, but I did them all anyway.
I am currently auditing the remaining conditional printk's and will send
out a patch for those soon.
Signed-off-by: Andy Gospodarek <andy@greyhouse.net>
Signed-off-by: Jeff Garzik <jeff@garzik.org>
From: Michal Piotrowski <michal.k.k.piotrowski@gmail.com>
Signed-off-by: Michal Piotrowski <michal.k.k.piotrowski@gmail.com>
Signed-off-by: Jeff Garzik <jeff@garzik.org>
For messages prior to register_netdev(), prefer dev_printk() because
that prints out both our driver name and our [PCI | whatever] bus id.
Updates: 8139{cp,too}, b44, bnx2, cassini, {eepro,epic}100, fealnx,
hamachi, ne2k-pci, ns83820, pci-skeleton, r8169.
Signed-off-by: Jeff Garzik <jeff@garzik.org>
- Remove in-source changelog, it's in the global kernel history.
- convert silly and useless version to useful one
- replace invariant pci_id_tbl[]::io_size uses with EPIC_TOTAL_SIZE
- remove now-unused io_size member from pci_id_tbl[]
- current kernel style prefers dev_printk() for the rare ethernet driver
messages that cannot print an 'eth%d' prefix.
Signed-off-by: Jeff Garzik <jeff@garzik.org>
Symbols such as PCI_USES_IO, PCI_ADDR0, etc. originated from Donald
Becker's net driver template, but have been long unused. Remove.
In a few drivers, this allows the further eliminate of the pci_flags (or
just plain flags) member in the template driver probe structure.
Most of this logic is simply open-coded in most drivers, since it never
changes.
Made a few other cleanups while I was in there, too:
* constify, __devinitdata several PCI ID tables
* replace table terminating entries such as "{0,}," and "{NULL},"
with a more-clean "{ }".
Signed-off-by: Jeff Garzik <jeff@garzik.org>
First of all it is unnecessary to allocate a new skb in skb_pad since
the existing one is not shared. More importantly, our hard_start_xmit
interface does not allow a new skb to be allocated since that breaks
requeueing.
This patch uses pskb_expand_head to expand the existing skb and linearize
it if needed. Actually, someone should sift through every instance of
skb_pad on a non-linear skb as they do not fit the reasons why this was
originally created.
Incidentally, this fixes a minor bug when the skb is cloned (tcpdump,
TCP, etc.). As it is skb_pad will simply write over a cloned skb. Because
of the position of the write it is unlikely to cause problems but still
it's best if we don't do it.
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
work_done is overwritten each time through the rx_action loop in
epic_poll. This screws-up the NAPI accounting if the loop is executed
more than once.
Signed-off-by: John W. Linville <linville@tuxdriver.com>
Signed-off-by: Jeff Garzik <jgarzik@pobox.com>
Many drivers use skb->tail unnecessarily.
In these situations, the code roughly looks like:
dev = dev_alloc_skb(...);
[optional] skb_reserve(skb, ...);
... skb->tail ...
But even if the skb_reserve() happens, skb->data equals
skb->tail. So it doesn't make any sense to use anything
other than skb->data in these cases.
Another case was the s2io.c driver directly mucking with
the skb->data and skb->tail pointers. It really just wanted
to do an skb_reserve(), so that's what the code was changed
to do instead.
Another reason I'm making this change as it allows some SKB
cleanups I have planned simpler to merge. In those cleanups,
skb->head, skb->tail, and skb->end pointers are removed, and
replaced with skb->head_room and skb->tail_room integers.
Signed-off-by: David S. Miller <davem@davemloft.net>
Acked-by: Jeff Garzik <jgarzik@pobox.com>
Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.
Let it rip!
David Howells