Because it is not used.
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Jan Kratochvil <jan.kratochvil@redhat.com>
Cc: Michael Neuling <mikey@neuling.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Paul Mundt <lethal@linux-sh.org>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Prasad <prasad@linux.vnet.ibm.com>
Cc: Russell King <linux@arm.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The soft-dirty is a bit on a PTE which helps to track which pages a task
writes to. In order to do this tracking one should
1. Clear soft-dirty bits from PTEs ("echo 4 > /proc/PID/clear_refs)
2. Wait some time.
3. Read soft-dirty bits (55'th in /proc/PID/pagemap2 entries)
To do this tracking, the writable bit is cleared from PTEs when the
soft-dirty bit is. Thus, after this, when the task tries to modify a
page at some virtual address the #PF occurs and the kernel sets the
soft-dirty bit on the respective PTE.
Note, that although all the task's address space is marked as r/o after
the soft-dirty bits clear, the #PF-s that occur after that are processed
fast. This is so, since the pages are still mapped to physical memory,
and thus all the kernel does is finds this fact out and puts back
writable, dirty and soft-dirty bits on the PTE.
Another thing to note, is that when mremap moves PTEs they are marked
with soft-dirty as well, since from the user perspective mremap modifies
the virtual memory at mremap's new address.
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
Cc: Matt Mackall <mpm@selenic.com>
Cc: Xiao Guangrong <xiaoguangrong@linux.vnet.ibm.com>
Cc: Glauber Costa <glommer@parallels.com>
Cc: Marcelo Tosatti <mtosatti@redhat.com>
Cc: KOSAKI Motohiro <kosaki.motohiro@gmail.com>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Pull x86 tracing updates from Ingo Molnar:
"This tree adds IRQ vector tracepoints that are named after the handler
and which output the vector #, based on a zero-overhead approach that
relies on changing the IDT entries, by Seiji Aguchi.
The new tracepoints look like this:
# perf list | grep -i irq_vector
irq_vectors:local_timer_entry [Tracepoint event]
irq_vectors:local_timer_exit [Tracepoint event]
irq_vectors:reschedule_entry [Tracepoint event]
irq_vectors:reschedule_exit [Tracepoint event]
irq_vectors:spurious_apic_entry [Tracepoint event]
irq_vectors:spurious_apic_exit [Tracepoint event]
irq_vectors:error_apic_entry [Tracepoint event]
irq_vectors:error_apic_exit [Tracepoint event]
[...]"
* 'x86-tracing-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86/tracing: Add config option checking to the definitions of mce handlers
trace,x86: Do not call local_irq_save() in load_current_idt()
trace,x86: Move creation of irq tracepoints from apic.c to irq.c
x86, trace: Add irq vector tracepoints
x86: Rename variables for debugging
x86, trace: Introduce entering/exiting_irq()
tracing: Add DEFINE_EVENT_FN() macro
Pull x86 RAS update from Ingo Molnar:
"The changes in this tree are:
- ACPI APEI (ACPI Platform Error Interface) improvements, by Chen
Gong
- misc MCE fixes/cleanups"
* 'x86-ras-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86/mce: Update MCE severity condition check
mce: acpi/apei: Add comments to clarify usage of the various bitfields in the MCA subsystem
ACPI/APEI: Update einj documentation for param1/param2
ACPI/APEI: Add parameter check before error injection
ACPI, APEI, EINJ: Fix error return code in einj_init()
x86, mce: Fix "braodcast" typo
Pull x86 mm changes from Ingo Molnar:
"Misc improvements:
- Fix /proc/mtrr reporting
- Fix ioremap printout
- Remove the unused pvclock fixmap entry on 32-bit
- misc cleanups"
* 'x86-mm-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86/ioremap: Correct function name output
x86: Fix /proc/mtrr with base/size more than 44bits
ix86: Don't waste fixmap entries
x86/mm: Drop unneeded include <asm/*pgtable, page*_types.h>
x86_64: Correct phys_addr in cleanup_highmap comment
Pull x86 microcode loading update from Ingo Molnar:
"Two main changes that improve microcode loading on AMD CPUs:
- Add support for all-in-one binary microcode files that concatenate
the microcode images of multiple processor families, by Jacob Shin
- Add early microcode loading (embedded in the initrd) support, also
by Jacob Shin"
* 'x86-microcode-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86, microcode, amd: Another early loading fixup
x86, microcode, amd: Allow multiple families' bin files appended together
x86, microcode, amd: Make find_ucode_in_initrd() __init
x86, microcode, amd: Fix warnings and errors on with CONFIG_MICROCODE=m
x86, microcode, amd: Early microcode patch loading support for AMD
x86, microcode, amd: Refactor functions to prepare for early loading
x86, microcode: Vendor abstract out save_microcode_in_initrd()
x86, microcode, intel: Correct typo in printk
Pull x86 FPU changes from Ingo Molnar:
"There are two bigger changes in this tree:
- Add an [early-use-]safe static_cpu_has() variant and other
robustness improvements, including the new X86_DEBUG_STATIC_CPU_HAS
configurable debugging facility, motivated by recent obscure FPU
code bugs, by Borislav Petkov
- Reimplement FPU detection code in C and drop the old asm code, by
Peter Anvin."
