Printing the list of loaded modules is really unrelated to what
this function is about, and is particularly unnecessary in the
context of the SysRQ key handling (gets printed so far over and
over).
It should really be the caller of the function to decide whether
this piece of information is useful (and to avoid redundantly
printing it).
Signed-off-by: Jan Beulich <jbeulich@suse.com>
Link: http://lkml.kernel.org/r/4FDF21A4020000780008A67F@nat28.tlf.novell.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
It's not being used for other than creating module aliases (i.e.
no loadable section has any reference to it).
Signed-off-by: Jan Beulich <jbeulich@suse.com>
Link: http://lkml.kernel.org/r/4FDF1EFD020000780008A65D@nat28.tlf.novell.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Implement a cleaner and easier to maintain version for the section
warning fixes implemented in commit eeaaa96a3a
("x86/nmi: Fix section mismatch warnings on 32-bit").
Signed-off-by: Li Zhong <zhong@linux.vnet.ibm.com>
Signed-off-by: Don Zickus <dzickus@redhat.com>
Cc: Jan Beulich <JBeulich@suse.com>
Link: http://lkml.kernel.org/r/1340049393-17771-1-git-send-email-dzickus@redhat.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
The uncore subsystem in Sandy Bridge-EP consists of 8 components:
Ubox, Cacheing Agent, Home Agent, Memory controller, Power Control,
QPI Link Layer, R2PCIe, R3QPI.
Signed-off-by: Zheng Yan <zheng.z.yan@intel.com>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/1339741902-8449-9-git-send-email-zheng.z.yan@intel.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
This patch adds generic support for uncore PMUs presented as
PCI devices. (These come in addition to the CPU/MSR based
uncores.)
Signed-off-by: Zheng Yan <zheng.z.yan@intel.com>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/1339741902-8449-8-git-send-email-zheng.z.yan@intel.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
This patch adds the generic Intel uncore PMU support, including helper
functions that add/delete uncore events, a hrtimer that periodically
polls the counters to avoid overflow and code that places all events
for a particular socket onto a single cpu.
The code design is based on the structure of Sandy Bridge-EP's uncore
subsystem, which consists of a variety of components, each component
contains one or more "boxes".
(Tooling support follows in the next patches.)
Signed-off-by: Zheng Yan <zheng.z.yan@intel.com>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/1339741902-8449-6-git-send-email-zheng.z.yan@intel.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
The RDPMC index calculation is wrong for AMD family 15h
(X86_FEATURE_ PERFCTR_CORE set). This leads to a #GP when
accessing the counter:
Pid: 2237, comm: syslog-ng Not tainted 3.5.0-rc1-perf-x86_64-standard-g130ff90 #135 AMD Pike/Pike
RIP: 0010:[<ffffffff8100dc33>] [<ffffffff8100dc33>] x86_perf_event_update+0x27/0x66
While the msr address offset is (index << 1) we must use index to
select the correct rdpmc.
Signed-off-by: Robert Richter <robert.richter@amd.com>
Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Vince Weaver <vweaver1@eecs.utk.edu>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
With the revamped realmode trampoline code, it is trivial to extend
support for reboot=bios to x86-64. Furthermore, while we are at it,
remove the restriction that only we can only override the reboot CPU
on 32 bits.
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
Link: http://lkml.kernel.org/n/tip-jopx7y6g6dbcx4tpal8q0jlr@git.kernel.org
Pull DMA-mapping fixes from Marek Szyprowski:
"A set of minor fixes for dma-mapping code (ARM and x86) required for
Contiguous Memory Allocator (CMA) patches merged in v3.5-rc1."
* 'fixes-for-linus' of git://git.linaro.org/people/mszyprowski/linux-dma-mapping:
x86: dma-mapping: fix broken allocation when dma_mask has been provided
ARM: dma-mapping: fix debug messages in dmabounce code
ARM: mm: fix type of the arm_dma_limit global variable
ARM: dma-mapping: Add missing static storage class specifier
Move the ->irq_set_affinity() routines out of the #ifdef CONFIG_SMP
sections and use config_enabled(CONFIG_SMP) checks inside those
routines. Thus making those routines simple null stubs for
!CONFIG_SMP and retaining those routines with no additional
runtime overhead for CONFIG_SMP kernels.
