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27673 commits

Author SHA1 Message Date
Joerg Roedel
ee893c24ed AMD IOMMU: save pci segment from ACPI tables
This patch adds the pci_seg field to the amd_iommu structure and fills
it with the corresponding value from the ACPI table.

Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-09-19 12:59:12 +02:00
Joerg Roedel
335503e57b AMD IOMMU: add event buffer allocation
This patch adds the allocation of a event buffer for each AMD IOMMU in
the system. The hardware will log events like device page faults or
other errors to this buffer once this is enabled.

Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-09-19 12:59:11 +02:00
Joerg Roedel
1c65577398 AMD IOMMU: implement lazy IO/TLB flushing
The IO/TLB flushing on every unmaping operation is the most expensive
part in AMD IOMMU code and not strictly necessary. It is sufficient to
do the flush before any entries are reused. This is patch implements
lazy IO/TLB flushing which does exactly this.

Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-09-19 12:59:07 +02:00
Joerg Roedel
2842e5bf31 x86: move GART TLB flushing options to generic code
The GART currently implements the iommu=[no]fullflush command line
parameters which influence its IO/TLB flushing strategy. This patch
makes these parameters generic so that they can be used by the AMD IOMMU
too.

Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-09-19 12:59:06 +02:00
FUJITA Tomonori
07a2c01a0c convert swiotlb to use dma_get_mask
swiotlb can use dma_get_mask() instead of the homegrown function.

Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Cc: tony.luck@intel.com
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-09-19 10:20:41 +02:00
Ingo Molnar
5e51900be6 Merge commit 'v2.6.27-rc6' into x86/cleanups 2008-09-19 09:15:50 +02:00
Lennert Buytenhek
4fd5f812c2 phylib: allow incremental scanning of an mii bus
This patch splits the bus scanning code in mdiobus_register() off
into a separate function, and makes this function available for
calling from external code.  This allows incrementally scanning an
mii bus, e.g. as information about which addresses are 'safe' to
scan becomes available.

Signed-off-by: Lennert Buytenhek <buytenh@marvell.com>
Acked-by: Andy Fleming <afleming@freescale.com>
2008-09-19 05:13:54 +02:00
Guillaume GARDET
fbd03a1cbc [ARM] 5228/1: Add the RGB555 wiring for the atmel LCD
Add the RGB555 wiring for the atmel LCD.

Acked-by: Nicolas Ferre <nicolas.ferre@atmel.com>
Acked-by: Haavard Skinnemoen <haavard.skinnemoen@atmel.com>
Signed-off-by: Guillaume GARDET <guillaume.gardet@free.fr>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2008-09-18 23:11:56 +01:00
Scott Feldman
01f2e4ead2 enic: add Cisco 10G Ethernet NIC driver
Signed-off-by: Scott Feldman <scofeldm@cisco.com>
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>
2008-09-18 11:34:53 -04:00
Chris Snook
452c1ce218 atl2: add atl2 driver
Driver for Atheros L2 10/100 network device. Includes necessary
changes for Kconfig, Makefile, and pci_ids.h.

Signed-off-by: Chris Snook <csnook@redhat.com>
Signed-off-by: Jay Cliburn <jacliburn@bellsouth.net>
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>
2008-09-18 11:34:52 -04:00
Eric Miao
6ae19b04ab Input: ads7846 - introduce .gpio_pendown to get pendown state
The GPIO connected to ADS7846 nPENIRQ signal is usually used to get
the pendown state as well. Introduce a .gpio_pendown, and use this
to decide the pendown state if .get_pendown_state is NULL.

Signed-off-by: Eric Miao <eric.miao@marvell.com>
Signed-off-by: Dmitry Torokhov <dtor@mail.ru>
2008-09-17 17:33:37 +01:00
David Vrabel
b60066c141 uwb: add symlinks in sysfs between radio controllers and PALs
Add a facility for PALs to have symlinks to their radio controller
(and vice-versa) and make WUSB host controllers use this.

Signed-off-by: David Vrabel <david.vrabel@csr.com>
2008-09-17 16:54:35 +01:00
Inaky Perez-Gonzalez
c7f736484f wusb: add the Wireless USB include files.
Common header files derived from the WUSB 1.0 specification.