* 'x86-fpu-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86, fpu: Use static_cpu_has_safe before alternatives
x86: Add a static_cpu_has_safe variant
x86: Sanity-check static_cpu_has usage
x86, cpu: Add a synthetic, always true, cpu feature
x86: Get rid of ->hard_math and all the FPU asm fu
Pull x86 EFI changes from Ingo Molnar:
"Two fixes that should in principle increase robustness of our
interaction with the EFI firmware, and a cleanup"
* 'x86-efi-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86, efi: retry ExitBootServices() on failure
efi: Convert runtime services function ptrs
UEFI: Don't pass boot services regions to SetVirtualAddressMap()
Pull x86 cpu updates from Ingo Molnar:
"Two changes:
- Extend 32-bit double fault debugging aid to 64-bit
- Fix a build warning"
* 'x86-cpu-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86/intel/cacheinfo: Shut up last long-standing warning
x86: Extend #DF debugging aid to 64-bit
Pull x86 cleanups from Ingo Molnar:
"Misc x86 cleanups"
* 'x86-cleanups-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86, reloc: Use xorl instead of xorq in relocate_kernel_64.S
x86, cleanups: Remove extra tab in __flush_tlb_one()
x86/mce: Remove check for CONFIG_X86_MCE_P4THERMAL
Pull asm/x86 changes from Ingo Molnar:
"Misc changes, with a bigger processor-flags cleanup/reorganization by
Peter Anvin"
* 'x86-asm-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86, asm, cleanup: Replace open-coded control register values with symbolic
x86, processor-flags: Fix the datatypes and add bit number defines
x86: Rename X86_CR4_RDWRGSFS to X86_CR4_FSGSBASE
x86, flags: Rename X86_EFLAGS_BIT1 to X86_EFLAGS_FIXED
linux/const.h: Add _BITUL() and _BITULL()
x86/vdso: Convert use of typedef ctl_table to struct ctl_table
x86: __force_order doesn't need to be an actual variable
Pull voluntary preemption fixes from Ingo Molnar:
"This tree contains a speedup which is achieved through better
might_sleep()/might_fault() preemption point annotations for uaccess
functions, by Michael S Tsirkin:
1. The only reason uaccess routines might sleep is if they fault.
Make this explicit for all architectures.
2. A voluntary preemption point in uaccess functions means compiler
can't inline them efficiently, this breaks assumptions that they
are very fast and small that e.g. net code seems to make. Remove
this preemption point so behaviour matches with what callers
assume.
3. Accesses (e.g through socket ops) to kernel memory with KERNEL_DS
like net/sunrpc does will never sleep. Remove an unconditinal
might_sleep() in the might_fault() inline in kernel.h (used when
PROVE_LOCKING is not set).
4. Accesses with pagefault_disable() return EFAULT but won't cause
caller to sleep. Check for that and thus avoid might_sleep() when
PROVE_LOCKING is set.
These changes offer a nice speedup for CONFIG_PREEMPT_VOLUNTARY=y
kernels, here's a network bandwidth measurement between a virtual
machine and the host:
before:
incoming: 7122.77 Mb/s
outgoing: 8480.37 Mb/s
after:
incoming: 8619.24 Mb/s [ +21.0% ]
outgoing: 9455.42 Mb/s [ +11.5% ]
I kept these changes in a separate tree, separate from scheduler
changes, because it's a mixed MM and scheduler topic"
* 'sched-mm-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
mm, sched: Allow uaccess in atomic with pagefault_disable()
mm, sched: Drop voluntary schedule from might_fault()
x86: uaccess s/might_sleep/might_fault/
tile: uaccess s/might_sleep/might_fault/
powerpc: uaccess s/might_sleep/might_fault/
mn10300: uaccess s/might_sleep/might_fault/
microblaze: uaccess s/might_sleep/might_fault/
m32r: uaccess s/might_sleep/might_fault/
frv: uaccess s/might_sleep/might_fault/
arm64: uaccess s/might_sleep/might_fault/
asm-generic: uaccess s/might_sleep/might_fault/
Pull perf updates from Ingo Molnar:
"Kernel improvements:
- watchdog driver improvements by Li Zefan
- Power7 CPI stack events related improvements by Sukadev Bhattiprolu
- event multiplexing via hrtimers and other improvements by Stephane
Eranian
- kernel stack use optimization by Andrew Hunter
- AMD IOMMU uncore PMU support by Suravee Suthikulpanit
- NMI handling rate-limits by Dave Hansen
- various hw_breakpoint fixes by Oleg Nesterov
- hw_breakpoint overflow period sampling and related signal handling
fixes by Jiri Olsa
- Intel Haswell PMU support by Andi Kleen
Tooling improvements:
- Reset SIGTERM handler in workload child process, fix from David
Ahern.
