This closes a couple holes in our attribute aliasing avoidance scheme:
- The current kernel fails mmaps of some /dev/mem MMIO regions because
they don't appear in the EFI memory map. This keeps X from working
on the Intel Tiger box.
- The current kernel allows UC mmap of the 0-1MB region of
/sys/.../legacy_mem even when the chipset doesn't support UC
access. This causes an MCA when starting X on HP rx7620 and rx8620
boxes in the default configuration.
There's more detail in the Documentation/ia64/aliasing.txt file this
adds, but the general idea is that if a region might be covered by
a granule-sized kernel identity mapping, any access via /dev/mem or
mmap must use the same attribute as the identity mapping.
Otherwise, we fall back to using an attribute that is supported
according to the EFI memory map, or to using UC if the EFI memory
map doesn't mention the region.
Signed-off-by: Bjorn Helgaas <bjorn.helgaas@hp.com>
Signed-off-by: Tony Luck <tony.luck@intel.com>
* 'release' of git://git.kernel.org/pub/scm/linux/kernel/git/aegl/linux-2.6:
[IA64] update sn2 defconfig
[IA64] Add mca recovery failure messages
[IA64-SGI] fix SGI Altix tioce_reserve_m32() bug
[IA64] enable dumps to capture second page of kernel stack
[IA64-SGI] - Reduce overhead of reading sn_topology
[IA64-SGI] - Fix discover of nearest cpu node to IO node
[IA64] IOC4 config option ordering
[IA64] Setup an IA64 specific reclaim distance
[IA64] eliminate compile time warnings
[IA64] eliminate compile time warnings
[IA64-SGI] SN SAL call to inject memory errors
[IA64] - Fix MAX_PXM_DOMAINS for systems with > 256 nodes
[IA64] Remove unused variable in sn_sal.h
[IA64] Remove redundant NULL checks before kfree
[IA64] wire up compat_sys_adjtimex()
When the mca recovery code encounters a condition that makes
the MCA non-recoverable, print the reason it could not recover.
This will make it easier to identify why the recovery code did
not recover.
Signed-off-by: Russ Anderson <rja@sgi.com>
Signed-off-by: Tony Luck <tony.luck@intel.com>
Few of the notifier_chain_register() callers use __init in the definition
of notifier_call. It is incorrect as the function definition should be
available after the initializations (they do not unregister them during
initializations).
This patch fixes all such usages to _not_ have the notifier_call __init
section.
Signed-off-by: Chandra Seetharaman <sekharan@us.ibm.com>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
sys_splice() moves data to/from pipes with a file input/output. sys_vmsplice()
moves data to a pipe, with the input being a user address range instead.
This uses an approach suggested by Linus, where we can hold partial ranges
inside the pages[] map. Hopefully this will be useful for network
receive support as well.
Signed-off-by: Jens Axboe <axboe@suse.de>
Andrew Morton pointed out that compiler might not inline the functions
marked for inline in kprobes. There-by allowing the insertion of probes
on these kprobes routines, which might cause recursion.
This patch removes all such inline and adds them to kprobes section
there by disallowing probes on all such routines. Some of the routines
can even still be inlined, since these routines gets executed after the
kprobes had done necessay setup for reentrancy.
Signed-off-by: Prasanna S Panchamukhi <prasanna@in.ibm.com>
Cc: "Luck, Tony" <tony.luck@intel.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
dmi_scan.c is arch-independent and is used by i386, x86_64, and ia64.
Currently all three arches compile it from arch/i386, which means that ia64
and x86_64 depend on things in arch/i386 that they wouldn't otherwise care
about.
This is simply "mv arch/i386/kernel/dmi_scan.c drivers/firmware/" (removing
trailing whitespace) and the associated Makefile changes. All three
architectures already set CONFIG_DMI in their top-level Kconfig files.
Signed-off-by: Bjorn Helgaas <bjorn.helgaas@hp.com>
Cc: Andi Kleen <ak@muc.de>
Cc: "Luck, Tony" <tony.luck@intel.com>
Cc: Andrey Panin <pazke@orbita1.ru>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
* 'tee' of git://brick.kernel.dk/data/git/linux-2.6-block:
[PATCH] splice: add support for sys_tee()
[PATCH] splice: pass offset around for ->splice_read() and ->splice_write()
ia64_wait_for_slaves() was changed in 2.6.17-rc1 to report the slave
state. It incorrectly assumes that all slaves are for MCA, but
ia64_wait_for_slaves() is also called from the INIT monarch handler.
The existing message is very misleading, so correct it.
Signed-off-by: Keith Owens <kaos@sgi.com>
Signed-off-by: Tony Luck <tony.luck@intel.com>
Basically an in-kernel implementation of tee, which uses splice and the
pipe buffers as an intelligent way to pass data around by reference.
Where the user space tee consumes the input and produces a stdout and
file output, this syscall merely duplicates the data inside a pipe to
another pipe. No data is copied, the output just grabs a reference to the
input pipe data.
Signed-off-by: Jens Axboe <axboe@suse.de>
The OS INIT handler is loading incorrect values into cr.ifa on exit.
This shows up as a hang when resuming after an INIT that is delivered
while a cpu is in user space. Correct the value loaded into cr.ifa.
Signed-off-by: Keith Owens <kaos@sgi.com>
Signed-off-by: Tony Luck <tony.luck@intel.com>
The MCA/INIT handlers maintain important state in the SAL to OS (sos)
area and in the monarch_cpu flag. Kernel debuggers (such as KDB) need
this data, and may need to adjust the monarch_cpu field so make the
data available to the notify_die hooks. Define two more events for
calling the functions on the notify_die chain.
Signed-off-by: Keith Owens <kaos@sgi.com>
Signed-off-by: Tony Luck <tony.luck@intel.com>
for_each_cpu() actually iterates across all possible CPUs. We've had mistakes
in the past where people were using for_each_cpu() where they should have been
iterating across only online or present CPUs. This is inefficient and
possibly buggy.
We're renaming for_each_cpu() to for_each_possible_cpu() to avoid this in the
future.
This patch replaces for_each_cpu with for_each_possible_cpu under
arch/ia64/kernel/.
Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fjitsu.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Tony Luck <tony.luck@intel.com>
Get rid of the manual search of _CRS, in favor of
acpi_get_vendor_resource() which is now provided by the ACPI CA. And fall
back to searching for a consumer-only address space descriptor if no
vendor-defined resource is found.
Signed-off-by: Bjorn Helgaas <bjorn.helgaas@hp.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Tony Luck <tony.luck@intel.com>
gcc3 thinks that a 32-bit field of a u64 type is itself a u64, so
should be printed with "%ld". gcc4 thinks it needs just "%d".
Make both versions happy by avoiding this construct.
Signed-off-by: Tony Luck <tony.luck@intel.com>
* 'release' of git://git.kernel.org/pub/scm/linux/kernel/git/aegl/linux-2.6:
[IA64] ioremap() should prefer WB over UC
[IA64] Add __mca_table to the DISCARD list in gate.lds
[IA64] Move __mca_table out of the __init section
[IA64] simplify some condition checks in iosapic_check_gsi_range
[IA64] correct some messages and fixes some minor things
[IA64-SGI] fix for-loop in sn_hwperf_geoid_to_cnode()
[IA64-SGI] sn_hwperf use of num_online_cpus()
[IA64] optimize flush_tlb_range on large numa box
[IA64] lazy_mmu_prot_update needs to be aware of huge pages
This adds support for the sys_splice system call. Using a pipe as a
transport, it can connect to files or sockets (latter as output only).
From the splice.c comments:
"splice": joining two ropes together by interweaving their strands.
This is the "extended pipe" functionality, where a pipe is used as
an arbitrary in-memory buffer. Think of a pipe as a small kernel
buffer that you can use to transfer data from one end to the other.
The traditional unix read/write is extended with a "splice()" operation
that transfers data buffers to or from a pipe buffer.
Named by Larry McVoy, original implementation from Linus, extended by
Jens to support splicing to files and fixing the initial implementation
bugs.
Signed-off-by: Jens Axboe <axboe@suse.de>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Add __mca_table to the DISCARD list for the gate.lds linker script to
avoid broken linker references when linking the final vmlinux file.
Also add comment to include/asm-ia64/asmmacros.h to avoid anyone else
hitting this problem in the future.
Credits to James Bottomley <James.Bottomley@SteelEye.com> for spotting
the DISCARD list in gate.lds.S
Signed-off-by: Jes Sorensen <jes@sgi.com>
Signed-off-by: Tony Luck <tony.luck@intel.com>
Some condition checks on iosapic_check_gsi_range() can be omitted
because always `base <= end' is assured. This patch simplifies those
checks.
