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>
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>
This patch removes the following warnings and related ones.
Plus some cosmetics.
arch/ia64/kernel/patch.c:112: warning: passing argument 1 of 'paravirt_fc' makes integer from pointer without a cast
arch/ia64/kernel/patch.c:135: warning: passing argument 1 of 'paravirt_fc' makes integer from pointer without a cast
arch/ia64/kernel/patch.c:166: warning: passing argument 1 of 'paravirt_fc' makes integer from pointer without a cast
arch/ia64/kernel/patch.c:202: warning: passing argument 1 of 'paravirt_fc' makes integer from pointer without a cast
arch/ia64/kernel/patch.c:220: warning: passing argument 1 of 'paravirt_fc' makes integer from pointer without a cast
Signed-off-by: Isaku Yamahata <yamahata@valinux.co.jp>
Signed-off-by: Tony Luck <tony.luck@intel.com>
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>
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>
pv_cpu_ops.getreg(_IA64_REG_IP) returned constant.
But the returned ip valued should be the one in the caller, not of the callee.
This patch fixes that.
Signed-off-by: Isaku Yamahata <yamahata@valinux.co.jp>
Signed-off-by: Tony Luck <tony.luck@intel.com>
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>
Introduce pv_time_ops which adds hook to steal time accounting.
On virtualized environment, cpus are shared by many guests and
steal time is the time which is used for other guests.
On virtualized environtment, streal time should be accounted.
Signed-off-by: Isaku Yamahata <yamahata@valinux.co.jp>
Signed-off-by: Tony Luck <tony.luck@intel.com>
introduce pv_irq_ops which adds hooks to paravirtualize irq related
operations.
On virtualized environment, interruption may be replaced by something
virtualization friendly. So the irq related operation also may need
paravirtualization.
This patch adds necessary hooks to paravirtualize irq related operations.
Signed-off-by: Yaozu (Eddie) Dong <eddie.dong@intel.com>
Signed-off-by: Isaku Yamahata <yamahata@valinux.co.jp>
Signed-off-by: Tony Luck <tony.luck@intel.com>
add hooks to paravirtualize iosapic which is a real hardware resource.
On virtualized environment it may be replaced something virtualized
friendly.
Define pv_iosapic_ops and add the hooks.
Signed-off-by: Isaku Yamahata <yamahata@valinux.co.jp>
Signed-off-by: Tony Luck <tony.luck@intel.com>
define pv_init_ops hooks which represents various initialization
hooks for paravirtualized environment. and add hooks.
Signed-off-by: Alex Williamson <alex.williamson@hp.com>
Signed-off-by: Isaku Yamahata <yamahata@valinux.co.jp>
Signed-off-by: Tony Luck <tony.luck@intel.com>
paravirtualize ia64_swtich_to, ia64_leave_syscall and ia64_leave_kernel.
They include sensitive or performance critical privileged instructions
so that they need paravirtualization.
To paravirtualize them by single source and multi compile
they are converted into indirect jump. And define each pv instances.
Cc: Keith Owens <kaos@ocs.com.au>
Cc: "Dong, Eddie" <eddie.dong@intel.com>
Signed-off-by: Isaku Yamahata <yamahata@valinux.co.jp>
Signed-off-by: Tony Luck <tony.luck@intel.com>
introduce pv_cpu_ops to paravirtualize privleged instructions
which are defined by ia64 intrinsics.
make them indirect C function calls by introducing function
tables, pv_cpu_ops.
Signed-off-by: Yaozu (Eddie) Dong <eddie.dong@intel.com>
Signed-off-by: Isaku Yamahata <yamahata@valinux.co.jp>
Signed-off-by: Tony Luck <tony.luck@intel.com>
introduce pv_info which describes some randome info about
underlying execution environment.
Cc: Jes Sorensen <jes@sgi.com>
Signed-off-by: Isaku Yamahata <yamahata@valinux.co.jp>
Signed-off-by: Tony Luck <tony.luck@intel.com>
