Commit Graph

80048 Commits

Author SHA1 Message Date
Harvey Harrison
e7b5e11eaa x86: kprobes leftover cleanups
Eliminate __always_inline, all of these static functions are
only called once.  Minor whitespace cleanup.  Eliminate one
supefluous return at end of void function.  Change the one
#ifndef to #ifdef to match the sense of the rest of the config
tests.

Signed-off-by: Harvey Harrison <harvey.harrison@gmail.com>
Acked-by: Masami Hiramatsu <mhiramat@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2008-01-30 13:31:43 +01:00
Joe Perches
ab4a574ef2 arch/x86/: spelling fixes
Spelling fixes.

Signed-off-by: Joe Perches <joe@perches.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2008-01-30 13:31:42 +01:00
Harvey Harrison
85f2adf169 x86: use helper in fault_64.c
Use the fixup_exception() helper in fault_64.c

Signed-off-by: Harvey Harrison <harvey.harrison@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2008-01-30 13:31:42 +01:00
Harvey Harrison
6d48583ba9 x86: unify extable_{32|64}.c
Introduce fixup_exception() on 64-bit and use it in kprobes to
eliminate an #ifdef.

Only 64-bit needs search_extable() due to a stepping bug.

Signed-off-by: Harvey Harrison <harvey.harrison@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2008-01-30 13:31:41 +01:00
Glauber de Oliveira Costa
46265df040 x86: move i387 definitions to processor.h
This patch moves i387 definitions from processor_32.h and processor_64.h
to processor.h. They are different. Very different. And there's appearently
nothing we can do about it, so they're enclosed inside ifdefs.

Signed-off-by: Glauber de Oliveira Costa <gcosta@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2008-01-30 13:31:41 +01:00
Glauber de Oliveira Costa
ea5e3593a4 x86: unify asm nops
There's only one difference between the NOPs used in asm code for i386 and x86_64:
i386 has a lot more variants. The code is moved to processor.h, and adjusted
accordingly.

Signed-off-by: Glauber de Oliveira Costa <gcosta@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2008-01-30 13:31:40 +01:00
Glauber de Oliveira Costa
ae2e15eb3b x86: unify prefetch operations
This patch moves the prefetch[w]? functions to processor.h

Signed-off-by: Glauber de Oliveira Costa <gcosta@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2008-01-30 13:31:40 +01:00
Glauber de Oliveira Costa
1a53905add x86: move definitions to processor.h
This patch moves definitions that are present in only one of the files
(between processor_32.h and processor_64.h), to processor.h. They're mostly
structures and function definitions.

Signed-off-by: Glauber de Oliveira Costa <gcosta@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2008-01-30 13:31:39 +01:00
Glauber de Oliveira Costa
fc87e9061a x86: unify mm_segment_t definition
This patch moves the mm_segment_t structure definition to processor.h
This makes mmsegment.h file useless, and it is deleted.

Signed-off-by: Glauber de Oliveira Costa <gcosta@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2008-01-30 13:31:38 +01:00
Glauber de Oliveira Costa
2c1c468a38 x86: remove legacy stuff from processor_64.h
This patch removes definitions and macros that are not used anymore
from processor_64.h

Signed-off-by: Glauber de Oliveira Costa <gcosta@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2008-01-30 13:31:37 +01:00
Glauber de Oliveira Costa
5300db887e x86: unify x86_cpuinfo struct.
x86_cpuinfo is one more to the family of "not fundamentally different"
structs. It's unified in processor.h, with very specific fields enclosed
around ifdefs.

Signed-off-by: Glauber de Oliveira Costa <gcosta@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2008-01-30 13:31:33 +01:00
Glauber de Oliveira Costa
26996dd22b x86: change bitwise operations to get a void parameter.
This patch changes the bitwise operations in bitops.h to get
a void pointers as a parameter. Before this patch, a lot of warnings
can be seen. They're gone after it.

Signed-off-by: Glauber de Oliveira Costa <gcosta@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2008-01-30 13:31:31 +01:00
Glauber de Oliveira Costa
dbcb466024 x86: unify TASK_ALIGN definitions
This patch moves the TASK_ALIGN constraints to common header.
The base of it is the same for x86_64 and i386. The only difference
is the presence of vSMP in x86_64. As it's not a worry in i386, we can
safely use the same code for both.