Cleans up the ifdef CONFIG_SMP in and around routines related to
irq_set_affinity in io_apic and irq_remapping subsystems.
Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com>
Cc: torvalds@linux-foundation.org
Cc: joerg.roedel@amd.com
Cc: Sam Ravnborg <sam@ravnborg.org>
Cc: Paul Gortmaker <paul.gortmaker@windriver.com>
Link: http://lkml.kernel.org/r/1339723729.3475.63.camel@sbsiddha-desk.sc.intel.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
set_vsmp_pv_ops() references no_irq_affinity which is undeclared
if CONFIG_PROC_FS isn't set. Fix this by adding an #ifdef around
this variable's access.
Reported-by: Fengguang Wu <wfg@linux.intel.com>
Signed-off-by: Ido Yariv <ido@wizery.com>
Acked-by: Shai Fultheim <shai@scalemp.com>
Link: http://lkml.kernel.org/r/1339688588-12674-1-git-send-email-ido@wizery.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Commit 0a2b9a6ea9 ("X86: integrate CMA with DMA-mapping subsystem")
broke memory allocation with dma_mask. This patch fixes possible kernel
ops caused by lack of resetting page variable when jumping to 'again' label.
Reported-by: Konrad Rzeszutek Wilk <konrad@darnok.org>
Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
Acked-by: Michal Nazarewicz <mina86@mina86.com>
cpu_mask_to_apicid_and() always returns apicid of a single CPU,
even in case multiple CPUs were requested. This update fixes a
typo and forces apicid of a cluster to be returned.
Signed-off-by: Alexander Gordeev <agordeev@redhat.com>
Cc: Suresh Siddha <suresh.b.siddha@intel.com>
Cc: Yinghai Lu <yinghai@kernel.org>
Link: http://lkml.kernel.org/r/20120614075043.GI3383@dhcp-26-207.brq.redhat.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
In case of invalid parameters cpu_mask_to_apicid_and() might
return apicid value of 0 (on Summit) or a uninitialized value
(on ES7000), although it is supposed to return apicid of cpu-0
at least. Fix the operation to always return a valid apicid.
Signed-off-by: Alexander Gordeev <agordeev@redhat.com>
Cc: Suresh Siddha <suresh.b.siddha@intel.com>
Cc: Yinghai Lu <yinghai@kernel.org>
Link: http://lkml.kernel.org/r/20120614075026.GH3383@dhcp-26-207.brq.redhat.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Since there are only two locations where cpu_mask_to_apicid() is
called from, remove the operation and use only
cpu_mask_to_apicid_and() instead.
Signed-off-by: Alexander Gordeev <agordeev@redhat.com>
Suggested-and-acked-by: Suresh Siddha <suresh.b.siddha@intel.com>
Acked-by: Yinghai Lu <yinghai@kernel.org>
Link: http://lkml.kernel.org/r/20120614074935.GE3383@dhcp-26-207.brq.redhat.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Since commit 8637e38 ("x86/apic: Avoid useless scanning thru a
cpumask in assign_irq_vector()") vector_allocation_domain()
operation indicates if a cpumask is dynamic or static. This
update fixes the oversight and makes the operation to return a
value.
Signed-off-by: Alexander Gordeev <agordeev@redhat.com>
Cc: Suresh Siddha <suresh.b.siddha@intel.com>
Cc: Yinghai Lu <yinghai@kernel.org>
Link: http://lkml.kernel.org/r/20120614103933.GJ3383@dhcp-26-207.brq.redhat.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Add "read-mostly" qualifier to the following variables in
smp.h:
- cpu_sibling_map
- cpu_core_map
- cpu_llc_shared_map
- cpu_llc_id
- cpu_number
- x86_cpu_to_apicid
- x86_bios_cpu_apicid
- x86_cpu_to_logical_apicid
As long as all the variables above are only written during the
initialization, this change is meant to prevent the false
sharing. More specifically, on vSMP Foundation platform
x86_cpu_to_apicid shared the same internode_cache_line with
frequently written lapic_events.
