Commit Graph

354 Commits

Author SHA1 Message Date
Nick Piggin
4f629d7db3 [PATCH] powerpc: newline for ISYNC_ON_SMP
Add a newline at the end of the ISYNC_ON_SMP string.
Needed for a subsequent patch.

Signed-off-by: Nick Piggin <npiggin@suse.de>
Signed-off-by: Paul Mackerras <paulus@samba.org>
2006-02-24 14:06:00 +11:00
David Gibson
20f4eb3e50 [PATCH] powerpc: Fixup for STRICT_MM_TYPECHECKS
Currently ARCH=powerpc will not compile when STRICT_MM_TYPECHECKS is
turned on and CONFIG_64K_PAGES is turned off.  This corrects the
problem.

Signed-off-by: David Gibson <dwg@au1.ibm.com>
Signed-off-by: Paul Mackerras <paulus@samba.org>
2006-02-24 14:05:58 +11:00
Paul Mackerras
c6622f63db powerpc: Implement accurate task and CPU time accounting
This implements accurate task and cpu time accounting for 64-bit
powerpc kernels.  Instead of accounting a whole jiffy of time to a
task on a timer interrupt because that task happened to be running at
the time, we now account time in units of timebase ticks according to
the actual time spent by the task in user mode and kernel mode.  We
also count the time spent processing hardware and software interrupts
accurately.  This is conditional on CONFIG_VIRT_CPU_ACCOUNTING.  If
that is not set, we do tick-based approximate accounting as before.

To get this accurate information, we read either the PURR (processor
utilization of resources register) on POWER5 machines, or the timebase
on other machines on

* each entry to the kernel from usermode
* each exit to usermode
* transitions between process context, hard irq context and soft irq
  context in kernel mode
* context switches.

On POWER5 systems with shared-processor logical partitioning we also
read both the PURR and the timebase at each timer interrupt and
context switch in order to determine how much time has been taken by
the hypervisor to run other partitions ("steal" time).  Unfortunately,
since we need values of the PURR on both threads at the same time to
accurately calculate the steal time, and since we can only calculate
steal time on a per-core basis, the apportioning of the steal time
between idle time (time which we ceded to the hypervisor in the idle
loop) and actual stolen time is somewhat approximate at the moment.

This is all based quite heavily on what s390 does, and it uses the
generic interfaces that were added by the s390 developers,
i.e. account_system_time(), account_user_time(), etc.

This patch doesn't add any new interfaces between the kernel and
userspace, and doesn't change the units in which time is reported to
userspace by things such as /proc/stat, /proc/<pid>/stat, getrusage(),
times(), etc.  Internally the various task and cpu times are stored in
timebase units, but they are converted to USER_HZ units (1/100th of a
second) when reported to userspace.  Some precision is therefore lost
but there should not be any accumulating error, since the internal
accumulation is at full precision.

Signed-off-by: Paul Mackerras <paulus@samba.org>
2006-02-24 14:05:56 +11:00
Paul Mackerras
a00428f5b1 Merge ../powerpc-merge 2006-02-24 14:05:47 +11:00
Anton Blanchard
cb2c9b2741 [PATCH] powerpc: Fix runlatch performance issues
The runlatch SPR can take a lot of time to write. My original runlatch
code would set it on every exception entry even though most of the time
this was not required. It would also continually set it in the idle
loop, which is an issue on an SMT capable processor.

Now we cache the runlatch value in a threadinfo bit, and only check for
it in decrementer and hardware interrupt exceptions as well as the idle
loop. Boot on POWER3, POWER5 and iseries, and compile tested on pmac32.

Signed-off-by: Anton Blanchard <anton@samba.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>
2006-02-24 11:36:31 +11:00
Kumar Gala
1775dbbcd0 [PATCH] powerpc: Enable coherency for all pages on 83xx to fix PCI data corruption
On the 83xx platform to ensure the PCI inbound memory is handled properly we
have to turn on coherency for all pages in the MMU.  Otherwise we see
corruption if inbound "prefetching/streaming" is enabled on the PCI controller.

Signed-off-by: Randy Vinson <rvinson@mvista.com>
Signed-off-by: Kumar Gala <galak@kernel.crashing.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>
2006-02-24 11:36:25 +11:00
Michael Ellerman
337a7128db [PATCH] powerpc: Only calculate htab_size in one place for kexec
For kexec we need to know the size of the MMU hash table.