Signed-off-by: Glauber de Oliveira Costa <gcosta@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2008-01-30 13:31:31 +01:00
Glauber de Oliveira Costa
cb38d37733 x86: unify thread struct.
The thread_struct is not fundamentally different between architectures, and
this patch puts it in the common header. What's really unique for each of
them is enclosed in ifdefs.

Signed-off-by: Glauber de Oliveira Costa <gcosta@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2008-01-30 13:31:31 +01:00
Glauber de Oliveira Costa
7818a1e029 x86: provide 64-bit with a load_sp0 function.
Paravirt guests need to inform the underlying hypervisor whenever the sp0
tss field changes. i386 already has such a function, and we use it for
x86_64 too. There's an unnecessary (for 64-bit) msr handling part in the original
version, and it is placed around an ifdef. Making no more sense in
processor_32.h, it is moved to the common header

Signed-off-by: Glauber de Oliveira Costa <gcosta@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2008-01-30 13:31:31 +01:00
Glauber de Oliveira Costa
ca241c7503 x86: unify tss_struct
Although slighly different, the tss_struct is very similar in x86_64 and
i386. The really different part, which matchs the hardware vision of it, is
now called x86_hw_tss, and each of the architectures provides yours.
It's then used as a field in the outter tss_struct.

Signed-off-by: Glauber de Oliveira Costa <gcosta@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2008-01-30 13:31:31 +01:00
Glauber de Oliveira Costa
0ccb8acc51 x86: unify current_text_addr
current_text_addr() has a different implementation in x86_64 and
i386, but it is not fundamentally different. I stick to the i386
implementation, that seem to be a common base, and move it to processor.h

Signed-off-by: Glauber de Oliveira Costa <gcosta@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2008-01-30 13:31:27 +01:00
Glauber de Oliveira Costa
683e0253db x86: unify common parts of processor.h
This patch moves the pieces of processor_32.h and processor_64 that are
equal to processor.h. Only what's exactly the same is moved around, the rest
not being touched.

Signed-off-by: Glauber de Oliveira Costa <gcosta@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2008-01-30 13:31:27 +01:00
Glauber de Oliveira Costa
62d7d7ed11 x86: move the definition of set_iopl_mask to common header
This patch moves the definition of set_iopl_mask to processor.h,
instead of letting it at processor_32.h.
For x86_64, nothing is done, as we don't really need such a function.
However, having it on both arches saves us from putting an ifdef in the
pv_cpu_ops struct.

Signed-off-by: Glauber de Oliveira Costa <gcosta@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2008-01-30 13:31:27 +01:00
Glauber de Oliveira Costa
1b46cbe0cc x86: unify paravirt pieces of processor.h
This patch unifies the paravirt pieces of processor.h
The functionality present in 32 bit, but not (yet) in 64-bit,
like load_sp0 is _not_ done here, and let to a different patch.

With this unification, we get paravirt for free in x86_64 processor.h

Signed-off-by: Glauber de Oliveira Costa <gcosta@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2008-01-30 13:31:27 +01:00
Glauber de Oliveira Costa
c72dcf83ff x86: move load_cr3 to a common place.
There are currently two definitions of load_cr3, that essentially do the
same thing. This patch moves them all to processor.h.

Signed-off-by: Glauber de Oliveira Costa <gcosta@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2008-01-30 13:31:27 +01:00
Glauber de Oliveira Costa
746ff60f26 x86: move desc_empty to where they belong
This patch moves the (duplicated) desc_empty implementation to desc.h,
where the descriptor things belong.

Signed-off-by: Glauber de Oliveira Costa <gcosta@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2008-01-30 13:31:27 +01:00
Glauber de Oliveira Costa
053de04441 x86: get rid of _MASK flags
There's no need for the *_MASK flags (TF_MASK, IF_MASK, etc), found in
processor.h (both _32 and _64). They have a one-to-one mapping with the
EFLAGS value. This patch removes the definitions, and use the already
existent X86_EFLAGS_ version when applicable.