Signed-off-by: David Vrabel <david.vrabel@csr.com>
2008-09-17 16:54:29 +01:00
David Vrabel
8f1b678ab9 uwb: add the driver to enumerate WHCI capabilities
This enumerates the capabilties of a WHCI device, adding a umc device for
each one.

Signed-off-by: David Vrabel <david.vrabel@csr.com>
2008-09-17 16:54:26 +01:00
David Vrabel
da389eac31 uwb: add the umc bus
The UMC bus is used for the capabilities exposed by a UWB Multi-interface
Controller as described in the WHCI specification.

Signed-off-by: David Vrabel <david.vrabel@csr.com>
2008-09-17 16:54:25 +01:00
Inaky Perez-Gonzalez
34e95e41f1 uwb: add the uwb include files
Signed-off-by: David Vrabel <david.vrabel@csr.com>
2008-09-17 16:54:23 +01:00
David Vrabel
ccbe329bcd bitmap: add bitmap_copy_le()
bitmap_copy_le() copies a bitmap, putting the bits into little-endian
order (i.e., each unsigned long word in the bitmap is put into
little-endian order).

The UWB stack used bitmaps to manage Medium Access Slot availability,
and these bitmaps need to be written to the hardware in LE order.

Signed-off-by: David Vrabel <david.vrabel@csr.com>
2008-09-17 16:54:22 +01:00
Uwe Kleine-König
fbdbf70993 x86, debug: gpio_free might sleep
According to the documentation gpio_free should only be called from task
context only.  To make this more explicit add a might sleep to all
implementations.

This patch changes the gpio_free implementations for the x86
architecture.

Signed-off-by: Uwe Kleine-König <ukleinek@informatik.uni-freiburg.de>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-09-17 14:58:46 +02:00
Arjan van de Ven
45e9c0de2e warn: Turn the netdev timeout WARN_ON() into a WARN()
this patch turns the netdev timeout WARN_ON_ONCE() into a WARN_ONCE(),
so that the device and driver names are inside the warning message.
This helps automated tools like kerneloops.org to collect the data
and do statistics, as well as making it more likely that humans
cut-n-paste the important message as part of a bugreport.

Signed-off-by: Arjan van de Ven <arjan@linux.intel.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-09-16 19:39:33 -07:00
David Miller
ef3d7714f6 Fix PNP build failure, bugzilla #11276
This fill fix the following regression list entry:

Bug-Entry	: http://bugzilla.kernel.org/show_bug.cgi?id=11276
Subject		: build error: CONFIG_OPTIMIZE_INLINING=y causes gcc 4.2 to do stupid things
Submitter	: Randy Dunlap <randy.dunlap@oracle.com>
Date		: 2008-08-06 17:18 (38 days old)
References	: http://marc.info/?l=linux-kernel&m=121804329014332&w=4
		  http://lkml.org/lkml/2008/7/22/353
Handled-By	: Bjorn Helgaas <bjorn.helgaas@hp.com>
Patch		: http://lkml.org/lkml/2008/7/22/364

with what I believe is a better fix than the one referenced
in the regression entry above.

These PNP header interfaces try to work in such a way that
you can reference some of them even if PNP is not enabled,
and the compiler was expected to optimize everything away.

Which is mostly fine, except that there was one interface
for which there was not provided an inline "NOP" implementation.

Once we add that, all of these compile failures cannot handle
any more.

pnp: Provide NOP inline implementation of pnp_get_resource() when !PNP

Fixes kernel bugzilla #11276.

Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-09-16 19:35:05 -07:00
Greg KH
b08508c40a PCI: fix compiler warnings in pci_get_subsys()
pci_get_subsys() changed in 2.6.26 so that the from pointer is modified
when the call is being invoked, so fix up the 'const' marking of it that
the compiler is complaining about.

Reported-by: Rufus & Azrael <rufus-azrael@numericable.fr>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
2008-09-16 15:52:08 -07:00
David S. Miller
2e57572a50 Merge branch 'master' of master.kernel.org:/pub/scm/linux/kernel/git/davem/sparc-2.6
Conflicts:

	arch/sparc64/kernel/pci_psycho.c
2008-09-16 14:11:43 -07:00
Kumar Gala
48d6c64311 math-emu: Add support for reporting exact invalid exception
Some architectures (like powerpc) provide status information on the exact
type of invalid exception.  This is pretty straight forward as we already
report invalid exceptions via FP_SET_EXCEPTION.

