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>
This is the x86_64 implementation of the crashkernel option. It reserves
a window of memory very early in the bootup process, so we never use
it for anything but the kernel to switch to when the running
kernel panics.
In addition to reserving this memory a resource structure is registered
so looking at /proc/iomem it is clear what happened to that memory.
ISSUES:
Is it possible to implement this in a architecture generic way?
What should be done with architectures that always use an iommu and
thus don't report their RAM memory resources in /proc/iomem?
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 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>
Factor out the apic and smp shutdown code from machine_restart so it can be
called by in the kexec reboot path as well.
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_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>
The vmlinux on x86_64 does not report the correct physical address of
the kernel. Instead in the physical address field it currently
reports the virtual address of the kernel.
This is patch is a bug fix that corrects vmlinux to report the
proper physical addresses.
This is potentially a help for crash dump analysis tools.
This definitiely allows bootloaders that load vmlinux as a standard
ELF executable. Bootloaders directly loading vmlinux become of
practical importance when we consider the kexec on panic case.
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: Eric W. Biederman <ebiederm@xmission.com
The following patch simply adds a shutdown method to the x86_64 i8259 code.
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: Eric W. Biederman <ebiederm@xmission.com>
It is ok to reserve resources > 4G on x86_64 struct resource is 64bit now :)
Signed-off-by: Eric Biederman <ebiederm@xmission.com>
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 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>
Sleep code uses wrong version of lgdt, that does the wrong thing when
gdt is beyond 16MB or so.
Signed-off-by: Pavel Machek <pavel@suse.cz>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This patch provides an option to switch broadcast or use mask version for
sending IPI's. If CONFIG_HOTPLUG_CPU is defined, we choose not to use
broadcast shortcuts by default, otherwise we choose broadcast mode as default.
both cases, one can change this via startup cmd line option, to choose
no-broadcast mode.
no_ipi_broadcast=1
This is provided on request from Andi Kleen, since he doesnt agree with
replacing IPI shortcuts as a solution for CPU hotplug. Without removing
broadcast IPI's, it would mean lots of new code for __cpu_up() path, which
would acheive the same results.
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: 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>
This patch is a minor cleanup to the cpu sibling/core map. It is required
that this setup happens on a per-cpu bringup time.
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: 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>
This patch adds __cpuinit and __cpuinitdata sections that need to exist past
boot to support cpu hotplug.
Caveat: This is done *only* for EM64T CPU Hotplug support, on request from
Andi Kleen. Much of the generic hotplug code in kernel, and none of the other
archs that support CPU hotplug today, i386, ia64, ppc64, s390 and parisc dont
mark sections with __cpuinit, but only mark them as __devinit, and
__devinitdata.
If someone is motivated to change generic code, we need to make sure all
existing hotplug code does not break, on other arch's that dont use __cpuinit,
and __cpudevinit.
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: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This patch includes x86_64 architecture specific changes to support temporary
disarming on reentrancy of probes.
Signed-of-by: Prasanna S Panchamukhi <prasanna@in.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
The architecture independent code of the current kprobes implementation is
arming and disarming kprobes at registration time. The problem is that the
code is assuming that arming and disarming is a just done by a simple write
of some magic value to an address. This is problematic for ia64 where our
instructions look more like structures, and we can not insert break points
by just doing something like:
*p->addr = BREAKPOINT_INSTRUCTION;
The following patch to 2.6.12-rc4-mm2 adds two new architecture dependent
functions:
* void arch_arm_kprobe(struct kprobe *p)
* void arch_disarm_kprobe(struct kprobe *p)
and then adds the new functions for each of the architectures that already
implement kprobes (spar64/ppc64/i386/x86_64).
I thought arch_[dis]arm_kprobe was the most descriptive of what was really
happening, but each of the architectures already had a disarm_kprobe()
function that was really a "disarm and do some other clean-up items as
needed when you stumble across a recursive kprobe." So... I took the
liberty of changing the code that was calling disarm_kprobe() to call
arch_disarm_kprobe(), and then do the cleanup in the block of code dealing
with the recursive kprobe case.