Signed-off-by: Satoru Takeuchi <takeuchi_satoru@jp.fujitsu.com>
Signed-off-by: Tony Luck <tony.luck@intel.com>
This patch corrects some wrong comments and a printk message.
It also fixes some minor things, and makes all lines fit in
80 columns.
Signed-off-by: Satoru Takeuchi <takeuchi_satoru@jp.fujitsu.com>
Signed-off-by: Tony Luck <tony.luck@intel.com>
The kernel's implementation of notifier chains is unsafe. There is no
protection against entries being added to or removed from a chain while the
chain is in use. The issues were discussed in this thread:
http://marc.theaimsgroup.com/?l=linux-kernel&m=113018709002036&w=2
We noticed that notifier chains in the kernel fall into two basic usage
classes:
"Blocking" chains are always called from a process context
and the callout routines are allowed to sleep;
"Atomic" chains can be called from an atomic context and
the callout routines are not allowed to sleep.
We decided to codify this distinction and make it part of the API. Therefore
this set of patches introduces three new, parallel APIs: one for blocking
notifiers, one for atomic notifiers, and one for "raw" notifiers (which is
really just the old API under a new name). New kinds of data structures are
used for the heads of the chains, and new routines are defined for
registration, unregistration, and calling a chain. The three APIs are
explained in include/linux/notifier.h and their implementation is in
kernel/sys.c.
With atomic and blocking chains, the implementation guarantees that the chain
links will not be corrupted and that chain callers will not get messed up by
entries being added or removed. For raw chains the implementation provides no
guarantees at all; users of this API must provide their own protections. (The
idea was that situations may come up where the assumptions of the atomic and
blocking APIs are not appropriate, so it should be possible for users to
handle these things in their own way.)
There are some limitations, which should not be too hard to live with. For
atomic/blocking chains, registration and unregistration must always be done in
a process context since the chain is protected by a mutex/rwsem. Also, a
callout routine for a non-raw chain must not try to register or unregister
entries on its own chain. (This did happen in a couple of places and the code
had to be changed to avoid it.)
Since atomic chains may be called from within an NMI handler, they cannot use
spinlocks for synchronization. Instead we use RCU. The overhead falls almost
entirely in the unregister routine, which is okay since unregistration is much
less frequent that calling a chain.
Here is the list of chains that we adjusted and their classifications. None
of them use the raw API, so for the moment it is only a placeholder.
ATOMIC CHAINS
-------------
arch/i386/kernel/traps.c: i386die_chain
arch/ia64/kernel/traps.c: ia64die_chain
arch/powerpc/kernel/traps.c: powerpc_die_chain
arch/sparc64/kernel/traps.c: sparc64die_chain
arch/x86_64/kernel/traps.c: die_chain
drivers/char/ipmi/ipmi_si_intf.c: xaction_notifier_list
kernel/panic.c: panic_notifier_list
kernel/profile.c: task_free_notifier
net/bluetooth/hci_core.c: hci_notifier
net/ipv4/netfilter/ip_conntrack_core.c: ip_conntrack_chain
net/ipv4/netfilter/ip_conntrack_core.c: ip_conntrack_expect_chain
net/ipv6/addrconf.c: inet6addr_chain
net/netfilter/nf_conntrack_core.c: nf_conntrack_chain
net/netfilter/nf_conntrack_core.c: nf_conntrack_expect_chain
net/netlink/af_netlink.c: netlink_chain
BLOCKING CHAINS
---------------
arch/powerpc/platforms/pseries/reconfig.c: pSeries_reconfig_chain
arch/s390/kernel/process.c: idle_chain
arch/x86_64/kernel/process.c idle_notifier
drivers/base/memory.c: memory_chain
drivers/cpufreq/cpufreq.c cpufreq_policy_notifier_list
drivers/cpufreq/cpufreq.c cpufreq_transition_notifier_list
drivers/macintosh/adb.c: adb_client_list
drivers/macintosh/via-pmu.c sleep_notifier_list
drivers/macintosh/via-pmu68k.c sleep_notifier_list
drivers/macintosh/windfarm_core.c wf_client_list
drivers/usb/core/notify.c usb_notifier_list
drivers/video/fbmem.c fb_notifier_list
kernel/cpu.c cpu_chain
kernel/module.c module_notify_list
kernel/profile.c munmap_notifier
kernel/profile.c task_exit_notifier
kernel/sys.c reboot_notifier_list
net/core/dev.c netdev_chain
net/decnet/dn_dev.c: dnaddr_chain
net/ipv4/devinet.c: inetaddr_chain
It's possible that some of these classifications are wrong. If they are,
please let us know or submit a patch to fix them. Note that any chain that
gets called very frequently should be atomic, because the rwsem read-locking
used for blocking chains is very likely to incur cache misses on SMP systems.
(However, if the chain's callout routines may sleep then the chain cannot be
atomic.)
The patch set was written by Alan Stern and Chandra Seetharaman, incorporating
material written by Keith Owens and suggestions from Paul McKenney and Andrew
Morton.
[jes@sgi.com: restructure the notifier chain initialization macros]
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Chandra Seetharaman <sekharan@us.ibm.com>
Signed-off-by: Jes Sorensen <jes@sgi.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Provide proper kprobes fault handling, if a user-specified pre/post handlers
tries to access user address space, through copy_from_user(), get_user() etc.
The user-specified fault handler gets called only if the fault occurs while
executing user-specified handlers. In such a case user-specified handler is
allowed to fix it first, later if the user-specifed fault handler does not fix
it, we try to fix it by calling fix_exception().
The user-specified handler will not be called if the fault happens when single
stepping the original instruction, instead we reset the current probe and
allow the system page fault handler to fix it up.
Signed-off-by: Prasanna S Panchamukhi <prasanna@in.ibm.com>
Acked-by: Anil S Keshavamurthy<anil.s.keshavamurthy@intel.com>
Cc: "Luck, Tony" <tony.luck@intel.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Currently kprobe handler traps only happen in kernel space, so function
kprobe_exceptions_notify should skip traps which happen in user space.
This patch modifies this, and it is based on 2.6.16-rc4.
Signed-off-by: bibo mao <bibo.mao@intel.com>
Cc: Ananth N Mavinakayanahalli <ananth@in.ibm.com>
Cc: "Keshavamurthy, Anil S" <anil.s.keshavamurthy@intel.com>
Cc: <hiramatu@sdl.hitachi.co.jp>
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>
When kretprobe probes the schedule() function, if the probed process exits
then schedule() will never return, so some kretprobe instances will never
be recycled.
In this patch the parent process will recycle retprobe instances of the
probed function and there will be no memory leak of kretprobe instances.
Signed-off-by: bibo mao <bibo.mao@intel.com>
Cc: Masami Hiramatsu <hiramatu@sdl.hitachi.co.jp>
Cc: Prasanna S Panchamukhi <prasanna@in.ibm.com>
Cc: Ananth N Mavinakayanahalli <ananth@in.ibm.com>
Cc: Anil S Keshavamurthy <anil.s.keshavamurthy@intel.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Almost all users of the table addresses from the EFI system table want
physical addresses. So rather than doing the pa->va->pa conversion, just keep
physical addresses in struct efi.
This fixes a DMI bug: the efi structure contained the physical SMBIOS address
on x86 but the virtual address on ia64, so dmi_scan_machine() used ioremap()
on a virtual address on ia64.
This is essentially the same as an earlier patch by Matt Tolentino:
http://marc.theaimsgroup.com/?l=linux-kernel&m=112130292316281&w=2
except that this changes all table addresses, not just ACPI addresses.
Matt's original patch was backed out because it caused MCAs on HP sx1000
systems. That problem is resolved by the ioremap() attribute checking added
for ia64.
Signed-off-by: Bjorn Helgaas <bjorn.helgaas@hp.com>
Cc: Matt Domsch <Matt_Domsch@dell.com>
Cc: "Tolentino, Matthew E" <matthew.e.tolentino@intel.com>
Cc: "Brown, Len" <len.brown@intel.com>
Cc: Andi Kleen <ak@muc.de>
Acked-by: "Luck, Tony" <tony.luck@intel.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Pass the size, not a pointer to the size, to efi_mem_attribute_range().
This function validates memory regions for the /dev/mem read/write/mmap paths.
The pointer allows arches to reduce the size of the range, but I think that's
unnecessary complexity. Simplifying it will let me use
efi_mem_attribute_range() to improve the ia64 ioremap() implementation.
