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  1. 16 12月, 2006 3 次提交
  3. 04 12月, 2006 1 次提交
  5. 02 12月, 2006 1 次提交
  7. 24 11月, 2006 1 次提交
  9. 22 11月, 2006 1 次提交
    • D
      WorkStruct: Pass the work_struct pointer instead of context data · 65f27f38
      由 David Howells 提交于 
      Pass the work_struct pointer to the work function rather than context data.
The work function can use container_of() to work out the data.

For the cases where the container of the work_struct may go away the moment the
pending bit is cleared, it is made possible to defer the release of the
structure by deferring the clearing of the pending bit.

To make this work, an extra flag is introduced into the management side of the
work_struct.  This governs auto-release of the structure upon execution.

Ordinarily, the work queue executor would release the work_struct for further
scheduling or deallocation by clearing the pending bit prior to jumping to the
work function.  This means that, unless the driver makes some guarantee itself
that the work_struct won't go away, the work function may not access anything
else in the work_struct or its container lest they be deallocated..  This is a
problem if the auxiliary data is taken away (as done by the last patch).

However, if the pending bit is *not* cleared before jumping to the work
function, then the work function *may* access the work_struct and its container
with no problems.  But then the work function must itself release the
work_struct by calling work_release().

In most cases, automatic release is fine, so this is the default.  Special
initiators exist for the non-auto-release case (ending in _NAR).
Signed-Off-By: NDavid Howells <dhowells@redhat.com>
      65f27f38
  11. 18 11月, 2006 1 次提交
    • L
      Revert "ACPI: created a dedicated workqueue for notify() execution" · b976fe19
      由 Linus Torvalds 提交于 
      This reverts commit 37605a69.

Again.

This same bug has now been introduced twice: it was done earlier by
commit b8d35192, only to be reverted
last time in commit 72945b2b.

We must NOT try to queue up notify handlers to another thread than the
normal ACPI execution thread, because the notifications on some systems
seem to just keep on accumulating until we run out of memory and/or
threads.

Keeping events within the one deferred execution thread automatically
throttles the events properly.

At least the Compaq N620c will lock up completely on the first thermal
event without this patch reverted.

Cc: David Brownell <david-b@pacbell.net>
Cc: Len Brown <len.brown@intel.com>
Cc: Alexey Starikovskiy <alexey.y.starikovskiy@linux.intel.com>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>
      b976fe19
  13. 21 10月, 2006 3 次提交
  15. 17 10月, 2006 1 次提交
  17. 14 10月, 2006 23 次提交
  19. 11 10月, 2006 2 次提交
  21. 05 10月, 2006 1 次提交
    • D
      IRQ: Maintain regs pointer globally rather than passing to IRQ handlers · 7d12e780
      由 David Howells 提交于 
      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: NDavid Howells <dhowells@redhat.com>
(cherry picked from 1b16e7ac850969f38b375e511e3fa2f474a33867 commit)
      7d12e780
  23. 04 10月, 2006 1 次提交
  25. 01 10月, 2006 1 次提交
    • A
      [PATCH] maximum latency tracking infrastructure · 5c87579e
      由 Arjan van de Ven 提交于 
      Add infrastructure to track "maximum allowable latency" for power saving
policies.

The reason for adding this infrastructure is that power management in the
idle loop needs to make a tradeoff between latency and power savings
(deeper power save modes have a longer latency to running code again).  The
code that today makes this tradeoff just does a rather simple algorithm;
however this is not good enough: There are devices and use cases where a
lower latency is required than that the higher power saving states provide.
 An example would be audio playback, but another example is the ipw2100
wireless driver that right now has a very direct and ugly acpi hook to
disable some higher power states randomly when it gets certain types of
error.

The proposed solution is to have an interface where drivers can

* announce the maximum latency (in microseconds) that they can deal with
* modify this latency
* give up their constraint

and a function where the code that decides on power saving strategy can
query the current global desired maximum.

This patch has a user of each side: on the consumer side, ACPI is patched
to use this, on the producer side the ipw2100 driver is patched.

A generic maximum latency is also registered of 2 timer ticks (more and you
lose accurate time tracking after all).

While the existing users of the patch are x86 specific, the infrastructure
is not.  I'd like to ask the arch maintainers of other architectures if the
infrastructure is generic enough for their use (assuming the architecture
has such a tradeoff as concept at all), and the sound/multimedia driver
owners to look at the driver facing API to see if this is something they
can use.

[akpm@osdl.org: cleanups]
Signed-off-by: NArjan van de Ven <arjan@linux.intel.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>
Acked-by: NJesse Barnes <jesse.barnes@intel.com>
Cc: "Brown, Len" <len.brown@intel.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>
      5c87579e