Currently we calculate the size once in the htab code, and then twice more in
the kexec code, once using htab_hash_mask and once using ppc64_pft_size.
On some machines the ppc64_pft_size calculation is broken because
ppc64_pft_size is not set.

So we need to fix the second calculation, but better still we should just
calculate the size once and use it everywhere else.

Tested on Power5 LPAR, Power4 non-LPAR and Power3.

Signed-off-by: Michael Ellerman <michael@ellerman.id.au>
Signed-off-by: Paul Mackerras <paulus@samba.org>
2006-02-24 11:36:18 +11:00
David Gibson
200a4552af [PATCH] powerpc: Fix accidentally-working typo in __pud_free_tlb
One of the parameters to the __pud_free_tlb() macro for powerpc is
incorrect (see patch) .  We get away with it by accident, because the one
place the macro is called, the second parameter is a variable named "pud".

Signed-off-by: David Gibson <dwg@au1.ibm.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-02-17 13:59:27 -08:00
Michael S. Tsirkin
5f6164f309 [PATCH] add asm-generic/mman.h
Make new MADV_REMOVE, MADV_DONTFORK, MADV_DOFORK consistent across all
arches.  The idea is to make it possible to use them portably even before
distros include them in libc headers.

Move common flags to asm-generic/mman.h

Signed-off-by: Michael S. Tsirkin <mst@mellanox.co.il>
Cc: Roland Dreier <rolandd@cisco.com>
Cc: Badari Pulavarty <pbadari@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-02-15 15:32:22 -08:00
Michael S. Tsirkin
f822566165 [PATCH] madvise MADV_DONTFORK/MADV_DOFORK
Currently, copy-on-write may change the physical address of a page even if the
user requested that the page is pinned in memory (either by mlock or by
get_user_pages).  This happens if the process forks meanwhile, and the parent
writes to that page.  As a result, the page is orphaned: in case of
get_user_pages, the application will never see any data hardware DMA's into
this page after the COW.  In case of mlock'd memory, the parent is not getting
the realtime/security benefits of mlock.

In particular, this affects the Infiniband modules which do DMA from and into
user pages all the time.

This patch adds madvise options to control whether memory range is inherited
across fork.  Useful e.g.  for when hardware is doing DMA from/into these
pages.  Could also be useful to an application wanting to speed up its forks
by cutting large areas out of consideration.

Signed-off-by: Michael S. Tsirkin <mst@mellanox.co.il>
Acked-by: Hugh Dickins <hugh@veritas.com>
Cc: Michael Kerrisk <mtk-manpages@gmx.net>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-02-14 16:09:34 -08:00
Jon Mason
2ef9481e66 [PATCH] powerpc: trivial: modify comments to refer to new location of files
This patch removes all self references and fixes references to files
in the now defunct arch/ppc64 tree.  I think this accomplises
everything wanted, though there might be a few references I missed.

Signed-off-by: Jon Mason <jdmason@us.ibm.com>
Signed-off-by: Paul Mackerras <paulus@samba.org>
2006-02-10 16:53:51 +11:00
Michael Ellerman
1965746bce [PATCH] powerpc: Move pSeries firmware feature setup into platforms/pseries
Currently we have some stuff in firmware.h and kernel/firmware.c that is
#ifdef CONFIG_PPC_PSERIES. Move it all into platforms/pseries.

Signed-off-by: Michael Ellerman <michael@ellerman.id.au>
Signed-off-by: Paul Mackerras <paulus@samba.org>
2006-02-10 16:52:03 +11:00
Paul Mackerras
d6d93856cb Merge ../powerpc-merge 2006-02-10 16:51:29 +11:00
JANAK DESAI
b37ce281d7 [PATCH] powerpc: unshare system call registration
Registers system call for the powerpc architecture.

Signed-off-by: Janak Desai <janak@us.ibm.com>
Cc: Al Viro <viro@ftp.linux.org.uk>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Michael Kerrisk <mtk-manpages@gmx.net>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Andi Kleen <ak@muc.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>
2006-02-10 16:34:54 +11:00
Linus Torvalds
423ab71a8b Merge branch 'for-linus2' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/bird 2006-02-08 08:06:09 -08:00
Benjamin Herrenschmidt
ac171c4666 [PATCH] powerpc: Thermal control for dual core G5s
This patch adds a windfarm module, windfarm_pm112, for the dual core G5s
(both 2 and 4 core models), keeping the machine from getting into
vacuum-cleaner mode ;) For proper credits, the patch was initially
written by Paul Mackerras, and slightly reworked by me to add overtemp
handling among others. The patch also removes the sysfs attributes from
windfarm_pm81 and windfarm_pm91 and instead adds code to the windfarm
core to automagically expose attributes for sensor & controls.

Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-02-07 22:05:14 -08:00
Al Viro
e795638bb9 [PATCH] __user annotations in powerpc thread_info
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2006-02-08 01:04:36 -05:00
Al Viro
29e646df78 [PATCH] powerpc signal __user annotations
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2006-02-08 01:03:46 -05:00
Linus Torvalds
fe69102188 Merge git://git.kernel.org/pub/scm/linux/kernel/git/paulus/powerpc-merge 2006-02-07 20:32:13 -08:00
Al Viro
1b8623545b [PATCH] remove bogus asm/bug.h includes.
A bunch of asm/bug.h includes are both not needed (since it will get
pulled anyway) and bogus (since they are done too early).  Removed.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2006-02-07 20:56:35 -05:00
Michael Ellerman
56b5c9737c [PATCH] powerpc: Put parameter names in lmb.h prototypes
Prototypes aren't so useful without parameter names, add them to lmb.h based
on the names in lmb.c

Signed-off-by: Michael Ellerman <michael@ellerman.id.au>
Signed-off-by: Paul Mackerras <paulus@samba.org>
2006-02-07 22:38:37 +11:00
Michael Ellerman
3b9331dac1 [PATCH] powerpc: Move LMB_ALLOC_ANYWHERE out of lmb.h
LMB_ALLOC_ANYWHERE doesn't need to be part of the API, it's only used in
lmb.c - so move it out of the header file.

Signed-off-by: Michael Ellerman <michael@ellerman.id.au>
Signed-off-by: Paul Mackerras <paulus@samba.org>
2006-02-07 22:38:36 +11:00
Michael Ellerman
d7a5b2ffa1 [PATCH] powerpc: Always panic if lmb_alloc() fails
Currently most callers of lmb_alloc() don't check if it worked or not, if it
ever does weird bad things will probably happen. The few callers who do check
just panic or BUG_ON.

So make lmb_alloc() panic internally, to catch bugs at the source. The few
callers who did check the result no longer need to.

The only caller that did anything interesting with the return result was
careful_allocation(). For it we create __lmb_alloc_base() which _doesn't_ panic
automatically, a little messy, but passable.

Signed-off-by: Michael Ellerman <michael@ellerman.id.au>
Signed-off-by: Paul Mackerras <paulus@samba.org>
2006-02-07 22:38:34 +11:00
Michael Ellerman
b68239ee74 [PATCH] powerpc: Don't overwrite flat device tree with kdump kernel
It's possible for prom_init to allocate the flat device tree inside the
kdump crash kernel region. If this happens, when we load the kdump kernel we
overwrite the flattened device tree, which is bad.

We could make prom_init try and avoid allocating inside the crash kernel
region, but then we run into issues if the crash kernel region uses all the
space inside the RMO. The easiest solution is to move the flat device tree
once we're running in the kernel.

Signed-off-by: Michael Ellerman <michael@ellerman.id.au>
Signed-off-by: Paul Mackerras <paulus@samba.org>
2006-02-07 21:32:44 +11:00
Albert Herranz
39931e41be [PATCH] powerpc: fix for kexec ppc32
- kexec.h is included from assembly code, thus C code must be properly
  protected.

- (embedded) ppc32 systems use machine_kexec_simple whose declaration
  vanished during a recent powerpc merge change.

Signed-off-by: Albert Herranz <albert_herranz@yahoo.es>
Cc: <fastboot@osdl.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-02-01 08:53:19 -08:00
Ben Collins
cc0fa84a01 [PATCH] powerpc: enable irq's for platform functions.
Make the platform function interrupt functions actually work.  Calls
irq_enable() for the first in the list, and irq_disable() for the last.

Added *func to struct irq_client so the the user can pass just that to
pmf_unregister_irq_client().

Signed-off-by: Ben Collins <bcollins@ubuntu.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-02-01 08:53:10 -08:00
David Woodhouse
f27201da5c [PATCH] TIF_RESTORE_SIGMASK support for arch/powerpc
Implement the TIF_RESTORE_SIGMASK flag in the new arch/powerpc kernel, for
both 32-bit and 64-bit system call paths.

