We never look at it except for the old megaraid driver that abuses it
for sending internal commands. That usage can be fixed easily because
those internal commands are single-threaded by a mutex and we can easily
use a completion there.
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>
it's never set to anything, and just three broken drivers are looking
at it and doing odd things.
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>
scsi_add_host is the proper place to set the device, but people copy
the scsi_set_device usage from older drivers again and again.
note that this leaves some legacy drivers like qlogicisp/qlogicfc
without pci association in sysfs, but they're scheduled to go away soon
anyway.
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>
1. Establish a simple API for process freezing defined in linux/include/sched.h:
frozen(process) Check for frozen process
freezing(process) Check if a process is being frozen
freeze(process) Tell a process to freeze (go to refrigerator)
thaw_process(process) Restart process
frozen_process(process) Process is frozen now
2. Remove all references to PF_FREEZE and PF_FROZEN from all
kernel sources except sched.h
3. Fix numerous locations where try_to_freeze is manually done by a driver
4. Remove the argument that is no longer necessary from two function calls.
5. Some whitespace cleanup
6. Clear potential race in refrigerator (provides an open window of PF_FREEZE
cleared before setting PF_FROZEN, recalc_sigpending does not check
PF_FROZEN).
This patch does not address the problem of freeze_processes() violating the rule
that a task may only modify its own flags by setting PF_FREEZE. This is not clean
in an SMP environment. freeze(process) is therefore not SMP safe!
Signed-off-by: Christoph Lameter <christoph@lameter.com>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This patch contains the following cleanups:
- make needlessly global code static
- remove the following unused global functions:
- blkdev_scsi_issue_flush_fn
- __blk_attempt_remerge
- remove the following unused EXPORT_SYMBOL's:
- blk_phys_contig_segment
- blk_hw_contig_segment
- blkdev_scsi_issue_flush_fn
- __blk_attempt_remerge
Signed-off-by: Adrian Bunk <bunk@stusta.de>
Acked-by: Jens Axboe <axboe@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This patch contains the following possible cleanups:
- make the needlessly global function __nvram_set_checksum static
- #if 0 the unused global function nvram_set_checksum
- remove the EXPORT_SYMBOL's for both functions
Signed-off-by: Adrian Bunk <bunk@stusta.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This patch makes use of ALIGN() to remove duplicate round-up code.
Signed-off-by: Nick Wilson <njw@osdl.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
o Following patch provides purely cosmetic changes and corrects CodingStyle
guide lines related certain issues like below in kexec related files
o braces for one line "if" statements, "for" loops,
o more than 80 column wide lines,
o No space after "while", "for" and "switch" key words
o Changes:
o take-2: Removed the extra tab before "case" key words.
o take-3: Put operator at the end of line and space before "*/"
Signed-off-by: Maneesh Soni <maneesh@in.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Makes kexec_crashdump() take a pt_regs * as an argument. This allows to
get exact register state at the point of the crash. If we come from direct
panic assertion NULL will be passed and the current registers saved before
crashdump.
This hooks into two places:
die(): check the conditions under which we will panic when calling
do_exit and go there directly with the pt_regs that caused the fatal
fault.
die_nmi(): If we receive an NMI lockup while in the kernel use the
pt_regs and go directly to crash_kexec(). We're probably nested up badly
at this point so this might be the only chance to escape with proper
information.
Signed-off-by: Alexander Nyberg <alexn@telia.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
From: "Vivek Goyal" <vgoyal@in.ibm.com>
o Support for /proc/vmcore interface. This interface exports elf core image
either in ELF32 or ELF64 format, depending on the format in which elf headers
have been stored by crashed kernel.
o Added support for CONFIG_VMCORE config option.
o Removed the dependency on /proc/kcore.
From: "Eric W. Biederman" <ebiederm@xmission.com>
This patch has been refactored to more closely match the prevailing style in
the affected files. And to clearly indicate the dependency between
/proc/kcore and proc/vmcore.c
From: Hariprasad Nellitheertha <hari@in.ibm.com>
This patch contains the code that provides an ELF format interface to the
previous kernel's memory post kexec reboot.
Signed off by Hariprasad Nellitheertha <hari@in.ibm.com>
Signed-off-by: Eric Biederman <ebiederm@xmission.com>
Signed-off-by: Vivek Goyal <vgoyal@in.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This patch adds support for retrieving the address of elf core header if one
is passed in command line.