So far this patch as been tested on i386, x86_64, and ppc64, but still
needs to be tested in sparc64.
Signed-off-by: Rusty Lynch <rusty.lynch@intel.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 patch adds the x86_64 architecture specific implementation
for function return probes.
Function return probes is a mechanism built on top of kprobes that allows
a caller to register a handler to be called when a given function exits.
For example, to instrument the return path of sys_mkdir:
static int sys_mkdir_exit(struct kretprobe_instance *i, struct pt_regs *regs)
{
printk("sys_mkdir exited\n");
return 0;
}
static struct kretprobe return_probe = {
.handler = sys_mkdir_exit,
};
<inside setup function>
return_probe.kp.addr = (kprobe_opcode_t *) kallsyms_lookup_name("sys_mkdir");
if (register_kretprobe(&return_probe)) {
printk(KERN_DEBUG "Unable to register return probe!\n");
/* do error path */
}
<inside cleanup function>
unregister_kretprobe(&return_probe);
The way this works is that:
* At system initialization time, kernel/kprobes.c installs a kprobe
on a function called kretprobe_trampoline() that is implemented in
the arch/x86_64/kernel/kprobes.c (More on this later)
* When a return probe is registered using register_kretprobe(),
kernel/kprobes.c will install a kprobe on the first instruction of the
targeted function with the pre handler set to arch_prepare_kretprobe()
which is implemented in arch/x86_64/kernel/kprobes.c.
* arch_prepare_kretprobe() will prepare a kretprobe instance that stores:
- nodes for hanging this instance in an empty or free list
- a pointer to the return probe
- the original return address
- a pointer to the stack address
With all this stowed away, arch_prepare_kretprobe() then sets the return
address for the targeted function to a special trampoline function called
kretprobe_trampoline() implemented in arch/x86_64/kernel/kprobes.c
* The kprobe completes as normal, with control passing back to the target
function that executes as normal, and eventually returns to our trampoline
function.
* Since a kprobe was installed on kretprobe_trampoline() during system
initialization, control passes back to kprobes via the architecture
specific function trampoline_probe_handler() which will lookup the
instance in an hlist maintained by kernel/kprobes.c, and then call
the handler function.
* When trampoline_probe_handler() is done, the kprobes infrastructure
single steps the original instruction (in this case just a top), and
then calls trampoline_post_handler(). trampoline_post_handler() then
looks up the instance again, puts the instance back on the free list,
and then makes a long jump back to the original return instruction.
So to recap, to instrument the exit path of a function this implementation
will cause four interruptions:
- A breakpoint at the very beginning of the function allowing us to
switch out the return address
- A single step interruption to execute the original instruction that
we replaced with the break instruction (normal kprobe flow)
- A breakpoint in the trampoline function where our instrumented function
returned to
- A single step interruption to execute the original instruction that
we replaced with the break instruction (normal kprobe flow)
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Make use of the user_mode macro where it's possible. This is useful for Xen
because it will need only to redefine only the macro to a hypervisor call.
Signed-off-by: Vincent Hanquez <vincent.hanquez@cl.cam.ac.uk>
Cc: Ian Pratt <m+Ian.Pratt@cl.cam.ac.uk>
Cc: Andi Kleen <ak@muc.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Add 2 macros to set and get debugreg on x86_64. This is useful for Xen
because it will need only to redefine each macro to a hypervisor call.
Signed-off-by: Vincent Hanquez <vincent.hanquez@cl.cam.ac.uk>
Cc: Ian Pratt <m+Ian.Pratt@cl.cam.ac.uk>
Cc: Andi Kleen <ak@muc.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
I suggest to change the way IRQs are handed out to PCI devices.
Currently, each I/O APIC pin gets associated with an IRQ, no matter if the
pin is used or not. It is expected that each pin can potentually be
engaged by a device inserted into the corresponding PCI slot. However,
this imposes severe limitation on systems that have designs that employ
many I/O APICs, only utilizing couple lines of each, such as P64H2 chipset.
It is used in ES7000, and currently, there is no way to boot the system
with more that 9 I/O APICs.
