This patch rebase the implementation of the breakpoints API on top of
perf events instances.
Each breakpoints are now perf events that handle the
register scheduling, thread/cpu attachment, etc..
The new layering is now made as follows:
ptrace kgdb ftrace perf syscall
\ | / /
\ | / /
/
Core breakpoint API /
/
| /
| /
Breakpoints perf events
|
|
Breakpoints PMU ---- Debug Register constraints handling
(Part of core breakpoint API)
|
|
Hardware debug registers
Reasons of this rewrite:
- Use the centralized/optimized pmu registers scheduling,
implying an easier arch integration
- More powerful register handling: perf attributes (pinned/flexible
events, exclusive/non-exclusive, tunable period, etc...)
Impact:
- New perf ABI: the hardware breakpoints counters
- Ptrace breakpoints setting remains tricky and still needs some per
thread breakpoints references.
Todo (in the order):
- Support breakpoints perf counter events for perf tools (ie: implement
perf_bpcounter_event())
- Support from perf tools
Changes in v2:
- Follow the perf "event " rename
- The ptrace regression have been fixed (ptrace breakpoint perf events
weren't released when a task ended)
- Drop the struct hw_breakpoint and store generic fields in
perf_event_attr.
- Separate core and arch specific headers, drop
asm-generic/hw_breakpoint.h and create linux/hw_breakpoint.h
- Use new generic len/type for breakpoint
- Handle off case: when breakpoints api is not supported by an arch
Changes in v3:
- Fix broken CONFIG_KVM, we need to propagate the breakpoint api
changes to kvm when we exit the guest and restore the bp registers
to the host.
Changes in v4:
- Drop the hw_breakpoint_restore() stub as it is only used by KVM
- EXPORT_SYMBOL_GPL hw_breakpoint_restore() as KVM can be built as a
module
- Restore the breakpoints unconditionally on kvm guest exit:
TIF_DEBUG_THREAD doesn't anymore cover every cases of running
breakpoints and vcpu->arch.switch_db_regs might not always be
set when the guest used debug registers.
(Waiting for a reliable optimization)
Changes in v5:
- Split-up the asm-generic/hw-breakpoint.h moving to
linux/hw_breakpoint.h into a separate patch
- Optimize the breakpoints restoring while switching from kvm guest
to host. We only want to restore the state if we have active
breakpoints to the host, otherwise we don't care about messed-up
address registers.
- Add asm/hw_breakpoint.h to Kbuild
- Fix bad breakpoint type in trace_selftest.c
Changes in v6:
- Fix wrong header inclusion in trace.h (triggered a build
error with CONFIG_FTRACE_SELFTEST
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Prasad <prasad@linux.vnet.ibm.com>
Cc: Alan Stern <stern@rowland.harvard.edu>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Jan Kiszka <jan.kiszka@web.de>
Cc: Jiri Slaby <jirislaby@gmail.com>
Cc: Li Zefan <lizf@cn.fujitsu.com>
Cc: Avi Kivity <avi@redhat.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Masami Hiramatsu <mhiramat@redhat.com>
Cc: Paul Mundt <lethal@linux-sh.org>
We plan to make the breakpoints parameters generic among architectures.
For that it's better to move the asm-generic header to a generic linux
header.
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
flush_thread() tries to do a TIF_DEBUG check before calling in to
flush_thread_hw_breakpoint() (which subsequently clears the thread flag),
but for some reason, the x86 code is manually clearing TIF_DEBUG
immediately before the test, so this path will never be taken.
This kills off the erroneous clear_tsk_thread_flag() and lets
flush_thread_hw_breakpoint() actually get invoked.
Presumably folks were getting lucky with testing and the
free_thread_info() -> free_thread_xstate() path was taking care of the
flush there.
Signed-off-by: Paul Mundt <lethal@linux-sh.org>
Acked-by: "K.Prasad" <prasad@linux.vnet.ibm.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Alan Stern <stern@rowland.harvard.edu>
LKML-Reference: <20091005102306.GA7889@linux-sh.org>
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Conflicts:
kernel/Makefile
kernel/trace/Makefile
kernel/trace/trace.h
samples/Makefile
Merge reason: We need to be uptodate with the perf events development
branch because we plan to rewrite the breakpoints API on top of
perf events.