Signed-off-by: David Woodhouse <dwmw2@infradead.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-01-18 19:20:30 -08:00
David Woodhouse
150256d8aa [PATCH] Generic sys_rt_sigsuspend()
The TIF_RESTORE_SIGMASK flag allows us to have a generic implementation of
sys_rt_sigsuspend() instead of duplicating it for each architecture.  This
provides such an implementation and makes arch/powerpc use it.

It also tidies up the ppc32 sys_sigsuspend() to use TIF_RESTORE_SIGMASK.

Signed-off-by: David Woodhouse <dwmw2@infradead.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-01-18 19:20:29 -08:00
Bryan O'Sullivan
c6b3feaf57 [PATCH] Fix sparse parse error in lppaca.h
sparse can't parse a struct definition in include/asm-powerpc/lppaca.h,
even though gcc can accept it.  The form looks like this:

        struct __attribute__((whatever)) foo { };

An equivalent that both gcc and sparse can handle is

        struct foo { } __attribute__((whatever));

This is the only definition of this type in the tree, and fixing it is
easier than fixing sparse.

Signed-off-by: Bryan O'Sullivan <bos@serpentine.com>
[ Side note: fixing sparse wouldn't be hard, but the "attribute at the
  end" version is the canonical one, and the one that makes sense. So
  let's just fix the kernel instead. Luc Van Oostenryck already sent
  out a sparse patch to the sparse mailing list in case anybody cares.
               -- Linus ]
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-01-17 17:18:25 -08:00
Haren Myneni
8385a6a3ac [PATCH] powerpc: Fix kdump copy regs and dynamic allocate per-cpu crash notes
- This contains the arch specific changes for the following the
kdump generic fixes which were already accepted in the upstream.
       .   Capturing CPU registers (for the case of 'panic' and invoking
the dump using 'sysrq-trigger') from a function (stack frame) which will
be not be available during the kdump boot. Hence, might result in
invalid stack trace.
       .   Dynamically allocating per cpu ELF notes section instead of
statically for NR_CPUS.

- Fix the compiler warning in prom_init.c.

Signed-off-by: Haren Myneni <haren@us.ibm.com>
Signed-off-by: Paul Mackerras <paulus@samba.org>
2006-01-15 13:14:42 +11:00
Andy Whitcroft
7a45fb19ce [PATCH] powerpc: oprofile cpu type names clash with other code
In 2.6.15-git6 a change was commited in the oprofile support in
the powerpc architecture.  It introduced the powerpc_oprofile_type
which contains the define G4.  This causes a name clash with the
existing wacom usb tablet driver.

      CC [M]  drivers/usb/input/wacom.o
    drivers/usb/input/wacom.c:98: error: conflicting types for `G4'
    include/asm/cputable.h:37: error: previous declaration of `G4'
      CC [M]  drivers/usb/mon/mon_text.o
    make[3]: *** [drivers/usb/input/wacom.o] Error 1
    make[2]: *** [drivers/usb/input] Error 2

The elements of an enum declared in global scope are effectivly
global identifiers themselves.  As such we need to ensure the names
are unique.  This patch updates the later oprofile support to use
unique names.

Signed-off-by: Andy Whitcroft <apw@shadowen.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>
2006-01-14 11:12:16 +11:00
Paul Mackerras
80f15dc703 powerpc: Provide a suitable AT_PLATFORM value
The glibc folks want to use AT_PLATFORM to select between possible
alternative versions of shared libraries.  This commit makes the kernel
supply an AT_PLATFORM string that indicates what class of processor
we are running on.  Processors with the same set of user-level
instructions and roughly the same instruction scheduling characteristics
are given the same AT_PLATFORM value; for example, 821, 823 and 860
are all reported as "ppc823", and 7447, 7447A, 7448, 7450, 7451, 7455
are all called "ppc7450".

The intention is that the AT_PLATFORM values match the values that
gcc accepts for the -mcpu= option.  For values which are numeric
(e.g. -mcpu=750), "ppc" has been prepended.

This also adds a PPC_FEATURE_BOOKE bit to the AT_HWCAP value and sets
it for the 440 family and the Freescale 85xx family.

Signed-off-by: Paul Mackerras <paulus@samba.org>
2006-01-14 10:11:39 +11:00
Anton Blanchard
b11fa580ac [PATCH] powerpc: reformat atomic_add_unless
It makes my eyes hurt.