[ roland@redhat.com: KVM build fixes. ]

Signed-off-by: Glauber de Oliveira Costa <gcosta@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2008-01-30 13:31:27 +01:00
Glauber de Oliveira Costa
73018a66e7 x86: move tsc definitions to were they belong
This patch wipes out the definitions of tsc_disable from processor_32.h
and move it to tsc.h, were it belongs

Signed-off-by: Glauber de Oliveira Costa <gcosta@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2008-01-30 13:31:26 +01:00
Neil Horman
7bcbc78dea x86: clean up arch/x86/kernel/early-quirks.c
clean up checkpatch errors. No code changed.

      text    data     bss     dec     hex filename
       705     120       0     825     339 early-quirks.o.before
       705     120       0     825     339 early-quirks.o.after

Signed-off-by: Neil Horman <nhorman@tuxdriver.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2008-01-30 13:31:26 +01:00
Cyrill Gorcunov
3b095a04e7 x86: cleanup i387_32.c according to checkpatch
clean up checkpatch warnings/errors on i387_32.c

The old and new i387_32.s (asm listings) were checked with diff to
be identical so it's safe to apply this patch.

Signed-off-by: Cyrill Gorcunov <gorunov@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2008-01-30 13:31:26 +01:00
Harvey Harrison
3c233d1334 x86: unify kexec_{32|64}.h
One section collecting all constant defines.  Ifdef the asm
blocks for X86_32/64.

Signed-off-by: Harvey Harrison <harvey.harrison@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Vivek Goyal <vgoyal@redhat.com>
2008-01-30 13:31:26 +01:00
Harvey Harrison
01c57fb6a3 x86: local.h fix checkpatch warnings
Mostly space after comma, one space after if.

Signed-off-by: Harvey Harrison <harvey.harrison@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2008-01-30 13:31:26 +01:00
Harvey Harrison
5638f99394 x86: unify local_{32|64}.h
Signed-off-by: Harvey Harrison <harvey.harrison@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2008-01-30 13:31:26 +01:00
Harvey Harrison
8ee5797a91 x86: introduce asm helpers in local_{32|64}.h
Handle the use of long on X86_32 and quad on X86_64

Signed-off-by: Harvey Harrison <harvey.harrison@gmail.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-01-30 13:31:26 +01:00
Harvey Harrison
992b95920a x86: fix asm memory constraints in local_64.h
Use the shorter +m form rather than =m and m.

Signed-off-by: Harvey Harrison <harvey.harrison@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2008-01-30 13:31:26 +01:00
Harvey Harrison
4ad0271834 x86: clean up local_{32|64}.h
Common prefix from both files moved to local.h

Change __inline__ to inline

Signed-off-by: Harvey Harrison <harvey.harrison@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2008-01-30 13:31:26 +01:00
Cyrill Gorcunov
fe758fb119 x86: clean up include/asm-x86/pda.h
clean up include/asm-x86/pda.h, as suggested by checkpatch.pl.

Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2008-01-30 13:31:25 +01:00
Neil Horman
c6b4832432 x86, kexec: force x86 arches to boot kdump kernels on boot cpu
Recently a kdump bug was discovered in which a system would hang inside
calibrate_delay during the booting of the kdump kernel.  This was caused
by the fact that the jiffies counter was not being incremented during
timer calibration.  The root cause of this problem was found to be a
bios misconfiguration of the hypertransport bus.  On system affected by
this hang, the bios had assigned APIC ids which used extended apic bits
(more than the nominal 4 bit ids's), but failed to configure bit 17 of
the hypertransport transaction config register, which indicated that the
mask for the destination field of interrupt packets accross the ht bus
(see section 3.3.9 of
http://www.amd.com/us-en/assets/content_type/white_papers_and_tech_docs/26094.PDF).
If a crash occurs on a cpu with an APIC id that extends beyond 4 bits,
it will not recieve interrupts during the kdump kernel boot, and this
hang will be the result.  The fix is to add this patch, whcih add an
early pci quirk check, to forcibly enable this bit in the httcfg
register.  This enables all cpus on a system to receive interrupts, and
allows kdump kernel bootup to procede normally.