We add new flags (FP_EX_INVALID_*) the architecture code can define if it
wants the exact invalid exception reported.

We had to split out the INF/INF and 0/0 cases for divide to allow reporting
the two invalid forms properly.

Signed-off-by: Kumar Gala <galak@kernel.crashing.org>
Acked-by: David S. Miller <davem@davemloft.net>
2008-09-16 10:01:37 -05:00
Kumar Gala
40d3057ac0 math-emu: Fix compiler warnings
Fix warnings of the form:
arch/powerpc/math-emu/fsubs.c:15: warning: 'R_f1' may be used uninitialized in this function
arch/powerpc/math-emu/fsubs.c:15: warning: 'R_f0' may be used uninitialized in this function

Signed-off-by: Kumar Gala <galak@kernel.crashing.org>
2008-09-16 10:01:37 -05:00
Ingo Molnar
e3bbaa3cb6 Merge commit 'v2.6.27-rc6' into x86/memory-corruption-check 2008-09-16 09:34:23 +02:00
Vladimir Sokolovsky
29bdc88384 IB/mlx4: Fix up fast register page list format
Byte swap the addresses in the page list for fast register work requests
to big endian to match what the HCA expectx.  Also, the addresses must
have the "present" bit set so that the HCA knows it can access them.
Otherwise the HCA will fault the first time it accesses the memory
region.

Signed-off-by: Vladimir Sokolovsky <vlad@mellanox.co.il>
Signed-off-by: Roland Dreier <rolandd@cisco.com>
2008-09-15 14:25:23 -07:00
Johannes Berg
25d834e162 mac80211: fix virtual interfaces vs. injection
Currently, virtual interface pointers passed to drivers might be
from monitor interfaces and as such completely uninitialised
because we do not tell the driver about monitor interfaces when
those are created. Instead of passing them, we should therefore
indicate to the driver that there is no information; do that by
passing a NULL value and adjust drivers to cope with it.

As a result, some mac80211 API functions also need to cope with
a NULL vif pointer so drivers can still call them unconditionally.

Also, when injecting frames we really don't want to pass NULL all
the time, if we know we are the source address of a frame and have
a local interface for that address, we can to use that interface.
This also helps with processing the frame correctly for that
interface which will help the 802.11w implementation. It's not
entirely correct for VLANs or WDS interfaces because there the MAC
address isn't unique, but it's already a lot better than what we
do now.

Finally, when injecting without a matching local interface, don't
assign sequence numbers at all.

Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
2008-09-15 16:48:25 -04:00
Johannes Berg
687c7c0807 mac80211: share sta_info->ht_info
Rate control algorithms may need access to a station's
HT capabilities, so share the ht_info struct in the
public station API.

Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
2008-09-15 16:48:24 -04:00
Johannes Berg
323ce79a9c mac80211: share sta->supp_rates
As more preparation for a saner rate control algorithm API,
share the supported rates bitmap in the public API.

Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
2008-09-15 16:48:24 -04:00
Johannes Berg
17741cdc26 mac80211: share STA information with driver
This patch changes mac80211 to share some more data about
stations with drivers. Should help iwlwifi and ath9k when
 they get around to updating, and might also help with
implementing rate control algorithms without internals.

Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Cc: Sujith Manoharan <Sujith.Manoharan@atheros.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
2008-09-15 16:48:23 -04:00
Johannes Berg
05c914fe33 mac80211: use nl80211 interface types
There's really no reason for mac80211 to be using its
own interface type defines. Use the nl80211 types and
simplify the configuration code a bit: there's no need
to translate them any more now.

Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
2008-09-15 16:48:23 -04:00
Johannes Berg
96dd22ac06 mac80211: inform driver of basic rateset
Drivers need to know the basic rateset to be able to configure
the ACK/CTS programming in hardware correctly.

Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
2008-09-15 16:48:22 -04:00
Johannes Berg
5bc75728fd mac80211: fix scan vs. interface removal race
When we remove an interface, we can currently end up having
a pointer to it left in local->scan_sdata after it has been
set down, and then with a hardware scan the scan completion
can try to access it which is a bug. Alternatively, a scan
that started as a hardware scan may terminate as though it
was a software scan, if the timing is just right.

