Commit Graph

5189 Commits (9b6695a8adfe0916e81ddd810a5b9db3eb8b0e46)

Author SHA1 Message Date
Ralf Baechle 9b6695a8ad [MIPS] SMP: Fix initialization order bug.
A recent change requires cpu_possible_map to be initialized before
smp_sched_init() but most MIPS platforms were initializing their
processors in the prom_prepare_cpus callback of smp_prepare_cpus.  The
simple fix of calling prom_prepare_cpus from one of the earlier SMP
initialization hooks doesn't work well either since IPIs may require
init_IRQ() to have completed, so bit the bullet and split
prom_prepare_cpus into two initialization functions, plat_smp_setup
which is called early from setup_arch and plat_prepare_cpus called where
prom_prepare_cpus used to be called.
    
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2006-02-27 17:30:36 +00:00
Ralf Baechle 3e6cb2d38a [MIPS] Use "=R" constraint to avoid compiler errors in cmpxchg().
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2006-02-27 17:30:35 +00:00
David S. Miller 7abea92145 [SPARC64]: Make cpu_present_map available earlier.
The change to kernel/sched.c's init code to use for_each_cpu()
requires that the cpu_possible_map be setup much earlier.

Set it up via setup_arch(), constrained to NR_CPUS, and later
constrain it to max_cpus in smp_prepare_cpus().

This fixes SMP booting on sparc64.

Signed-off-by: David S. Miller <davem@davemloft.net>
2006-02-26 19:36:00 -08:00
David S. Miller 043df59eb3 [SPARC64]: Implement futex_atomic_op_inuser().
Signed-off-by: David S. Miller <davem@davemloft.net>
2006-02-26 19:35:58 -08:00
Andi Kleen e8b917775b [PATCH] x86_64: Move the SMP time selection earlier
SMP time selection originally ran after all CPUs were brought up because
it needed to know the number of CPUs to decide if it needs an MP safe
timer or not.

This is not needed anymore because we know present CPUs early.

This fixes a couple of problems:
 - apicmaintimer didn't always work because it relied on state that was
   set up time_init_gtod too late.
 - The output for the used timer in early kernel log was misleading
   because time_init_gtod could actually change it later.  Now always
   print the final timer choice

Signed-off-by: Andi Kleen <ak@suse.de>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-02-26 09:53:31 -08:00
Andi Kleen e2c0388866 [PATCH] x86_64: Fix the additional_cpus=.. option
It didn't set up the CPU possible map early enough, so the
option didn't actually work.

Noticed by Heiko Carstens

Signed-off-by: Andi Kleen <ak@suse.de>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-02-26 09:53:30 -08:00
Andi Kleen 13a229abc2 [PATCH] x86_64: Only do the clustered systems have unsynchronized TSC assumption on IBM systems
Big Unisys systems have multiple clusters too, but they have an
synchronized TSC.

I'm using the SMBIOS to check for vendor == IBM.

Cc: Chris McDermott <lcm@us.ibm.com>
Cc: "Protasevich, Natalie" <Natalie.Protasevich@unisys.com>

Signed-off-by: Andi Kleen <ak@suse.de>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-02-26 09:53:30 -08:00
Jan Beulich f83f2b5fba [PATCH] x86_64: fix USER_PTRS_PER_PGD
The value, while currently unused in the native kernel, was off by one.

Signed-Off-By: Jan Beulich <jbeulich@novell.com>
Signed-off-by: Andi Kleen <ak@suse.de>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-02-26 09:53:30 -08:00
Jon Mason 60b08c6722 [PATCH] x86_64: no_iommu removal in pci-gart.c
In previous versions of pci-gart.c, no_iommu was used to determine if IOMMU was
disabled in the GART DMA mapping functions.  This changed in 2.6.16 and now
gart_xxx() functions are only called if gart is enabled.  Therefore, uses of
no_iommu in the GART code are no longer necessary and can be removed.

Also, it removes double deceleration of no_iommu and force_iommu in pci.h and
proto.h, by removing the deceleration in pci.h.

Lastly, end_pfn off by one error.

Tested (along with patch 1/2) on dual opteron with gart enabled, iommu=soft,
and iommu=off.

Signed-off-by: Jon Mason <jdmason@us.ibm.com>
Signed-off-by: Andi Kleen <ak@suse.de>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-02-26 09:53:29 -08:00
Linus Torvalds 5c1ca65c93 Merge master.kernel.org:/home/rmk/linux-2.6-serial 2006-02-24 16:01:07 -08:00
Ulrich Drepper c04030e16d [PATCH] flags parameter for linkat
I'm currently at the POSIX meeting and one thing covered was the
incompatibility of Linux's link() with the POSIX definition.  The name.
Linux does not follow symlinks, POSIX requires it does.

