Currently the code tries up to spin_retry times to grab a lock using the cs
instruction. The cs instruction has exclusive access to a memory region
and therefore invalidates the appropiate cache line of all other cpus. If
there is contention on a lock this leads to cache line trashing. This can
be avoided if we first check wether a cs instruction is likely to succeed
before the instruction gets actually executed.
Signed-off-by: Christian Ehrhardt <ehrhardt@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
/usr/src/ctest/git/kernel/mm/rmap.c: In function `page_referenced_one':
/usr/src/ctest/git/kernel/mm/rmap.c:354: warning: implicit declaration of function `rwsem_is_locked'
Signed-off-by: Adrian Bunk <bunk@stusta.de>
Cc: <chris@zankel.net>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Fix a lockup which was introduced during the conversion to the generic IRQ
framework.
Cc: Richard Henderson <rth@twiddle.net>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
At times gcc will place bits of __exit functions into .rodata. If
compiled into the kernle itself we used to discard .exit.text - but
not the bits left in .rodata. While harmless this did at times result
in a large number of warnings. So until gcc fixes this, discard
.exit.text at runtime.
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
In case a particular system doesn't support highmem the runtime checks
will ensure nothing bad is going to happen.
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
ATI chipsets tend to generate double timer interrupts for the local APIC
timer when both the 8254 and the IO-APIC timer pins are enabled. This is
because they route it to both and the result is anded together and the CPU
ends up processing it twice.
This patch changes check_timer to disable the 8254 routing for interrupt 0.
I think it would be safe on all chipsets actually (i tested it on a couple
and it worked everywhere) and Windows seems to do it in a similar way, but
to be conservative this patch only enables this mode on ATI (and adds
options to enable/disable too)
Ported over from a similar x86-64 change.
I reused the ACPI earlyquirk infrastructure for the ATI bridge check, but
tweaked it a bit to work even without ACPI.
Inspired by a patch from Chuck Ebbert, but redone.
Cc: Chuck Ebbert <76306.1226@compuserve.com>
Cc: "Brown, Len" <len.brown@intel.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
A pte may be zapped by the swapper, exiting process, unmapping or page
migration while the accessed or dirty bit handers are about to run. In that
case the accessed bit or dirty is set on an zeroed pte which leads the VM to
conclude that this is a swap pte. This may lead to
- Messages from the vm like
swap_free: Bad swap file entry 4000000000000000
- Processes being aborted
swap_dup: Bad swap file entry 4000000000000000
VM: killing process ....
Page migration is particular suitable for the creation of this race since
it needs to remove and restore page table entries.
The fix here is to check for the present bit and simply not update
the pte if the page is not present anymore. If the page is not present
then the fault handler should run next which will take care of the problem
by bringing the page back and then mark the page dirty or move it onto the
active list.
Signed-off-by: Christoph Lameter <clameter@sgi.com>
Signed-off-by: Tony Luck <tony.luck@intel.com>
While testing kexec and kdump we hit problems where the new kernel would
freeze or instantly reboot. The easiest way to trigger it was to kexec a
kernel compiled for CONFIG_M586 on an athlon cpu. Compiling for CONFIG_MK7
instead would work fine.
The patch fixes a few problems with the kexec inline asm.
Signed-off-by: Chris Mason <mason@suse.com>
Acked-by: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
The x86_model calculation also applies for family 6. early_cpu_detect
does the right thing, but generic_identify misses.
Signed-off-by: Shaohua Li<shaohua.li@intel.com>
Cc: Dave Jones <davej@codemonkey.org.uk>
Cc: "Seth, Rohit" <rohit.seth@intel.com>
Acked-by: Andi Kleen <ak@muc.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
strnlen_user is supposed to return then length count + 1 if no terminating \0
is found, and it should return 0 on exception. Found by David Howells
<dhowells@redhat.com>.