Signed-off-by: Neil Horman <nhorman@tuxdriver.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2008-01-30 13:31:25 +01:00
Ingo Molnar
41e191e85a x86: replace outb_p() with udelay(2) in drivers/input/mouse/pc110pad.c
replace outb_p() with udelay(2). This is a real ISA device so it likely
needs this particular delay.

Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2008-01-30 13:31:24 +01:00
Jan Beulich
ded9aa0db8 x86: also define AT_VECTOR_SIZE_ARCH
The patch introducing this left out x86-64, despite it also having
extra entries.

[ mingo@elte.hu: re-merged this to after the unification patches. ]

Signed-off-by: Jan Beulich <jbeulich@novell.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2008-01-30 13:31:24 +01:00
Jan Beulich
e94271017f x86: adjust enable_NMI_through_LVT0()
Its previous use in a call to on_each_cpu() was pointless, as at the
time that code gets executed only one CPU is online. Further, the
function can be __cpuinit, and for this to work without
CONFIG_HOTPLUG_CPU setup_nmi() must also get an attribute (this one
can even be __init; on 64-bits check_timer() also was lacking that
attribute).

Signed-off-by: Jan Beulich <jbeulich@novell.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2008-01-30 13:31:24 +01:00
Jan Beulich
cae4595764 x86: make __{save,restore}_processor_state static
.. allowing to remove their declarations from a global include file
(the symbols don't exist for anything but x86).

Likewise for 64-bits' fix_processor_context(), just that that one was
properly declared in an arch-specific header.

Signed-off-by: Jan Beulich <jbeulich@novell.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2008-01-30 13:31:23 +01:00
Jan Beulich
3e7622f9d7 x86: move to .rodata/.init.data
The array is never written, and on 64-bits it's not even being used
past initial boot.

Signed-off-by: Jan Beulich <jbeulich@novell.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2008-01-30 13:31:23 +01:00
Jan Beulich
22f5991c85 x86-64: honor notify_die() returning NOTIFY_STOP
This requires making die() return a value, making its callers honor
this (and be prepared that it may return), and making oops_end() have
two additional parameters.

Signed-off-by: Jan Beulich <jbeulich@novell.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2008-01-30 13:31:23 +01:00
Jan Beulich
d88879b2d0 x86-64: make pda's cpunumber and nodenumber unsigned
This generally allows better code to be generated, since the zero-
extension during 32-bit operations comes for free (needed when the
result is used as array index or similar), whereas sign extension must
be done explicitly and frequently requires a one byte larger
instruction due to the necessary rex64 prefix.

Signed-off-by: Jan Beulich <jbeulich@novell.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2008-01-30 13:31:21 +01:00
Jan Beulich
bdb4f15606 i386: hard_{en,dis}able_TSC can be static
Signed-off-by: Jan Beulich <jbeulich@novell.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2008-01-30 13:31:21 +01:00
Masami Hiramatsu
d6be29b871 x86: kprobes code for x86 unification
This patch unifies kprobes code.

- Unify kprobes_*.h to kprobes.h
- Unify kprobes_*.c to kprobes.c
  (Differences are separated by ifdefs)
 - Most differences are related to REX prefix and rip relatives.
 - Two inline assembly code are different.
 - One difference in kprobe_handlre()
 - One fixup exception code is different, but it will be unified
   if mm/extable_*.c are unified.
- Merge history logs into arch/x86/kernel/kprobes.c.

Signed-off-by: Masami Hiramatsu <mhiramat@redhat.com>
Signed-off-by: Jim Keniston <jkenisto@us.ibm.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2008-01-30 13:31:21 +01:00
Masami Hiramatsu
8533bbe9f8 x86: prepare kprobes code for x86 unification
This patch cleanup kprobes code on x86 for unification.
This patch is based on Arjan's previous work.

- Remove spurious whitespace changes
- Add harmless includes
- Make the 32/64 files more identical
 - Generalize structure fields' and local variable name.
 - Wrap accessing to stack address by macros.
 - Modify bitmap making macro.
 - Merge fixup code into is_riprel() and change its name to fix_riprel().
 - Set MAX_INSN_SIZE to 16 on both arch.
 - Use u32 for bitmaps on both architectures.
 - Clarify some comments.