From the analysis of the first 33 per_cpu variables out of 219
(memories they describe, to be more specific) the 8 have read_mostly
nature (tlb_vector_offset, cpu_loops_per_jiffy, xen_debug_irq, etc.)
and 25 are frequently written (irq_stack_union, gdt_page,
exception_stacks, idt_desc, etc.).
Assuming that the spread of the rest of the per_cpu variables is
similar, identifying the read mostly memories will make more sense
in terms of long-term code maintenance comparing to identifying
frequently written memories.
Signed-off-by: Vlad Zolotarov <vlad@scalemp.com>
Acked-by: Shai Fultheim <shai@scalemp.com>
Cc: Shai Fultheim (Shai@ScaleMP.com) <Shai@scalemp.com>
Cc: ido@wizery.com
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/1719258.EYKzE4Zbq5@vlad
Signed-off-by: Ingo Molnar <mingo@kernel.org>
stop_machine_text_poke() uses atomic_dec_and_test() to select one of
the CPUs executing that function to actually modify the code.
Since the variable is initialized to 1, subsequent CPUs will make the
variable go negative. Since going negative is uncommon/unexpected in
typical dec_and_test usage change this user to atomic_xchg().
This was found using a patch that warns on dec_and_test going
negative.
Signed-off-by: OGAWA Hirofumi <hirofumi@mail.parknet.co.jp>
Acked-by: Steven Rostedt <rostedt@goodmis.org>
[ Rewrote changelog ]
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/87zk8fgsx9.fsf@devron.myhome.or.jp
Signed-off-by: Ingo Molnar <mingo@kernel.org>
The warning below triggers on AMD MCM packages because physical package
IDs on the cores of a _physical_ socket are the same. I.e., this field
says which CPUs belong to the same physical package.
However, the same two CPUs belong to two different internal, i.e.
"logical" nodes in the same physical socket which is reflected in the
CPU-to-node map on x86 with NUMA.
Which makes this check wrong on the above topologies so circumvent it.
[ 0.444413] Booting Node 0, Processors #1#2#3#4#5 Ok.
[ 0.461388] ------------[ cut here ]------------
[ 0.465997] WARNING: at arch/x86/kernel/smpboot.c:310 topology_sane.clone.1+0x6e/0x81()
[ 0.473960] Hardware name: Dinar
[ 0.477170] sched: CPU #6's mc-sibling CPU #0 is not on the same node! [node: 1 != 0]. Ignoring dependency.
[ 0.486860] Booting Node 1, Processors #6
[ 0.491104] Modules linked in:
[ 0.494141] Pid: 0, comm: swapper/6 Not tainted 3.4.0+ #1
[ 0.499510] Call Trace:
[ 0.501946] [<ffffffff8144bf92>] ? topology_sane.clone.1+0x6e/0x81
[ 0.508185] [<ffffffff8102f1fc>] warn_slowpath_common+0x85/0x9d
[ 0.514163] [<ffffffff8102f2b7>] warn_slowpath_fmt+0x46/0x48
[ 0.519881] [<ffffffff8144bf92>] topology_sane.clone.1+0x6e/0x81
[ 0.525943] [<ffffffff8144c234>] set_cpu_sibling_map+0x251/0x371
[ 0.532004] [<ffffffff8144c4ee>] start_secondary+0x19a/0x218
[ 0.537729] ---[ end trace 4eaa2a86a8e2da22 ]---
[ 0.628197] #7#8#9#10#11 Ok.
[ 0.807108] Booting Node 3, Processors #12#13#14#15#16#17 Ok.
[ 0.897587] Booting Node 2, Processors #18#19#20#21#22#23 Ok.
[ 0.917443] Brought up 24 CPUs
We ran a topology sanity check test we have here on it and
it all looks ok... hopefully :).
Signed-off-by: Borislav Petkov <borislav.petkov@amd.com>
Cc: Andreas Herrmann <andreas.herrmann3@amd.com>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/20120529135442.GE29157@aftab.osrc.amd.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
The fixups are executed once the pci-device is found which is during
boot process so __init seems fine as long as the platform does not
support hotplug.
However it is possible to remove the PCI bus at run time and have it
rediscovered again via "echo 1 > /sys/bus/pci/rescan" and this will call
the fixups again.