Signed-off-by: Bjorn Helgaas <bjorn.helgaas@hp.com>
Cc: Matt Domsch <Matt_Domsch@dell.com>
Cc: "Tolentino, Matthew E" <matthew.e.tolentino@intel.com>
Cc: "Brown, Len" <len.brown@intel.com>
Cc: Andi Kleen <ak@muc.de>
Acked-by: "Luck, Tony" <tony.luck@intel.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Enable DMI table parsing on ia64.
Andi Kleen has a patch in his x86_64 tree which enables the use of i386
dmi_scan.c on x86_64. dmi_scan.c functions are being used by the
drivers/char/ipmi/ipmi_si_intf.c driver for autodetecting the ports or
memory spaces where the IPMI controllers may be found.
This patch adds equivalent changes for ia64 as to what is in the x86_64
tree. In addition, I reworked the DMI detection, such that on EFI-capable
systems, it uses the efi.smbios pointer to find the table, rather than
brute-force searching from 0xF0000. On non-EFI systems, it continues the
brute-force search.
My test system, an Intel S870BN4 'Tiger4', aka Dell PowerEdge 7250, with
latest BIOS, does not list the IPMI controller in the ACPI namespace, nor
does it have an ACPI SPMI table. Also note, currently shipping Dell x8xx
EM64T servers don't have these either, so DMI is the only method for
obtaining the address of the IPMI controller.
Signed-off-by: Matt Domsch <Matt_Domsch@dell.com>
Acked-by: "Luck, Tony" <tony.luck@intel.com>
Cc: Andi Kleen <ak@muc.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* 'audit.b3' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/audit-current: (22 commits)
[PATCH] fix audit_init failure path
[PATCH] EXPORT_SYMBOL patch for audit_log, audit_log_start, audit_log_end and audit_format
[PATCH] sem2mutex: audit_netlink_sem
[PATCH] simplify audit_free() locking
[PATCH] Fix audit operators
[PATCH] promiscuous mode
[PATCH] Add tty to syscall audit records
[PATCH] add/remove rule update
[PATCH] audit string fields interface + consumer
[PATCH] SE Linux audit events
[PATCH] Minor cosmetic cleanups to the code moved into auditfilter.c
[PATCH] Fix audit record filtering with !CONFIG_AUDITSYSCALL
[PATCH] Fix IA64 success/failure indication in syscall auditing.
[PATCH] Miscellaneous bug and warning fixes
[PATCH] Capture selinux subject/object context information.
[PATCH] Exclude messages by message type
[PATCH] Collect more inode information during syscall processing.
[PATCH] Pass dentry, not just name, in fsnotify creation hooks.
[PATCH] Define new range of userspace messages.
[PATCH] Filter rule comparators
...
Fixed trivial conflict in security/selinux/hooks.c
* 'release' of git://git.kernel.org/pub/scm/linux/kernel/git/aegl/linux-2.6:
[IA64] New IA64 core/thread detection patch
[IA64] Increase max node count on SN platforms
[IA64] Increase max node count on SN platforms
[IA64] Increase max node count on SN platforms
[IA64] Increase max node count on SN platforms
[IA64] Tollhouse HP: IA64 arch changes
[IA64] cleanup dig_irq_init
[IA64] MCA recovery: kernel context recovery table
IA64: Use early_parm to handle mvec_name and nomca
[IA64] move patchlist and machvec into init section
[IA64] add init declaration - nolwsys
[IA64] add init declaration - gate page functions
[IA64] add init declaration to memory initialization functions
[IA64] add init declaration to cpu initialization functions
[IA64] add __init declaration to mca functions
[IA64] Ignore disabled Local SAPIC Affinity Structure in SRAT
[IA64] sn_check_intr: use ia64_get_irr()
[IA64] fix ia64 is_hugepage_only_range
IPF SDM 2.2 changes definition of PAL_LOGICAL_TO_PHYSICAL to add
proc_number=-1 to get core/thread mapping info on the running processer.
Based on this change, we had better to update existing core/thread
detection in IA64 kernel correspondingly. The attached patch implements
this change. It simplifies detection code and eliminates potential race
condition. It also runs a bit faster and has better scalability especially
when cores and threads number grows up in one package.
Signed-off-by: Fenghua Yu <fenghua.yu@intel.com>
Signed-off-by: Tony Luck <tony.luck@intel.com>
Node number are kept in the cpu_to_node_map which is
currently defined as u8. Change to u16 to accomodate
larger node numbers.
Signed-off-by: Jack Steiner <steiner@sgi.com>
Signed-off-by: Tony Luck <tony.luck@intel.com>
Add support in IA64 acpi for platforms that support more than
256 nodes. Currently, ACPI is limited to 256 nodes because the
proximity domain number is 8-bits.
Long term, we expect to use ACPI3.0 to support >256 nodes.
This patch is an interim solution that works with platforms
that pass the high order bits of the proximity domain in
"reserved" fields of the ACPI tables. This code is enabled
ONLY on SN platforms.
Signed-off-by: Jack Steiner <steiner@sgi.com>
Signed-off-by: Tony Luck <tony.luck@intel.com>
Memory errors encountered by user applications may surface
when the CPU is running in kernel context. The current code
will not attempt recovery if the MCA surfaces in kernel
context (privilage mode 0). This patch adds a check for cases
where the user initiated the load that surfaces in kernel
interrupt code.
An example is a user process lauching a load from memory
and the data in memory had bad ECC. Before the bad data
gets to the CPU register, and interrupt comes in. The
code jumps to the IVT interrupt entry point and begins
execution in kernel context. The process of saving the
user registers (SAVE_REST) causes the bad data to be loaded
into a CPU register, triggering the MCA. The MCA surfaces in
kernel context, even though the load was initiated from
user context.
As suggested by David and Tony, this patch uses an exception
table like approach, puting the tagged recovery addresses in
a searchable table. One difference from the exception table
is that MCAs do not surface in precise places (such as with
a TLB miss), so instead of tagging specific instructions,
address ranges are registers. A single macro is used to do
the tagging, with the input parameter being the label
of the starting address and the macro being the ending
address. This limits clutter in the code.
This patch only tags one spot, the interrupt ivt entry.
Testing showed that spot to be a "heavy hitter" with
MCAs surfacing while saving user registers. Other spots
can be added as needed by adding a single macro.
Signed-off-by: Russ Anderson (rja@sgi.com)
Signed-off-by: Tony Luck <tony.luck@intel.com>
include/linux/platform.h contained nothing that was actually used except
the default_idle() prototype, and is therefore removed by this patch.
This patch does the following with the platform specific default_idle()
functions on different architectures:
- remove the unused function:
- parisc
- sparc64
- make the needlessly global function static:
- arm
- h8300
- m68k
- m68knommu
- s390
- v850
- x86_64
- add a prototype in asm/system.h:
- cris
- i386
- ia64
Signed-off-by: Adrian Bunk <bunk@stusta.de>
Acked-by: Patrick Mochel <mochel@digitalimplant.org>
Acked-by: Kyle McMartin <kyle@parisc-linux.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
I'm not sure of the worthiness of this idea, so please consider it an RFC.
Its key merits are:
* Reuse existing infrastructure
* Greatly tightens up the parsing of nomca
* Greatly simplifies the parsing of machvec
Addition cleanup (moving setup_mvec() to machvec.c) by Ken Chen.
Signed-Off-By: Horms <horms@verge.net.au>
Signed-Off-By: Tony Luck <tony.luck@intel.com>
ia64_mv is initialized based on platform detected or specified.
However, there is one instantiation of each platform type. We
don't expect to switch platform vector during run time. Move
those platform specific type into init section since a copy is
made into global ia64_mv at initialization.
Also move instruction patch list into init section as well.
Signed-off-by: Ken Chen <kenneth.w.chen@intel.com>
Signed-off-by: Tony Luck <tony.luck@intel.com>
Add init declaration to bunch of patch functions and gate
page setup function.
Signed-off-by: Ken Chen <kenneth.w.chen@intel.com>
Signed-off-by: Tony Luck <tony.luck@intel.com>
Add init declaration to variables/functions used for memory
initialization. I don't think they would clash with memory
hotplug. If they do, please yell.
Signed-off-by: Ken Chen <kenneth.w.chen@intel.com>
Signed-off-by: Tony Luck <tony.luck@intel.com>
Add init declaration to cpu initialization functions.
Signed-off-by: Ken Chen <kenneth.w.chen@intel.com>
Signed-off-by: Tony Luck <tony.luck@intel.com>
Mark init related variable and functions with appropriate
__init* declaration to mca functions.
Signed-off-by: Ken Chen <kenneth.w.chen@intel.com>
Signed-off-by: Tony Luck <tony.luck@intel.com>
According to the ACPI spec, the OSPM must ignore the contents of the
Processor Local APIC/SAPIC Affinity Structure in System Resource
Affinity Table (SRAT), if its enable flag is cleared. However, ia64
linux refers all of the Processor Local APIC/SAPIC Affinity Structures
in SRAT regardless of the enable flag. This is obviously against the
ACPI spec. This patch fixes this bug.