Merge reason: to add event filter support we need the following
commits from the tracing tree:
3f6fe06: tracing/filters: Unify the regex parsing helpers
1889d20: tracing/filters: Provide basic regex support
737f453: tracing/filters: Cleanup useless headers
Signed-off-by: Ingo Molnar <mingo@elte.hu>
* 'x86-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
x86/paravirt: Use normal calling sequences for irq enable/disable
x86: fix kernel panic on 32 bits when profiling
x86: Fix Suspend to RAM freeze on Acer Aspire 1511Lmi laptop
x86, vmi: Mark VMI deprecated and schedule it for removal
The linker scripts grew some use of weirdly wrong linker script syntax.
It happens to work, but it's not what the syntax is documented to be.
Clean it up to use the official syntax.
Signed-off-by: Roland McGrath <roland@redhat.com>
CC: Ian Lance Taylor <iant@google.com>
Most of the syscalls metadata processing is done from arch.
But these operations are mostly generic accross archs. Especially now
that we have a common variable name that expresses the number of
syscalls supported by an arch: NR_syscalls, the only remaining bits
that need to reside in arch is the syscall nr to addr translation.
v2: Compare syscalls symbols only after the "sys" prefix so that we
avoid spurious mismatches with archs that have syscalls wrappers,
in which case syscalls symbols have "SyS" prefixed aliases.
(Reported by: Heiko Carstens)
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Acked-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Li Zefan <lizf@cn.fujitsu.com>
Cc: Masami Hiramatsu <mhiramat@redhat.com>
Cc: Jason Baron <jbaron@redhat.com>
Cc: Lai Jiangshan <laijs@cn.fujitsu.com>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Paul Mundt <lethal@linux-sh.org>
The function graph tracer replaces the return address with a hook
to trace the exit of the function call. This hook will finish by
returning to the real location the function should return to.
But the current implementation uses a ret to jump to the real
return location. This causes a imbalance between calls and ret.
That is the original function does a call, the ret goes to the
handler and then the handler does a ret without a matching call.
Although the function graph tracer itself still breaks the branch
predictor by replacing the original ret, by using a second ret and
causing an imbalance, it breaks the predictor even more.
This patch replaces the ret with a jmp to keep the calls and ret
balanced. I tested this on one box and it showed a 1.7% increase in
performance. Another box only showed a small 0.3% increase. But no
box that I tested this on showed a decrease in performance by
making this change.
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Acked-by: Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
LKML-Reference: <20091013203425.042034383@goodmis.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
* git://git.infradead.org/~dwmw2/iommu-2.6.32:
x86: Move pci_iommu_init to rootfs_initcall()
Run pci_apply_final_quirks() sooner.
Mark pci_apply_final_quirks() __init rather than __devinit
Rename pci_init() to pci_apply_final_quirks(), move it to quirks.c
intel-iommu: Yet another BIOS workaround: Isoch DMAR unit with no TLB space
intel-iommu: Decode (and ignore) RHSA entries
intel-iommu: Make "Unknown DMAR structure" message more informative
Bastian Blank reported a boot crash with stackprotector enabled,
and debugged it back to edx register corruption.
For historical reasons irq enable/disable/save/restore had special
calling sequences to make them more efficient. With the more
recent introduction of higher-level and more general optimisations
this is no longer necessary so we can just use the normal PVOP_
macros.
This fixes some residual bugs in the old implementations which left
edx liable to inadvertent clobbering. Also, fix some bugs in
__PVOP_VCALLEESAVE which were revealed by actual use.
Reported-by: Bastian Blank <bastian@waldi.eu.org>
Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Cc: Stable Kernel <stable@kernel.org>
Cc: Xen-devel <xen-devel@lists.xensource.com>
LKML-Reference: <4AD3BC9B.7040501@goop.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
There was namespace overlap due to a rename i did - this caused
the following build warning, reported by Stephen Rothwell against
linux-next x86_64 allmodconfig:
arch/x86/kernel/cpu/perf_event.c: In function 'intel_get_event_idx':
arch/x86/kernel/cpu/perf_event.c:1445: warning: 'event_constraint' is used uninitialized in this function
This is a real bug not just a warning: fix it by renaming the
global event-constraints table pointer to 'event_constraints'.
Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Cc: Stephane Eranian <eranian@gmail.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
LKML-Reference: <20091013144223.369d616d.sfr@canb.auug.org.au>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Latest kernel has a kernel panic in booting on i386 machine when
profile=2 setting in cmdline. It is due to 'sp' being incorrect in
profile_pc().