Signed-off-by: Vivek Goyal <vgoyal@in.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This patch provides the interfaces necessary to read the dump contents,
treating it as a high memory device.
Signed off by Hariprasad Nellitheertha <hari@in.ibm.com>
Signed-off-by: Eric Biederman <ebiederm@xmission.com>
Signed-off-by: Vivek Goyal <vgoyal@in.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This patch retrieves the max_pfn being used by previous kernel and stores it
in a safe location (saved_max_pfn) before it is overwritten due to user
defined memory map. This pfn is used to make sure that user does not try to
read the physical memory beyond saved_max_pfn.
Signed-off-by: Vivek Goyal <vgoyal@in.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
o Following patch exports kexec global variable "crash_notes" to user space
through sysfs as kernel attribute in /sys/kernel.
Signed-off-by: Maneesh Soni <maneesh@in.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Add kexec support for s390 architecture.
From: Milton Miller <miltonm@bga.com>
- Fix passing of first argument to relocate_kernel assembly.
- Fix Kconfig description.
- Remove wrong comment and comments that describe obvious things.
- Allow only KEXEC_TYPE_DEFAULT as image type -> dump not supported.
Acked-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
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>
This patch implements the kexec support for ppc64 platforms.
A couple of notes:
1) We copy the pages in virtual mode, using the full base kernel
and a statically allocated stack. At kexec_prepare time we
scan the pages and if any overlap our (0, _end[]) range we
return -ETXTBSY.
On PowerPC 64 systems running in LPAR (logical partitioning)
mode, only a small region of memory, referred to as the RMO,
can be accessed in real mode. Since Linux runs with only one
zone of memory in the memory allocator, and it can be orders of
magnitude more memory than the RMO, looping until we allocate
pages in the source region is not feasible. Copying in virtual
means we don't have to write a hash table generation and call
hypervisor to insert translations, instead we rely on the pinned
kernel linear mapping. The kernel already has move to linked
location built in, so there is no requirement to load it at 0.
If we want to load something other than a kernel, then a stub
can be written to copy a linear chunk in real mode.
2) The start entry point gets passed parameters from the kernel.
Slaves are started at a fixed address after copying code from
the entry point.
All CPUs get passed their firmware assigned physical id in r3
(most calling conventions use this register for the first
argument).
This is used to distinguish each CPU from all other CPUs.
Since firmware is not around, there is no other way to obtain
this information other than to pass it somewhere.
A single CPU, referred to here as the master and the one executing
the kexec call, branches to start with the address of start in r4.
While this can be calculated, we have to load it through a gpr to
branch to this point so defining the register this is contained
in is free. A stack of unspecified size is available at r1
(also common calling convention).
All remaining running CPUs are sent to start at absolute address
0x60 after copying the first 0x100 bytes from start to address 0.
This convention was chosen because it matches what the kernel
has been doing itself. (only gpr3 is defined).
Note: This is not quite the convention of the kexec bootblock v2
in the kernel. A stub has been written to convert between them,
and we may adjust the kernel in the future to allow this directly
without any stub.
3) Destination pages can be placed anywhere, even where they
would not be accessible in real mode. This will allow us to
place ram disks above the RMO if we choose.
Signed-off-by: Milton Miller <miltonm@bga.com>
Signed-off-by: R Sharada <sharada@in.ibm.com>
Signed-off-by: Paul Mackerras <paulus@samba.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Add code to clear the hash table and invalidate the tlb for native (SMP,
non-LPAR) mode. Supports 16M and 4k pages.
Signed-off-by: Milton Miller <miltonm@bga.com>
Signed-off-by: R Sharada <sharada@in.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
I have tweaked this patch slightly to handle an empty list
of pages to relocate passed to relocate_new_kernel. And
I have added ppc_md.machine_crash_shutdown. To keep up with
the changes in the generic kexec infrastructure.
From: Albert Herranz <albert_herranz@yahoo.es>
The following patch adds support for kexec on the ppc32 platform.
Non-OpenFirmware based platforms are likely to work directly without
additional changes on the kernel side. The kexec-tools userland package
may need to be slightly updated, though.
For OpenFirmware based machines, additional work is still needed on the
kernel side before kexec support is ready. Benjamin Herrenschmidt is
kindly working on that part.