The simple change below allows to boot a system with say 64 (or more) I/O
APICs, each providing 1 slot, which otherwise impossible because of the IRQ
gaps created for unused lines on each I/O APIC. It does not resolve the
problem with number of devices that exceeds number of possible IRQs, but
eases up a tension for IRQs on any large system with potentually large
number of devices.
I only implemented this for the ACPI boot, since if the system is this big
and using newer chipsets it is probably (better be!) an ACPI based system
:). The change is completely "mechanical" and does not alter any internal
structures or interrupt model/implementation. The patch works for both
i386 and x86_64 archs. It works with MSIs just fine, and should not
intervene with implementations like shared vectors, when they get worked
out and incorporated.
To illustrate, below is the interrupt distribution for 2-cell ES7000 with
20 I/O APICs, and an Ethernet card in the last slot, which should be eth1
and which was not configured because its IRQ exceeded allowable number (it
actially turned out huge - 480!):
zorro-tb2:~ # cat /proc/interrupts
CPU0 CPU1 CPU2 CPU3 CPU4 CPU5 CPU6 CPU7
0: 65716 30012 30007 30002 30009 30010 30010 30010 IO-APIC-edge timer
4: 373 0 725 280 0 0 0 0 IO-APIC-edge serial
8: 0 0 0 0 0 0 0 0 IO-APIC-edge rtc
9: 0 0 0 0 0 0 0 0 IO-APIC-level acpi
14: 39 3 0 0 0 0 0 0 IO-APIC-edge ide0
16: 108 13 0 0 0 0 0 0 IO-APIC-level uhci_hcd:usb1
18: 0 0 0 0 0 0 0 0 IO-APIC-level uhci_hcd:usb3
19: 15 0 0 0 0 0 0 0 IO-APIC-level uhci_hcd:usb2
23: 3 0 0 0 0 0 0 0 IO-APIC-level ehci_hcd:usb4
96: 4240 397 18 0 0 0 0 0 IO-APIC-level aic7xxx
97: 15 0 0 0 0 0 0 0 IO-APIC-level aic7xxx
192: 847 0 0 0 0 0 0 0 IO-APIC-level eth0
NMI: 0 0 0 0 0 0 0 0
LOC: 273423 274528 272829 274228 274092 273761 273827 273694
ERR: 7
MIS: 0
Even though the system doesn't have that many devices, some don't get
enabled only because of IRQ numbering model.
This is the IRQ picture after the patch was applied:
zorro-tb2:~ # cat /proc/interrupts
CPU0 CPU1 CPU2 CPU3 CPU4 CPU5 CPU6 CPU7
0: 44169 10004 10004 10001 10004 10003 10004 6135 IO-APIC-edge timer
4: 345 0 0 0 0 244 0 0 IO-APIC-edge serial
8: 0 0 0 0 0 0 0 0 IO-APIC-edge rtc
9: 0 0 0 0 0 0 0 0 IO-APIC-level acpi
14: 39 0 3 0 0 0 0 0 IO-APIC-edge ide0
17: 4425 0 9 0 0 0 0 0 IO-APIC-level aic7xxx
18: 15 0 0 0 0 0 0 0 IO-APIC-level aic7xxx, uhci_hcd:usb3
21: 231 0 0 0 0 0 0 0 IO-APIC-level uhci_hcd:usb1
22: 26 0 0 0 0 0 0 0 IO-APIC-level uhci_hcd:usb2
23: 3 0 0 0 0 0 0 0 IO-APIC-level ehci_hcd:usb4
24: 348 0 0 0 0 0 0 0 IO-APIC-level eth0
25: 6 192 0 0 0 0 0 0 IO-APIC-level eth1
NMI: 0 0 0 0 0 0 0 0
LOC: 107981 107636 108899 108698 108489 108326 108331 108254
ERR: 7
MIS: 0
Not only we see the card in the last I/O APIC, but we are not even close to
using up available IRQs, since we didn't waste any.
Signed-off-by: Natalie Protasevich <Natalie.Protasevich@unisys.com>
Acked-by: Andi Kleen <ak@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This is the x86_64 version of the signal fix I just posted for i386.