On SMP systems, software scan also has a similar problem,
just canceling the delayed work and setting a flag isn't
enough since it may be running concurrently; in this case
we would also never restore state of other interfaces.

This patch hopefully fixes the problems by always invoking
ieee80211_scan_completed or requiring it to be invoked by
the driver, I suspect the drivers that have ->hw_scan() are
buggy. The bug will not manifest itself unless you remove
the interface while hw-scanning which will also turn off
the hw, and then add a new interface which will be unusable
until you scan once.

Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
2008-09-15 16:48:20 -04:00
Luis R. Rodriguez
b2e1b30290 cfg80211: Add new wireless regulatory infrastructure
This adds the new wireless regulatory infrastructure. The
main motiviation behind this was to centralize regulatory
code as each driver was implementing their own regulatory solution,
and to replace the initial centralized code we have where:

* only 3 regulatory domains are supported: US, JP and EU
* regulatory domains can only be changed through module parameter
* all rules were built statically in the kernel

We now have support for regulatory domains for many countries
and regulatory domains are now queried through a userspace agent
through udev allowing distributions to update regulatory rules
without updating the kernel.

Each driver can regulatory_hint() a regulatory domain
based on either their EEPROM mapped regulatory domain value to a
respective ISO/IEC 3166-1 country code or pass an internally built
regulatory domain. We also add support to let the user set the
regulatory domain through userspace in case of faulty EEPROMs to
further help compliance.

Support for world roaming will be added soon for cards capable of
this.

For more information see:

http://wireless.kernel.org/en/developers/Regulatory/CRDA

For now we leave an option to enable the old module parameter,
ieee80211_regdom, and to build the 3 old regdomains statically
(US, JP and EU). This option is CONFIG_WIRELESS_OLD_REGULATORY.
These old static definitions and the module parameter is being
scheduled for removal for 2.6.29. Note that if you use this
you won't make use of a world regulatory domain as its pointless.
If you leave this option enabled and if CRDA is present and you
use US or JP we will try to ask CRDA to update us a regulatory
domain for us.

Signed-off-by: Luis R. Rodriguez <lrodriguez@atheros.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
2008-09-15 16:48:19 -04:00
Ingo Molnar
83bd6998b0 Merge commit 'v2.6.27-rc6' into timers/hpet 2008-09-14 18:24:00 +02:00
Ingo Molnar
f81b691a3d Merge commit 'v2.6.27-rc6' into x86/pat 2008-09-14 17:26:53 +02:00
Jeremy Fitzhardinge
8308c54d7e generic: redefine resource_size_t as phys_addr_t
There's no good reason why a resource_size_t shouldn't just be a
physical address, so simply redefine it in terms of phys_addr_t.

Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-09-14 17:24:27 +02:00
Jeremy Fitzhardinge
947d0496cf generic: make PFN_PHYS explicitly return phys_addr_t
PFN_PHYS, as its name suggests, turns a pfn into a physical address.
However, it is a macro which just operates on its argument without
modifying its type.  pfns are typed unsigned long, but an unsigned
long may not be long enough to hold a physical address (32-bit systems
with more than 32 bits of physcial address).

Make sure we cast to phys_addr_t to return a complete result.

Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-09-14 17:24:26 +02:00
Jeremy Fitzhardinge
600715dcdf generic: add phys_addr_t for holding physical addresses
Add a kernel-wide "phys_addr_t" which is guaranteed to be able to hold
any physical address.  By default it equals the word size of the
architecture, but a 32-bit architecture can set ARCH_PHYS_ADDR_T_64BIT
if it needs a 64-bit phys_addr_t.

Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-09-14 17:24:25 +02:00
Ingo Molnar
9dfed08eb4 Merge commit 'v2.6.27-rc6' into core/resources 2008-09-14 17:23:29 +02:00
Ingo Molnar
5ce73a4a5a timers: fix itimer/many thread hang, cleanups
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-09-14 17:11:46 +02:00
Ingo Molnar
0a8eaa4f9b timers: fix itimer/many thread hang, fix #2
fix the UP build:

In file included from arch/x86/kernel/asm-offsets_32.c:9,
                 from arch/x86/kernel/asm-offsets.c:3:
include/linux/sched.h: In function ‘thread_group_cputime_clone_thread’:
include/linux/sched.h:2272: warning: no return statement in function returning non-void
include/linux/sched.h: In function ‘thread_group_cputime_account_user’:
include/linux/sched.h:2284: error: invalid type argument of ‘->’ (have ‘struct task_cputime’)
include/linux/sched.h:2284: error: invalid type argument of ‘->’ (have ‘struct task_cputime’)
include/linux/sched.h: In function ‘thread_group_cputime_account_system’:
include/linux/sched.h:2291: error: invalid type argument of ‘->’ (have ‘struct task_cputime’)
include/linux/sched.h:2291: error: invalid type argument of ‘->’ (have ‘struct task_cputime’)
include/linux/sched.h: In function ‘thread_group_cputime_account_exec_runtime’:
include/linux/sched.h:2298: error: invalid type argument of ‘->’ (have ‘struct task_cputime’)
distcc[14501] ERROR: compile arch/x86/kernel/asm-offsets.c on a/30 failed
make[1]: *** [arch/x86/kernel/asm-offsets.s] Error 1

Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-09-14 17:02:43 +02:00
FUJITA Tomonori
589fc9a6e2 iommu: add dma_get_mask helper function
Several IOMMUs do the same thing to get the dma_mask of a device. This
adds a helper function to do the same thing to sweep them.

Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-09-14 16:42:37 +02:00
FUJITA Tomonori
eecfffc154 iommu: add iommu_device_max_index IOMMU helper function
This function helps IOMMUs to know the highest address that a device
can access to.

Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-09-14 16:42:36 +02:00
Frank Mayhar
f06febc96b timers: fix itimer/many thread hang
Overview

This patch reworks the handling of POSIX CPU timers, including the
ITIMER_PROF, ITIMER_VIRT timers and rlimit handling.  It was put together
with the help of Roland McGrath, the owner and original writer of this code.

The problem we ran into, and the reason for this rework, has to do with using
a profiling timer in a process with a large number of threads.  It appears
that the performance of the old implementation of run_posix_cpu_timers() was
at least O(n*3) (where "n" is the number of threads in a process) or worse.
Everything is fine with an increasing number of threads until the time taken
for that routine to run becomes the same as or greater than the tick time, at
which point things degrade rather quickly.

This patch fixes bug 9906, "Weird hang with NPTL and SIGPROF."

Code Changes

This rework corrects the implementation of run_posix_cpu_timers() to make it
run in constant time for a particular machine.  (Performance may vary between
one machine and another depending upon whether the kernel is built as single-
or multiprocessor and, in the latter case, depending upon the number of
running processors.)  To do this, at each tick we now update fields in
signal_struct as well as task_struct.  The run_posix_cpu_timers() function
uses those fields to make its decisions.

We define a new structure, "task_cputime," to contain user, system and
scheduler times and use these in appropriate places:

struct task_cputime {
	cputime_t utime;
	cputime_t stime;
	unsigned long long sum_exec_runtime;
};

This is included in the structure "thread_group_cputime," which is a new
substructure of signal_struct and which varies for uniprocessor versus
multiprocessor kernels.  For uniprocessor kernels, it uses "task_cputime" as
a simple substructure, while for multiprocessor kernels it is a pointer:

struct thread_group_cputime {
	struct task_cputime totals;
};

struct thread_group_cputime {
	struct task_cputime *totals;
};

We also add a new task_cputime substructure directly to signal_struct, to
cache the earliest expiration of process-wide timers, and task_cputime also
replaces the it_*_expires fields of task_struct (used for earliest expiration
of thread timers).  The "thread_group_cputime" structure contains process-wide
timers that are updated via account_user_time() and friends.  In the non-SMP
case the structure is a simple aggregator; unfortunately in the SMP case that
simplicity was not achievable due to cache-line contention between CPUs (in
one measured case performance was actually _worse_ on a 16-cpu system than
the same test on a 4-cpu system, due to this contention).  For SMP, the
thread_group_cputime counters are maintained as a per-cpu structure allocated
using alloc_percpu().  The timer functions update only the timer field in
the structure corresponding to the running CPU, obtained using per_cpu_ptr().