- Makefile reorganization, prep work for Kconfig patches, from Jiri
Olsa.
- Add automated make test suite, from Jiri Olsa.
- Add --percent-limit option to 'top' and 'report', from Namhyung
Kim.
- Sorting improvements, from Namhyung Kim.
- Expand definition of sysfs format attribute, from Michael Ellerman.
Tooling fixes:
- 'perf tests' fixes from Jiri Olsa.
- Make Power7 CPI stack events available in sysfs, from Sukadev
Bhattiprolu.
- Handle death by SIGTERM in 'perf record', fix from David Ahern.
- Fix printing of perf_event_paranoid message, from David Ahern.
- Handle realloc failures in 'perf kvm', from David Ahern.
- Fix divide by 0 in variance, from David Ahern.
- Save parent pid in thread struct, from David Ahern.
- Handle JITed code in shared memory, from Andi Kleen.
- Fixes for 'perf diff', from Jiri Olsa.
- Remove some unused struct members, from Jiri Olsa.
- Add missing liblk.a dependency for python/perf.so, fix from Jiri
Olsa.
- Respect CROSS_COMPILE in liblk.a, from Rabin Vincent.
- No need to do locking when adding hists in perf report, only 'top'
needs that, from Namhyung Kim.
- Fix alignment of symbol column in in the hists browser (top,
report) when -v is given, from NAmhyung Kim.
- Fix 'perf top' -E option behavior, from Namhyung Kim.
- Fix bug in isupper() and islower(), from Sukadev Bhattiprolu.
- Fix compile errors in bp_signal 'perf test', from Sukadev
Bhattiprolu.
... and more things"
* 'perf-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (102 commits)
perf/x86: Disable PEBS-LL in intel_pmu_pebs_disable()
perf/x86: Fix shared register mutual exclusion enforcement
perf/x86/intel: Support full width counting
x86: Add NMI duration tracepoints
perf: Drop sample rate when sampling is too slow
x86: Warn when NMI handlers take large amounts of time
hw_breakpoint: Introduce "struct bp_cpuinfo"
hw_breakpoint: Simplify *register_wide_hw_breakpoint()
hw_breakpoint: Introduce cpumask_of_bp()
hw_breakpoint: Simplify the "weight" usage in toggle_bp_slot() paths
hw_breakpoint: Simplify list/idx mess in toggle_bp_slot() paths
perf/x86/intel: Add mem-loads/stores support for Haswell
perf/x86/intel: Support Haswell/v4 LBR format
perf/x86/intel: Move NMI clearing to end of PMI handler
perf/x86/intel: Add Haswell PEBS support
perf/x86/intel: Add simple Haswell PMU support
perf/x86/intel: Add Haswell PEBS record support
perf/x86/intel: Fix sparse warning
perf/x86/amd: AMD IOMMU Performance Counter PERF uncore PMU implementation
perf/x86/amd: Add IOMMU Performance Counter resource management
...
Pull WW mutex support from Ingo Molnar:
"This tree adds support for wound/wait style locks, which the graphics
guys would like to make use of in the TTM graphics subsystem.
Wound/wait mutexes are used when other multiple lock acquisitions of a
similar type can be done in an arbitrary order. The deadlock handling
used here is called wait/wound in the RDBMS literature: The older
tasks waits until it can acquire the contended lock. The younger
tasks needs to back off and drop all the locks it is currently
holding, ie the younger task is wounded.
See this LWN.net description of W/W mutexes:
https://lwn.net/Articles/548909/
The comments there outline specific usecases for this facility (which
have already been implemented for the DRM tree).
Also see Documentation/ww-mutex-design.txt for more details"
* 'core-mutexes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
locking-selftests: Handle unexpected failures more strictly
mutex: Add more w/w tests to test EDEADLK path handling
mutex: Add more tests to lib/locking-selftest.c
mutex: Add w/w tests to lib/locking-selftest.c
mutex: Add w/w mutex slowpath debugging
mutex: Add support for wound/wait style locks
arch: Make __mutex_fastpath_lock_retval return whether fastpath succeeded or not
Pull VFS patches (part 1) from Al Viro:
"The major change in this pile is ->readdir() replacement with
->iterate(), dealing with ->f_pos races in ->readdir() instances for
good.
There's a lot more, but I'd prefer to split the pull request into
several stages and this is the first obvious cutoff point."