This problem was first noticed on PPC and has already been fixed there.
But the exact same issue applies to other platforms in the same way. The
signal blocking for sa_mask and the handled signal takes place after the
handler setup. When the stack is bogus, the handler setup forces a
SIGSEGV. But then this will be blocked, and returning to user mode will
fault again and iterate. This patch fixes the problem by checking whether
signal handler setup failed, and not doing the signal-blocking if so. This
copies what was done in the ppc code. I think all architectures' signal
handler setup code follows this pattern and needs the change.
Signed-off-by: Roland McGrath <roland@redhat.com>
Cc: Andi Kleen <ak@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Currently the x86-64 HPET code assumes the entire HPET implementation from
the spec is present. This breaks on boxes that do not implement the
optional legacy timer replacement functionality portion of the spec.
This patch fixes this issue, allowing x86-64 systems that cannot use the
HPET for the timer interrupt and RTC to still use the HPET as a time
source. I've tested this patch on a system systems without HPET, with HPET
but without legacy timer replacement, as well as HPET with legacy timer
replacement.
This version adds a minor check to cap the HPET counter value in
gettimeoffset_hpet to avoid possible time inconsistencies. Please ignore
the A2 version I sent to you earlier.
Acked-by: Andi Kleen <ak@muc.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Allow early printk code to take advantage of the full size of the screen, not
just the first 25 lines.
Signed-off-by: Jan Beulich <jbeulich@novell.com>
Acked-by: Andi Kleen <ak@muc.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Define pcibus_to_node to be able to figure out which NUMA node contains a
given PCI device. This defines pcibus_to_node(bus) in
include/linux/topology.h and adjusts the macros for i386 and x86_64 that
already provided a way to determine the cpumask of a pci device.
x86_64 was changed to not build an array of cpumasks anymore. Instead an
array of nodes is build which can be used to generate the cpumask via
node_to_cpumask.
Signed-off-by: Christoph Lameter <christoph@lameter.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This patch adds in the necessary support for sparsemem such that x86-64
kernels may use sparsemem as an alternative to discontigmem for NUMA
kernels. Note that this does no preclude one from continuing to build NUMA
kernels using discontigmem, but merely allows the option to build NUMA
kernels with sparsemem.
Interestingly, the use of sparsemem in lieu of discontigmem in NUMA kernels
results in reduced text size for otherwise equivalent kernels as shown in
the example builds below:
text data bss dec hex filename
2371036 765884 1237108 4374028 42be0c vmlinux.discontig
2366549 776484 1302772 4445805 43d66d vmlinux.sparse
Signed-off-by: Matt Tolentino <matthew.e.tolentino@intel.com>
Signed-off-by: Dave Hansen <haveblue@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
In order to use the alternative sparsemem implmentation for NUMA kernels,
we need to reorganize the config options. This patch effectively abstracts
out the CONFIG_DISCONTIGMEM options to CONFIG_NUMA in most cases. Thus,
the discontigmem implementation may be employed as always, but the
sparsemem implementation may be used alternatively.
Signed-off-by: Matt Tolentino <matthew.e.tolentino@intel.com>
Signed-off-by: Dave Hansen <haveblue@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This patch pulls out all remaining direct references to contig_page_data
from arch/x86-64, thus saving an ifdef in one case.
Signed-off-by: Matt Tolentino <matthew.e.tolentino@intel.com>
Signed-off-by: Dave Hansen <haveblue@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Ingo recently introduced a great speedup for allocating new mmaps using the
free_area_cache pointer which boosts the specweb SSL benchmark by 4-5% and
causes huge performance increases in thread creation.
The downside of this patch is that it does lead to fragmentation in the
mmap-ed areas (visible via /proc/self/maps), such that some applications
that work fine under 2.4 kernels quickly run out of memory on any 2.6
kernel.
The problem is twofold:
1) the free_area_cache is used to continue a search for memory where
the last search ended. Before the change new areas were always
searched from the base address on.
So now new small areas are cluttering holes of all sizes
throughout the whole mmap-able region whereas before small holes
tended to close holes near the base leaving holes far from the base
large and available for larger requests.