BUG: unable to handle kernel NULL pointer dereference at 00000246
IP: [<c01288b6>] profile_pc+0x2a/0x48
*pde = 00000000
Oops: 0000 [#1] SMP
This differs from the original version by Alex Shi in that we use the
kernel_stack_pointer() inline already defined in <asm/ptrace.h> for
this purpose, instead of #ifdef.
Originally-by: Alex Shi <alex.shi@intel.com>
Cc: "Chen, Tim C" <tim.c.chen@intel.com>
Cc: "Rafael J. Wysocki" <rjw@sisk.pl>
Cc: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
Move the trampoline and accessors back out of .cpuinit.* for the
case of 64-bits+ACPI_SLEEP.
This solves s2ram hangs reported in:
http://bugzilla.kernel.org/show_bug.cgi?id=14279
Reported-and-bisected-by: Christian Casteyde <casteyde.christian@free.fr>
Signed-off-by: Jan Beulich <jbeulich@novell.com>
Cc: <bugzilla-daemon@bugzilla.kernel.org>
Cc: "Andrew Morton" <akpm@linux-foundation.org>
Cc: "Rafael J. Wysocki" <rjw@sisk.pl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
We want this to happen after the PCI quirks, which are now running at
the very end of the fs_initcalls.
This works around the BIOS problems which were originally addressed by
commit db8be50c43 ('USB: Work around BIOS
bugs by quiescing USB controllers earlier'), which was reverted in
commit d93a8f829f.
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
- Remove prefixes from pr_<level>, use pr_fmt(fmt).
No change in output.
Signed-off-by: Joe Perches <joe@perches.com>
Acked-by: Steven Rostedt <rostedt@goodmis.org>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
LKML-Reference: <9b377eefae9e28c599dd4a17bdc81172965e9931.1254701151.git.joe@perches.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
As reported in
http://bugzilla.kernel.org/show_bug.cgi?id=13940
on some system when acpi are enabled, acpi clears some BAR for some
devices without reason, and kernel will need to allocate devices for
them. It then apparently hits some undocumented resource conflict,
resulting in non-working devices.
Try to increase alignment to get more safe range for unassigned devices.
Signed-off-by: Yinghai Lu <yinghai@kernel.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
After m68k's task_thread_info() doesn't refer to current,
it's possible to remove sched.h from interrupt.h and not break m68k!
Many thanks to Heiko Carstens for allowing this.
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
This reverts commit 9bcbdd9c58.
The real bug producing LatencyTop latencies has been fixed in:
f5dc375: sched: Update the clock of runqueue select_task_rq() selected
And the commit being reverted here triggers local timer processing
from every device IRQ. If device IRQs come in at a high frequency,
this could cause a performance regression.
The commit being reverted here purely 'fixed' the reported latency
as a side effect, because CPUs were being moved out of idle more
often.
Acked-by: Peter Zijlstra <peterz@infradead.org>
Cc: Arjan van de Ven <arjan@linux.intel.com>
Cc: Frans Pop <elendil@planet.nl>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Thomas Gleixner <tglx@linutronix.de>
LKML-Reference: <20091008064041.67219b13@infradead.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Refuse to add events when the group wouldn't fit onto the PMU
anymore.
Naive implementation.
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Stephane Eranian <eranian@gmail.com>
LKML-Reference: <1254911461.26976.239.camel@twins>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
On some Intel processors, not all events can be measured in all
counters. Some events can only be measured in one particular
counter, for instance. Assigning an event to the wrong counter does
not crash the machine but this yields bogus counts, i.e., silent
error.
This patch changes the event to counter assignment logic to take
into account event constraints for Intel P6, Core and Nehalem
processors. There is no contraints on Intel Atom. There are
constraints on Intel Yonah (Core Duo) but they are not provided in
this patch given that this processor is not yet supported by
perf_events.
As a result of the constraints, it is possible for some event
groups to never actually be loaded onto the PMU if they contain two
events which can only be measured on a single counter. That
situation can be detected with the scaling information extracted
with read().
Signed-off-by: Stephane Eranian <eranian@gmail.com>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <1254840129-6198-3-git-send-email-eranian@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Intel fixed counters do not support all the filters possible with a
generic counter. Thus, if a fixed counter event is passed but with
certain filters set, then the fixed_mode_idx() function must fail
and the event must be measured in a generic counter instead.
