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8 commits

Author SHA1 Message Date
Ingo Molnar
c5905afb0e static keys: Introduce 'struct static_key', static_key_true()/false() and static_key_slow_[inc|dec]()
So here's a boot tested patch on top of Jason's series that does
all the cleanups I talked about and turns jump labels into a
more intuitive to use facility. It should also address the
various misconceptions and confusions that surround jump labels.

Typical usage scenarios:

        #include <linux/static_key.h>

        struct static_key key = STATIC_KEY_INIT_TRUE;

        if (static_key_false(&key))
                do unlikely code
        else
                do likely code

Or:

        if (static_key_true(&key))
                do likely code
        else
                do unlikely code

The static key is modified via:

        static_key_slow_inc(&key);
        ...
        static_key_slow_dec(&key);

The 'slow' prefix makes it abundantly clear that this is an
expensive operation.

I've updated all in-kernel code to use this everywhere. Note
that I (intentionally) have not pushed through the rename
blindly through to the lowest levels: the actual jump-label
patching arch facility should be named like that, so we want to
decouple jump labels from the static-key facility a bit.

On non-jump-label enabled architectures static keys default to
likely()/unlikely() branches.

Signed-off-by: Ingo Molnar <mingo@elte.hu>
Acked-by: Jason Baron <jbaron@redhat.com>
Acked-by: Steven Rostedt <rostedt@goodmis.org>
Cc: a.p.zijlstra@chello.nl
Cc: mathieu.desnoyers@efficios.com
Cc: davem@davemloft.net
Cc: ddaney.cavm@gmail.com
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Link: http://lkml.kernel.org/r/20120222085809.GA26397@elte.hu
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2012-02-24 10:05:59 +01:00
Glauber Costa
747f292583 ia64: add jump labels for paravirt
Since in a later patch I intend to call jump labels inside
CONFIG_PARAVIRT, IA64 would fail to compile if they are not
provided. This patch provides those jump labels for the IA64
architecture.

Signed-off-by: Glauber Costa <glommer@redhat.com>
Acked-by: Isaku Yamahata <yamahata@valinux.co.jp>
Acked-by: Rik van Riel <riel@redhat.com>
CC: Tony Luck <tony.luck@intel.com>
CC: Eddie Dong <eddie.dong@intel.com>
CC: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
CC: Peter Zijlstra <peterz@infradead.org>
CC: Anthony Liguori <aliguori@us.ibm.com>
CC: Eric B Munson <emunson@mgebm.net>
Signed-off-by: Avi Kivity <avi@redhat.com>
2011-07-14 12:59:45 +03:00
Isaku Yamahata
03f511dd02 ia64/pv_ops: implement binary patching optimization for native.
implement binary patching optimization for pv_cpu_ops.
With this optimization, indirect call for pv_cpu_ops methods can be
converted into inline execution or direct call.

Signed-off-by: Isaku Yamahata <yamahata@valinux.co.jp>
Signed-off-by: Tony Luck <tony.luck@intel.com>
2009-03-26 11:02:42 -07:00
Isaku Yamahata
e4ff5b8f54 ia64/pv_ops: gate page paravirtualization.
paravirtualize gate page by allowing each pv_ops instances
to define its own gate page.

Signed-off-by: Isaku Yamahata <yamahata@valinux.co.jp>
Signed-off-by: Tony Luck <tony.luck@intel.com>
2009-03-26 10:51:02 -07:00
Isaku Yamahata
f927da1786 ia64/pv_ops/pv_time_ops: add sched_clock hook.
add sched_clock() hook to paravirtualize sched_clock().
ia64 sched_clock() is based on ar.itc which isn't stable
on virtualized environment because vcpu may move around on
pcpus. So it needs paravirtualization.

Signed-off-by: Isaku Yamahata <yamahata@valinux.co.jp>
Signed-off-by: Tony Luck <tony.luck@intel.com>
2009-03-26 10:50:42 -07:00
Isaku Yamahata
dd97d5cb54 ia64/pv_ops: add hooks to paravirtualize fsyscall implementation.
Add two hooks, paravirt_get_fsyscall_table() and
paravirt_get_fsys_bubble_doen() to paravirtualize fsyscall implementation.
This patch just add the hooks fsyscall and don't paravirtualize it.

Signed-off-by: Isaku Yamahata <yamahata@valinux.co.jp>
Signed-off-by: Tony Luck <tony.luck@intel.com>
2009-03-26 10:48:33 -07:00
Isaku Yamahata
ce1fc742f9 ia64/pv_ops: avoid name conflict of get_irq_chip().
The macro get_irq_chip() is defined in linux/include/linux/irq.h
which cause name conflict with one in linux/arch/ia64/include/asm/paravirt.h.
rename the latter to __get_irq_chip().

Signed-off-by: Isaku Yamahata <yamahata@valinux.co.jp>
Signed-off-by: Tony Luck <tony.luck@intel.com>
2008-10-17 09:50:55 -07:00
Tony Luck
7f30491ccd [IA64] Move include/asm-ia64 to arch/ia64/include/asm
After moving the the include files there were a few clean-ups:

1) Some files used #include <asm-ia64/xyz.h>, changed to <asm/xyz.h>

2) Some comments alerted maintainers to look at various header files to
make matching updates if certain code were to be changed. Updated these
comments to use the new include paths.

3) Some header files mentioned their own names in initial comments. Just
deleted these self references.

Signed-off-by: Tony Luck <tony.luck@intel.com>
2008-08-01 10:21:21 -07:00
Renamed from include/asm-ia64/paravirt.h (Browse further)