In order for a ppc platform to use the kexec kernel services it must
implement some ppc_md hooks. Otherwise, kexec will be explicitly disabled,
as suggested by benh.
There are 3+1 new ppc_md hooks that a platform supporting kexec may
implement. Two of them are mandatory for kexec to work. See
include/asm-ppc/machdep.h for details.
- machine_kexec_prepare(image)
This function is called to make any arrangements to the image before it
is loaded.
This hook _MUST_ be provided by a platform in order to activate kexec
support for that platform. Otherwise, the platform is considered to not
support kexec and the kexec_load system call will fail (that makes all
existing platforms by default non-kexec'able).
- machine_kexec_cleanup(image)
This function is called to make any cleanups on image after the loaded
image data it is freed. This hook is optional. A platform may or may
not provide this hook.
- machine_kexec(image)
This function is called to perform the _actual_ kexec. This hook
_MUST_ be provided by a platform in order to activate kexec support for
that platform.
If a platform provides machine_kexec_prepare but forgets to provide
machine_kexec, a kexec will fall back to a reboot.
A ready-to-use machine_kexec_simple() generic function is provided to,
hopefully, simplify kexec adoption for embedded platforms. A platform
may call this function from its specific machine_kexec hook, like this:
void myplatform_kexec(struct kimage *image)
{
machine_kexec_simple(image);
}
- machine_shutdown()
This function is called to perform any machine specific shutdowns, not
already done by drivers. This hook is optional. A platform may or may
not provide this hook.
An example (trimmed) platform specific module for a platform supporting
kexec through the existing machine_kexec_simple follows:
/* ... */
#ifdef CONFIG_KEXEC
int myplatform_kexec_prepare(struct kimage *image)
{
/* here, we can place additional preparations
*/
return 0; /* yes, we support kexec */
}
void myplatform_kexec(struct kimage *image)
{
machine_kexec_simple(image);
}
#endif /* CONFIG_KEXEC */
/* ... */
void __init
platform_init(unsigned long r3, unsigned long r4,
unsigned long r5,
unsigned long r6, unsigned long r7)
{
/* ... */
#ifdef CONFIG_KEXEC
ppc_md.machine_kexec_prepare =
myplatform_kexec_prepare;
ppc_md.machine_kexec =
myplatform_kexec;
#endif /* CONFIG_KEXEC */
/* ... */
}
The kexec ppc kernel support has been heavily tested on the GameCube Linux
port, and, as reported in the fastboot mailing list, it has been tested too
on a Moto 82xx ppc by Rick Richardson.
Signed-off-by: Albert Herranz <albert_herranz@yahoo.es>
Signed-off-by: Eric Biederman <ebiederm@xmission.com>
Acked-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This is the x86_64 implementation of machine kexec. 32bit compatibility
support has been implemented, and machine_kexec has been enhanced to not care
about the changing internal kernel paget table structures.
From: Alexander Nyberg <alexn@dsv.su.se>
build fix
Signed-off-by: Eric Biederman <ebiederm@xmission.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This is the i386 implementation of kexec.
Signed-off-by: Eric Biederman <ebiederm@xmission.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This patch introduces the architecture independent implementation the
sys_kexec_load, the compat_sys_kexec_load system calls.
Kexec on panic support has been integrated into the core patch and is
relatively clean.
In addition the hopefully architecture independent option
crashkernel=size@location has been docuemented. It's purpose is to reserve
space for the panic kernel to live, and where no DMA transfer will ever be
setup to access.
Signed-off-by: Eric Biederman <ebiederm@xmission.com>
Signed-off-by: Alexander Nyberg <alexn@telia.com>
Signed-off-by: Adrian Bunk <bunk@stusta.de>
Signed-off-by: Vivek Goyal <vgoyal@in.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
For one kernel to report a crash another kernel has created we need
to have 2 kernels loaded simultaneously in memory. To accomplish this
the two kernels need to built to run at different physical addresses.
This patch adds the CONFIG_PHYSICAL_START option to the x86_64 kernel
so we can do just that. You need to know what you are doing and
the ramifications are before changing this value, and most users
won't care so I have made it depend on CONFIG_EMBEDDED
bzImage kernels will work and run at a different address when compiled
with this option but they will still load at 1MB. If you need a kernel
loaded at a different address as well you need to boot a vmlinux.