Reject filters are: inv, edge, cnt-mask.
Signed-off-by: Stephane Eranian <eranian@gmail.com>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <1254840129-6198-2-git-send-email-eranian@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Add text in feature-removal.txt indicating that VMI will be removed in
the 2.6.37 timeframe.
Signed-off-by: Alok N Kataria <akataria@vmware.com>
Acked-by: Chris Wright <chrisw@sous-sol.org>
LKML-Reference: <1254193238.13456.48.camel@ank32.eng.vmware.com>
[ removed a bogus Kconfig change, marked (DEPRECATED) in Kconfig ]
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Now that range timers and deferred timers are common, I found a
problem with these using the "perf timechart" tool. Frans Pop also
reported high scheduler latencies via LatencyTop, when using
iwlagn.
It turns out that on x86, these two 'opportunistic' timers only get
checked when another "real" timer happens. These opportunistic
timers have the objective to save power by hitchhiking on other
wakeups, as to avoid CPU wakeups by themselves as much as possible.
The change in this patch runs this check not only at timer
interrupts, but at all (device) interrupts. The effect is that:
1) the deferred timers/range timers get delayed less
2) the range timers cause less wakeups by themselves because
the percentage of hitchhiking on existing wakeup events goes up.
I've verified the working of the patch using "perf timechart", the
original exposed bug is gone with this patch. Frans also reported
success - the latencies are now down in the expected ~10 msec
range.
Signed-off-by: Arjan van de Ven <arjan@linux.intel.com>
Tested-by: Frans Pop <elendil@planet.nl>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Mike Galbraith <efault@gmx.de>
LKML-Reference: <20091008064041.67219b13@infradead.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
* 'kvm-updates/2.6.32' of git://git.kernel.org/pub/scm/virt/kvm/kvm:
KVM: add support for change_pte mmu notifiers
KVM: MMU: add SPTE_HOST_WRITEABLE flag to the shadow ptes
KVM: MMU: dont hold pagecount reference for mapped sptes pages
KVM: Prevent overflow in KVM_GET_SUPPORTED_CPUID
KVM: VMX: flush TLB with INVEPT on cpu migration
KVM: fix LAPIC timer period overflow
KVM: s390: fix memsize >= 4G
KVM: SVM: Handle tsc in svm_get_msr/svm_set_msr correctly
KVM: SVM: Fix tsc offset adjustment when running nested
this is needed for kvm if it want ksm to directly map pages into its
shadow page tables.
[marcelo: cast pfn assignment to u64]
Signed-off-by: Izik Eidus <ieidus@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
this flag notify that the host physical page we are pointing to from
the spte is write protected, and therefore we cant change its access
to be write unless we run get_user_pages(write = 1).
(this is needed for change_pte support in kvm)
Signed-off-by: Izik Eidus <ieidus@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
When using mmu notifiers, we are allowed to remove the page count
reference tooken by get_user_pages to a specific page that is mapped
inside the shadow page tables.
This is needed so we can balance the pagecount against mapcount
checking.
(Right now kvm increase the pagecount and does not increase the
mapcount when mapping page into shadow page table entry,
so when comparing pagecount against mapcount, you have no
reliable result.)
Signed-off-by: Izik Eidus <ieidus@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
The number of entries is multiplied by the entry size, which can
overflow on 32-bit hosts. Bound the entry count instead.
Reported-by: David Wagner <daw@cs.berkeley.edu>
Cc: stable@kernel.org
Signed-off-by: Avi Kivity <avi@redhat.com>
It is possible that stale EPTP-tagged mappings are used, if a
vcpu migrates to a different pcpu.
Set KVM_REQ_TLB_FLUSH in vmx_vcpu_load, when switching pcpus, which
will invalidate both VPID and EPT mappings on the next vm-entry.
Cc: stable@kernel.org
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
When running nested we need to touch the l1 guests
tsc_offset. Otherwise changes will be lost or a wrong value
be read.
Cc: stable@kernel.org
Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
When svm_vcpu_load is called while the vcpu is running in
guest mode the tsc adjustment made there is lost on the next
emulated #vmexit. This causes the tsc running backwards in
the guest. This patch fixes the issue by also adjusting the
tsc_offset in the emulated hsave area so that it will not
get lost.