Cc: x86@kernel.org
Signed-off-by: Sebastian Andrzej Siewior <sebastian@breakpoint.cc>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
CPU offline path calls the hrtimer interrupt handler with interrupts
disabled, without touching preempt_count, triggering this warning.
Remove the warning since it is supposed to be used from hrtimer
interrupt context only.
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
This is the 2nd part of fix for kernel bugzilla 40002:
"IRQ 0 assigned to VGA"
https://bugzilla.kernel.org/show_bug.cgi?id=40002
The root cause is the buggy FW, whose ACPI tables assign the GSI 16
to 2 irqs 0 and 16(VGA), and the VGA is the right owner of GSI 16.
So add a quirk to ignore the irq0 overriding GSI 16 for the
FUJITSU SIEMENS AMILO PRO V2030 platform will solve this issue.
Reported-and-tested-by: Szymon Kowalczyk <fazerxlo@o2.pl>
Signed-off-by: Feng Tang <feng.tang@intel.com>
Signed-off-by: Len Brown <len.brown@intel.com>
Current WARN msg is only for the ati_ixp4x0 board, while this function
is used by mulitple platforms. So this one board specific warning
is not appropriate any more.
Signed-off-by: Feng Tang <feng.tang@intel.com>
Signed-off-by: Len Brown <len.brown@intel.com>
Currently when acpi_skip_timer_override is set, it only cover the
(source_irq == 0 && global_irq == 2) cases. While there is also
platform which need use this option and its global_irq is not 2.
This patch will extend acpi_skip_timer_override to cover all
timer overriding cases as long as the source irq is 0.
This is the first part of a fix to kernel bug bugzilla 40002:
"IRQ 0 assigned to VGA"
https://bugzilla.kernel.org/show_bug.cgi?id=40002
Reported-and-tested-by: Szymon Kowalczyk <fazerxlo@o2.pl>
Signed-off-by: Feng Tang <feng.tang@intel.com>
Signed-off-by: Len Brown <len.brown@intel.com>
vSMP can route interrupts more optimally based on internal
knowledge the OS does not have. In order to support this
optimization, all CPUs must be able to handle all possible
IOAPIC interrupts.
Fix this by setting the vector allocation domain for all CPUs
and by enabling this feature in vSMP.
Signed-off-by: Ravikiran Thirumalai <kiran.thirumalai@gmail.com>
Signed-off-by: Shai Fultheim <shai@scalemp.com>
[ Rebased, simplified, and reworded the commit message. ]
Signed-off-by: Ido Yariv <ido@wizery.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Avi Kivity reported that page faults in NMIs could cause havic if
the NMI preempted another page fault handler:
The recent changes to NMI allow exceptions to take place in NMI
handlers, but I think that a #PF (say, due to access to vmalloc space)
is still problematic. Consider the sequence
#PF (cr2 set by processor)
NMI
...
#PF (cr2 clobbered)
do_page_fault()
IRET
...
IRET
do_page_fault()
address = read_cr2()
The last line reads the overwritten cr2 value.
This is the i386 version, which has the luxury of doing the work
in C code.
Link: http://lkml.kernel.org/r/4FBB8C40.6080304@redhat.com
Reported-by: Avi Kivity <avi@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
I've been informed by someone on LWN called 'slashdot' that
some i386 machines do not support a true cmpxchg. The cmpxchg
used by the i386 NMI nesting code must be a true cmpxchg as
disabling interrupts will not work for NMIs (which is the work
around for i386s that do not have a true cmpxchg).
This 'slashdot' character also suggested a fix to the issue.
As the state of the nesting NMIs goes as follows:
NOT_RUNNING -> EXECUTING
EXECUTING -> NOT_RUNNING
EXECUTING -> LATCHED
LATCHED -> EXECUTING
Having these states as enum values of:
NOT_RUNNING = 0
EXECUTING = 1
LATCHED = 2
Instead of a cmpxchg to make EXECUTING -> NOT_RUNNING a
dec_and_test() would work as well. If the dec_and_test brings
the state to NOT_RUNNING, that is the same as a cmpxchg
succeeding to change EXECUTING to NOT_RUNNING. If a nested NMI
were to come in and change it to LATCHED, the dec_and_test() would
convert the state to EXECUTING (what we want it to be in such a
case anyway).