Signed-off-by: Eric Biederman <ebiederm@xmission.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
For one kernel to report a crash another kernel has created we need
to have 2 kernels loaded simultaneously in memory. To accomplish this
the two kernels need to built to run at different physical addresses.
This patch adds the CONFIG_PHYSICAL_START option to the x86 kernel
so we can do just that. You need to know what you are doing and
the ramifications are before changing this value, and most users
won't care so I have made it depend on CONFIG_EMBEDDED
bzImage kernels will work and run at a different address when compiled
with this option but they will still load at 1MB. If you need a kernel
loaded at a different address as well you need to boot a vmlinux.
Signed-off-by: Eric Biederman <ebiederm@xmission.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
In vmlinux.lds.h the code is carefull to define every section so vmlinux
properly reports the correct physical load address of code, as well as
it's virtual address.
The new SECURITY_INIT definition fails to follow that convention and
and causes incorrect physical address to appear in the vmlinux if
there are any security initcalls.
This patch updates the SECURITY_INIT to follow the convention in the rest of
the file.
Signed-off-by: Eric Biederman <ebiederm@xmission.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
When coming out of apic mode attempt to set the appropriate
apic back into virtual wire mode. This improves on previous versions
of this patch by by never setting bot the local apic and the ioapic
into veritual wire mode.
This code looks at data from the mptable to see if an ioapic has
an ExtInt input to make this decision. A future improvement
is to figure out which apic or ioapic was in virtual wire mode
at boot time and to remember it. That is potentially a more accurate
method, of selecting which apic to place in virutal wire mode.
Signed-off-by: Eric Biederman <ebiederm@xmission.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
When coming out of apic mode attempt to set the appropriate
apic back into virtual wire mode. This improves on previous versions
of this patch by by never setting bot the local apic and the ioapic
into veritual wire mode.
This code looks at data from the mptable to see if an ioapic has
an ExtInt input to make this decision. A future improvement
is to figure out which apic or ioapic was in virtual wire mode
at boot time and to remember it. That is potentially a more accurate
method, of selecting which apic to place in virutal wire mode.
Signed-off-by: Eric Biederman <ebiederm@xmission.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
From: "Maciej W. Rozycki" <macro@linux-mips.org>
Fix a kexec problem whcih causes local APIC detection failure.
The problem is detect_init_APIC() is called early, before the command line
have been processed. Therefore "lapic" (and "nolapic") have not been seen,
yet.
Signed-off-by: Maciej W. Rozycki <macro@linux-mips.org>
Signed-off-by: Eric Biederman <ebiederm@xmission.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
From: "Maciej W. Rozycki" <macro@linux-mips.org>
Rename APIC_MODE_EXINT to APIC_MODE_EXTINT - I think it should be named
after what the mode is called in documentation.
From: "Eric W. Biederman" <ebiederm@lnxi.com>
I have reduced this patch to just the name change in the header. And
integrated the changes into the patches that add those
lines. Otherwise I ran into some ugly dependencies.
Signed-off-by: Maciej W. Rozycki <macro@linux-mips.org
Signed-off-by: Eric Biederman <ebiederm@xmission.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This patch adds a new preemption model: 'Voluntary Kernel Preemption'. The
3 models can be selected from a new menu:
(X) No Forced Preemption (Server)
( ) Voluntary Kernel Preemption (Desktop)
( ) Preemptible Kernel (Low-Latency Desktop)
we still default to the stock (Server) preemption model.
Voluntary preemption works by adding a cond_resched()
(reschedule-if-needed) call to every might_sleep() check. It is lighter
than CONFIG_PREEMPT - at the cost of not having as tight latencies. It
represents a different latency/complexity/overhead tradeoff.
It has no runtime impact at all if disabled. Here are size stats that show
how the various preemption models impact the kernel's size:
text data bss dec hex filename
3618774 547184 179896 4345854 424ffe vmlinux.stock
3626406 547184 179896 4353486 426dce vmlinux.voluntary +0.2%
3748414 548640 179896 4476950 445016 vmlinux.preempt +3.5%
voluntary-preempt is +0.2% of .text, preempt is +3.5%.