Cc: stable@kernel.org
Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
The current bound checks for copy_from_user in the MTRR driver are
not as obvious as they could be, and gcc agrees with that.
This patch simplifies the boundary checks to the point that gcc can
now prove to itself that the copy_from_user() is never going past
its bounds.
Signed-off-by: Arjan van de Ven <arjan@linux.intel.com>
Cc: Yinghai Lu <yinghai@kernel.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
LKML-Reference: <20090926205150.30797709@infradead.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Make decoding of MCEs happen only on AMD hardware by registering a
non-default callback only on CPU families which support it.
While looking at the interaction of decode_mce() with the other MCE
code i also noticed a few other things and made the following
cleanups/fixes:
- Fixed the mce_decode() weak alias - a weak alias is really not
good here, it should be a proper callback. A weak alias will be
overriden if a piece of code is built into the kernel - not
good, obviously.
- The patch initializes the callback on AMD family 10h and 11h.
- Added the more correct fallback printk of:
No support for human readable MCE decoding on this CPU type.
Transcribe the message and run it through 'mcelog --ascii' to decode.
On CPUs that dont have a decoder.
- Made the surrounding code more readable.
Note that the callback allows us to have a default fallback -
without having to check the CPU versions during the printout
itself. When an EDAC module registers itself, it can install the
decode-print function.
(there's no unregister needed as this is core code.)
version -v2 by Borislav Petkov:
- add K8 to the set of supported CPUs
- always build in edac_mce_amd since we use an early_initcall now
- fix checkpatch warnings
Signed-off-by: Borislav Petkov <borislav.petkov@amd.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Andi Kleen <andi@firstfloor.org>
LKML-Reference: <20091001141432.GA11410@aftab>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Just like ip_fast_csum, the assembly snippet in csum_ipv6_magic needs a
memory clobber, as it is only passed the address of the buffer, not a
memory reference to the buffer itself.
This caused failures in Hurd's pfinetv4 when we tried to compile it with
gcc-4.3 (bogus checksums).
Signed-off-by: Samuel Thibault <samuel.thibault@ens-lyon.org>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Acked-by: "David S. Miller" <davem@davemloft.net>
Cc: Andi Kleen <andi@firstfloor.org>
Cc: <stable@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
While 32-bit processes can't directly access R8...R15, they can
gain access to these registers by temporarily switching themselves
into 64-bit mode.
Therefore, registers not preserved anyway by called C functions
(i.e. R8...R11) must be cleared prior to returning to user mode.
Signed-off-by: Jan Beulich <jbeulich@novell.com>
Cc: <stable@kernel.org>
LKML-Reference: <4AC34D73020000780001744A@vpn.id2.novell.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Remove unused CONFIG FAST_CMPXCHG_LOCAL from Kconfig.
Reported-by: Robert P. J. Day <rpjday@crashcourse.ca>
Signed-off-by: Jaswinder Singh Rajput <jaswinderrajput@gmail.com>
Acked-by: Christoph Lameter <cl@linux-foundation.org>
Cc: Pekka Enberg <penberg@cs.helsinki.fi>
Cc: Matt Mackall <mpm@selenic.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: "Robert P. J. Day" <rpjday@crashcourse.ca>
Cc: linux-mm@kvack.org
LKML-Reference: <1253981501.4568.61.camel@ht.satnam>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Commit c953094 ("early_printk: Allow more than one early console")
introduced a regression in the parsing of the earlyprintk= kernel
arguments.
If you specify "earlyprintk=serial,ttyS0,115200" as a kernel
argument, the "serial,ttyS" should be parsed as a single argument
and not as "serial" and then "ttyS".
Also update the documentation to reflect you can specify the ttyS
directly without the "serial" argument.
Signed-off-by: Jason Wessel <jason.wessel@windriver.com>
Cc: Len Brown <lenb@kernel.org>
Cc: Greg KH <gregkh@suse.de>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Johannes Weiner <hannes@cmpxchg.org>
LKML-Reference: <4ABB7D5E.6000301@windriver.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Conditionaly compile cmpxchg8b_emu.o and EXPORT_SYMBOL(cmpxchg8b_emu).
This reduces the kernel size a bit.
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Cc: Arjan van de Ven <arjan@infradead.org>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: John Stultz <johnstul@us.ibm.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
LKML-Reference: <4AC43E7E.1000600@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
