Only allocate the FPU area when the application actually uses FPU, i.e., in the
first lazy FPU trap. This could save memory for non-fpu using apps.
for example: on my system after boot, there are around 300 processes, with
only 17 using FPU.
Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com>
Cc: Arjan van de Ven <arjan@linux.intel.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Split the FPU save area from the task struct. This allows easy migration
of FPU context, and it's generally cleaner. It also allows the following
two optimizations:
1) only allocate when the application actually uses FPU, so in the first
lazy FPU trap. This could save memory for non-fpu using apps. Next patch
does this lazy allocation.
2) allocate the right size for the actual cpu rather than 512 bytes always.
Patches enabling xsave/xrstor support (coming shortly) will take advantage
of this.
Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com>
Signed-off-by: Arjan van de Ven <arjan@linux.intel.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
this function doesnt just 'find' the max_pfn - it also has
other side-effects such as registering sparse memory maps.
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
We already catch most of the TSC problems by sanity checks, but there
is a subtle bug which has been in the code forever. This can cause
time jumps in the range of hours.
This was reported in:
http://lkml.org/lkml/2007/8/23/96
and
http://lkml.org/lkml/2008/3/31/23
I was able to reproduce the problem with a gettimeofday loop test on a
dual core and a quad core machine which both have sychronized
TSCs. The TSCs seems not to be perfectly in sync though, but the
kernel is not able to detect the slight delta in the sync check. Still
there exists an extremly small window where this delta can be observed
with a real big time jump. So far I was only able to reproduce this
with the vsyscall gettimeofday implementation, but in theory this
might be observable with the syscall based version as well.
CPU 0 updates the clock source variables under xtime/vyscall lock and
CPU1, where the TSC is slighty behind CPU0, is reading the time right
after the seqlock was unlocked.
The clocksource reference data was updated with the TSC from CPU0 and
the value which is read from TSC on CPU1 is less than the reference
data. This results in a huge delta value due to the unsigned
subtraction of the TSC value and the reference value. This algorithm
can not be changed due to the support of wrapping clock sources like
pm timer.
The huge delta is converted to nanoseconds and added to xtime, which
is then observable by the caller. The next gettimeofday call on CPU1
will show the correct time again as now the TSC has advanced above the
reference value.
To prevent this TSC specific wreckage we need to compare the TSC value
against the reference value and return the latter when it is larger
than the actual TSC value.
I pondered to mark the TSC unstable when the readout is smaller than
the reference value, but this would render an otherwise good and fast
clocksource unusable without a real good reason.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
This patch implements the PR_GET_TSC and PR_SET_TSC prctl()
commands on the x86 platform (both 32 and 64 bit.) These
commands control the ability to read the timestamp counter
from userspace (the RDTSC instruction.)
While the RDTSC instuction is a useful profiling tool,
it is also the source of some non-determinism in ring-3.
For deterministic replay applications it is useful to be
able to trap and emulate (and record the outcome of) this
instruction.
This patch uses code earlier used to disable the timestamp
counter for the SECCOMP framework. A side-effect of this
patch is that the SECCOMP environment will now also disable
the timestamp counter on x86_64 due to the addition of the
TIF_NOTSC define on this platform.
The code which enables/disables the RDTSC instruction during
context switches is in the __switch_to_xtra function, which
already handles other unusual conditions, so normal
performance should not have to suffer from this change.
Signed-off-by: Erik Bosman <ejbosman@cs.vu.nl>
Acked-by: Arjan van de Ven <arjan@linux.intel.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
This annotates NMI functions with notrace. Some tracers may be able
to live with this, but some cannot. The safest is to turn it off,
it's not particularly interesting anyway.
Signed-off-by: Steven Rostedt <srostedt@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
- noexec32 is on by default for years already
- add noexec32 to kernel-parameters and fix noexec typo in there
Signed-off-by: Jiri Slaby <jirislaby@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
cleanup: change the _end in compressed vmlinux_64.lds.
also change _heap to _ebss that is not needed.
Signed-off-by: Yinghai Lu <yhlu.kernel@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
The kernel decompressor wrapper uses memory located beyond the
end of the image. This might lead to hard to debug problems,
but even if it can be proven to be safe, it is at the very
least unclean. I don't see any advantages either, unless you
count it not being zeroed out as an advantage. This patch
moves the boot-heap area to the bss segment.