Signed-off-by: Masami Hiramatsu <mhiramat@redhat.com>
Signed-off-by: Arjan van de Ven <arjan@infradead.org>
Signed-off-by: Jim Keniston <jkenisto@us.ibm.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2008-01-30 13:31:21 +01:00
Masami Hiramatsu
da07ab0375 x86: return probe-booster for x86-64
This patch adds kretprobe-booster to kprobes_64.c.

- Changes are based on x86-32.
- Rewrite register saving/restoring code

Signed-off-by: Masami Hiramatsu <mhiramat@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2008-01-30 13:31:21 +01:00
Masami Hiramatsu
aa470140e8 x86: kprobe-booster for x86-64
This patch adds kprobe-booster to kprobes_64.c.

- Changes are based on x86-32.
- Add REX prefix checking code.

Signed-off-by: Masami Hiramatsu <mhiramat@redhat.com>
Signed-off-by: Jim Keniston <jkenisto@us.ibm.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2008-01-30 13:31:21 +01:00
Nick Piggin
314cdbefd1 x86: FIFO ticket spinlocks
Introduce ticket lock spinlocks for x86 which are FIFO. The implementation
is described in the comments. The straight-line lock/unlock instruction
sequence is slightly slower than the dec based locks on modern x86 CPUs,
however the difference is quite small on Core2 and Opteron when working out of
cache, and becomes almost insignificant even on P4 when the lock misses cache.
trylock is more significantly slower, but they are relatively rare.

On an 8 core (2 socket) Opteron, spinlock unfairness is extremely noticable,
with a userspace test having a difference of up to 2x runtime per thread, and
some threads are starved or "unfairly" granted the lock up to 1 000 000 (!)
times. After this patch, all threads appear to finish at exactly the same
time.

The memory ordering of the lock does conform to x86 standards, and the
implementation has been reviewed by Intel and AMD engineers.

The algorithm also tells us how many CPUs are contending the lock, so
lockbreak becomes trivial and we no longer have to waste 4 bytes per
spinlock for it.

After this, we can no longer spin on any locks with preempt enabled
and cannot reenable interrupts when spinning on an irq safe lock, because
at that point we have already taken a ticket and the would deadlock if
the same CPU tries to take the lock again.  These are questionable anyway:
if the lock happens to be called under a preempt or interrupt disabled section,
then it will just have the same latency problems. The real fix is to keep
critical sections short, and ensure locks are reasonably fair (which this
patch does).

Signed-off-by: Nick Piggin <npiggin@suse.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-01-30 13:31:21 +01:00
Nick Piggin
95c354fe9f spinlock: lockbreak cleanup
The break_lock data structure and code for spinlocks is quite nasty.
Not only does it double the size of a spinlock but it changes locking to
a potentially less optimal trylock.

Put all of that under CONFIG_GENERIC_LOCKBREAK, and introduce a
__raw_spin_is_contended that uses the lock data itself to determine whether
there are waiters on the lock, to be used if CONFIG_GENERIC_LOCKBREAK is
not set.

Rename need_lockbreak to spin_needbreak, make it use spin_is_contended to
decouple it from the spinlock implementation, and make it typesafe (rwlocks
do not have any need_lockbreak sites -- why do they even get bloated up
with that break_lock then?).

Signed-off-by: Nick Piggin <npiggin@suse.de>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2008-01-30 13:31:20 +01:00
Markus Metzger
a95d67f87e x86, ptrace: new ptrace BTS API
Here's the new ptrace BTS API that supports two different overflow handling mechanisms (wrap-around and buffer-full-signal) to support two different use cases (debugging and profiling).

It further combines buffer allocation and configuration.

Opens:
- memory rlimit
- overflow signal

What would be the right signal to use?

Signed-off-by: Markus Metzger <markus.t.metzger@intel.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2008-01-30 13:31:20 +01:00
Markus Metzger
e4811f2568 x86, ptrace: change BTS GET ptrace interface
Change the ptrace interface to mimick an array from newst to oldest.

Signed-off-by: Markus Metzger <markus.t.metzger@intel.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2008-01-30 13:31:20 +01:00