The test to check whether we have _PAGE_SPECIAL defined is broken,
since we always define it, just not always to a meaninful value :-)

That broke 8xx and 40x under some circumstances.

This fixes it by adding _PAGE_SPECIAL for both of these since they
had a free PTE bit, and removing the condition around advertising
it.
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

Sometimes this is used to hold a simple offset, and sometimes
it is used to hold a pointer.  This patch changes it to a union containing
void * and dma_addr_t.  get/set accessors are also provided, because it was
getting a bit ugly to get to the actual data.
Signed-off-by: NBecky Bruce <beckyb@kernel.crashing.org>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

The former is no longer really accurate with the swiotlb case now
a possibility.  I also move it into dma-mapping.h - it no longer
needs to be in dma.c, and there are about to be some more accessors
that should all end up in the same place.  A comment is added to
indicate that this function is not used in configs where there is no
simple dma offset, such as the iommu case.
Signed-off-by: NBecky Bruce <beckyb@kernel.crashing.org>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

It doesn't exist !
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

Now everyone is converted to arch_send_call_function_ipi_mask, remove
the shim and the #defines.
Signed-off-by: NRusty Russell <rusty@rustcorp.com.au>

We're weaning the core code off handing cpumask's around on-stack.
This introduces arch_send_call_function_ipi_mask(), and by defining
it, the old arch_send_call_function_ipi is defined by the core code.
Signed-off-by: NRusty Russell <rusty@rustcorp.com.au>

There were replaced by topology_core_cpumask and topology_thread_cpumask.
Signed-off-by: NRusty Russell <rusty@rustcorp.com.au>

Signed-off-by: NRusty Russell <rusty@rustcorp.com.au>

cpumask_of_pcibus() is the new version.
Signed-off-by: NRusty Russell <rusty@rustcorp.com.au>

Add a flag for mmap that will be used to request a huge page region that
will look like anonymous memory to user space.  This is accomplished by
using a file on the internal vfsmount.  MAP_HUGETLB is a modifier of
MAP_ANONYMOUS and so must be specified with it.  The region will behave
the same as a MAP_ANONYMOUS region using small pages.

The patch also adds the MAP_STACK flag, which was previously defined only
on some architectures but not on others.  Since MAP_STACK is meant to be a
hint only, architectures can define it without assigning a specific
meaning to it.
Signed-off-by: NArnd Bergmann <arnd@arndb.de>
Cc: Eric B Munson <ebmunson@us.ibm.com>
Cc: Hugh Dickins <hugh.dickins@tiscali.co.uk>
Cc: David Rientjes <rientjes@google.com>
Cc: <linux-arch@vger.kernel.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

This fixes two places in the powerpc perf_event (perf_counter) code
where 'list_entry' needs to be changed to 'group_entry', but were
missed in commit 65abc865 ("perf_counter: Rename list_entry ->
group_entry, counter_list -> group_list").

This also changes 'event' back to 'counter' in a couple of
contexts:

* Field and function names that deal with the limited-function
  counters: it's really the hardware counters whose function is
  limited, not the events that they count.  Hence:

  MAX_LIMITED_HWEVENTS -> MAX_LIMITED_HWCOUNTERS
  limited_event -> limited_counter
  freeze/thaw_limited_events -> freeze/thaw_limited_counters

* The machine-specific PMU description struct (struct power_pmu): this
  renames 'n_event' back to 'n_counter' since it really describes how
  many hardware counters the machine has.  (Renaming this back avoids
  a compile error in each of the machine-specific PMU back-ends where
  they initialize their power_pmu struct.)
Signed-off-by: NPaul Mackerras <paulus@samba.org>
Cc: linuxppc-dev@ozlabs.org
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <19128.4280.813369.589704@cargo.ozlabs.ibm.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

 - provide compatibility Kconfig entry for existing PERF_COUNTERS .config's

 - provide courtesy copy of old perf_counter.h, for user-space projects

 - small indentation fixups

 - fix up MAINTAINERS

 - fix small x86 printout fallout

 - fix up small PowerPC comment fallout (use 'counter' as in register)
Reviewed-by: NArjan van de Ven <arjan@linux.intel.com>
Acked-by: NPeter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
LKML-Reference: <new-submission>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Bye-bye Performance Counters, welcome Performance Events!