Signed-off-by: Kenji Kaneshige <kaneshige.kenji@jp.fujitsu.com>
Signed-off-by: Tony Luck <tony.luck@intel.com>
Original 2.6.9 patch and explanation from somewhere within HP via
bugzilla...
ia64 stores a success/failure code in r10, and the return value (normal
return, or *positive* errno) in r8. The patch also sets the exit code to
negative errno if it's a failure result for consistency with other
architectures.
Signed-off-by: David Woodhouse <dwmw2@infradead.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>
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>
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>
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>
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>
arch/ia64/kernel/unaligned.c erroneously marked die_if_kernel()
with a "noreturn" attribute ... which is silly (it returns whenever
the argument regs say that the fault happened in user mode, as one
might expect given the "if_kernel" part of its name!). Thanks to
Alan and Gareth for pointing this out.
Signed-off-by: Tony Luck <tony.luck@intel.com>
unaligned_access does fetch cr.ipsr, then calls
dispatch_unaligned_handler, but dispatch_unaligned_handler fetches
cr.ipsr again, so delete the first one.
Signed-off-by: Zhang Yanmin <yanmin.zhang@intel.com>
Signed-off-by: Tony Luck <tony.luck@intel.com>
Minor updates to earlier patch.
- Added to documentation to add ia64 as well.
- Minor clarification on how to use disabled cpus
- used plain max instead of max_t per Andew Morton.
Signed-off-by: Ashok Raj <ashok.raj@intel.com>
Signed-off-by: Tony Luck <tony.luck@intel.com>
It appears that if auditing is enabled, the kernel fails to
check for pending signals before returning to user mode.
Signed-off-by: Jack Steiner <steiner@sgi.com>
Acked-by: Ken Chen <kenneth.w.chen@intel.com>
Signed-off-by: Tony Luck <tony.luck@intel.com>
Trivial port of this feature from i386
As it stands, panic_on_oops but does nothing on ia64
Signed-Off-By: Horms <horms@verge.net.au>
Signed-off-by: Tony Luck <tony.luck@intel.com>
The original ia64 udelay() was simple, but flawed for platforms without
synchronized ITCs: a preemption and migration to another CPU during the
while-loop likely resulted in too-early termination or very, very
lengthy looping.
The first fix (now in 2.6.15) broke the delay loop into smaller,
non-preemptible chunks, reenabling preemption between the chunks. This
fix is flawed in that the total udelay is computed to be the sum of just
the non-premptible while-loop pieces, i.e., not counting the time spent
in the interim preemptible periods. If an interrupt or a migration
occurs during one of these interim periods, then that time is invisible
and only serves to lengthen the effective udelay().
This new fix backs out the current flawed fix and returns to a simple
udelay(), fully preemptible and interruptible. It implements two simple
alternative udelay() routines: one a default generic version that uses
ia64_get_itc(), and the other an sn-specific version that uses that
platform's RTC.
Signed-off-by: John Hawkes <hawkes@sgi.com>
Signed-off-by: Tony Luck <tony.luck@intel.com>
Remove symbol exports from ia64_ksyms.c that are already exported in
lib/string.c.
Signed-off-by: Andreas Schwab <schwab@suse.de>
Signed-off-by: Tony Luck <tony.luck@intel.com>
Have a facility to account for potentially hot-pluggable CPUs. ACPI doesnt
give a determinstic method to find hot-pluggable CPUs. Hence we use 2 methods
to assist.
- BIOS can mark potentially hot-pluggable CPUs as disabled in the MADT tables.
- User can specify the number of hot-pluggable CPUs via parameter
additional_cpus=X
The option is enabled only if ACPI_CONFIG_HOTPLUG_CPU=y which enables the
physical hotplug option. Without which user can still use logical onlining
and offlining of CPUs by enabling CONFIG_HOTPLUG_CPU=y
Adds more bits to cpu_possible_map for potentially hot-pluggable cpus.
Signed-off-by: Ashok Raj <ashok.raj@intel.com>
Signed-off-by: Tony Luck <tony.luck@intel.com>
Do not set cpu_possible_map for NR_CPUS when ACPI_CONFIG_HOTPLUG_CPU is set.
Signed-off-by: Ashok Raj <ashok.raj@intel.com>
Signed-off-by: Tony Luck <tony.luck@intel.com>
MCA driver can cause panic if kernel gets a state info with no minstate.
This patch adds minstate validation before handling it.
Signed-off-by: Hidetoshi Seto <seto.hidetoshi@jp.fujitsu.com>
Signed-off-by: Tony Luck <tony.luck@intel.com>
Registers system call for the ia64 architecture.
Reserves space for ppoll and pselect, and adds unshare at system
call number 1296.
Signed-off-by: Janak Desai <janak@us.ibm.com>
Signed-off-by: Tony Luck <tony.luck@intel.com>
No platform in the community tree uses PLATFORM_MCA_HANDLERS, remove
the references.
Signed-off-by: Keith Owens <kaos@sgi.com>
Signed-off-by: Tony Luck <tony.luck@intel.com>
Update the comm field on the MCA handler for user tasks as well as for
verified kernel tasks. This helps to identify the task that was
running when the MCA occurred.
Signed-off-by: Keith Owens <kaos@sgi.com>
Signed-off-by: Tony Luck <tony.luck@intel.com>
Print a message identifying the monarch MCA handler. Print a summary
of the status of the slave MCA cpus.
Signed-off-by: Keith Owens <kaos@sgi.com>
Signed-off-by: Tony Luck <tony.luck@intel.com>
There were two problems with enabling the PRINTK_TIME config
option:
1) The first calls to printk() occur before per-cpu data virtual
address is pinned into the TLB, so sched_clock() can fault.
2) sched_clock() is based on ar.itc, which may not be synchronized
across cpus.
Ken Chen started this patch, Tony Luck tinkered with it, and Jes
Sorensen perfected it.
Signed-off-by: Tony Luck <tony.luck@intel.com>
The check of (end != cp) after memparse in efi.c looks wrong to me.
The result is that we can't use mem= and max_addr= kernel parameter at
the same time.
The following patch removed the check just like other arches do.
Signed-off-by: Zou Nan hai <nanhai.zou@intel.com>
Signed-off-by: Tony Luck <tony.luck@intel.com>
The patch implements cpu topology exportation by sysfs.
Items (attributes) are similar to /proc/cpuinfo.
1) /sys/devices/system/cpu/cpuX/topology/physical_package_id:
represent the physical package id of cpu X;
2) /sys/devices/system/cpu/cpuX/topology/core_id:
represent the cpu core id to cpu X;
3) /sys/devices/system/cpu/cpuX/topology/thread_siblings:
represent the thread siblings to cpu X in the same core;
4) /sys/devices/system/cpu/cpuX/topology/core_siblings:
represent the thread siblings to cpu X in the same physical package;
To implement it in an architecture-neutral way, a new source file,
driver/base/topology.c, is to export the 5 attributes.
If one architecture wants to support this feature, it just needs to
implement 4 defines, typically in file include/asm-XXX/topology.h.
The 4 defines are:
#define topology_physical_package_id(cpu)
#define topology_core_id(cpu)
#define topology_thread_siblings(cpu)
#define topology_core_siblings(cpu)
The type of **_id is int.
The type of siblings is cpumask_t.
To be consistent on all architectures, the 4 attributes should have
deafult values if their values are unavailable. Below is the rule.
1) physical_package_id: If cpu has no physical package id, -1 is the
default value.
2) core_id: If cpu doesn't support multi-core, its core id is 0.
3) thread_siblings: Just include itself, if the cpu doesn't support
HT/multi-thread.
4) core_siblings: Just include itself, if the cpu doesn't support
multi-core and HT/Multi-thread.
So be careful when declaring the 4 defines in include/asm-XXX/topology.h.
If an attribute isn't defined on an architecture, it won't be exported.
Thank Nathan, Greg, Andi, Paul and Venki.
The patch provides defines for i386/x86_64/ia64.
Signed-off-by: Zhang, Yanmin <yanmin.zhang@intel.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Nick Piggin <nickpiggin@yahoo.com.au>
Cc: Greg KH <greg@kroah.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
If SAL_CACHE_FLUSH drops interrupts, complain about it and fall back to
using PAL_CACHE_FLUSH instead.
This is to work around a defect in HP rx5670 firmware: when an interrupt
occurs during SAL_CACHE_FLUSH, SAL drops the interrupt but leaves it marked
"in-service", which leaves the interrupt (and others of equal or lower
priority) masked.