Even if somebody thinks this is a good default behavior we cannot change this
because it would break the ABI.  But the fact remains that some application
might want this behavior.

We have one chance to help implementing this without breaking the behavior.
 For this we could use the new linkat interface which would need a new
flags parameter.  If the new parameter is AT_SYMLINK_FOLLOW the new
behavior could be invoked.

I do not want to introduce such a patch now.  But we could add the
parameter now, just don't use it.  The patch below would do this.  Can we
get this late patch applied before the release more or less fixes the
syscall API?

Signed-off-by: Ulrich Drepper <drepper@redhat.com>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-02-24 14:31:39 -08:00
James Bottomley 2b932f6cf0 [PATCH] x86: fix broken SMP boot sequence
Recent GDT changes broke the SMP boot sequence if the booting CPU is
numbered anything other than zero.  There's also a subtle source of error
in that the boot time CPU now uses cpu_gdt_table (which is actually the GDT
for booting CPUs in head.S).  This patch fixes both problems by making GDT
descriptors themselves allocated from a per_cpu area and switching to them
in cpu_init(), which now means that cpu_gdt_table is exclusively used for
booting CPUs again.

Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>
Cc: Zachary Amsden <zach@vmware.com>
Cc: Matt Tolentino <metolent@snoqualmie.dp.intel.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-02-24 14:31:38 -08:00
Prasanna S Panchamukhi 124d90be62 [PATCH] Kprobes causes NX protection fault on i686 SMP
Fix a problem seen on i686 machine with NX support where the instruction
could not be single stepped because of NX bit set on the memory pages
allocated by kprobes module.  This patch provides allocation of instruction
solt so that the processor can execute the instruction from that location
similar to x86_64 architecture.  Thanks to Bibo and Masami for testing this
patch.

Signed-off-by: Prasanna S Panchamukhi <prasanna@in.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-02-24 14:31:37 -08:00
Hirokazu Takata 6ced13cdca [PATCH] m32r: fix and update for gcc-4.0
Fix and update for gcc-4.0.

- arch/m32r/kernel/signal.c:
  Change type of the 8th parameter of sys_rt_sigsuspend() from
  'struct pt_regs' to 'struct pt_regs *'.
  This functions make use of the 'regs' parameter to return status value,
  but gcc-4.0 optimizes and removes it as a dead code.
  Functions, sys_sigaltstack() and sys_rt_sigreturn(), have also modified.

- arch/m32r/lib/usercopy.c, include/asm-m32r/uaccess.h:
  Add early-clobber constraints('&') to output values of asm statements;
  these constraints seems to be required for gcc-4.0 register assignment.

Signed-off-by: Hayato Fujiwara <fujiwara@linux-m32r.org>
Signed-off-by: Hirokazu Takata <takata@linux-m32r.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-02-24 14:31:36 -08:00
Linus Torvalds c0eea79bd2 Merge master.kernel.org:/pub/scm/linux/kernel/git/davem/net-2.6 2006-02-23 20:40:17 -08:00
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
Herbert Xu 21380b81ef [XFRM]: Eliminate refcounting confusion by creating __xfrm_state_put().
We often just do an atomic_dec(&x->refcnt) on an xfrm_state object
because we know there is more than 1 reference remaining and thus
we can elide the heavier xfrm_state_put() call.

Do this behind an inline function called __xfrm_state_put() so that is
more obvious and also to allow us to more cleanly add refcount
debugging later.

Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
2006-02-23 16:10:53 -08:00
Michal Janusz Miroslaw 85edae14e4 [SERIAL] Trivial comment fix: include/linux/serial_reg.h
Trivial comment fix for include/linux/serial_reg.h

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2006-02-23 09:49:35 +00:00
Linus Torvalds 1a6a35894f Merge master.kernel.org:/home/rmk/linux-2.6-arm 2006-02-22 15:21:57 -08:00
Linus Torvalds 245599f573 Merge master.kernel.org:/home/rmk/linux-2.6-mmc 2006-02-22 15:21:22 -08:00
Andrew Victor df666b9c51 [ARM] 3325/2: GPIO function to control multi-drive (open collector) capability
Patch from Andrew Victor

This patch adds the at91_set_multi_drive() function to enable/disable
the multi-drive (open collector) pin capability on the AT91RM9200
processor.