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (67 commits)
[readdir] constify ->actor
[readdir] ->readdir() is gone
[readdir] convert ecryptfs
[readdir] convert coda
[readdir] convert ocfs2
[readdir] convert fatfs
[readdir] convert xfs
[readdir] convert btrfs
[readdir] convert hostfs
[readdir] convert afs
[readdir] convert ncpfs
[readdir] convert hfsplus
[readdir] convert hfs
[readdir] convert befs
[readdir] convert cifs
[readdir] convert freevxfs
[readdir] convert fuse
[readdir] convert hpfs
reiserfs: switch reiserfs_readdir_dentry to inode
reiserfs: is_privroot_deh() needs only directory inode, actually
...
This will allow me to call functions that have multiple
arguments if fastpath fails. This is required to support ticket
mutexes, because they need to be able to pass an extra argument
to the fail function.
Originally I duplicated the functions, by adding
__mutex_fastpath_lock_retval_arg. This ended up being just a
duplication of the existing function, so a way to test if
fastpath was called ended up being better.
This also cleaned up the reservation mutex patch some by being
able to call an atomic_set instead of atomic_xchg, and making it
easier to detect if the wrong unlock function was previously
used.
Signed-off-by: Maarten Lankhorst <maarten.lankhorst@canonical.com>
Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: dri-devel@lists.freedesktop.org
Cc: linaro-mm-sig@lists.linaro.org
Cc: robclark@gmail.com
Cc: rostedt@goodmis.org
Cc: daniel@ffwll.ch
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/20130620113105.4001.83929.stgit@patser
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Recent Intel CPUs like Haswell and IvyBridge have a new
alternative MSR range for perfctrs that allows writing the full
counter width. Enable this range if the hardware reports it
using a new capability bit.
Currently the perf code queries CPUID to get the counter width,
and sign extends the counter values as needed. The traditional
PERFCTR MSRs always limit to 32bit, even though the counter
internally is larger (usually 48 bits on recent CPUs)
When the new capability is set use the alternative range which
do not have these restrictions.
This lowers the overhead of perf stat slightly because it has to
do less interrupts to accumulate the counter value. On Haswell
it also avoids some problems with TSX aborting when the end of
the counter range is reached.
( See the patch "perf/x86/intel: Avoid checkpointed counters
causing excessive TSX aborts" for more details. )
Signed-off-by: Andi Kleen <ak@linux.intel.com>
Reviewed-by: Stephane Eranian <eranian@google.com>
Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/1372173153-20215-1-git-send-email-andi@firstfloor.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
The control registers are unsigned long (32 bits on i386, 64 bits on
x86-64), and so make that manifest in the data type for the various
constants. Add defines with a _BIT suffix which defines the bit
number, as opposed to the bit mask.
This should resolve some issues with ~bitmask that Linus discovered.
Reported-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
Link: http://lkml.kernel.org/n/tip-cwckhbrib2aux1qbteaebij0@git.kernel.org
Bit 1 in the x86 EFLAGS is always set. Name the macro something that
actually tries to explain what it is all about, rather than being a
tautology.
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: Gleb Natapov <gleb@redhat.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Link: http://lkml.kernel.org/n/tip-f10rx5vjjm6tfnt8o1wseb3v@git.kernel.org
As load_current_idt() is now what is used to update the IDT for the
switches needed for NMI, lockdep debug, and for tracing, it must not
call local_irq_save(). This is because one of the users of this is
lockdep, which does tracing of local_irq_save() and when the debug
trap is hit, we need to update the IDT before tracing interrupts
being disabled. As load_current_idt() is used to do this, calling
local_irq_save() which lockdep traces, defeats the point of calling
load_current_idt().
As interrupts are already disabled when used by lockdep and NMI, the
only other user is tracing that can disable interrupts itself. Simply
have the tracing update disable interrupts before calling load_current_idt()
instead of breaking the other users.