I asked 'slashdot' to post this as a patch, but it never came to
be. I decided to do the work instead.
Thanks to H. Peter Anvin for suggesting to use this_cpu_dec_and_return()
instead of local_dec_and_test(&__get_cpu_var()).
Link: http://lwn.net/Articles/484932/
Cc: H. Peter Anvin <hpa@zytor.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Pull x86 fixes from Ingo Molnar.
* 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86/nmi: Fix section mismatch warnings on 32-bit
x86/uv: Fix UV2 BAU legacy mode
x86/mm: Only add extra pages count for the first memory range during pre-allocation early page table space
x86, efi stub: Add .reloc section back into image
x86/ioapic: Fix NULL pointer dereference on CPU hotplug after disabling irqs
x86/reboot: Fix a warning message triggered by stop_other_cpus()
x86/intel/moorestown: Change intel_scu_devices_create() to __devinit
x86/numa: Set numa_nodes_parsed at acpi_numa_memory_affinity_init()
x86/gart: Fix kmemleak warning
x86: mce: Add the dropped timer interval init back
x86/mce: Fix the MCE poll timer logic
Pull perf fixes from Ingo Molnar:
"A bit larger than what I'd wish for - half of it is due to hw driver
updates to Intel Ivy-Bridge which info got recently released,
cycles:pp should work there now too, amongst other things. (but we
are generally making exceptions for hardware enablement of this type.)
There are also callchain fixes in it - responding to mostly
theoretical (but valid) concerns. The tooling side sports perf.data
endianness/portability fixes which did not make it for the merge
window - and various other fixes as well."
* 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (26 commits)
perf/x86: Check user address explicitly in copy_from_user_nmi()
perf/x86: Check if user fp is valid
perf: Limit callchains to 127
perf/x86: Allow multiple stacks
perf/x86: Update SNB PEBS constraints
perf/x86: Enable/Add IvyBridge hardware support
perf/x86: Implement cycles:p for SNB/IVB
perf/x86: Fix Intel shared extra MSR allocation
x86/decoder: Fix bsr/bsf/jmpe decoding with operand-size prefix
perf: Remove duplicate invocation on perf_event_for_each
perf uprobes: Remove unnecessary check before strlist__delete
perf symbols: Check for valid dso before creating map
perf evsel: Fix 32 bit values endianity swap for sample_id_all header
perf session: Handle endianity swap on sample_id_all header data
perf symbols: Handle different endians properly during symbol load
perf evlist: Pass third argument to ioctl explicitly
perf tools: Update ioctl documentation for PERF_IOC_FLAG_GROUP
perf tools: Make --version show kernel version instead of pull req tag
perf tools: Check if callchain is corrupted
perf callchain: Make callchain cursors TLS
...
It was reported that compiling for 32-bit caused a bunch of
section mismatch warnings:
VDSOSYM arch/x86/vdso/vdso32-syms.lds
LD arch/x86/vdso/built-in.o
LD arch/x86/built-in.o
WARNING: arch/x86/built-in.o(.data+0x5af0): Section mismatch in
reference from the variable test_nmi_ipi_callback_na.10451 to
the function .init.text:test_nmi_ipi_callback() [...]
WARNING: arch/x86/built-in.o(.data+0x5b04): Section mismatch in
reference from the variable nmi_unk_cb_na.10399 to the function
.init.text:nmi_unk_cb() The variable nmi_unk_cb_na.10399
references the function __init nmi_unk_cb() [...]
Both of these are attributed to the internal representation of
the nmiaction struct created during register_nmi_handler. The
reason for this is that those structs are not defined in the
init section whereas the rest of the code in nmi_selftest.c is.
To resolve this, I created a new #define,
register_nmi_handler_initonly, that tags the struct as
__initdata to resolve the mismatch. This #define should only be
used in rare situations where the register/unregister is called
during init of the kernel.
Big thanks to Jan Beulich for decoding this for me as I didn't
have a clue what was going on.