Signed-off-by: Gerald Schaefer <geraldsc@de.ibm.com>
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Acked-By: David Howells <dhowells@redhat.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Fix i386 nmi_watchdog that does not meet watchdog timeout condition. It
does not hit die_nmi when it should be triggered, because the current
nmi_watchdog_tick in arch/i386/kernel/nmi.c never count up alert_counter
like this:
void nmi_watchdog_tick (struct pt_regs * regs) {
if (last_irq_sums[cpu] == sum) {
alert_counter[cpu]++; <- count up alert_counter, but
if (alert_counter[cpu] == 5*nmi_hz)
die_nmi(regs, "NMI Watchdog detected LOCKUP");
alert_counter[cpu] = 0; <- reset alert_counter
This patch changes it back to the previous and working version.
This was found and originally written by Kohta NAKASHIMA.
(akpm: also uninline write_watchdog_counter(), saving 184 byets)
Signed-off-by: GOTO Masanori <gotom@sanori.org>
Cc: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* 'release' of git://git.kernel.org/pub/scm/linux/kernel/git/aegl/linux-2.6:
[IA64] mca recovery return value when no bus check
[IA64] SGI SN drivers: don't report !sn2 hardware as an error
[IA64] don't report !sn2 or !summit hardware as an error
[IA64] gensparse_defconfig: turn on PNPACPI
[IA64] Increase severity of MCA recovery messages
A careful reading of the recent changes to the system call entry/exit
paths revealed several problems, plus some things that could be
simplified and improved:
* 32-bit wasn't testing the _TIF_NOERROR bit in the syscall fast exit
path, so it was only doing anything with it once it saw some other
bit being set. In other words, the noerror behaviour would apply to
the next system call where we had to reschedule or deliver a signal,
which is not necessarily the current system call.
* 32-bit wasn't doing the call to ptrace_notify in the syscall exit
path when the _TIF_SINGLESTEP bit was set.
* _TIF_RESTOREALL was in both _TIF_USER_WORK_MASK and
_TIF_PERSYSCALL_MASK, which is odd since _TIF_RESTOREALL is only set
by system calls. I took it out of _TIF_USER_WORK_MASK.
* On 64-bit, _TIF_RESTOREALL wasn't causing the non-volatile registers
to be restored (unless perhaps a signal was delivered or the syscall
was traced or single-stepped). Thus the non-volatile registers
weren't restored on exit from a signal handler. We probably got
away with it mostly because signal handlers written in C wouldn't
alter the non-volatile registers.
* On 32-bit I simplified the code and made it more like 64-bit by
making the syscall exit path jump to ret_from_except to handle
preemption and signal delivery.
* 32-bit was calling do_signal unnecessarily when _TIF_RESTOREALL was
set - but I think because of that 32-bit was actually restoring the
non-volatile registers on exit from a signal handler.
* I changed the order of enabling interrupts and saving the
non-volatile registers before calling do_syscall_trace_leave; now we
enable interrupts first.
Signed-off-by: Paul Mackerras <paulus@samba.org>
When there is no bus check, the return code should be failure, not success.
Signed-off-by: Russ Anderson (rja@sgi.com)
Signed-off-by: Tony Luck <tony.luck@intel.com>
This stuff is all in the generic ia64 kernel, and the new initcall error
reporting complains about them.
Signed-off-by: Bjorn Helgaas <bjorn.helgaas@hp.com>
Signed-off-by: Tony Luck <tony.luck@intel.com>
Turn on CONFIG_PNPACPI. I recently removed 8250_acpi.c. All devices
previously claimed by 8250_acpi.c should now be claimed by 8250_pnp.c.
This depends on having CONFIG_PNPACPI so ACPI devices show up as PNP
devices.
All other ia64 defconfigs either have CONFIG_PNPACPI already, or
don't have 8250 support turned on at all.
Signed-off-by: Bjorn Helgaas <bjorn.helgaas@hp.com>
Signed-off-by: Tony Luck <tony.luck@intel.com>
The MCA recovery messages are currently KERN_DEBUG,
so they don't show up in /var/log/messages (by default).
Increase the severity to KERN_ERR, for the initial
message (and also add the physical address to this
message). Leave the successful isolation message as
KERN_DEBUG, but increase the severity when isolation
fails to KERN_CRIT.