Here's the dump that happened:
------------[ cut here ]------------
WARNING: at /work/autotest/nobackup/linux-test.git/kernel/fork.c:1196 copy_process+0x2c3/0x1398()
DEBUG_LOCKS_WARN_ON(!p->hardirqs_enabled)
Modules linked in:
CPU: 1 PID: 4570 Comm: gdm-simple-gree Not tainted 3.10.0-rc3-test+ #5
Hardware name: /DG965MQ, BIOS MQ96510J.86A.0372.2006.0605.1717 06/05/2006
ffffffff81d2a7a5 ffff88006ed13d50 ffffffff8192822b ffff88006ed13d90
ffffffff81035f25 ffff8800721c6000 ffff88006ed13da0 0000000001200011
0000000000000000 ffff88006ed5e000 ffff8800721c6000 ffff88006ed13df0
Call Trace:
[<ffffffff8192822b>] dump_stack+0x19/0x1b
[<ffffffff81035f25>] warn_slowpath_common+0x67/0x80
[<ffffffff81035fe1>] warn_slowpath_fmt+0x46/0x48
[<ffffffff812bfc5d>] ? __raw_spin_lock_init+0x31/0x52
[<ffffffff810341f7>] copy_process+0x2c3/0x1398
[<ffffffff8103539d>] do_fork+0xa8/0x260
[<ffffffff810ca7b1>] ? trace_preempt_on+0x2a/0x2f
[<ffffffff812afb3e>] ? trace_hardirqs_on_thunk+0x3a/0x3f
[<ffffffff81937fe7>] ? sysret_check+0x1b/0x56
[<ffffffff81937fe7>] ? sysret_check+0x1b/0x56
[<ffffffff810355cf>] SyS_clone+0x16/0x18
[<ffffffff81938369>] stub_clone+0x69/0x90
[<ffffffff81937fc2>] ? system_call_fastpath+0x16/0x1b
---[ end trace 8b157a9d20ca1aa2 ]---
in fork.c:
#ifdef CONFIG_PROVE_LOCKING
DEBUG_LOCKS_WARN_ON(!p->hardirqs_enabled); <-- bug here
DEBUG_LOCKS_WARN_ON(!p->softirqs_enabled);
#endif
Cc: Seiji Aguchi <seiji.aguchi@hds.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
[Purpose of this patch]
As Vaibhav explained in the thread below, tracepoints for irq vectors
are useful.
http://www.spinics.net/lists/mm-commits/msg85707.html
<snip>
The current interrupt traces from irq_handler_entry and irq_handler_exit
provide when an interrupt is handled. They provide good data about when
the system has switched to kernel space and how it affects the currently
running processes.
There are some IRQ vectors which trigger the system into kernel space,
which are not handled in generic IRQ handlers. Tracing such events gives
us the information about IRQ interaction with other system events.
The trace also tells where the system is spending its time. We want to
know which cores are handling interrupts and how they are affecting other
processes in the system. Also, the trace provides information about when
the cores are idle and which interrupts are changing that state.
<snip>
On the other hand, my usecase is tracing just local timer event and
getting a value of instruction pointer.
I suggested to add an argument local timer event to get instruction pointer before.
But there is another way to get it with external module like systemtap.
So, I don't need to add any argument to irq vector tracepoints now.
[Patch Description]
Vaibhav's patch shared a trace point ,irq_vector_entry/irq_vector_exit, in all events.
But there is an above use case to trace specific irq_vector rather than tracing all events.
In this case, we are concerned about overhead due to unwanted events.
So, add following tracepoints instead of introducing irq_vector_entry/exit.
so that we can enable them independently.
- local_timer_vector
- reschedule_vector
- call_function_vector
- call_function_single_vector
- irq_work_entry_vector
- error_apic_vector
- thermal_apic_vector
- threshold_apic_vector
- spurious_apic_vector
- x86_platform_ipi_vector
Also, introduce a logic switching IDT at enabling/disabling time so that a time penalty
makes a zero when tracepoints are disabled. Detailed explanations are as follows.
- Create trace irq handlers with entering_irq()/exiting_irq().
- Create a new IDT, trace_idt_table, at boot time by adding a logic to
_set_gate(). It is just a copy of original idt table.
- Register the new handlers for tracpoints to the new IDT by introducing
macros to alloc_intr_gate() called at registering time of irq_vector handlers.
- Add checking, whether irq vector tracing is on/off, into load_current_idt().
This has to be done below debug checking for these reasons.
- Switching to debug IDT may be kicked while tracing is enabled.
- On the other hands, switching to trace IDT is kicked only when debugging
is disabled.
In addition, the new IDT is created only when CONFIG_TRACING is enabled to avoid being
used for other purposes.
Signed-off-by: Seiji Aguchi <seiji.aguchi@hds.com>
Link: http://lkml.kernel.org/r/51C323ED.5050708@hds.com
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Rename variables for debugging to describe meaning of them precisely.
Also, introduce a generic way to switch IDT by checking a current state,
debug on/off.
Signed-off-by: Seiji Aguchi <seiji.aguchi@hds.com>
Link: http://lkml.kernel.org/r/51C323A8.7050905@hds.com
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
When implementing tracepoints in interrupt handers, if the tracepoints are
simply added in the performance sensitive path of interrupt handers,
it may cause potential performance problem due to the time penalty.
To solve the problem, an idea is to prepare non-trace/trace irq handers and
switch their IDTs at the enabling/disabling time.
So, let's introduce entering_irq()/exiting_irq() for pre/post-
processing of each irq handler.
A way to use them is as follows.
Non-trace irq handler:
smp_irq_handler()
{
entering_irq(); /* pre-processing of this handler */
__smp_irq_handler(); /*
* common logic between non-trace and trace handlers
* in a vector.