This is necessary to fix the UDC (USB Gadget) driver for the AT91RM9200
board as it will not allow the board reset line to be pulled low if the
pullup is not driven as an open collector output as the boards are wired
to the USB connector on both the DK/EK.

This version of the patch updates it to 2.6.16-rc4.
Orignal patch by Jeff Warren.

Signed-off-by: Andrew Victor <andrew@sanpeople.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2006-02-22 21:23:35 +00:00
Alessandro Zummo af898b8f60 [ARM] 3343/1: NAS100d: Fix incorrect I2C pin assignment
Patch from Alessandro Zummo

The I2C pin assignment for the Iomega NAS100d board was incorrect.  This
patch fixes it.  The correct assignment has now been tested using the
new RTC class and a new driver for the RTC on the NAS100d.

Signed-off-by: Rod Whitby <rod@whitby.id.au>
Signed-off-by: Alessandro Zummo <a.zummo@towertech.it>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2006-02-22 21:12:06 +00:00
Greg Kroah-Hartman fa675765af Revert mount/umount uevent removal
This change reverts the 033b96fd30 commit
from Kay Sievers that removed the mount/umount uevents from the kernel.
Some older versions of HAL still depend on these events to detect when a
new device has been mounted.  These events are not correctly emitted,
and are broken by design, and so, should not be relied upon by any
future program.  Instead, the /proc/mounts file should be polled to
properly detect this kind of event.

A feature-removal-schedule.txt entry has been added, noting when this
interface will be removed from the kernel.

Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2006-02-22 09:39:02 -08:00
Russell King 5bd546aa78 [MMC] Fix mmc_cmd_type() mask
It's MMC_CMD_MASK not MMC_CMD_TYPE.

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2006-02-22 09:32:46 +00:00
Linus Torvalds 808c783e9b Merge branch 'upstream' of git://ftp.linux-mips.org/pub/scm/upstream-linus 2006-02-21 10:13:22 -08:00
Linus Torvalds 52aa536f5a Merge branch 'upstream-fixes' of master.kernel.org:/pub/scm/linux/kernel/git/jgarzik/libata-dev 2006-02-21 10:11:32 -08:00
Ralf Baechle 1242737735 [MIPS] Follow Uli's latest *at syscall changes.
(This really is only the half of the patch which was forgotten in
326a625748 ...)
    
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2006-02-21 16:58:23 +00:00
Atsushi Nemoto 8ecbbcaf08 [MIPS] Fixes for uaccess.h with gcc >= 4.0.1
It seems current get_user() incorrectly sign-extend an unsigned int
value on 64bit kernel.  I think this is because '(__typeof__(val))'
cast in final assignment.  I suppose the cast should be
'(__typeof__(*(addr))'.
    
Signed-off-by: Atsushi Nemoto <anemo@mba.ocn.ne.jp>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2006-02-21 16:58:22 +00:00
Linus Torvalds cf70a6f264 Merge branch 'fixes.b8' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/bird 2006-02-20 20:09:44 -08:00
Linus Torvalds 6bd25e7821 Merge git://git.kernel.org/pub/scm/linux/kernel/git/paulus/powerpc-merge 2006-02-20 20:05:45 -08:00
Hirokazu Takata b04ec261bd [PATCH] m32r: __cmpxchg_u32 fix
This patch fixes a bug of include/asm-m32r/system.h:__cmpxchg_u32().

  static __inline__ unsigned long
  __cmpxchg_u32(volatile unsigned int *p, unsigned int old, unsigned int new);

In __cmpxchg_u32(), the "old" value must not be changed to the previous "*p"
value.  But the former code modifies the previous "*p" value.

A deadlock at _atomic_dec_and_lock sometimes happened due to this bug.

Signed-off-by: Hayato Fujiwara <fujiwara@linux-m32r.org>
Signed-off-by: Hirokazu Takata <takata@linux-m32r.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-02-20 20:00:12 -08:00
Heiko Carstens 49d9c81a69 [PATCH] s390: revert dasd eer module
Revert dasd eer module until we have a common understanding of how the
interface should be.

Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-02-20 20:00:12 -08:00
Stephen Rothwell 7fd105e758 [PATCH] Fix compile for CONFIG_SYSVIPC=n or CONFIG_SYSCTL=n
The compat syscalls are added to sys_ni.c since they are not defined if the
above CONFIG options are off.  Also, nfs would not build with CONFIG_SYSCTL
off.