Signed-off-by: Anton Blanchard <anton@samba.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>
2006-01-13 21:18:54 +11:00
Anton Blanchard
144b9c135b [PATCH] powerpc: use lwsync in atomics, bitops, lock functions
eieio is only a store - store ordering. When used to order an unlock
operation loads may leak out of the critical region. This is potentially
buggy, one example is if a user wants to atomically read a couple of
values.

We can solve this with an lwsync which orders everything except store - load.

I removed the (now unused) EIEIO_ON_SMP macros and the c versions
isync_on_smp and eieio_on_smp now we dont use them. I also removed some
old comments that were used to identify inline spinlocks in assembly,
they dont make sense now our locks are out of line.

Another interesting thing was that read_unlock was using an eieio even
though the rest of the spinlock code had already been converted to
use lwsync.

Signed-off-by: Anton Blanchard <anton@samba.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>
2006-01-13 21:18:50 +11:00
David Gibson
3356bb9f7b [PATCH] powerpc: Remove lppaca structure from the PACA
At present the lppaca - the structure shared with the iSeries
hypervisor and phyp - is contained within the PACA, our own low-level
per-cpu structure.  This doesn't have to be so, the patch below
removes it, making a separate array of lppaca structures.

This saves approximately 500*NR_CPUS bytes of image size and kernel
memory, because we don't need aligning gap between the Linux and
hypervisor portions of every PACA.  On the other hand it means an
extra level of dereference in many accesses to the lppaca.

The patch also gets rid of several places where we assign the paca
address to a local variable for no particular reason.

Signed-off-by: David Gibson <dwg@au1.ibm.com>
Signed-off-by: Paul Mackerras <paulus@samba.org>
2006-01-13 21:17:39 +11:00
David Gibson
e58c3495e6 [PATCH] powerpc: Cleanup LOADADDR etc. asm macros
This patch consolidates the variety of macros used for loading 32 or
64-bit constants in assembler (LOADADDR, LOADBASE, SET_REG_TO_*).  The
idea is to make the set of macros consistent across 32 and 64 bit and
to make it more obvious which is the appropriate one to use in a given
situation.  The new macros and their semantics are described in the
comments in ppc_asm.h.

In the process, we change several places that were unnecessarily using
immediate loads on ppc64 to use the GOT/TOC.  Likewise we cleanup a
couple of places where we were clumsily subtracting PAGE_OFFSET with
asm instructions to use assemble-time arithmetic or the toreal() macro
instead.

Signed-off-by: David Gibson <dwg@au1.ibm.com>
Signed-off-by: Paul Mackerras <paulus@samba.org>
2006-01-13 21:16:23 +11:00
Dave C Boutcher
ecaa8b0ff3 [PATCH] powerpc: Add of_find_property function
Add an of_find_property function that returns a struct property
given a property name.  Then change the get_property function to
use that routine internally.

Signed-off-by: Dave Boutcher <sleddog@us.ibm.com>
Signed-off-by: Paul Mackerras <paulus@samba.org>
2006-01-13 21:11:57 +11:00
Dave C Boutcher
088186ded4 [PATCH] powerpc: Add/remove/update properties in firmware device tree
Add support for updating and removing device tree
properties.  Since we hand out pointers to properties with gay
abandon, we can't just free the property storage.  Instead we
move deleted, or the old copy of an updated property, to a
"dead properties" list.

Also note, its not feasable to kref device tree properties.
we call get_property() all over the kernel in a wild variety
of contexts.

One consequence of this change is that we now take a
read_lock(&devtree_lock) when doing get_property().

Signed-off-by: Dave Boutcher <sleddog@us.ibm.com>
Signed-off-by: Paul Mackerras <paulus@samba.org>
2006-01-13 21:02:50 +11:00
Dave C Boutcher
43ccf20221 [PATCH] powerpc: Add some more pSeries hypervisor call constants
Adds a few more hypervisor call constants.

Signed-off-by: Dave Boutcher <sleddog@us.ibm.com>
Signed-off-by: Paul Mackerras <paulus@samba.org>
2006-01-13 20:56:38 +11:00
Linus Torvalds
45bfe98bd7 Merge git://git.kernel.org/pub/scm/linux/kernel/git/paulus/powerpc-merge
Fix up delete/modify conflict of arch/ppc/kernel/process.c by hand (it's
gone, gone, gone).

Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-01-12 10:21:22 -08:00
Al Viro
f5a61d0c13 [PATCH] death of get_thread_info/put_thread_info
{get,put}_thread_info() were introduced in 2.5.4 and never
had been called by anything in the tree.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-01-12 09:08:59 -08:00
akpm@osdl.org
198e2f1811 [PATCH] scheduler cache-hot-autodetect
)

From: Ingo Molnar <mingo@elte.hu>

This is the latest version of the scheduler cache-hot-auto-tune patch.

The first problem was that detection time scaled with O(N^2), which is
unacceptable on larger SMP and NUMA systems. To solve this:

- I've added a 'domain distance' function, which is used to cache
  measurement results. Each distance is only measured once. This means
  that e.g. on NUMA distances of 0, 1 and 2 might be measured, on HT
  distances 0 and 1, and on SMP distance 0 is measured. The code walks
  the domain tree to determine the distance, so it automatically follows
  whatever hierarchy an architecture sets up. This cuts down on the boot
  time significantly and removes the O(N^2) limit. The only assumption
  is that migration costs can be expressed as a function of domain
  distance - this covers the overwhelming majority of existing systems,
  and is a good guess even for more assymetric systems.

  [ People hacking systems that have assymetries that break this
    assumption (e.g. different CPU speeds) should experiment a bit with
    the cpu_distance() function. Adding a ->migration_distance factor to
    the domain structure would be one possible solution - but lets first
    see the problem systems, if they exist at all. Lets not overdesign. ]

Another problem was that only a single cache-size was used for measuring
the cost of migration, and most architectures didnt set that variable
up. Furthermore, a single cache-size does not fit NUMA hierarchies with
L3 caches and does not fit HT setups, where different CPUs will often
have different 'effective cache sizes'. To solve this problem:

- Instead of relying on a single cache-size provided by the platform and
  sticking to it, the code now auto-detects the 'effective migration
  cost' between two measured CPUs, via iterating through a wide range of
  cachesizes. The code searches for the maximum migration cost, which
  occurs when the working set of the test-workload falls just below the
  'effective cache size'. I.e. real-life optimized search is done for
  the maximum migration cost, between two real CPUs.

  This, amongst other things, has the positive effect hat if e.g. two
  CPUs share a L2/L3 cache, a different (and accurate) migration cost
  will be found than between two CPUs on the same system that dont share
  any caches.

(The reliable measurement of migration costs is tricky - see the source
for details.)

Furthermore i've added various boot-time options to override/tune
migration behavior.

Firstly, there's a blanket override for autodetection:

	migration_cost=1000,2000,3000

will override the depth 0/1/2 values with 1msec/2msec/3msec values.

Secondly, there's a global factor that can be used to increase (or
decrease) the autodetected values:

	migration_factor=120

will increase the autodetected values by 20%. This option is useful to
tune things in a workload-dependent way - e.g. if a workload is
cache-insensitive then CPU utilization can be maximized by specifying
migration_factor=0.

I've tested the autodetection code quite extensively on x86, on 3
P3/Xeon/2MB, and the autodetected values look pretty good:

Dual Celeron (128K L2 cache):

 ---------------------
 migration cost matrix (max_cache_size: 131072, cpu: 467 MHz):
 ---------------------
           [00]    [01]
 [00]:     -     1.7(1)
 [01]:   1.7(1)    -
 ---------------------
 cacheflush times [2]: 0.0 (0) 1.7 (1784008)
 ---------------------

Here the slow memory subsystem dominates system performance, and even
though caches are small, the migration cost is 1.7 msecs.

Dual HT P4 (512K L2 cache):

 ---------------------
 migration cost matrix (max_cache_size: 524288, cpu: 2379 MHz):
 ---------------------
           [00]    [01]    [02]    [03]
 [00]:     -     0.4(1)  0.0(0)  0.4(1)
 [01]:   0.4(1)    -     0.4(1)  0.0(0)
 [02]:   0.0(0)  0.4(1)    -     0.4(1)
 [03]:   0.4(1)  0.0(0)  0.4(1)    -
 ---------------------
 cacheflush times [2]: 0.0 (33900) 0.4 (448514)
 ---------------------

Here it can be seen that there is no migration cost between two HT
siblings (CPU#0/2 and CPU#1/3 are separate physical CPUs). A fast memory
system makes inter-physical-CPU migration pretty cheap: 0.4 msecs.