In the past few months the perfcounters subsystem has grown out its
initial role of counting hardware events, and has become (and is
becoming) a much broader generic event enumeration, reporting, logging,
monitoring, analysis facility.

Naming its core object 'perf_counter' and naming the subsystem
'perfcounters' has become more and more of a misnomer. With pending
code like hw-breakpoints support the 'counter' name is less and
less appropriate.

All in one, we've decided to rename the subsystem to 'performance
events' and to propagate this rename through all fields, variables
and API names. (in an ABI compatible fashion)

The word 'event' is also a bit shorter than 'counter' - which makes
it slightly more convenient to write/handle as well.

Thanks goes to Stephane Eranian who first observed this misnomer and
suggested a rename.

User-space tooling and ABI compatibility is not affected - this patch
should be function-invariant. (Also, defconfigs were not touched to
keep the size down.)

This patch has been generated via the following script:

  FILES=$(find * -type f | grep -vE 'oprofile|[^K]config')

  sed -i \
    -e 's/PERF_EVENT_/PERF_RECORD_/g' \
    -e 's/PERF_COUNTER/PERF_EVENT/g' \
    -e 's/perf_counter/perf_event/g' \
    -e 's/nb_counters/nb_events/g' \
    -e 's/swcounter/swevent/g' \
    -e 's/tpcounter_event/tp_event/g' \
    $FILES

  for N in $(find . -name perf_counter.[ch]); do
    M=$(echo $N | sed 's/perf_counter/perf_event/g')
    mv $N $M
  done

  FILES=$(find . -name perf_event.*)

  sed -i \
    -e 's/COUNTER_MASK/REG_MASK/g' \
    -e 's/COUNTER/EVENT/g' \
    -e 's/\<event\>/event_id/g' \
    -e 's/counter/event/g' \
    -e 's/Counter/Event/g' \
    $FILES

... to keep it as correct as possible. This script can also be
used by anyone who has pending perfcounters patches - it converts
a Linux kernel tree over to the new naming. We tried to time this
change to the point in time where the amount of pending patches
is the smallest: the end of the merge window.

Namespace clashes were fixed up in a preparatory patch - and some
stylistic fallout will be fixed up in a subsequent patch.

( NOTE: 'counters' are still the proper terminology when we deal
  with hardware registers - and these sed scripts are a bit
  over-eager in renaming them. I've undone some of that, but
  in case there's something left where 'counter' would be
  better than 'event' we can undo that on an individual basis
  instead of touching an otherwise nicely automated patch. )
Suggested-by: NStephane Eranian <eranian@google.com>
Acked-by: NPeter Zijlstra <a.p.zijlstra@chello.nl>
Acked-by: NPaul Mackerras <paulus@samba.org>
Reviewed-by: NArjan van de Ven <arjan@linux.intel.com>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: David Howells <dhowells@redhat.com>
Cc: Kyle McMartin <kyle@mcmartin.ca>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: <linux-arch@vger.kernel.org>
LKML-Reference: <new-submission>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Sysbench thinks SD_BALANCE_WAKE is too agressive and kbuild doesn't
really mind too much, SD_BALANCE_NEWIDLE picks up most of the
slack.

On a dual socket, quad core, dual thread nehalem system:

sysbench (--num_threads=16):

 SD_BALANCE_WAKE-: 13982 tx/s
 SD_BALANCE_WAKE+: 15688 tx/s

kbuild (-j16):

 SD_BALANCE_WAKE-: 47.648295846  seconds time elapsed   ( +-   0.312% )
 SD_BALANCE_WAKE+: 47.608607360  seconds time elapsed   ( +-   0.026% )

(same within noise)
Signed-off-by: NPeter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <new-submission>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Make the idle balancer more agressive, to improve a
x264 encoding workload provided by Jason Garrett-Glaser:

 NEXT_BUDDY NO_LB_BIAS
 encoded 600 frames, 252.82 fps, 22096.60 kb/s
 encoded 600 frames, 250.69 fps, 22096.60 kb/s
 encoded 600 frames, 245.76 fps, 22096.60 kb/s