Noticed by Arthur Othieno.

Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Trond Myklebust <trond.myklebust@fys.uio.no>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-02-20 20:00:11 -08:00
Luke Yang 7a9166e3b0 [PATCH] Fix undefined symbols for nommu architecture
Signed-off-by: Luke Yang <luke.adi@gmail.com>
Acked-by: David Howells <dhowells@redhat.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-02-20 20:00:11 -08:00
Pavel Machek c255d844dd [PATCH] suspend-to-ram: allow video options to be set at runtime
Currently, acpi video options can only be set on kernel command line.  That's
little inflexible; I'd like userland s2ram application that just works, and
modifying kernel command line according to whitelist is not fun.  It is better
to just allow s2ram application to set video options just before suspend
(according to the whitelist).

This implements sysctl to allow setting suspend video options without reboot.

(akpm: Documentation updates for this new sysctl are pending..)

Signed-off-by: Pavel Machek <pavel@suse.cz>
Cc: "Brown, Len" <len.brown@intel.com>
Cc: "Antonino A. Daplas" <adaplas@pol.net>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-02-20 20:00:10 -08:00
Christoph Lameter 9b0f8b040a [PATCH] Terminate process that fails on a constrained allocation
Some allocations are restricted to a limited set of nodes (due to memory
policies or cpuset constraints).  If the page allocator is not able to find
enough memory then that does not mean that overall system memory is low.

In particular going postal and more or less randomly shooting at processes
is not likely going to help the situation but may just lead to suicide (the
whole system coming down).

It is better to signal to the process that no memory exists given the
constraints that the process (or the configuration of the process) has
placed on the allocation behavior.  The process may be killed but then the
sysadmin or developer can investigate the situation.  The solution is
similar to what we do when running out of hugepages.

This patch adds a check before we kill processes.  At that point
performance considerations do not matter much so we just scan the zonelist
and reconstruct a list of nodes.  If the list of nodes does not contain all
online nodes then this is a constrained allocation and we should kill the
current process.

Signed-off-by: Christoph Lameter <clameter@sgi.com>
Cc: Nick Piggin <nickpiggin@yahoo.com.au>
Cc: Andi Kleen <ak@muc.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-02-20 20:00:09 -08:00
Tejun Heo cc1887f3d8 [PATCH] libata: fix qc->n_elem == 0 case handling in ata_qc_next_sg
This patch makes ata_for_each_sg() start with pad_sgent when
qc->n_elem is zero.  Previously, ata_for_each_sg() unconditionally
started with qc->__sg, handling the first sg to fill_sg() routines
even when the entry was invalid.  And while at it, unwind ?: in
ata_qc_next_sg() into if statement.

Signed-off-by: Tejun Heo <htejun@gmail.com>
Signed-off-by: Jeff Garzik <jgarzik@pobox.com>
2006-02-20 16:48:18 -05:00
Olaf Hering 0728a2f99e [PATCH] powerpc: remove duplicate exports
A few symbols are exported twice, remove them from ppc_ksyms.c
Remove users of sys_ctrler in arch/ppc/

WARNING: vmlinux: duplicate symbol '__delay' previous definition was in vmlinux
WARNING: vmlinux: duplicate symbol '__up' previous definition was in vmlinux
WARNING: vmlinux: duplicate symbol '__down' previous definition was in vmlinux
WARNING: vmlinux: duplicate symbol '__down_interruptible' previous definition was in vmlinux
WARNING: vmlinux: duplicate symbol 'sys_ctrler' previous definition was in vmlinux
WARNING: vmlinux: duplicate symbol 'strncat' previous definition was in vmlinux
WARNING: vmlinux: duplicate symbol 'strncmp' previous definition was in vmlinux
WARNING: vmlinux: duplicate symbol 'strchr' previous definition was in vmlinux
WARNING: vmlinux: duplicate symbol 'strrchr' previous definition was in vmlinux
WARNING: vmlinux: duplicate symbol 'strnlen' previous definition was in vmlinux
WARNING: vmlinux: duplicate symbol 'strpbrk' previous definition was in vmlinux
WARNING: vmlinux: duplicate symbol 'memscan' previous definition was in vmlinux
WARNING: vmlinux: duplicate symbol 'strstr' previous definition was in vmlinux

Signed-off-by: Olaf Hering <olh@suse.de>
Signed-off-by: Paul Mackerras <paulus@samba.org>
2006-02-20 10:44:31 +11:00
Al Viro ad6b97fc92 [PATCH] iomap_copy fallout (m68k)
added __raw_writel(), sanitized include order in iomap_copy.c

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2006-02-18 16:30:40 -05:00
Al Viro 00fc00df9e [PATCH] m68k: restore disable_irq_nosync()
Patch claiming to remove enable_irq_nosync() had left it alive but killed
disable_irq_nosync() instead...