2) the free_area_cache also is set to the location of the last
munmap-ed area so in scenarios where we allocate e.g. five regions of
1K each, then free regions 4 2 3 in this order the next request for 1K
will be placed in the position of the old region 3, whereas before we
appended it to the still active region 1, placing it at the location
of the old region 2. Before we had 1 free region of 2K, now we only
get two free regions of 1K -> fragmentation.
The patch addresses thes issues by introducing yet another cache descriptor
cached_hole_size that contains the largest known hole size below the
current free_area_cache. If a new request comes in the size is compared
against the cached_hole_size and if the request can be filled with a hole
below free_area_cache the search is started from the base instead.
The results look promising: Whereas 2.6.12-rc4 fragments quickly and my
(earlier posted) leakme.c test program terminates after 50000+ iterations
with 96 distinct and fragmented maps in /proc/self/maps it performs nicely
(as expected) with thread creation, Ingo's test_str02 with 20000 threads
requires 0.7s system time.
Taking out Ingo's patch (un-patch available per request) by basically
deleting all mentions of free_area_cache from the kernel and starting the
search for new memory always at the respective bases we observe: leakme
terminates successfully with 11 distinctive hardly fragmented areas in
/proc/self/maps but thread creating is gringdingly slow: 30+s(!) system
time for Ingo's test_str02 with 20000 threads.
Now - drumroll ;-) the appended patch works fine with leakme: it ends with
only 7 distinct areas in /proc/self/maps and also thread creation seems
sufficiently fast with 0.71s for 20000 threads.
Signed-off-by: Wolfgang Wander <wwc@rentec.com>
Credit-to: "Richard Purdie" <rpurdie@rpsys.net>
Signed-off-by: Ken Chen <kenneth.w.chen@intel.com>
Acked-by: Ingo Molnar <mingo@elte.hu> (partly)
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Appended patch will setup compatibility mode TASK_SIZE properly. This will
fix atleast three known bugs that can be encountered while running
compatibility mode apps.
a) A malicious 32bit app can have an elf section at 0xffffe000. During
exec of this app, we will have a memory leak as insert_vm_struct() is
not checking for return value in syscall32_setup_pages() and thus not
freeing the vma allocated for the vsyscall page. And instead of exec
failing (as it has addresses > TASK_SIZE), we were allowing it to
succeed previously.
b) With a 32bit app, hugetlb_get_unmapped_area/arch_get_unmapped_area
may return addresses beyond 32bits, ultimately causing corruption
because of wrap-around and resulting in SEGFAULT, instead of returning
ENOMEM.
c) 32bit app doing this below mmap will now fail.
mmap((void *)(0xFFFFE000UL), 0x10000UL, PROT_READ|PROT_WRITE,
MAP_FIXED|MAP_PRIVATE|MAP_ANON, 0, 0);
Signed-off-by: Zou Nan hai <nanhai.zou@intel.com>
Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com>
Cc: Andi Kleen <ak@muc.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Martin Bligh determined that this patch is causing his test box to not boot.
Revert.
Andi Kleen <ak@muc.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This works around the too fast timer seen on some ATI boards.
I don't feel confident enough about it yet to enable it by default, but give
users the option.
Patch and debugging from Christopher Allen Wing <wingc@engin.umich.edu>, with
minor tweaks (renamed the option and documented it)
Signed-off-by: Andi Kleen <ak@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
The test case at
http://cvs.sourceforge.net/viewcvs.py/posixtest/posixtestsuite/conforman
ce/interfaces/clock_nanosleep/1-5.c fails if it runs as a 32bit process on
x86_86 machines.
The root cause is the sub 32bit process fails to restart the syscall after it
is interrupted by a signal.
The syscall number of sys_restart_syscall in table sys_call_table is
__NR_restart_syscall (219) while it's __NR_ia32_restart_syscall
(0) in ia32_sys_call_table. When regs->rax==(unsigned
long)-ERESTART_RESTARTBLOCK, function do_signal doesn't distinguish if
the process is 64bit or 32bit, and always sets restart syscall number
as __NR_restart_syscall (219).