 NO_NEXT_BUDDY LB_BIAS
 encoded 600 frames, 344.44 fps, 22096.60 kb/s
 encoded 600 frames, 346.66 fps, 22096.60 kb/s
 encoded 600 frames, 352.59 fps, 22096.60 kb/s

 NO_NEXT_BUDDY NO_LB_BIAS
 encoded 600 frames, 425.75 fps, 22096.60 kb/s
 encoded 600 frames, 425.45 fps, 22096.60 kb/s
 encoded 600 frames, 422.49 fps, 22096.60 kb/s

Peter pointed out that this is better done via newidle_idx,
not via LB_BIAS, newidle balancing should look for where
there is load _now_, not where there was load 2 ticks ago.

Worst-case latencies are improved as well as no buddies
means less vruntime spread. (as per prior lkml discussions)

This change improves kbuild-peak parallelism as well.
Reported-by: NJason Garrett-Glaser <darkshikari@gmail.com>
Signed-off-by: NMike Galbraith <efault@gmx.de>
Signed-off-by: NPeter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <1253011667.9128.16.camel@marge.simson.net>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

When merging select_task_rq_fair() and sched_balance_self() we lost
the use of wake_idx, restore that and set them to 0 to make wake
balancing more aggressive.
Signed-off-by: NPeter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <new-submission>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

The problem with wake_idle() is that is doesn't respect things like
cpu_power, which means it doesn't deal well with SMT nor the recent
RT interaction.

To cure this, it needs to do what sched_balance_self() does, which
leads to the possibility of merging select_task_rq_fair() and
sched_balance_self().

Modify sched_balance_self() to:

  - update_shares() when walking up the domain tree,
    (it only called it for the top domain, but it should
     have done this anyway), which allows us to remove
    this ugly bit from try_to_wake_up().

  - do wake_affine() on the smallest domain that contains
    both this (the waking) and the prev (the wakee) cpu for
    WAKE invocations.

Then use the top-down balance steps it had to replace wake_idle().

This leads to the dissapearance of SD_WAKE_BALANCE and
SD_WAKE_IDLE_FAR, with SD_WAKE_IDLE replaced with SD_BALANCE_WAKE.

SD_WAKE_AFFINE needs SD_BALANCE_WAKE to be effective.

Touch all topology bits to replace the old with new SD flags --
platforms might need re-tuning, enabling SD_BALANCE_WAKE
conditionally on a NUMA distance seems like a good additional
feature, magny-core and small nehalem systems would want this
enabled, systems with slow interconnects would not.
Signed-off-by: NPeter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <new-submission>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Remove the reliance on a staticly defined NVRAM size, allowing
platforms to support NVRAMs with sizes differing from the standard.

A fall back value is provided for platforms not supporting this extension.
Signed-off-by: NMartyn Welch <martyn.welch@gefanuc.com>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

Currently there is a bug where if you use oprofile on a pSeries
machine, then use perf_counters, then use oprofile again, oprofile
will not work correctly; it will lose the PMU configuration the next
time the hypervisor does a partition context switch, and thereafter
won't count anything.

Maynard Johnson identified the sequence causing the problem:
- oprofile setup calls ppc_enable_pmcs(), which calls
  pseries_lpar_enable_pmcs, which tells the hypervisor that we want
  to use the PMU, and sets the "PMU in use" flag in the lppaca.
  This flag tells the hypervisor whether it needs to save and restore
  the PMU config.
- The perf_counter code sets and clears the "PMU in use" flag directly
  as it context-switches the PMU between tasks, and leaves it clear
  when it finishes.
- oprofile setup, called for a new oprofile run, calls ppc_enable_pmcs,
  which does nothing because it has already been called.  In particular
  it doesn't set the "PMU in use" flag.

This fixes the problem by arranging for ppc_enable_pmcs to always set
the "PMU in use" flag.  It makes the perf_counter code call
ppc_enable_pmcs also rather than calling the lower-level function
directly, and removes the setting of the "PMU in use" flag from
pseries_lpar_enable_pmcs, since that is now done in its caller.