*/
exiting_irq(); /* post-processing of this handler */
}
Trace irq_handler:
smp_trace_irq_handler()
{
entering_irq(); /* pre-processing of this handler */
trace_irq_entry(); /* tracepoint for irq entry */
__smp_irq_handler(); /*
* common logic between non-trace and trace handlers
* in a vector.
*/
trace_irq_exit(); /* tracepoint for irq exit */
exiting_irq(); /* post-processing of this handler */
}
If tracepoints can place outside entering_irq()/exiting_irq() as follows,
it looks cleaner.
smp_trace_irq_handler()
{
trace_irq_entry();
smp_irq_handler();
trace_irq_exit();
}
But it doesn't work.
The problem is with irq_enter/exit() being called. They must be called before
trace_irq_enter/exit(), because of the rcu_irq_enter() must be called before
any tracepoints are used, as tracepoints use rcu to synchronize.
As a possible alternative, we may be able to call irq_enter() first as follows
if irq_enter() can nest.
smp_trace_irq_hander()
{
irq_entry();
trace_irq_entry();
smp_irq_handler();
trace_irq_exit();
irq_exit();
}
But it doesn't work, either.
If irq_enter() is nested, it may have a time penalty because it has to check if it
was already called or not. The time penalty is not desired in performance sensitive
paths even if it is tiny.
Signed-off-by: Seiji Aguchi <seiji.aguchi@hds.com>
Link: http://lkml.kernel.org/r/51C3238D.9040706@hds.com
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
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Merge tag 'v3.10-rc6' into x86/cleanups
Linux 3.10-rc6
We need a change that is the mainline tree for further work.
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
The call stack below shows how this happens: basically eager_fpu_init()
calls __thread_fpu_begin(current) which then does if (!use_eager_fpu()),
which, in turn, uses static_cpu_has.
And we're executing before alternatives so static_cpu_has doesn't work
there yet.
Use the safe variant in this path which becomes optimal after
alternatives have run.
WARNING: at arch/x86/kernel/cpu/common.c:1368 warn_pre_alternatives+0x1e/0x20()
You're using static_cpu_has before alternatives have run!
Modules linked in:
Pid: 0, comm: swapper Not tainted 3.9.0-rc8+ #1
Call Trace:
warn_slowpath_common
warn_slowpath_fmt
? fpu_finit
warn_pre_alternatives
eager_fpu_init
fpu_init
cpu_init
trap_init
start_kernel
? repair_env_string
x86_64_start_reservations
x86_64_start_kernel
Signed-off-by: Borislav Petkov <bp@suse.de>
Link: http://lkml.kernel.org/r/1370772454-6106-6-git-send-email-bp@alien8.de
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
We want to use this in early code where alternatives might not have run
yet and for that case we fall back to the dynamic boot_cpu_has.
For that, force a 5-byte jump since the compiler could be generating
differently sized jumps for each label.
Signed-off-by: Borislav Petkov <bp@suse.de>
Link: http://lkml.kernel.org/r/1370772454-6106-5-git-send-email-bp@alien8.de
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
static_cpu_has may be used only after alternatives have run. Before that
it always returns false if constant folding with __builtin_constant_p()
doesn't happen. And you don't want that.
This patch is the result of me debugging an issue where I overzealously
put static_cpu_has in code which executed before alternatives have run
and had to spend some time with scratching head and cursing at the
monitor.
So add a jump to a warning which screams loudly when we use this
function too early. The alternatives patch that check away in
conjunction with patching the rest of the kernel image.
[ hpa: factored this into its own configuration option. If we want to
have an overarching option, it should be an option which selects
other options, not as a group option in the source code. ]
Signed-off-by: Borislav Petkov <bp@suse.de>
Link: http://lkml.kernel.org/r/1370772454-6106-4-git-send-email-bp@alien8.de
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
The following change fixes the x86 implementation of
trigger_all_cpu_backtrace(), which was previously (accidentally,
as far as I can tell) disabled to always return false as on
architectures that do not implement this function.
trigger_all_cpu_backtrace(), as defined in include/linux/nmi.h,
should call arch_trigger_all_cpu_backtrace() if available, or
return false if the underlying arch doesn't implement this
function.
x86 did provide a suitable arch_trigger_all_cpu_backtrace()
implementation, but it wasn't actually being used because it was
declared in asm/nmi.h, which linux/nmi.h doesn't include. Also,
linux/nmi.h couldn't easily be fixed by including asm/nmi.h,
because that file is not available on all architectures.
I am proposing to fix this by moving the x86 definition of
arch_trigger_all_cpu_backtrace() to asm/irq.h.