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2006-02-18 15:59:06 -05:00
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
Heiko Carstens 255acee706 [PATCH] s390: additional_cpus parameter
Introduce additional_cpus command line option.  By default no additional cpu
can be attached to the system anymore.  Only the cpus present at IPL time can
be switched on/off.  If it is desired that additional cpus can be attached to
the system the maximum number of additional cpus needs to be specified with
this option.

This change is necessary in order to limit the waste of per_cpu data
structures.

Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-02-17 13:59:26 -08:00
Chuck Ebbert cfe91f9ce2 [PATCH] i386: fix singlestepping though a syscall
Do not mask TIF_SINGLESTEP bit in _TIF_WORK_MASK. Masking this stopped
do_notify_resume() from being called when it should have been.

Signed-off-by: Chuck Ebbert <76306.1226@compuserve.com>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-02-17 08:55:21 -08:00
Paul Mackerras 726c14bf49 [PATCH] Provide an interface for getting the current tick length
This provides an interface for arch code to find out how many
nanoseconds are going to be added on to xtime by the next call to
do_timer.  The value returned is a fixed-point number in 52.12 format
in nanoseconds.  The reason for this format is that it gives the
full precision that the timekeeping code is using internally.

The motivation for this is to fix a problem that has arisen on 32-bit
powerpc in that the value returned by do_gettimeofday drifts apart
from xtime if NTP is being used.  PowerPC is now using a lockless
do_gettimeofday based on reading the timebase register and performing
some simple arithmetic.  (This method of getting the time is also
exported to userspace via the VDSO.)  However, the factor and offset
it uses were calculated based on the nominal tick length and weren't
being adjusted when NTP varied the tick length.

Note that 64-bit powerpc has had the lockless do_gettimeofday for a
long time now.  It also had an extremely hairy routine that got called
from the 32-bit compat routine for adjtimex, which adjusted the
factor and offset according to what it thought the timekeeping code
was going to do.  Not only was this only called if a 32-bit task did
adjtimex (i.e. not if a 64-bit task did adjtimex), it was also
duplicating computations from kernel/timer.c and it wasn't clear that
it was (still) correct.

The simple solution is to ask the timekeeping code how long the
current jiffy will be on each timer interrupt, after calling
do_timer.  If this jiffy will be a different length from the last one,
we then need to compute new values for the factor and offset used in
the lockless do_gettimeofday.  In this way we can keep xtime and
do_gettimeofday in sync, even when NTP is varying the tick length.

Note that when adjtimex varies the tick length, it almost always
introduces the variation from the next tick on.  The only case I could
see where adjtimex would vary the length of the current tick is when
an old-style adjtime adjustment is being cancelled.  (It's not clear
to me why the adjustment has to be cancelled immediately rather than
from the next tick on.)  Thus I don't see any real need for a hook in
adjtimex; the rare case of an old-style adjustment being cancelled can
be fixed up at the next tick.

Signed-off-by: Paul Mackerras <paulus@samba.org>
Acked-by: john stultz <johnstul@us.ibm.com>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-02-17 08:24:29 -08:00
Linus Torvalds 759b650f54 Merge branch 'release' of git://git.kernel.org/pub/scm/linux/kernel/git/aegl/linux-2.6 2006-02-17 08:16:35 -08:00
Linus Torvalds a5222049f3 Merge master.kernel.org:/home/rmk/linux-2.6-arm 2006-02-17 08:13:11 -08:00
Andi Kleen 7fd67843b9 [PATCH] x86_64: Disable tsc when apicpmtimer is active
Otherwise it has no effect anyways.

Signed-off-by: Andi Kleen <ak@suse.de>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-02-17 08:00:40 -08:00
Andi Kleen a62eaf151d [PATCH] x86_64: Add boot option to disable randomized mappings and cleanup
AMD SimNow!'s JIT doesn't like them at all in the guest. For distribution
installation it's easiest if it's a boot time option.

Also I moved the variable to a more appropiate place and make
it independent from sysctl

And marked __read_mostly which it is.

Signed-off-by: Andi Kleen <ak@suse.de>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-02-17 08:00:40 -08:00