[Russ' patch made these all KERN_CRIT]
Signed-off-by: Russ Anderson (rja@sgi.com)
Signed-off-by: Tony Luck <tony.luck@intel.com>
Patch from Alessandro Zummo
nas100d_power_exit(void) gets some protection
to avoid freeing an irq when it is not appropriate to do so.
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>
Patch from Catalin Marinas
Chapter B2.7.3 in the latest ARM ARM (with v6 information) states that
the completion of a TLB maintenance operation is only guaranteed by
the execution of a DSB (Data Syncronization Barrier, formerly Data
Write Barrier or Drain Write Buffer).
Note that a DSB is only needed in the flush_tlb_kernel_* functions
since the completion is guaranteed by a mode change (i.e. switching
back to user mode) for the flush_tlb_user_* functions.
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
This patch makes the kernel bootable again on ia32 EFI systems.
Signed-off-by: Edgar Hucek <hostmaster@ed-soft.at>
Cc: Matt Domsch <Matt_Domsch@dell.com>
Cc: Zachary Amsden <zach@vmware.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Add the missing pm_power_off's for the h8300, v850 and xtensa
architectures.
Signed-off-by: Adrian Bunk <bunk@stusta.de>
Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
Cc: Miles Bader <uclinux-v850@lsi.nec.co.jp>
Cc: Chris Zankel <chris@zankel.net>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Also from Thomas Gleixner <tglx@linutronix.de>
Function next_timer_interrupt() got broken with a recent patch
6ba1b91213 as sys_nanosleep() was moved to
hrtimer. This broke things as next_timer_interrupt() did not check hrtimer
tree for next event.
Function next_timer_interrupt() is needed with dyntick (CONFIG_NO_IDLE_HZ,
VST) implementations, as the system can be in idle when next hrtimer event
was supposed to happen. At least ARM and S390 currently use
next_timer_interrupt().
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Russell King <rmk@arm.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
i386 timer_resume is updating jiffies, not jiffies_64. It looks there is a
potential overflow problem. And jiffies_64 and wall_jiffies should be
protected by xtime_lock.
Signed-off-by: Atsushi Nemoto <anemo@mba.ocn.ne.jp>
Cc: john stultz <johnstul@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
We must use the "a" (allocate) attribute every time we
emit an entry into the __ex_table section.
For consistency, use "a" instead of #alloc which is some
Solaris compat cruft GNU as provides on Sparc.
Signed-off-by: David S. Miller <davem@davemloft.net>
yaboot is scrogged and calls us with an invalid stack alignment,
it seems.
Thanks to David Woodhouse to pointing me to the problem.
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
On Thu, 2006-03-02 at 19:55 +0100, Olaf Hering wrote:
> My iBook1 has 2 memory regions in reg. Depending on how I boot it
> (vmlinux+initrd) or zImage.initrd, it will not boot with current Linus
> tree.
> rmo_top should be 160MB instead of 32MB.
On logically-partitioned machines the first element of the reg
property in the memory node is defined to be the "RMO" region,
i.e. the memory that the processor can access in real mode. On other
machines the first element has no special meaning, so only take it to
be the RMO region on LPAR machines.
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>
This patch makes userland aware of the icache snoop capability of the
POWER5 (and possibly others in the future) and of SMT capabilities.
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>
The variable `timebase' used to transfer the current timebase value
from one cpu to the other in smp_core99_give/take_timebase was only
an unsigned long, i.e. 32 bits on 32-bit machines. It needs to be
64 bits. This makes it a u64, and fixes the issue reported by Kyle
Moffett, that the two cpus see wildly different values for the time
of day.
Signed-off-by: Paul Mackerras <paulus@samba.org>
This is along the lines suggested by Chris Lumens but goes further
in that it leaves the DEBUG symbol undefined, making the DBG macro
empty.