Tested via: echo l > /proc/sysrq-trigger
Before the change, this uses a fallback implementation which
shows backtraces on active CPUs (using
smp_call_function_interrupt() )
After the change, this shows NMI backtraces on all CPUs
Signed-off-by: Michel Lespinasse <walken@google.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Link: http://lkml.kernel.org/r/1370518875-1346-1-git-send-email-walken@google.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
We are in the process of removing all the __cpuinit annotations.
While working on making that change, an existing problem was
made evident:
WARNING: arch/x86/kernel/built-in.o(.text+0x198f2): Section mismatch
in reference from the function cpu_init() to the function
.init.text:load_ucode_ap() The function cpu_init() references
the function __init load_ucode_ap(). This is often because cpu_init
lacks a __init annotation or the annotation of load_ucode_ap is wrong.
This now appears because in my working tree, cpu_init() is no longer
tagged as __cpuinit, and so the audit picks up the mismatch. The 2nd
hypothesis from the audit is the correct one, as there was an incorrect
__init tag on the prototype in the header (but __cpuinit was used on
the function itself.)
The audit is telling us that the prototype's __init annotation took
effect and the function did land in the .init.text section. Checking
with objdump on a mainline tree that still has __cpuinit shows that
the __cpuinit on the function takes precedence over the __init on the
prototype, but that won't be true once we make __cpuinit a no-op.
Even though we are removing __cpuinit, we temporarily align both
the function and the prototype on __cpuinit so that the changeset
can be applied to stable trees if desired.
[ hpa: build fix only, no object code change ]
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: stable <stable@vger.kernel.org> # 3.9+
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Link: http://lkml.kernel.org/r/1371654926-11729-1-git-send-email-paul.gortmaker@windriver.com
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
Similar to SandyBridge, but has a few new events and two
new counter bits.
There are some new counter flags that need to be prevented
from being set on fixed counters, and allowed to be set
for generic counters.
Also we add support for the counter 2 constraint to handle
all raw events.
(Contains fixes from Stephane Eranian.)
Reviewed-by: Stephane Eranian <eranian@google.com>
Signed-off-by: Andi Kleen <ak@linux.intel.com>
Cc: Andi Kleen <ak@linux.jf.intel.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Link: http://lkml.kernel.org/r/1371515812-9646-3-git-send-email-andi@firstfloor.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
few users were reporting boot regressions in v3.9. This has now been
fixed with a more accurate "minimum storage requirement to avoid
bricking" value from Samsung (5K instead of 50%) and code to trigger
garbage collection when we near our limit - Matthew Garrett.
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Merge tag 'efi-urgent' into x86/urgent
* More tweaking to the EFI variable anti-bricking algorithm. Quite a
few users were reporting boot regressions in v3.9. This has now been
fixed with a more accurate "minimum storage requirement to avoid
bricking" value from Samsung (5K instead of 50%) and code to trigger
garbage collection when we near our limit - Matthew Garrett.
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
... to void * like the boot services and lose all the void * casts. No
functionality change.
Signed-off-by: Borislav Petkov <bp@suse.de>
Signed-off-by: Matt Fleming <matt.fleming@intel.com>
This patch reworks the UEFI anti-bricking code, including an effective
reversion of cc5a080c and 31ff2f20. It turns out that calling
QueryVariableInfo() from boot services results in some firmware
implementations jumping to physical addresses even after entering virtual
mode, so until we have 1:1 mappings for UEFI runtime space this isn't
going to work so well.
Reverting these gets us back to the situation where we'd refuse to create
variables on some systems because they classify deleted variables as "used"
until the firmware triggers a garbage collection run, which they won't do
until they reach a lower threshold. This results in it being impossible to
install a bootloader, which is unhelpful.
Feedback from Samsung indicates that the firmware doesn't need more than
5KB of storage space for its own purposes, so that seems like a reasonable
threshold. However, there's still no guarantee that a platform will attempt
garbage collection merely because it drops below this threshold. It seems
that this is often only triggered if an attempt to write generates a
genuine EFI_OUT_OF_RESOURCES error. We can force that by attempting to
create a variable larger than the remaining space. This should fail, but if
it somehow succeeds we can then immediately delete it.
I've tested this on the UEFI machines I have available, but I don't have
a Samsung and so can't verify that it avoids the bricking problem.
Signed-off-by: Matthew Garrett <matthew.garrett@nebula.com>
Signed-off-by: Lee, Chun-Y <jlee@suse.com> [ dummy variable cleanup ]
Cc: <stable@vger.kernel.org>
Signed-off-by: Matt Fleming <matt.fleming@intel.com>
Reimplement FPU detection code in C and drop old, not-so-recommended
detection method in asm. Move all the relevant stuff into i387.c where
it conceptually belongs. Finally drop cpuinfo_x86.hard_math.