This also removes the declaration of pasemi_enable_pmcs because it
isn't defined anywhere.
Reported-by: NMaynard Johnson <mpjohn@us.ibm.com>
Signed-off-by: NPaul Mackerras <paulus@samba.org>
Cc: <stable@kernel.org)
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

The OF helpers look like nanodoc but are missing the header. Fix this and a
typo (s/nad/and/) while we are here.
Signed-off-by: NWolfram Sang <w.sang@pengutronix.de>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

[avi: fix build on non-x86]
Signed-off-by: NJoerg Roedel <joerg.roedel@amd.com>
Signed-off-by: NAvi Kivity <avi@redhat.com>

Signed-off-by: NLiu Yu <yu.liu@freescale.com>
Signed-off-by: NAvi Kivity <avi@redhat.com>

This was #define'd as 0 on all platforms, so let's get rid of it.

This change makes pci_scan_slot() slightly easier to read.

Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
Cc: Tony Luck <tony.luck@intel.com>
Cc: David Howells <dhowells@redhat.com>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Jeff Dike <jdike@addtoit.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru>
Reviewed-by: NMatthew Wilcox <willy@linux.intel.com>
Acked-by: NRussell King <linux@arm.linux.org.uk>
Acked-by: NRalf Baechle <ralf@linux-mips.org>
Acked-by: NKyle McMartin <kyle@mcmartin.ca>
Acked-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>
Acked-by: NPaul Mundt <lethal@linux-sh.org>
Acked-by: NArnd Bergmann <arnd@arndb.de>
Signed-off-by: NAlex Chiang <achiang@hp.com>
Signed-off-by: NJesse Barnes <jbarnes@virtuousgeek.org>

Use the DMA_SLAVE capability of the DMAEngine API to copy/from a
scatterlist into an arbitrary list of hardware address/length pairs.

This allows a single DMA transaction to copy data from several different
devices into a scatterlist at the same time.

This also adds support to enable some controller-specific features such as
external start and external pause for a DMA transaction.

[dan.j.williams@intel.com: rebased on tx_list movement]
Signed-off-by: NIra W. Snyder <iws@ovro.caltech.edu>
Acked-by: NLi Yang <leoli@freescale.com>
Acked-by: NKumar Gala <galak@kernel.crashing.org>
Signed-off-by: NDan Williams <dan.j.williams@intel.com>

Switch to using the Power ISA defined PTE format when we have a 64-bit
PTE.  This makes the code handling between fsl-booke and book3e-64
similiar for TLB faults.

Additionally this lets use take advantage of the page size encodings and
full permissions that the HW PTE defines.

Also defined _PMD_PRESENT, _PMD_PRESENT_MASK, and _PMD_BAD since the
32-bit ppc arch code expects them.
Signed-off-by: NKumar Gala <galak@kernel.crashing.org>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

Add defines for the other page sizes.  Even if HW doesn't support them
we made them use them for hugetlbfs support.
Signed-off-by: NKumar Gala <galak@kernel.crashing.org>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

The SLB can change sizes across a live migration, which was not
being handled, resulting in possible machine crashes during
migration if migrating to a machine which has a smaller max SLB
size than the source machine. Fix this by first reducing the
SLB size to the minimum possible value, which is 32, prior to
migration. Then during the device tree update which occurs after
migration, we make the call to ensure the SLB gets updated. Also
add the slb_size to the lparcfg output so that the migration
tools can check to make sure the kernel has this capability
before allowing migration in scenarios where the SLB size will change.

BenH: Fixed #include <asm/mmu-hash64.h> -> <asm/mmu.h> to avoid
      breaking ppc32 build
Signed-off-by: NBrian King <brking@linux.vnet.ibm.com>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

The two versions are doing almost exactly the same thing.  No need to
maintain them as separate files.  This patch also has the side effect
of making the PCI device tree scanning code available to 32 bit powerpc
machines, but no board ports actually make use of this feature at this
point.
Signed-off-by: NGrant Likely <grant.likely@secretlab.ca>
Acked-by: NKumar Gala <galak@kernel.crashing.org>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