This feature has been tested for many months by lots of people (and it's
also included in the RHEL4 distribution and earlier variants were in Fedora
as well), and it's intended for users and distributions who dont want to
use full-blown CONFIG_PREEMPT for one reason or another.
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
The following patches add dynamic sched domains functionality that was
extensively discussed on lkml and lse-tech. I would like to see this added to
-mm
o The main advantage with this feature is that it ensures that the scheduler
load balacing code only balances against the cpus that are in the sched
domain as defined by an exclusive cpuset and not all of the cpus in the
system. This removes any overhead due to load balancing code trying to
pull tasks outside of the cpu exclusive cpuset only to be prevented by
the tasks' cpus_allowed mask.
o cpu exclusive cpusets are useful for servers running orthogonal
workloads such as RT applications requiring low latency and HPC
applications that are throughput sensitive
o It provides a new API partition_sched_domains in sched.c
that makes dynamic sched domains possible.
o cpu_exclusive cpusets sets are now associated with a sched domain.
Which means that the users can dynamically modify the sched domains
through the cpuset file system interface
o ia64 sched domain code has been updated to support this feature as well
o Currently, this does not support hotplug. (However some of my tests
indicate hotplug+preempt is currently broken)
o I have tested it extensively on x86.
o This should have very minimal impact on performance as none of
the fast paths are affected
Signed-off-by: Dinakar Guniguntala <dino@in.ibm.com>
Acked-by: Paul Jackson <pj@sgi.com>
Acked-by: Nick Piggin <nickpiggin@yahoo.com.au>
Acked-by: Matthew Dobson <colpatch@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Consolidate balance-on-exec with balance-on-fork. This is made easy by the
sched-domains RCU patches.
As well as the general goodness of code reduction, this allows the runqueues
to be unlocked during balance-on-fork.
schedstats is a problem. Maybe just have balance-on-event instead of
distinguishing fork and exec?
Signed-off-by: Nick Piggin <nickpiggin@yahoo.com.au>
Acked-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Instead of requiring architecture code to interact with the scheduler's
locking implementation, provide a couple of defines that can be used by the
architecture to request runqueue unlocked context switches, and ask for
interrupts to be enabled over the context switch.
Also replaces the "switch_lock" used by these architectures with an oncpu
flag (note, not a potentially slow bitflag). This eliminates one bus
locked memory operation when context switching, and simplifies the
task_running function.
Signed-off-by: Nick Piggin <nickpiggin@yahoo.com.au>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Do some basic initial tuning.
Signed-off-by: Nick Piggin <nickpiggin@yahoo.com.au>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Reimplement the balance on exec balancing to be sched-domains aware. Use this
to also do balance on fork balancing. Make x86_64 do balance on fork over the
NUMA domain.
The problem that the non sched domains aware blancing became apparent on dual
core, multi socket opterons. What we want is for the new tasks to be sent to
a different socket, but more often than not, we would first load up our
sibling core, or fill two cores of a single remote socket before selecting a
new one.
This gives large improvements to STREAM on such systems.
Signed-off-by: Nick Piggin <nickpiggin@yahoo.com.au>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Remove the very aggressive idle stuff that has recently gone into 2.6 - it is
going against the direction we are trying to go. Hopefully we can regain
performance through other methods.
Signed-off-by: Nick Piggin <nickpiggin@yahoo.com.au>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Do CPU load averaging over a number of different intervals. Allow each
interval to be chosen by sending a parameter to source_load and target_load.
0 is instantaneous, idx > 0 returns a decaying average with the most recent
sample weighted at 2^(idx-1). To a maximum of 3 (could be easily increased).
So generally a higher number will result in more conservative balancing.
Signed-off-by: Nick Piggin <nickpiggin@yahoo.com.au>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2.6.12-rc6-mm1 has a few remaining synchronize_kernel()s, some (but not
all) in comments. This patch changes these synchronize_kernel() calls (and
comments) to synchronize_rcu() or synchronize_sched() as follows:
- arch/x86_64/kernel/mce.c mce_read(): change to synchronize_sched() to
handle races with machine-check exceptions (synchronize_rcu() would not cut
it given RCU implementations intended for hardcore realtime use.
- drivers/input/serio/i8042.c i8042_stop(): change to synchronize_sched() to
handle races with i8042_interrupt() interrupt handler. Again,
synchronize_rcu() would not cut it given RCU implementations intended for
hardcore realtime use.