Signed-off-by: Zhang Yanmin <yanmin.zhang@intel.com>
Signed-off-by: Andi Kleen <ak@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
There was a "off by one quad word" error in there. I don't think it is
exploitable because it will only store into a unused area, but better to plug
it.
Found and fixed by John Blackwood
Signed-off-by: Andi Kleen <ak@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
- Remove duplicated ifdef
- Make core_id match what Intel uses
- Initialize phys_proc_id correctly for non DC case
- Handle non power of two core numbers.
Fixes for both i386 and x86-64
Signed-off-by: Andi Kleen <ak@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This patch removes the assumption that LAPIC entries contain the BSP as its
first entry. This is a slight improvement to the temporary fix submitted by
Suresh Siddha.
- Removes assumption that LAPIC entries contain BSP first.
- Builds x86_acpiid_to_apicid[] and bios_cpu_apicid[] properly with BSP as
first entry.
- Made maxcpus=1 boot on these systems. Since the parsing earlier in
arch/x86_64/kernel/mpparse.c stopped after maxcpus entries, other entries
were not processed, this causes kernel not to boot on these systems.
TBD: x86_acpiid_to_apicid and bios_cpu_apicid[] seem to be exactly the
same. This could be removed, but might need more work to cleanup.
Signed-off-by: Ashok Raj <ashok.raj@intel.com>
Signed-off-by: Andi Kleen <ak@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Collected NMI watchdog fixes.
- Fix call of check_nmi_watchdog
- Remove earlier move of check_nmi_watchdog to later. It does not fix the
race it was supposed to fix fully.
- Remove unused P6 definitions
- Add support for performance counter based watchdog on P4 systems.
This allows to run it only once per second, which saves some CPU time.
Previously it would run at 1000Hz, which was too much.
Code ported from i386
Make this the default on Intel systems.
- Use check_nmi_watchdog with local APIC based nmi
- Fix race in touch_nmi_watchdog
- Fix bug that caused incorrect performance counters to be programmed in a
few cases on K8.
- Remove useless check for local APIC
- Use local_t and per_cpu variables for per CPU data.
- Keep other CPUs busy during check_nmi_watchdog to make sure they really
tick when in lapic mode.
- Only check CPUs that are actually online.
- Various other fixes.
- Fix fallback path when MSRs are unimplemented
Signed-off-by: Andi Kleen <ak@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Originally from Matt Tolentino
Signed-off-by: Andi Kleen <ak@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Use bitmap_zero instead of bitmap_empty to initialise cpu mask This makes it
actually run reliable instead of relying on stack state.
Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com>
Signed-off-by: Andi Kleen <ak@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Allowed user programs to set a non canonical segment base, which would cause
oopses in the kernel later.
Credit-to: Alexander Nyberg <alexn@dsv.su.se>
For identifying and reporting this bug.
Signed-off-by: Andi Kleen <ak@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This works around an AMD Erratum.
Signed-off-by: Andi Kleen <ak@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
There are unfortunately more and more multi processor Opteron systems which
don't have HPET timer support in the southbridge. This covers in particular
Nvidia and VIA chipsets. They also don't guarantee that the TSCs are
synchronized between CPUs; and especially with MP powernow the systems are
nearly unusable because the time gets very inconsistent between CPUs.
The timer code for x86-64 was originally written under the assumption that we
could fall back to the HPET timer on such systems. But this doesn't work
there.
Another alternative is to use the ACPI PM timer as primary time source. This
patch does that. The kernel only uses PM timer when there is no other choice
because it has some disadvantages.
Ported over from i386. It should be faster than the i386 version because I
dropped the "read three times" workaround, but is still considerable slower
than HPET and also does not work together with vsyscalls which have to be
disabled.
Cc: <mark.langsdorf@amd.com>
Signed-off-by: Andi Kleen <ak@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
It is unnecessary on modern Intel or AMD systems, and that is all we support
on x86-64
Also causes problems on various systems
Signed-off-by: Andi Kleen <ak@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Vivek Goyal