Reported-by: Witold Baryluk <baryluk@smp.if.uj.edu.pl>
Tested-by: Witold Baryluk <baryluk@smp.if.uj.edu.pl>
Cc: Jan Beulich <JBeulich@suse.com>
Signed-off-by: Don Zickus <dzickus@redhat.com>
Link: http://lkml.kernel.org/r/1338991542-23000-1-git-send-email-dzickus@redhat.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Currently cpu_mask_to_apicid() should not get a offline CPU with
the cpumask. Otherwise some apic drivers might try to access
non-existent per-cpu variables (i.e. x2apic). In that regard
cpu_mask_to_apicid() and cpu_mask_to_apicid_and() operations are
inconsistent.
This fix makes the two operations do not rely on calling
functions and always return the apicid for only online CPUs. As
result, the meaning and implementations of cpu_mask_to_apicid()
and cpu_mask_to_apicid_and() operations become straight.
Signed-off-by: Alexander Gordeev <agordeev@redhat.com>
Acked-by: Suresh Siddha <suresh.b.siddha@intel.com>
Cc: Yinghai Lu <yinghai@kernel.org>
Link: http://lkml.kernel.org/r/20120607131624.GG4759@dhcp-26-207.brq.redhat.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Current cpu_mask_to_apicid() and cpu_mask_to_apicid_and()
implementations have few shortcomings:
1. A value returned by cpu_mask_to_apicid() is written to
hardware registers unconditionally. Should BAD_APICID get ever
returned it will be written to a hardware too. But the value of
BAD_APICID is not universal across all hardware in all modes and
might cause unexpected results, i.e. interrupts might get routed
to CPUs that are not configured to receive it.
2. Because the value of BAD_APICID is not universal it is
counter- intuitive to return it for a hardware where it does not
make sense (i.e. x2apic).
3. cpu_mask_to_apicid_and() operation is thought as an
complement to cpu_mask_to_apicid() that only applies a AND mask
on top of a cpumask being passed. Yet, as consequence of 18374d8
commit the two operations are inconsistent in that of:
cpu_mask_to_apicid() should not get a offline CPU with the cpumask
cpu_mask_to_apicid_and() should not fail and return BAD_APICID
These limitations are impossible to realize just from looking at
the operations prototypes.
Most of these shortcomings are resolved by returning a error
code instead of BAD_APICID. As the result, faults are reported
back early rather than possibilities to cause a unexpected
behaviour exist (in case of [1]).
The only exception is setup_timer_IRQ0_pin() routine. Although
obviously controversial to this fix, its existing behaviour is
preserved to not break the fragile check_timer() and would
better addressed in a separate fix.
Signed-off-by: Alexander Gordeev <agordeev@redhat.com>
Acked-by: Suresh Siddha <suresh.b.siddha@intel.com>
Cc: Yinghai Lu <yinghai@kernel.org>
Link: http://lkml.kernel.org/r/20120607131559.GF4759@dhcp-26-207.brq.redhat.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
In case of static vector allocation domains (i.e. flat) if all
vector numbers are exhausted, an attempt to assign a new vector
will lead to useless scans through all CPUs in the cpumask, even
though it is known that each new pass would fail. Make this
corner case less painful by letting report whether the vector
allocation domain depends on passed arguments or not and stop
scanning early.
The same could have been achived by introducing a static flag to
the apic operations. But let's allow vector_allocation_domain()
have more intelligence here and decide dynamically, in case we
would need it in the future.
Signed-off-by: Alexander Gordeev <agordeev@redhat.com>
Acked-by: Suresh Siddha <suresh.b.siddha@intel.com>
Cc: Yinghai Lu <yinghai@kernel.org>
Link: http://lkml.kernel.org/r/20120607131542.GE4759@dhcp-26-207.brq.redhat.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
When assigning a new vector it is primarially done by adding 8
to the previously given out vector number. Hence, two
consequently allocated vector numbers would likely fall into the
same priority level. Try to spread vector numbers to different
priority levels better by changing the step from 8 to 16.
Signed-off-by: Alexander Gordeev <agordeev@redhat.com>
Acked-by: Suresh Siddha <suresh.b.siddha@intel.com>
Cc: Yinghai Lu <yinghai@kernel.org>
Link: http://lkml.kernel.org/r/20120607131514.GD4759@dhcp-26-207.brq.redhat.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