Signed-off-by: Bjorn Helgaas <bjorn.helgaas@hp.com>
Signed-off-by: Tony Luck <tony.luck@intel.com>
The only user of the MCA/INIT sigdelayed code (SGI's I/O probing) has
moved from the kernel into SAL. Delete the MCA/INIT sigdelayed code.
Signed-off-by: Keith Owens <kaos@sgi.com>
Signed-off-by: Tony Luck <tony.luck@intel.com>
Eliminate a hot shared cacheline that occurs if multiple cpus are
taking unaligned exceptions.
Signed-off-by: Jack Steiner <steiner@sgi.com>
Signed-off-by: Tony Luck <tony.luck@intel.com>
sos->os_status is set to a default value of IA64_MCA_COLD_BOOT for an
MCA, but then is incorrectly overwritten with IA64_MCA_SAME_CONTEXT (0).
This makes SAL think that all MCAs have been recovered.
Signed-off-by: Keith Owens <kaos@sgi.com>
Signed-off-by: Tony Luck <tony.luck@intel.com>
Fix an unnecessary softlockup watchdog warning in the ia64
uncached_build_memmap() that occurs occasionally at 256p and always at
512p. The problem occurs at boot time.
Signed-off-by: John Hawkes <hawkes@sgi.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Tony Luck <tony.luck@intel.com>
Migrate perfmon from using an old semaphore to a completion handler.
Signed-off-by: Jes Sorensen <jes@sgi.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Tony Luck <tony.luck@intel.com>
When jprobe is hit, the function parameters of the original function
should be saved before jprobe handler is executed, and restored it after
jprobe handler is executed, because jprobe handler might change the
register values due to tail call optimization by the gcc.
Signed-off-by: Zhang Yanmin <yanmin.zhang@intel.com>
Signed-off-by: Anil S Keshavamurthy <anil.s.keshavamurthy@intel.com>
Signed-off-by: Tony Luck <tony.luck@intel.com>
Add hotplug cpu support to salinfo.c.
The cpu_event field is a cpumask so use the cpu_* macros consistently,
replacing the existing mixture of cpu_* and *_bit macros.
Instead of counting the number of outstanding events in a semaphore and
trying to track that count over user space context, interrupt context,
non-maskable interrupt context and cpu hotplug, replace the semaphore
with a test for "any bits set" combined with a mutex.
Modify the locking to make the test for "work to do" an atomic
operation.
Signed-off-by: Keith Owens <kaos@sgi.com>
Signed-off-by: Tony Luck <tony.luck@intel.com>
We need to handle debug traps in fsys mode non-fatally. They can
happen now that we have fsyscalls which contain probe instructions.
Signed-off-by: Jason Uhlenkott <jasonuhl@sgi.com>
Signed-off-by: Tony Luck <tony.luck@intel.com>
On return from INIT handler we must convert the address of the
minstate area from a kernel virtual uncached address (0xC...)
to physical uncached (0x8...). A typo (or thinko?) in the code
converted to physical cached.
Signed-off-by: Tony Luck <tony.luck@intel.com>
When this new syscall was added to ia64 in commit
39743889aa
fsys.S was forgotten. Add a ".data8 0" there to keep
it in step. [Reported by Stephane Eranian]
Signed-off-by: Tony Luck <tony.luck@intel.com>
on ia64 thread_info is at the constant offset from task_struct and stack
is embedded into the same beast. Set __HAVE_THREAD_FUNCTIONS, made
task_thread_info() just add a constant.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
)
From: Ingo Molnar <mingo@elte.hu>
This is the latest version of the scheduler cache-hot-auto-tune patch.
The first problem was that detection time scaled with O(N^2), which is
unacceptable on larger SMP and NUMA systems. To solve this:
- I've added a 'domain distance' function, which is used to cache
measurement results. Each distance is only measured once. This means
that e.g. on NUMA distances of 0, 1 and 2 might be measured, on HT
distances 0 and 1, and on SMP distance 0 is measured. The code walks
the domain tree to determine the distance, so it automatically follows
whatever hierarchy an architecture sets up. This cuts down on the boot
time significantly and removes the O(N^2) limit. The only assumption
is that migration costs can be expressed as a function of domain
distance - this covers the overwhelming majority of existing systems,
and is a good guess even for more assymetric systems.
[ People hacking systems that have assymetries that break this
assumption (e.g. different CPU speeds) should experiment a bit with
the cpu_distance() function. Adding a ->migration_distance factor to
the domain structure would be one possible solution - but lets first
see the problem systems, if they exist at all. Lets not overdesign. ]
Another problem was that only a single cache-size was used for measuring
the cost of migration, and most architectures didnt set that variable
up. Furthermore, a single cache-size does not fit NUMA hierarchies with
L3 caches and does not fit HT setups, where different CPUs will often
have different 'effective cache sizes'. To solve this problem:
- Instead of relying on a single cache-size provided by the platform and
sticking to it, the code now auto-detects the 'effective migration
cost' between two measured CPUs, via iterating through a wide range of
cachesizes. The code searches for the maximum migration cost, which
occurs when the working set of the test-workload falls just below the
'effective cache size'. I.e. real-life optimized search is done for
the maximum migration cost, between two real CPUs.
This, amongst other things, has the positive effect hat if e.g. two
CPUs share a L2/L3 cache, a different (and accurate) migration cost
will be found than between two CPUs on the same system that dont share
any caches.
(The reliable measurement of migration costs is tricky - see the source
for details.)
Furthermore i've added various boot-time options to override/tune
migration behavior.
Firstly, there's a blanket override for autodetection:
migration_cost=1000,2000,3000
will override the depth 0/1/2 values with 1msec/2msec/3msec values.
Secondly, there's a global factor that can be used to increase (or
decrease) the autodetected values:
migration_factor=120
will increase the autodetected values by 20%. This option is useful to
tune things in a workload-dependent way - e.g. if a workload is
cache-insensitive then CPU utilization can be maximized by specifying
migration_factor=0.
I've tested the autodetection code quite extensively on x86, on 3
P3/Xeon/2MB, and the autodetected values look pretty good:
Dual Celeron (128K L2 cache):
---------------------
migration cost matrix (max_cache_size: 131072, cpu: 467 MHz):
---------------------
[00] [01]
[00]: - 1.7(1)
[01]: 1.7(1) -
---------------------
cacheflush times [2]: 0.0 (0) 1.7 (1784008)
---------------------
Here the slow memory subsystem dominates system performance, and even
though caches are small, the migration cost is 1.7 msecs.
Dual HT P4 (512K L2 cache):
---------------------
migration cost matrix (max_cache_size: 524288, cpu: 2379 MHz):
---------------------
[00] [01] [02] [03]
[00]: - 0.4(1) 0.0(0) 0.4(1)
[01]: 0.4(1) - 0.4(1) 0.0(0)
[02]: 0.0(0) 0.4(1) - 0.4(1)
[03]: 0.4(1) 0.0(0) 0.4(1) -
---------------------
cacheflush times [2]: 0.0 (33900) 0.4 (448514)
---------------------
Here it can be seen that there is no migration cost between two HT
siblings (CPU#0/2 and CPU#1/3 are separate physical CPUs). A fast memory
system makes inter-physical-CPU migration pretty cheap: 0.4 msecs.
8-way P3/Xeon [2MB L2 cache]:
---------------------
migration cost matrix (max_cache_size: 2097152, cpu: 700 MHz):
---------------------
[00] [01] [02] [03] [04] [05] [06] [07]
[00]: - 19.2(1) 19.2(1) 19.2(1) 19.2(1) 19.2(1) 19.2(1) 19.2(1)
[01]: 19.2(1) - 19.2(1) 19.2(1) 19.2(1) 19.2(1) 19.2(1) 19.2(1)
[02]: 19.2(1) 19.2(1) - 19.2(1) 19.2(1) 19.2(1) 19.2(1) 19.2(1)
[03]: 19.2(1) 19.2(1) 19.2(1) - 19.2(1) 19.2(1) 19.2(1) 19.2(1)
[04]: 19.2(1) 19.2(1) 19.2(1) 19.2(1) - 19.2(1) 19.2(1) 19.2(1)
[05]: 19.2(1) 19.2(1) 19.2(1) 19.2(1) 19.2(1) - 19.2(1) 19.2(1)
[06]: 19.2(1) 19.2(1) 19.2(1) 19.2(1) 19.2(1) 19.2(1) - 19.2(1)
[07]: 19.2(1) 19.2(1) 19.2(1) 19.2(1) 19.2(1) 19.2(1) 19.2(1) -
---------------------
cacheflush times [2]: 0.0 (0) 19.2 (19281756)
---------------------
This one has huge caches and a relatively slow memory subsystem - so the
migration cost is 19 msecs.