8-way P3/Xeon [2MB L2 cache]:

 ---------------------
 migration cost matrix (max_cache_size: 2097152, cpu: 700 MHz):
 ---------------------
           [00]    [01]    [02]    [03]    [04]    [05]    [06]    [07]
 [00]:     -    19.2(1) 19.2(1) 19.2(1) 19.2(1) 19.2(1) 19.2(1) 19.2(1)
 [01]:  19.2(1)    -    19.2(1) 19.2(1) 19.2(1) 19.2(1) 19.2(1) 19.2(1)
 [02]:  19.2(1) 19.2(1)    -    19.2(1) 19.2(1) 19.2(1) 19.2(1) 19.2(1)
 [03]:  19.2(1) 19.2(1) 19.2(1)    -    19.2(1) 19.2(1) 19.2(1) 19.2(1)
 [04]:  19.2(1) 19.2(1) 19.2(1) 19.2(1)    -    19.2(1) 19.2(1) 19.2(1)
 [05]:  19.2(1) 19.2(1) 19.2(1) 19.2(1) 19.2(1)    -    19.2(1) 19.2(1)
 [06]:  19.2(1) 19.2(1) 19.2(1) 19.2(1) 19.2(1) 19.2(1)    -    19.2(1)
 [07]:  19.2(1) 19.2(1) 19.2(1) 19.2(1) 19.2(1) 19.2(1) 19.2(1)    -
 ---------------------
 cacheflush times [2]: 0.0 (0) 19.2 (19281756)
 ---------------------

This one has huge caches and a relatively slow memory subsystem - so the
migration cost is 19 msecs.

Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Ashok Raj <ashok.raj@intel.com>
Signed-off-by: Ken Chen <kenneth.w.chen@intel.com>
Cc: <wilder@us.ibm.com>
Signed-off-by: John Hawkes <hawkes@sgi.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-01-12 09:08:50 -08:00
Ingo Molnar
4dc7a0bbeb [PATCH] sched: add cacheflush() asm
Add per-arch sched_cacheflush() which is a write-back cacheflush used by
the migration-cost calibration code at bootup time.

Signed-off-by: Ingo Molnar <mingo@elte.hu>
Cc: Nick Piggin <nickpiggin@yahoo.com.au>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-01-12 09:08:49 -08:00
Stephen Rothwell
9623b5d3d3 [PATCH] powerpc: small pci cleanups
pcibios_claim_one_bus is not needed on iSeries and phbs_remap_io can be
mode static.

Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Paul Mackerras <paulus@samba.org>
2006-01-12 20:09:30 +11:00
Stephen Rothwell
9bd7ea60b1 [PATCH] powerpc: clean up iommu.h a bit
There was a function declared for CONFIG_PSERIES which no longer exists
and the two function declarations for CONFIG_ISERIES have been moved
into an include file in platforms/iseries since they are defined and
used only there.

Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Paul Mackerras <paulus@samba.org>
2006-01-12 20:09:30 +11:00
Stephen Rothwell
ee2cdecec4 [PATCH] powerpc: iSeries fixes for build with no PCI
This reverts part of "ppc64 iSeries: allow build with no PCI"
(145d01e428) which affected generic code
and applies a fix in the arch specific code.

Commit "partly merge iseries do_IRQ"
(5fee9b3b39eb55c7e3619a3b36ceeabffeb8f144) introduced iSeries_get_irq
which was only available if CONFIG_PCI is set.

Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Paul Mackerras <paulus@samba.org>
2006-01-12 20:09:30 +11:00
Stephen Rothwell
511061049b [PATCH] powercp: iSeries include file comment cleanups
Mainly just removing file names from the comments.

Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Paul Mackerras <paulus@samba.org>
2006-01-12 20:09:30 +11:00
Stephen Rothwell
f9cb83ac1f [PATCH] powerpc: eliminate bitfields from ItLpNaca
Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Paul Mackerras <paulus@samba.org>
2006-01-12 20:09:30 +11:00
Stephen Rothwell
677f8c0d04 [PATCH] powerpc: remove bitfields from HvLpEvent
Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Paul Mackerras <paulus@samba.org>
2006-01-12 20:09:29 +11:00
Stephen Rothwell
6814350b80 [PATCH] powerpc: remove bitfields from hv_call_event.h
Also does some comment cleanups and removal of unnecessary
variables.

Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Paul Mackerras <paulus@samba.org>
2006-01-12 20:09:29 +11:00