Signed-off-by: Alexander van Heukelum <heukelum@fastmail.fm>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Fix printk formats in x86/mm/ioremap.c:
next-20080410/arch/x86/mm/ioremap.c:137: warning: format '%llx' expects type 'long long unsigned int', but argument 2 has type 'resource_size_t'
next-20080410/arch/x86/mm/ioremap.c:188: warning: format '%llx' expects type 'long long unsigned int', but argument 2 has type 'resource_size_t'
next-20080410/arch/x86/mm/ioremap.c:188: warning: format '%llx' expects type 'long long unsigned int', but argument 3 has type 'long unsigned int'
Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
fix section mismatch warnings which occurs on my x86_64 box while compiling
linux-next-20080410:
Warning messages:
WARNING: arch/x86/kernel/built-in.o(.text+0x7bc2): Section mismatch in reference from the function bad_addr() to the
variable .init.data:early_res
The function bad_addr() references
the variable __initdata early_res.
This is often because bad_addr lacks a __initdata
annotation or the annotation of early_res is wrong.
WARNING: arch/x86/kernel/built-in.o(.text+0x7c3b): Section mismatch in reference from the function bad_addr_size() to
the variable .init.data:early_res
The function bad_addr_size() references
the variable __initdata early_res.
This is often because bad_addr_size lacks a __initdata
annotation or the annotation of early_res is wrong.
Signed-off-by: Jacek Luczak <luczak.jacek@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
I've made a small investigation about vm86.h inclusion rules and it
looks like everything is more or less ok.
Files that rely on asm/vm86.h symbols are:
- kprobes.c
- process_32.c
- signal_32.c
- traps_32.c
- vm86_32.c
File process_32.c includes vm86.h explicitly. We can remove that
include and it won't break anything.
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Remove old comments that include the old arch/i386 directory.
Signed-off-by: WANG Cong <xiyou.wangcong@gmail.com>
Acked-by: H. Peter Anvin <hpa@zytor.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
ramdisk is reserved via reserve_early in x86_64_start_kernel,
later early_res_to_bootmem() will convert to reservation in bootmem.
so don't need to reserve that again.
Signed-off-by: Yinghai Lu <yhlu.kernel@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Make x86 EFI code works when EFI_PAGE_SHIFT != PAGE_SHIFT. The
memrage_efi_to_native() provided in this patch can be used on other
EFI platform such as IA64 too.
This patch has been tested on Intel x86_64 platform with EFI 64/32
firmware.
Signed-off-by: Huang Ying <ying.huang@intel.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
do not return a -EINVAL when mmap()-ing PCI holes.
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Acked-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
Acked-by: Suresh Siddha <suresh.b.siddha@intel.com>
Acked-by: H. Peter Anvin <hpa@zytor.com>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Arjan van de Ven <arjan@linux.intel.com>
TF_MASK is no longer defined, use X86_EFLAGS_TF.
Signed-off-by: Harvey Harrison <harvey.harrison@gmail.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
kgdb core fixes:
- Check to see that mm->mmap_cache is not null before calling
flush_cache_range(), else on arch=ARM it will cause a fatal
fault.
- Breakpoints should only be restored if they are in the BP_ACTIVE
state.
- Fix a typo in comments to "kgdb_register_io_module"
x86 kgdb fixes:
- Fix the x86 arch handler such that on a kill or detach that the
appropriate cleanup on the single stepping flags gets run.
- Add in the DIE_NMIWATCHDOG call for x86_64
- Touch the nmi watchdog before returning the system to normal
operation after performing any kind of kgdb operation, else
the possibility exists to trigger the watchdog.
Signed-off-by: Jason Wessel <jason.wessel@windriver.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Add HW breakpoints into the arch specific portion of x86 kgdb. In the
current x86 kernel.org kernels HW breakpoints are changed out in lazy
fashion because there is no infrastructure around changing them when
changing to a kernel task or entering the kernel mode via a system
call. This lazy approach means that if a user process uses HW
breakpoints the kgdb will loose out. This is an acceptable trade off
because the developer debugging the kernel is assumed to know what is
going on system wide and would be aware of this trade off.
There is a minor bug fix to the kgdb core so as to correctly call the
hw breakpoint functions with a valid value from the enum.
There is also a minor change to the x86_64 startup code when using
early HW breakpoints. When the debugger is connected, the cpu startup
code must not zero out the HW breakpoint registers or you cannot hit
the breakpoints you are interested in, in the first place.
Signed-off-by: Jason Wessel <jason.wessel@windriver.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
This patch fixes the hang regression with kgdb when the NMI interrupt
comes in while the master core is returning from an exception.
Adjust the NMI logic such that KGDB will not stop NMI exceptions from
occurring by in general returning NOTIFY_DONE. It is not possible to
distinguish the debug NMI sync vs the normal NMI apic interrupt so
kgdb needs to catch the unknown NMI if it the debugger was previously
active on one of the cpus.