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Ashok Raj <ashok.raj@intel.com>
Signed-off-by: Ken Chen <kenneth.w.chen@intel.com>
Cc: <wilder@us.ibm.com>
Signed-off-by: John Hawkes <hawkes@sgi.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Add per-arch sched_cacheflush() which is a write-back cacheflush used by
the migration-cost calibration code at bootup time.
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Cc: Nick Piggin <nickpiggin@yahoo.com.au>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
arch: Use <linux/capability.h> where capable() is used.
Signed-off-by: Randy Dunlap <rdunlap@xenotime.net>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
There is a window where a probe gets removed right after the probe is hit
on some different cpu. In this case probe handlers can't find a matching
probe instance related to break address. In this case we need to read the
original instruction at break address to see if that is not a break/int3
instruction and recover safely.
Previous code had a bug where we were not checking for the above race in
case of reentrant probes and the below patch fixes this race.
Tested on IA64, Powerpc, x86_64.
Signed-off-by: Anil S Keshavamurthy <anil.s.keshavamurthy@intel.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Currently arch_remove_kprobes() is only implemented/required for x86_64 and
powerpc. All other architecture like IA64, i386 and sparc64 implementes a
dummy function which is being called from arch independent kprobes.c file.
This patch removes the dummy functions and replaces it with
#define arch_remove_kprobe(p, s) do { } while(0)
Signed-off-by: Anil S Keshavamurthy <anil.s.keshavamurthy@intel.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Add a hook so architectures can validate /dev/mem mmap requests.
This is analogous to validation we already perform in the read/write
paths.
The identity mapping scheme used on ia64 requires that each 16MB or
64MB granule be accessed with exactly one attribute (write-back or
uncacheable). This avoids "attribute aliasing", which can cause a
machine check.
Sample problem scenario:
- Machine supports VGA, so it has uncacheable (UC) MMIO at 640K-768K
- efi_memmap_init() discards any write-back (WB) memory in the first granule
- Application (e.g., "hwinfo") mmaps /dev/mem, offset 0
- hwinfo receives UC mapping (the default, since memmap says "no WB here")
- Machine check abort (on chipsets that don't support UC access to WB
memory, e.g., sx1000)
In the scenario above, the only choices are
- Use WB for hwinfo mmap. Can't do this because it causes attribute
aliasing with the UC mapping for the VGA MMIO space.
- Use UC for hwinfo mmap. Can't do this because the chipset may not
support UC for that region.
- Disallow the hwinfo mmap with -EINVAL. That's what this patch does.
Signed-off-by: Bjorn Helgaas <bjorn.helgaas@hp.com>
Cc: Hugh Dickins <hugh@veritas.com>
Cc: "Luck, Tony" <tony.luck@intel.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Remove various things which were checking for gcc-1.x and gcc-2.x compilers.
From: Adrian Bunk <bunk@stusta.de>
Some documentation updates and removes some code paths for gcc < 3.2.
Acked-by: Russell King <rmk+kernel@arm.linux.org.uk>
Signed-off-by: Adrian Bunk <bunk@stusta.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
The ptrace_get_task_struct() helper that I added as part of the ptrace
consolidation is useful in variety of places that currently opencode it.
Switch them to the common helpers.
Add a ptrace_traceme() helper that needs to be explicitly called, and simplify
the ptrace_get_task_struct() interface. We don't need the request argument
now, and we return the task_struct directly, using ERR_PTR() for error
returns. It's a bit more code in the callers, but we have two sane routines
that do one thing well now.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
sys_migrate_pages implementation using swap based page migration
This is the original API proposed by Ray Bryant in his posts during the first
half of 2005 on linux-mm@kvack.org and linux-kernel@vger.kernel.org.
The intent of sys_migrate is to migrate memory of a process. A process may
have migrated to another node. Memory was allocated optimally for the prior
context. sys_migrate_pages allows to shift the memory to the new node.
sys_migrate_pages is also useful if the processes available memory nodes have
changed through cpuset operations to manually move the processes memory. Paul
Jackson is working on an automated mechanism that will allow an automatic
migration if the cpuset of a process is changed. However, a user may decide
to manually control the migration.
This implementation is put into the policy layer since it uses concepts and
functions that are also needed for mbind and friends. The patch also provides
a do_migrate_pages function that may be useful for cpusets to automatically
move memory. sys_migrate_pages does not modify policies in contrast to Ray's
implementation.
The current code here is based on the swap based page migration capability and
thus is not able to preserve the physical layout relative to it containing
nodeset (which may be a cpuset). When direct page migration becomes available
then the implementation needs to be changed to do a isomorphic move of pages
between different nodesets. The current implementation simply evicts all
pages in source nodeset that are not in the target nodeset.
Patch supports ia64, i386 and x86_64.
Signed-off-by: Christoph Lameter <clameter@sgi.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
arch/ia64/kernel/setup.c: In function `show_cpuinfo':
arch/ia64/kernel/setup.c:576: warning: long unsigned int format, different type arg (arg 12)
arch/ia64/kernel/setup.c:576: warning: long unsigned int format, different type arg (arg 13)
Introduced by 95235ca2c2
Signed-off-by: Tony Luck <tony.luck@intel.com>
here is the BSP removal support for IA64. Its pretty much the same thing that
was released a while back, but has your feedback incorporated.
- Removed CONFIG_BSP_REMOVE_WORKAROUND and associated cmdline param
- Fixed compile issue with sn2/zx1 due to a undefined fix_b0_for_bsp
- some formatting nits (whitespace etc)
This has been tested on tiger and long back by alex on hp systems as well.
Signed-off-by: Ashok Raj <ashok.raj@intel.com>
Signed-off-by: Tony Luck <tony.luck@intel.com>
Use the #define for ACPI_LEVEL_SENSITIVE instead of assuming
non-zero, because ACPICA 20051021 changes its value to zero.
Also, use uniform variable names:
edge_level -> triggering
active_high_low -> polarity
Signed-off-by: Len Brown <len.brown@intel.com>
sparc64, i386 and x86_64 have support for a special data section dedicated
to rarely updated data that is frequently read. The section was created to
avoid false sharing of those rarely read data with frequently written kernel
data.
This patch creates such a data section for ia64 and will group rarely written
data into this section.
Signed-off-by: Christoph Lameter <clameter@sgi.com>
Signed-off-by: Tony Luck <tony.luck@intel.com>
Use raw_smp_processor_id() instead of get_cpu() as we don't need the
extra features of get_cpu().
Signed-off-by: Jes Sorensen <jes@trained-monkey.org>
Signed-off-by: Tony Luck <tony.luck@intel.com>
The udelay() inline for ia64 uses the ITC. If CONFIG_PREEMPT is enabled
and the platform has unsynchronized ITCs and the calling task migrates
to another CPU while doing the udelay loop, then the effective delay may
be too short or very, very long.
This patch disables preemption around 100 usec chunks of the overall
desired udelay time. This minimizes preemption-holdoffs.
udelay() is now too big to be inline, move it out of line and export it.
Signed-off-by: John Hawkes <hawkes@sgi.com>
Signed-off-by: Tony Luck <tony.luck@intel.com>
When multiple probes are registered at the same address and if due to some
recursion (probe getting triggered within a probe handler), we skip calling
pre_handlers and just increment nmissed field.
The below patch make sure it walks the list for multiple probes case.
Without the below patch we get incorrect results of nmissed count for
multiple probe case.
Signed-off-by: Anil S Keshavamurthy <anil.s.keshavamurthy@intel.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Completed a major overhaul of the Resource Manager code -
specifically, optimizations in the area of the AML/internal
resource conversion code. The code has been optimized to
simplify and eliminate duplicated code, CPU stack use has
been decreased by optimizing function parameters and local
variables, and naming conventions across the manager have
been standardized for clarity and ease of maintenance (this
includes function, parameter, variable, and struct/typedef
names.)
All Resource Manager dispatch and information tables have
been moved to a single location for clarity and ease of
maintenance. One new file was created, named "rsinfo.c".
The ACPI return macros (return_ACPI_STATUS, etc.) have
been modified to guarantee that the argument is
not evaluated twice, making them less prone to macro
side-effects. However, since there exists the possibility
of additional stack use if a particular compiler cannot
optimize them (such as in the debug generation case),
the original macros are optionally available. Note that
some invocations of the return_VALUE macro may now cause
size mismatch warnings; the return_UINT8 and return_UINT32
macros are provided to eliminate these. (From Randy Dunlap)
Implemented a new mechanism to enable debug tracing for
individual control methods. A new external interface,
acpi_debug_trace(), is provided to enable this mechanism. The
intent is to allow the host OS to easily enable and disable
tracing for problematic control methods. This interface
can be easily exposed to a user or debugger interface if
desired. See the file psxface.c for details.
acpi_ut_callocate() will now return a valid pointer if a
length of zero is specified - a length of one is used
and a warning is issued. This matches the behavior of
acpi_ut_allocate().