Needed to avoid namespace conflicts when the common code
function bodies of _spin_try_lock() etc. are moved to a header
file where the function name would be __spin_try_lock().
Signed-off-by: NHeiko Carstens <heiko.carstens@de.ibm.com>
Acked-by: NPeter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Nick Piggin <nickpiggin@yahoo.com.au>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Horst Hartmann <horsth@linux.vnet.ibm.com>
Cc: Christian Ehrhardt <ehrhardt@linux.vnet.ibm.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: David Miller <davem@davemloft.net>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Roman Zippel <zippel@linux-m68k.org>
Cc: <linux-arch@vger.kernel.org>
LKML-Reference: <20090831124415.918799705@de.ibm.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

In some CPUs (i.e. MPC8569) QE shuts down completely during sleep,
drivers may want to know that to reinitialize registers and buffer
descriptors.

This patch implements qe_alive_during_sleep() helper function, so far
it just checks if MPC8569-compatible power management controller is
present, which is a sign that QE turns off during sleep.
Signed-off-by: NAnton Vorontsov <avorontsov@ru.mvista.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The default COMMAND_LINE_SIZE in asm-generic is 512, so the
net effect of this change is nil, aside from the cleanup
factor.  See also commit 2b74b856.
Signed-off-by: NPaul Gortmaker <paul.gortmaker@windriver.com>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

Some of the PCI features we have in ppc32 we will need on ppc64
platforms in the future.  These include support for:

* ppc_md.pci_exclude_device
* indirect config cycles
* early config cycles

We also simplified the logic in fake_pci_bus() to assume it will always
get a valid pci_controller.  Since all current callers seem to pass it
one.
Signed-off-by: NKumar Gala <galak@kernel.crashing.org>
Acked-by: NGrant Likely <grant.likely@secretlab.ca>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

The PCI device tree scanning code in pci_64.c is some useful functionality.
It allows PCI devices to be described in the device tree instead of being
probed for, which in turn allows pci devices to use all of the device tree
facilities to describe complex PCI bus architectures like GPIO and IRQ
routing (perhaps not a common situation for desktop or server systems,
but useful for embedded systems with on-board PCI devices).

This patch moves the device tree scanning into pci-common.c so it is
available for 32-bit powerpc machines too.
Signed-off-by: NGrant Likely <grant.likely@secretlab.ca>
Acked-by: NKumar Gala <galak@kernel.crashing.org>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

We now search through TLBnCFG looking for the first array that has IPROT
support (we assume that there is only one).  If that TLB has hardware
entry select (HES) support we use the existing code and with the proper
TLB select (the HES code still needs to clean up bolted entries from
firmware).  The non-HES code is pretty similiar to the 32-bit FSL Book-E
code but does make some new assumtions (like that we have tlbilx) and
simplifies things down a bit.
Signed-off-by: NKumar Gala <galak@kernel.crashing.org>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

Not all 64-bit Book-3E parts will have fixed IVORs so add a function that
cpusetup code can call to setup the base IVORs (0..15) to match the fixed
offsets.  We need to 'or' part of interrupt_base_book3e into the IVORs
since on parts that have them the IVPR doesn't extend as far down.
Signed-off-by: NKumar Gala <galak@kernel.crashing.org>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

Support for TLB reservation (or TLB Write Conditional) and Paired MAS
registers are optional for a processor implementation so we handle
them via MMU feature sections.

We currently only used paired MAS registers to access the full RPN + perm
bits that are kept in MAS7||MAS3.  We assume that if an implementation has
hardware page table at this time it also implements in TLB reservations.
Signed-off-by: NKumar Gala <galak@kernel.crashing.org>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

On POWER6 systems RA needs to be the base and RB the index.
If they are reversed you take a misdirect hit.
Signed-off-by: NMike Wolf <mjwolf@us.ibm.com>

----
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

Previously, the 36-bit code was using these bits, but they had
never been named in the pte format definition.  This patch just
gives those fields their proper names and adds a comment that
they are only present on some processors.

There is no functional code change.
Signed-off-by: NBecky Bruce <beckyb@kernel.crashing.org>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

Signed-off-by: NFUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

Signed-off-by: NFUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>