[ hpa: huge thanks to Borislav for taking my original concept patch
and productizing it ]
[ Boris, note to self: do not use static_cpu_has before alternatives! ]
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
Link: http://lkml.kernel.org/r/1367244262-29511-2-git-send-email-bp@alien8.de
Link: http://lkml.kernel.org/r/1365436666-9837-2-git-send-email-bp@alien8.de
Signed-off-by: Borislav Petkov <bp@suse.de>
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
Remove the extra tab in __flush_tlb_one().
CC: Alex Shi <alex.shi@intel.com>
CC: Fenghua Yu <fenghua.yu@intel.com>
Signed-off-by: Michael Wang <wangyun@linux.vnet.ibm.com>
Link: http://lkml.kernel.org/r/51AD8902.60603@linux.vnet.ibm.com
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
Fix section mismatch warnings on microcode_amd_early.
Compile error occurs when CONFIG_MICROCODE=m, change so that early
loading depends on microcode_core.
Reported-by: Yinghai Lu <yinghai@kernel.org>
Reported-by: Borislav Petkov <bp@alien8.de>
Signed-off-by: Jacob Shin <jacob.shin@amd.com>
Link: http://lkml.kernel.org/r/20130531150241.GA12006@jshin-Toonie
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
It being static causes over a dozen instances to be scattered
across the kernel image, with non of them ever being referenced
in any way. Making the variable extern without ever defining it
works as well - all we need is to have the compiler think the
variable is being accessed.
Signed-off-by: Jan Beulich <jbeulich@suse.com>
Link: http://lkml.kernel.org/r/51A610B802000078000D99A0@nat28.tlf.novell.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
The vsyscall related pvclock entries can only ever be used on
x86-64, and hence they shouldn't even get allocated for 32-bit
kernels (the more that it is there where address space is
relatively precious).
Signed-off-by: Jan Beulich <jbeulich@suse.com>
Cc: Marcelo Tosatti <mtosatti@redhat.com>
Link: http://lkml.kernel.org/r/51A60F1F02000078000D997C@nat28.tlf.novell.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
In preparation work for early loading, refactor some common functions
that will be shared, and move some struct defines to a common header file.
Signed-off-by: Jacob Shin <jacob.shin@amd.com>
Link: http://lkml.kernel.org/r/1369940959-2077-4-git-send-email-jacob.shin@amd.com
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
Cc: Fenghua Yu <fenghua.yu@intel.com>
Currently save_microcode_in_initrd() is declared in vendor neutural
microcode.h file, but defined in vendor specific
microcode_intel_early.c file. Vendor abstract it out to
microcode_core_early.c with a wrapper function.
Signed-off-by: Jacob Shin <jacob.shin@amd.com>
Link: http://lkml.kernel.org/r/1369940959-2077-3-git-send-email-jacob.shin@amd.com
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
Cc: Fenghua Yu <fenghua.yu@intel.com>
binutils prior to 2.18 (e.g. the ones found on SLE10) don't support
assembling PEXTRD, so a macro based approach like the one for PCLMULQDQ
in the same file should be used.
This requires making the helper macros capable of recognizing 32-bit
general purpose register operands.
[ hpa: tagging for stable as it is a low risk build fix ]
Signed-off-by: Jan Beulich <jbeulich@suse.com>
Link: http://lkml.kernel.org/r/51A6142A02000078000D99D8@nat28.tlf.novell.com
Cc: Alexander Boyko <alexander_boyko@xyratex.com>
Cc: Herbert Xu <herbert@gondor.apana.org.au>
Cc: Huang Ying <ying.huang@intel.com>
Cc: <stable@vger.kernel.org> v3.9
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
The only reason uaccess routines might sleep
is if they fault. Make this explicit.
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/1369577426-26721-9-git-send-email-mst@redhat.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
While porting Vince's perf overflow tests I found perf event
breakpoint overflow does not work properly.
I found the x86 RF EFLAG bit not being set when returning
from debug exception after triggering signal handler. Which
is exactly what you get when you set perf breakpoint overflow
SIGIO handler.
This patch and the next two patches fix the underlying bugs.
This patch adds the RF EFLAGS bit to be restored on return from
signal from the original register context before the signal was
entered.
This will prevent the RF flag to disappear when returning
from exception due to the signal handler being executed.
Signed-off-by: Jiri Olsa <jolsa@redhat.com>
Tested-by: Oleg Nesterov <oleg@redhat.com>
Reviewed-by: Frederic Weisbecker <fweisbec@gmail.com>
Originally-Reported-by: Vince Weaver <vincent.weaver@maine.edu>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Andi Kleen <andi@firstfloor.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Arnaldo Carvalho de Melo <acme@ghostprotocols.net>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Corey Ashford <cjashfor@linux.vnet.ibm.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Vince Weaver <vincent.weaver@maine.edu>
Cc: Stephane Eranian <eranian@google.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/1367421944-19082-2-git-send-email-jolsa@redhat.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