We define a set of inline functions in sched.h that we use to maintain the
thread_group_cputime structure and hide the differences between UP and SMP
implementations from the rest of the kernel.  The thread_group_cputime_init()
function initializes the thread_group_cputime structure for the given task.
The thread_group_cputime_alloc() is a no-op for UP; for SMP it calls the
out-of-line function thread_group_cputime_alloc_smp() to allocate and fill
in the per-cpu structures and fields.  The thread_group_cputime_free()
function, also a no-op for UP, in SMP frees the per-cpu structures.  The
thread_group_cputime_clone_thread() function (also a UP no-op) for SMP calls
thread_group_cputime_alloc() if the per-cpu structures haven't yet been
allocated.  The thread_group_cputime() function fills the task_cputime
structure it is passed with the contents of the thread_group_cputime fields;
in UP it's that simple but in SMP it must also safely check that tsk->signal
is non-NULL (if it is it just uses the appropriate fields of task_struct) and,
if so, sums the per-cpu values for each online CPU.  Finally, the three
functions account_group_user_time(), account_group_system_time() and
account_group_exec_runtime() are used by timer functions to update the
respective fields of the thread_group_cputime structure.

Non-SMP operation is trivial and will not be mentioned further.

The per-cpu structure is always allocated when a task creates its first new
thread, via a call to thread_group_cputime_clone_thread() from copy_signal().
It is freed at process exit via a call to thread_group_cputime_free() from
cleanup_signal().

All functions that formerly summed utime/stime/sum_sched_runtime values from
from all threads in the thread group now use thread_group_cputime() to
snapshot the values in the thread_group_cputime structure or the values in
the task structure itself if the per-cpu structure hasn't been allocated.

Finally, the code in kernel/posix-cpu-timers.c has changed quite a bit.
The run_posix_cpu_timers() function has been split into a fast path and a
slow path; the former safely checks whether there are any expired thread
timers and, if not, just returns, while the slow path does the heavy lifting.
With the dedicated thread group fields, timers are no longer "rebalanced" and
the process_timer_rebalance() function and related code has gone away.  All
summing loops are gone and all code that used them now uses the
thread_group_cputime() inline.  When process-wide timers are set, the new
task_cputime structure in signal_struct is used to cache the earliest
expiration; this is checked in the fast path.

Performance

The fix appears not to add significant overhead to existing operations.  It
generally performs the same as the current code except in two cases, one in
which it performs slightly worse (Case 5 below) and one in which it performs
very significantly better (Case 2 below).  Overall it's a wash except in those
two cases.

I've since done somewhat more involved testing on a dual-core Opteron system.

Case 1: With no itimer running, for a test with 100,000 threads, the fixed
	kernel took 1428.5 seconds, 513 seconds more than the unfixed system,
	all of which was spent in the system.  There were twice as many
	voluntary context switches with the fix as without it.

Case 2: With an itimer running at .01 second ticks and 4000 threads (the most
	an unmodified kernel can handle), the fixed kernel ran the test in
	eight percent of the time (5.8 seconds as opposed to 70 seconds) and
	had better tick accuracy (.012 seconds per tick as opposed to .023
	seconds per tick).

Case 3: A 4000-thread test with an initial timer tick of .01 second and an
	interval of 10,000 seconds (i.e. a timer that ticks only once) had
	very nearly the same performance in both cases:  6.3 seconds elapsed
	for the fixed kernel versus 5.5 seconds for the unfixed kernel.

With fewer threads (eight in these tests), the Case 1 test ran in essentially
the same time on both the modified and unmodified kernels (5.2 seconds versus
5.8 seconds).  The Case 2 test ran in about the same time as well, 5.9 seconds
versus 5.4 seconds but again with much better tick accuracy, .013 seconds per
tick versus .025 seconds per tick for the unmodified kernel.

Since the fix affected the rlimit code, I also tested soft and hard CPU limits.

Case 4: With a hard CPU limit of 20 seconds and eight threads (and an itimer
	running), the modified kernel was very slightly favored in that while
	it killed the process in 19.997 seconds of CPU time (5.002 seconds of
	wall time), only .003 seconds of that was system time, the rest was
	user time.  The unmodified kernel killed the process in 20.001 seconds
	of CPU (5.014 seconds of wall time) of which .016 seconds was system
	time.  Really, though, the results were too close to call.  The results
	were essentially the same with no itimer running.