Signed-off-by: Jason Wessel <jason.wessel@windriver.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
simplified and streamlined kgdb support on x86, both 32-bit and 64-bit,
based on patch from:
Subject: kgdb: core-lite
From: Jason Wessel <jason.wessel@windriver.com>
[ and countless other authors - see the patch for details. ]
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Jason Wessel <jason.wessel@windriver.com>
Signed-off-by: Jan Kiszka <jan.kiszka@web.de>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Move wakeup code to .c, so that video mode setting code can be shared
between boot and wakeup. Remove nasty assembly code in 64-bit case by
re-using trampoline code. Stack setup was fixed to clear high 16bits
of %esp, maybe that fixes some machines.
.c code sharing and morse code was done H. Peter Anvin, Sam Ravnborg
reviewed kbuild related stuff, and it seems okay to him. Rafael did
some cleanups.
[rjw:
* Made the patch stop breaking compilation on x86-32
* Added arch/x86/kernel/acpi/sleep.h
* Got rid of compiler warnings in arch/x86/kernel/acpi/sleep.c
* Fixed 32-bit compilation on x86-64 systems
* Added include/asm-x86/trampoline.h and fixed the non-SMP
compilation on 64-bit x86
* Removed arch/x86/kernel/acpi/sleep_32.c which was not used
* Fixed some breakage caused by the integration of smpboot.c done
under us in the meantime]
Signed-off-by: Pavel Machek <pavel@suse.cz>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
Reviewed-by: Sam Ravnborg <sam@ravnborg.org>
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
this patch fixes section mismatch warnings (on x86_64 host) in setup_trampoline(),
which was referencing __initdata variables trampoline_data and trampoline_end.
Warning messages:
WARNING: arch/x86/kernel/built-in.o(.cpuinit.text+0x2b6a): Section mismatch in reference from the function setup_trampoline()
to the variable .init.data:trampoline_data
The function __cpuinit setup_trampoline() references
a variable __initdata trampoline_data.
If trampoline_data is only used by setup_trampoline then
annotate trampoline_data with a matching annotation.
WARNING: arch/x86/kernel/built-in.o(.cpuinit.text+0x2b71): Section mismatch in reference from the function setup_trampoline()
to the variable .init.data:trampoline_end
The function __cpuinit setup_trampoline() references
a variable __initdata trampoline_end.
If trampoline_end is only used by setup_trampoline then
annotate trampoline_end with a matching annotation.
Signed-off-by: Ingo Molnar <mingo@elte.hu>
This patch fixes mismatch warnings in smp_checks() (in arch/x86/kernel/smpboot.c):
WARNING: arch/x86/kernel/built-in.o(.text+0x11922): Section mismatch in reference from the function smp_checks()
to the variable .cpuinit.data:smp_b_stepping
The function smp_checks() references
the variable __cpuinitdata smp_b_stepping.
This is often because smp_checks lacks a __cpuinitdata
annotation or the annotation of smp_b_stepping is wrong.
Signed-off-by: Jacek Luczak <luczak.jacek@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
> > Make sure that we clear the "shutdown status flag" in the CMOS
> > register after each CPU is brought up. This fixes a problem where the
> > "shutdown status flag" may remain set when a CPU is brought up after
> > booting.
>
> btw., what problem does this result in, exactly?
The shutdown status flag set to "0xA", corresponds to "JMP double word
request without INT init".
This JMP at reboot time is at an unintended location. And results in
Triple faults in our case.
Though this error at reboot can be safely ignored in a VM environment,
am not sure what the effect would be on a physical system. May be it
will result in a triple fault and an eventual hardware reset thus
masking this BUG in the kernel.
This fix just makes sure that we reset that status flag after
initialization is done.
Fix paranoia about using BIOS quickboot mechanism.
Make sure that we clear the "shutdown status flag" in the CMOS register
after each CPU is brought up. This fixes a problem where the "shutdown
status flag" may remain set when a CPU is brought up after booting.
Signed-off-by: Alok N Kataria <akataria@vmware.com>
Signed-off-by: Dan Arai <arai@vmware.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Use cpumask_of_cpu() rather than the pair of cpus_clear() and cpu_set().
Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
No need to clear the memory allocated by alloc_bootmem().
It is already filled with zero.
Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Remove duplicate code by using ioapic_read_entry() and ioapic_write_entry()
in io_apic_{32,64}.c
Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
If one can find an ack pending pin, there is no need to check
the rest of them.
Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
In arch/x86/boot/compressed/misc.c, the variable vidmem is
the only variable that ends up in de data segment. It's also
superfluous, because the first thing the code does is:
if (RM_SCREEN_INFO.orig_video_mode == 7) {
vidmem = (char *) 0xb0000;
vidport = 0x3b4;
} else {
vidmem = (char *) 0xb8000;
vidport = 0x3d4;
}
This patch removes the initialisation.
Signed-off-by: Ingo Molnar <mingo@elte.hu>