Signed-off-by: Bob Moore <robert.moore@intel.com>
Signed-off-by: Len Brown <len.brown@intel.com>
What is the value shown in "cpu MHz" of /proc/cpuinfo when CPUs are capable of
changing frequency?
Today the answer is: It depends.
On i386:
SMP kernel - It is always the boot frequency
UP kernel - Scales with the frequency change and shows that was last set.
On x86_64:
There is one single variable cpu_khz that gets written by all the CPUs. So,
the frequency set by last CPU will be seen on /proc/cpuinfo of all the
CPUs in the system. What you see also depends on whether you have constant_tsc
capable CPU or not.
On ia64:
It is always boot time frequency of a particular CPU that gets displayed.
The patch below changes this to:
Show the last known frequency of the particular CPU, when cpufreq is present. If
cpu doesnot support changing of frequency through cpufreq, then boot frequency
will be shown. The patch affects i386, x86_64 and ia64 architectures.
Signed-off-by: Venkatesh Pallipadi<venkatesh.pallipadi@intel.com>
Signed-off-by: Dave Jones <davej@redhat.com>
We have a customer application which trips a bug. The problem arises
when a driver attempts to call do_munmap on an area which is mapped, but
because current->thread.task_size has been set to 0xC0000000, the call
to do_munmap fails thinking it is an unmap beyond the user's address
space.
The comment in fs/binfmt_elf.c in load_elf_library() before the call
to SET_PERSONALITY() indicates that task_size must not be changed for
the running application until flush_thread, but is for ia64 executing
ia32 binaries.
This patch moves the setting of task_size from SET_PERSONALITY() to
flush_thread() as indicated. The customer application no longer is able
to trip the bug.
Signed-off-by: Robin Holt <holt@sgi.com>
Signed-off-by: Tony Luck <tony.luck@intel.com>
http://bugzilla.kernel.org/show_bug.cgi?id=5483
ZX1 config doesn't include cpufreq, so move move acpi-processor.c
up out of ia64/cpufreq directory.
no functional changes
Signed-off-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
Signed-off-by: Len Brown <len.brown@intel.com>
Return -EINTR instead of -ERESTARTSYS when signals are delivered during
a blocked read of /proc/sal/*/event. This allows salinfo_decode to
detect signals when it is blocked on a read of those files.
Signed-off-by: Keith Owens <kaos@sgi.com>
Signed-off-by: Tony Luck <tony.luck@intel.com>
Linux invokes the AML _PDC method (Processor Driver Capabilities)
to tell the BIOS what features it can handle. While the ACPI
spec says nothing about the OS invoking _PDC multiple times,
doing so with changing bits seems to hopelessly confuse the BIOS
on multiple platforms up to and including crashing the system.
Factor out the _PDC invocation so Linux invokes it only once.
http://bugzilla.kernel.org/show_bug.cgi?id=5483
Signed-off-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
Signed-off-by: Len Brown <len.brown@intel.com>
arch/ia64/kernel/acpi-ext.c: In function `acpi_vendor_resource_match':
arch/ia64/kernel/acpi-ext.c:38: error: structure has no member named `id'
Signed-off-by: MAEDA Naoaki <maeda.naoaki@jp.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Len Brown <len.brown@intel.com>
break.b always sets cr.iim to 0 and the current code tries to
get the break_num by decoding instruction. However, their
seems to be a race condition while reading the regs->cr_iip,
as on other cpu the break.b at regs->cr_iip might have been
replaced with the original instruction as a result of
unregister_kprobe() and hence decoding instruction to
obtain break_num will result in wrong value in this case.
Also includes changes to kprobes.c which now has to handle
break number zero.
Signed-off-by: Anil S Keshavamurthy <anil.s.keshavamurthy@intel.com>
Signed-off-by: Tony Luck <tony.luck@intel.com>
A single SGI Altix system can be divided into multiple partitions,
each running their own instance of the Linux kernel. pfn_valid()
is currently not optimal for any but the first partition, since it
does not compare the pfn with min_low_pfn before calling the more
costly ia64_pfn_valid().
Signed-off-by: Dean Roe <roe@sgi.com>
Signed-off-by: Tony Luck <tony.luck@intel.com>
Fix a bug in kprobes that can cause an Oops or even a crash when a return
probe is installed on one of the following functions: sys_execve,
do_execve, load_*_binary, flush_old_exec, or flush_thread. The fix is to
remove the call to kprobe_flush_task() in flush_thread(). This fix has
been tested on all architectures for which the return-probes feature has
been implemented (i386, x86_64, ppc64, ia64). Please apply.
BACKGROUND
Up to now, we have called kprobe_flush_task() under two situations: when a
task exits, and when it execs. Flushing kretprobe_instances on exit is
correct because (a) do_exit() doesn't return, and (b) one or more
return-probed functions may be active when a task calls do_exit(). Neither
is the case for sys_execve() and its callees.
Initially, the mistaken call to kprobe_flush_task() on exec was harmless
because we put the "real" return address of each active probed function
back in the stack, just to be safe, when we recycled its
kretprobe_instance. When support for ppc64 and ia64 was added, this safety
measure couldn't be employed, and was eventually dropped even for i386 and
x86_64. sys_execve() and its callees were informally blacklisted for
return probes until this fix was developed.
Acked-by: Prasanna S Panchamukhi <prasanna@in.ibm.com>
Signed-off-by: Jim Keniston <jkenisto@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Polish the comments specifically in vhpt_miss and nested_dtlb_miss
handlers. I think it's better to explicitly name each page table
level with its name instead of numerically name them. i.e., use
pgd, pud, pmd, and pte instead of referring as L1, L2, L3 etc.
Along the line, remove some magic number in the comments like:
"PTA + (((IFA(61,63) << 7) | IFA(33,39))*8)". No code change at
all, pure comment update. Feel free to shoot anything you have,
darts or tomahawk cruise missile. I will duck behind a bunker ;-)
Signed-off-by: Ken Chen <kenneth.w.chen@intel.com>
Acked-by: Robin Holt <holt@sgi.com>
Signed-off-by: Tony Luck <tony.luck@intel.com>
From source code inspection, I think there is a bug with 4 level
page table with vhpt_miss handler. In the code path of rechecking
page table entry against previously read value after tlb insertion,
*pte value in register r18 was overwritten with value newly read
from pud pointer, render the check of new *pte against previous
*pte completely wrong. Though the bug is none fatal and the penalty
is to purge the entry and retry. For functional correctness, it
should be fixed. The fix is to use a different register so new
*pud don't trash *pte. (btw, the comments in the cmp statement is
wrong as well, which I will address in the next patch).
Signed-off-by: Ken Chen <kenneth.w.chen@intel.com>
Signed-off-by: Tony Luck <tony.luck@intel.com>
Our performance validation on 2.6.15-rc1 caught a disastrous performance
regression on ia64 with netperf (-98%) and volanomark (-58%) compares to
previous kernel version 2.6.14-git7. See the following chart (result
group 1 & 2).
http://kernel-perf.sourceforge.net/results.machine_id=26.html
We have root caused it to commit 64c7c8f885
This changeset broke the ia64 task resched notification. In
sched.c:resched_task(), a reschedule IPI is conditioned upon
TIF_POLLING_NRFLAG. However, the above changeset unconditionally set
the polling thread flag for idle tasks regardless whether pal_halt_light
is in use or not. As a result, resched IPI is not sent from
resched_task(). And since the default behavior on ia64 is to use
pal_halt_light, we end up delaying the rescheduling task until next
timer tick, and thus cause the performance regression.
This fixes the performance bug. I'm glad our performance suite is
turning up bad performance bug like this in time.
Signed-off-by: Ken Chen <kenneth.w.chen@intel.com>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This patch introduces 4-level page tables to ia64. I have run
some benchmarks and found nothing interesting. Performance has
consistently fallen within the noise range.
It also introduces a config option (setting the default to 3
levels). The config option prevents having 4 level page
tables with 64k base page size.
Signed-off-by: Robin Holt <holt@sgi.com>
Signed-off-by: Tony Luck <tony.luck@intel.com>
Make some changes to the NEED_RESCHED and POLLING_NRFLAG to reduce
confusion, and make their semantics rigid. Improves efficiency of
resched_task and some cpu_idle routines.