Case 5: With a soft limit of 20 seconds and a hard limit of 2000 seconds
	(where the hard limit would never be reached) and an itimer running,
	the modified kernel exhibited worse tick accuracy than the unmodified
	kernel: .050 seconds/tick versus .028 seconds/tick.  Otherwise,
	performance was almost indistinguishable.  With no itimer running this
	test exhibited virtually identical behavior and times in both cases.

In times past I did some limited performance testing.  those results are below.

On a four-cpu Opteron system without this fix, a sixteen-thread test executed
in 3569.991 seconds, of which user was 3568.435s and system was 1.556s.  On
the same system with the fix, user and elapsed time were about the same, but
system time dropped to 0.007 seconds.  Performance with eight, four and one
thread were comparable.  Interestingly, the timer ticks with the fix seemed
more accurate:  The sixteen-thread test with the fix received 149543 ticks
for 0.024 seconds per tick, while the same test without the fix received 58720
for 0.061 seconds per tick.  Both cases were configured for an interval of
0.01 seconds.  Again, the other tests were comparable.  Each thread in this
test computed the primes up to 25,000,000.

I also did a test with a large number of threads, 100,000 threads, which is
impossible without the fix.  In this case each thread computed the primes only
up to 10,000 (to make the runtime manageable).  System time dominated, at
1546.968 seconds out of a total 2176.906 seconds (giving a user time of
629.938s).  It received 147651 ticks for 0.015 seconds per tick, still quite
accurate.  There is obviously no comparable test without the fix.

Signed-off-by: Frank Mayhar <fmayhar@google.com>
Cc: Roland McGrath <roland@redhat.com>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-09-14 16:25:35 +02:00
Ingo Molnar
6e03f99803 Merge branch 'linus' into x86/iommu
Conflicts:
	lib/swiotlb.c

Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-09-14 14:07:00 +02:00
Linus Torvalds
7c22a3d853 Merge branch 'upstream-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jgarzik/libata-dev
* 'upstream-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jgarzik/libata-dev:
  [libata] LBA28/LBA48 off-by-one bug in ata.h
  sata_inic162x: enable LED blinking
  ata: duplicate variable sparse warning
2008-09-13 14:48:14 -07:00
Linus Torvalds
c19e80808b Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-2.6
* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-2.6:
  niu: panic on reset
  netlink: fix overrun in attribute iteration
  [Bluetooth] Fix regression from using default link policy
  ath9k: Assign seq# when mac80211 requests this
2008-09-13 14:46:57 -07:00
Alex Dubov
8e82f8c34b memstick: fix MSProHG 8-bit interface mode support
- 8-bit interface mode never worked properly.  The only adapter I have
  which supports the 8b mode (the Jmicron) had some problems with its
  clock wiring and they discovered it only now.  We also discovered that
  ProHG media is more sensitive to the ordering of initialization
  commands.

- Make the driver fall back to highest supported mode instead of always
  falling back to serial.  The driver will attempt the switch to 8b mode
  for any new MSPro card, but not all of them support it.  Previously,
  these new cards ended up in serial mode, which is not the best idea
  (they work fine with 4b, after all).

- Edit some macros for better conformance to Sony documentation

Signed-off-by: Alex Dubov <oakad@yahoo.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-09-13 14:41:52 -07:00
Mel Gorman
5bead2a068 mm: mark the correct zone as full when scanning zonelists
The iterator for_each_zone_zonelist() uses a struct zoneref *z cursor when
scanning zonelists to keep track of where in the zonelist it is.  The
zoneref that is returned corresponds to the the next zone that is to be
scanned, not the current one.  It was intended to be treated as an opaque
list.

When the page allocator is scanning a zonelist, it marks elements in the
zonelist corresponding to zones that are temporarily full.  As the
zonelist is being updated, it uses the cursor here;

  if (NUMA_BUILD)
        zlc_mark_zone_full(zonelist, z);

This is intended to prevent rescanning in the near future but the zoneref
cursor does not correspond to the zone that has been found to be full.
This is an easy misunderstanding to make so this patch corrects the
problem by changing zoneref cursor to be the current zone being scanned
instead of the next one.

Signed-off-by: Mel Gorman <mel@csn.ul.ie>
Cc: Andy Whitcroft <apw@shadowen.org>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: <stable@kernel.org>		[2.6.26.x]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-09-13 14:41:52 -07:00