Signed-off-by: Paul Mackerras <paulus@samba.org>
On 32-bit, the exception prolog for the program check exception doesn't
enable interrupts early on. If it is an illegal instruction exception,
we read the instruction in order to emulate certain instructions, and
the get_user of the instruction triggers a WARN_ON since interrupts
are still disabled. This adds a local_irq_enable() to enable
interrupts before reading the instruction.
Signed-off-by: Paul Mackerras <paulus@samba.org>
The 'tick_usec' is USER_HZ period in usec. do_gettimeofday() should
use kernel HZ value.
Here is a patch for MIPS. It seems m32r, m68k and sparc have same
problem though their HZ and USER_HZ are same for now.
Signed-off-by: Atsushi Nemoto <anemo@mba.ocn.ne.jp>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
This patch adds mm->task_size to keep track of the task size of a given mm
and uses that to fix the powerpc vdso so that it uses the mm task size to
decide what pages to fault in instead of the current thread flags (which
broke when ptracing).
(akpm: I expect that mm_struct.task_size will become the way in which we
finally sort out the confusion between 32-bit processes and 32-bit mm's. It
may need tweaks, but at this stage this patch is powerpc-only.)
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>
This driver loops over 'num_online_cpus', but it doesn't account for holes
in the online map created by offlined cpus, and assumes that the cpu
numbers stay linear.
Signed-off-by: Dave Jones <davej@redhat.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Allow sysadmin to disable all warnings about userland apps
making unaligned accesses by using:
# echo 1 > /proc/sys/kernel/ignore-unaligned-usertrap
Rather than having to use prctl on a process by process basis.
Default behaivour leaves the warnings enabled.
Signed-off-by: Jes Sorensen <jes@sgi.com>
Signed-off-by: Tony Luck <tony.luck@intel.com>
When a CPU has no scache, the scache flushing functions currently
aren't getting initialized and the NULL pointer is eventually called
as a function. Initialize the scache flushing functions as a noop
when there's no scache.
Initial patch by me and most of the debugging done by Martin Michlmayr.
Signed-off-by: Martin Michlmayr <tbm@cyrius.com>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
beautify coding style for zeroing end of fsyscall_table entries.
Remove misleading __NR_syscall_last and add more comments.
Drop (now unneeded) "guard against failure to increase NR_syscalls"
Signed-off-by: Ken Chen <kenneth.w.chen@intel.com>
Signed-off-by: Tony Luck <tony.luck@intel.com>
Before the merge I updated create_pte_mapping() to work for iSeries, by
calling iSeries_hpte_bolt_or_insert. (4c55130b2a)
Later we changed iSeries_hpte_insert to cope with the bolting case, and called
that instead from create_pte_mapping() (which was renamed to htab_bolt_mapping)
(3c726f8dee).
Unfortunately that change introduced a subtle bug, where we pass an absolute
address to iSeries_hpte_insert() where it expects a physical address. This
leads to us calling phys_to_abs() twice on the physical address, which is
seriously bogus.
This only causes a problem if the absolute address from the first translation
can be looked up again in the chunk_map, which depends on the size and layout
of memory. I've seen it fail on one box, but not others.
The minimal fix is to pass the physical address to iSeries_hpte_insert(). For
2.6.17 we should make phys_to_abs() BUG if we try to double-translate an
address.
Signed-off-by: Michael Ellerman <michael@ellerman.id.au>
Signed-off-by: Paul Mackerras <paulus@samba.org>
A bug in the assembly code of the vdso can cause gettimeofday() to hang
or to return incorrect results. The wrong register was used to test for
pending updates of the calibration variables and to create a dependency
for subsequent loads. This fixes it.
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>
Some hotplug driver functions were migrated to the kernel for use by EEH
in commit 2bf6a8fa21.
Previously, the PCI Hotplug module had been changed to use the new
OFDT-based PCI probe when appropriate:
5fa80fcdca
When rpaphp_pci_config_slot() was moved from the rpaphp driver to the
new kernel function pcibios_add_pci_devices(), the OFDT-based probe
stuff was dropped. This patch restores it.
Signed-off-by: John Rose <johnrose@austin.ibm.com>
Signed-off-by: Paul Mackerras <paulus@samba.org>