* In resched_task:
- TIF_NEED_RESCHED is only cleared with the task's runqueue lock held,
and as we hold it during resched_task, then there is no need for an
atomic test and set there. The only other time this should be set is
when the task's quantum expires, in the timer interrupt - this is
protected against because the rq lock is irq-safe.
- If TIF_NEED_RESCHED is set, then we don't need to do anything. It
won't get unset until the task get's schedule()d off.
- If we are running on the same CPU as the task we resched, then set
TIF_NEED_RESCHED and no further action is required.
- If we are running on another CPU, and TIF_POLLING_NRFLAG is *not* set
after TIF_NEED_RESCHED has been set, then we need to send an IPI.
Using these rules, we are able to remove the test and set operation in
resched_task, and make clear the previously vague semantics of
POLLING_NRFLAG.
* In idle routines:
- Enter cpu_idle with preempt disabled. When the need_resched() condition
becomes true, explicitly call schedule(). This makes things a bit clearer
(IMO), but haven't updated all architectures yet.
- Many do a test and clear of TIF_NEED_RESCHED for some reason. According
to the resched_task rules, this isn't needed (and actually breaks the
assumption that TIF_NEED_RESCHED is only cleared with the runqueue lock
held). So remove that. Generally one less locked memory op when switching
to the idle thread.
- Many idle routines clear TIF_POLLING_NRFLAG, and only set it in the inner
most polling idle loops. The above resched_task semantics allow it to be
set until before the last time need_resched() is checked before going into
a halt requiring interrupt wakeup.
Many idle routines simply never enter such a halt, and so POLLING_NRFLAG
can be always left set, completely eliminating resched IPIs when rescheduling
the idle task.
POLLING_NRFLAG width can be increased, to reduce the chance of resched IPIs.
Signed-off-by: Nick Piggin <npiggin@suse.de>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Con Kolivas <kernel@kolivas.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Run idle threads with preempt disabled.
Also corrected a bugs in arm26's cpu_idle (make it actually call schedule()).
How did it ever work before?
Might fix the CPU hotplugging hang which Nigel Cunningham noted.
We think the bug hits if the idle thread is preempted after checking
need_resched() and before going to sleep, then the CPU offlined.
After calling stop_machine_run, the CPU eventually returns from preemption and
into the idle thread and goes to sleep. The CPU will continue executing
previous idle and have no chance to call play_dead.
By disabling preemption until we are ready to explicitly schedule, this bug is
fixed and the idle threads generally become more robust.
From: alexs <ashepard@u.washington.edu>
PPC build fix
From: Yoichi Yuasa <yuasa@hh.iij4u.or.jp>
MIPS build fix
Signed-off-by: Nick Piggin <npiggin@suse.de>
Signed-off-by: Yoichi Yuasa <yuasa@hh.iij4u.or.jp>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
When a page has a memory uncorrectable ECC error, the recovery
code wants to prevent the page from being reused. This change
bumps the reference count to prevent the page from getting back
on the free list.
Signed-off-by: Russ Anderson (rja@sgi.com)
Signed-off-by: Tony Luck <tony.luck@intel.com>
paddr needs to be shifted by PAGE_SHIFT to be valid
input for pfn_valid().
Signed-off-by: Russ Anderson <rja@sgi.com>
Signed-off-by: Tony Luck <tony.luck@intel.com>
The determination of whether an MCA is recoverable or not must
be based on the bits set in the PSP (Processor State Parameter).
The specific bits are shown in the Intel IA-64 Architecture Software
Developer's Manual, Vol 2, Table 11-6 Software Recovery Bits in
Processor State Parameter. Those bits should be consistent
across the entire IA-64 family of processors.
Signed-off-by: Russ Anderson <rja@sgi.com>
Signed-off-by: Tony Luck <tony.luck@intel.com>
At the moment, attempting to invoke a signal-handler on the normal
stack is guaranteed to fail if the stack-pointer happens not to be
16-byte aligned. This is because the signal-trampoline will attempt
to store fp-regs with stf.spill instructions, which will trap for
misaligned addresses. This isn't terribly useful behavior. It's
better to just always align the signal frame to the next lower 16-byte
boundary.
Signed-off-by: David Mosberger-Tang <David.Mosberger@acm.org>
Signed-off-by: Tony Luck <tony.luck@intel.com>
notify_die() added for MCA_{MONARCH,SLAVE,RENDEZVOUS}_{ENTER,PROCESS,LEAVE} and
INIT_{MONARCH,SLAVE}_{ENTER,PROCESS,LEAVE}. We need multiple
notification points for these events because they can take many seconds
to run which has nasty effects on the behaviour of the rest of the
system.
DIE_SS replaced by a generic DIE_FAULT which checks the vector number,
to allow interception of faults other than SS.
DIE_MACHINE_{HALT,RESTART} added to allow last minute close down
processing, especially when the halt/restart routines are called from
error handlers.
DIE_OOPS added.
The check for kprobe's break numbers has been moved from traps.c to
kprobes.c, allowing DIE_BREAK to be used for any additional break
numbers, i.e. it is no longer kprobes specific.
Hooks for kernel debuggers and kernel dumpers added, ENTER and LEAVE.
Both of these disable the system for long periods which impact on
watchdogs and heartbeat systems in general. More patches to come that
use these events to reset watchdogs and heartbeats.
unregister_die_notifier() added and both routines exported. Requested
by Dean Nelson.
Lock removed from {un,}register_die_notifier. notifier_chain_register()
already takes a lock. Also the generic notifier chain locking is being
reworked to distinguish between callbacks that can block and those that
cannot, the lock in {un,}register_die_notifier would interfere with
that change. http://marc.theaimsgroup.com/?l=linux-kernel&m=113018709002036&w=2
Leading white space removed from arch/ia64/kernel/kprobes.c.
Typo in mca.c in original version of this patch found & fixed by Dean
Nelson.
Signed-off-by: Keith Owens <kaos@sgi.com>
Acked-by: Dean Nelson <dcn@sgi.com>
Acked-by: Anil Keshavamurthy <anil.s.keshavamurthy@intel.com>
Signed-off-by: Tony Luck <tony.luck@intel.com>
This is the arch/ part of the big kfree cleanup patch.
Remove pointless checks for NULL prior to calling kfree() in arch/.
Signed-off-by: Jesper Juhl <jesper.juhl@gmail.com>
Acked-by: Grant Grundler <grundler@parisc-linux.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Reorganize the preempt_disable/enable calls to eliminate the extra preempt
depth. Changes based on Paul McKenney's review suggestions for the kprobes
RCU changeset.
Signed-off-by: Ananth N Mavinakayanahalli <ananth@in.ibm.com>
Signed-off-by: Anil S Keshavamurthy <anil.s.keshavamurthy@intel.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Changes to the arch kprobes infrastructure to take advantage of the locking
changes introduced by usage of RCU for synchronization. All handlers are now
run without any locks held, so they have to be re-entrant or provide their own
synchronization.
Signed-off-by: Ananth N Mavinakayanahalli <ananth@in.ibm.com>
Signed-off-by: Anil S Keshavamurthy <anil.s.keshavamurthy@intel.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
IA64 changes to track kprobe execution on a per-cpu basis. We now track the
kprobe state machine independently on each cpu using an arch specific kprobe
control block.
Signed-off-by: Ananth N Mavinakayanahalli <ananth@in.ibm.com>
Signed-off-by: Anil S Keshavamurthy <anil.s.keshavamurthy@intel.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
The following set of patches are aimed at improving kprobes scalability. We
currently serialize kprobe registration, unregistration and handler execution
using a single spinlock - kprobe_lock.
With these changes, kprobe handlers can run without any locks held. It also
allows for simultaneous kprobe handler executions on different processors as
we now track kprobe execution on a per processor basis. It is now necessary
that the handlers be re-entrant since handlers can run concurrently on
multiple processors.
All changes have been tested on i386, ia64, ppc64 and x86_64, while sparc64
has been compile tested only.
The patches can be viewed as 3 logical chunks:
patch 1: Reorder preempt_(dis/en)able calls
patches 2-7: Introduce per_cpu data areas to track kprobe execution
patches 8-9: Use RCU to synchronize kprobe (un)registration and handler
execution.
Thanks to Maneesh Soni, James Keniston and Anil Keshavamurthy for their
review and suggestions. Thanks again to Anil, Hien Nguyen and Kevin Stafford
for testing the patches.
This patch:
Reorder preempt_disable/enable() calls in arch kprobes files in preparation to
introduce locking changes. No functional changes introduced by this patch.
Signed-off-by: Ananth N Mavinakayahanalli <ananth@in.ibm.com>
Signed-off-by: Anil S Keshavamurthy <anil.s.keshavamurthy@intel.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