- include/*/kdebug.h comments: change to synchronize_sched() to handle races
with NMIs. As before, synchronize_rcu() would not cut it...
- include/linux/list.h comment: change to synchronize_rcu(), since this
comment is for list_del_rcu().
- security/keys/key.c unregister_key_type(): change to synchronize_rcu(),
since this is interacting with RCU read side.
- security/keys/process_keys.c install_session_keyring(): change to
synchronize_rcu(), since this is interacting with RCU read side.
Signed-off-by: "Paul E. McKenney" <paulmck@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This patch changes the memory allocation method for the s390 debug feature.
Trace buffers had been allocated using the get_free_pages() function before.
Therefore it was not possible to get big memory areas in a running system due
to memory fragmentation. Now the trace buffers are subdivided into several
subbuffers with pagesize. Therefore it is now possible to allocate more
memory for the trace buffers and more trace records can be written.
In addition to that, dynamic specification of the size of the trace buffers is
implemented. It is now possible to change the size of a trace buffer using a
new debugfs file instance. When writing a number into this file, the trace
buffer size is changed to 'number * pagesize'.
In the past all the traces could be obtained from userspace by accessing files
in the "proc" filesystem. Now with debugfs we have a new filesystem which
should be used for debugging purposes. This patch moves the debug feature
from procfs to debugfs.
Since the interface of debug_register() changed, all device drivers, which use
the debug feature had to be adjusted.
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>
Add interface to issue VM control program commands.
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>
Improved machine check handling. Kernel is now able to receive machine checks
while in kernel mode (system call, interrupt and program check handling).
Also register validation is now performed.
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>
Cope with a conditional i386 definition, which is wrong for UML. Before we
just used that one, but it wasn't defined for CONFIG_SMP, so in that case
we got link errors.
Signed-off-by: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>
Cc: Jeff Dike <jdike@addtoit.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This patch fixes register saving so that each register is only saved once,
and adds missing saving of %cr8 on x86-64. Some reordering so that
save/restore is more logical/safer (segment registers should be restored
after gdt).
Signed-off-by: Pavel Machek <pavel@suse.cz>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Without this patch, Linux provokes emergency disk shutdowns and
similar nastiness. It was in SuSE kernels for some time, IIRC.
Signed-off-by: Pavel Machek <pavel@suse.cz>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Using CPU hotplug to support suspend/resume SMP. Both S3 and S4 use
disable/enable_nonboot_cpus API. The S4 part is based on Pavel's original S4
SMP patch.
Signed-off-by: Li Shaohua<shaohua.li@intel.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Broadcast IPI's provide un-expected behaviour for cpu hotplug. CPU's in
offline state also end up receiving the IPI. Once the cpus become online they
receive these stale IPI's which are bad and introduce unexpected behaviour.
This is easily avoided by not sending a broadcast and addressing just the
CPU's in online map. Doing prelim cycle counts it appears there is no big
overhead and numbers seem around 0x3000-0x3900 on an average on x86 and x86_64
systems with CPUS running 3G, both for broadcast and mask version of the
API's.
The shortcuts are useful only for flat mode (where the perf shows no
degradation), and in cluster mode, its unicast anyway. Its simpler to just
not use broadcast anymore.
Signed-off-by: Ashok Raj <ashok.raj@intel.com>
Acked-by: Andi Kleen <ak@muc.de>
Acked-by: Zwane Mwaikambo <zwane@arm.linux.org.uk>
Signed-off-by: Shaohua Li <shaohua.li@intel.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Experimental CPU hotplug patch for x86_64
-----------------------------------------
This supports logical CPU online and offline.
- Test with maxcpus=1, and then kick other cpu's off to test if init code
is all cleaned up. CONFIG_SCHED_SMT works as well.
- idle threads are forked on demand from keventd threads for clean startup
TBD:
1. Not tested on a real NUMA machine (tested with numa=fake=2)
2. Handle ACPI pieces for physical hotplug support.
Signed-off-by: Ashok Raj <ashok.raj@intel.com>
Acked-by: Andi Kleen <ak@muc.de>
Acked-by: Zwane Mwaikambo <zwane@arm.linux.org.uk>
Signed-off-by: Shaohua.li<shaohua.li@intel.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
