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  • Christian Dietrich Christian Dietrich ccd5802
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  • Yannick Loeck Yannick Loeck cyl4616
4 authors
  1. Aug 05, 2013
    • Vince Weaver's avatar
      perf/x86: Fix intel QPI uncore event definitions · c9601247
      Vince Weaver authored 
      
John McCalpin reports that the "drs_data" and "ncb_data" QPI
uncore events are missing the "extra bit" and always return zero
values unless the bit is properly set.

More details from him:

 According to the Xeon E5-2600 Product Family Uncore Performance
 Monitoring Guide, Table 2-94, about 1/2 of the QPI Link Layer events
 (including the ones that "perf" calls "drs_data" and "ncb_data") require
 that the "extra bit" be set.

 This was confusing for a while -- a note at the bottom of page 94 says
 that the "extra bit" is bit 16 of the control register.
 Unfortunately, Table 2-86 clearly says that bit 16 is reserved and must
 be zero.  Looking around a bit, I found that bit 21 appears to be the
 correct "extra bit", and further investigation shows that "perf" actually
 agrees with me:
	[root@c560-003.stampede]# cat /sys/bus/event_source/devices/uncore_qpi_0/format/event
	config:0-7,21

 So the command
	# perf -e "uncore_qpi_0/event=drs_data/"
 Is the same as
	# perf -e "uncore_qpi_0/event=0x02,umask=0x08/"
 While it should be
	# perf -e "uncore_qpi_0/event=0x102,umask=0x08/"

 I confirmed that this last version gives results that agree with the
 amount of data that I expected the STREAM benchmark to move across the QPI
 link in the second (cross-chip) test of the original script.

Reported-by: default avatarJohn McCalpin <mccalpin@tacc.utexas.edu>
Signed-off-by: default avatarVince Weaver <vincent.weaver@maine.edu>
Cc: zheng.z.yan@intel.com
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Arnaldo Carvalho de Melo <acme@ghostprotocols.net>
Cc: Paul Mackerras <paulus@samba.org>
Cc: <stable@kernel.org>
Link: http://lkml.kernel.org/r/alpine.DEB.2.10.1308021037280.26119@vincent-weaver-1.um.maine.edu


Signed-off-by: default avatarIngo Molnar <mingo@kernel.org>
      c9601247
  3. Jul 31, 2013
  5. Jul 29, 2013
  7. Jul 24, 2013
  9. Jul 19, 2013
  11. Jul 18, 2013
  13. Jul 17, 2013
    • Kees Cook's avatar
      x86: Make sure IDT is page aligned · 4df05f36
      Kees Cook authored 
      
Since the IDT is referenced from a fixmap, make sure it is page aligned.
Merge with 32-bit one, since it was already aligned to deal with F00F
bug. Since bss is cleared before IDT setup, it can live there. This also
moves the other *_idt_table variables into common locations.

This avoids the risk of the IDT ever being moved in the bss and having
the mapping be offset, resulting in calling incorrect handlers. In the
current upstream kernel this is not a manifested bug, but heavily patched
kernels (such as those using the PaX patch series) did encounter this bug.

The tables other than idt_table technically do not need to be page
aligned, at least not at the current time, but using a common
declaration avoids mistakes.  On 64 bits the table is exactly one page
long, anyway.

Signed-off-by: default avatarKees Cook <keescook@chromium.org>
Link: http://lkml.kernel.org/r/20130716183441.GA14232@www.outflux.net


Reported-by: default avatarPaX Team <pageexec@gmail.com>
Signed-off-by: default avatarH. Peter Anvin <hpa@linux.intel.com>
      4df05f36
  15. Jul 15, 2013
    • H. Peter Anvin's avatar
      x86, suspend: Handle CPUs which fail to #GP on RDMSR · 5ff560fd
      H. Peter Anvin authored 
      
There are CPUs which have errata causing RDMSR of a nonexistent MSR to
not fault.  We would then try to WRMSR to restore the value of that
MSR, causing a crash.  Specifically, some Pentium M variants would
have this problem trying to save and restore the non-existent EFER,
causing a crash on resume.

Work around this by making sure we can write back the result at
suspend time.

Huge thanks to Christian Sünkenberg for finding the offending erratum
that finally deciphered the mystery.

Reported-and-tested-by: default avatarJohan Heinrich <onny@project-insanity.org>
Debugged-by: default avatarChristian Sünkenberg <christian.suenkenberg@student.kit.edu>
Acked-by: default avatarRafael J. Wysocki <rjw@sisk.pl>
Link: http://lkml.kernel.org/r/51DDC972.3010005@student.kit.edu
Cc: <stable@vger.kernel.org> # v3.7+
      5ff560fd
    • Paul Gortmaker's avatar
      x86: delete __cpuinit usage from all x86 files · 148f9bb8
      Paul Gortmaker authored 
      The __cpuinit type of throwaway sections might have made sense
some time ago when RAM was more constrained, but now the savings
do not offset the cost and complications.  For example, the fix in
commit 5e427ec2 ("x86: Fix bit corruption at CPU resume time")
is a good example of the nasty type of bugs that can be created
with improper use of the various __init prefixes.

After a discussion on LKML[1] it was decided that cpuinit should go
the way of devinit and be phased out.  Once all the users are gone,
we can then finally remove the macros themselves from linux/init.h.

Note that some harmless section mismatch warnings may result, since
notify_cpu_starting() and cpu_up() are arch independent (kernel/cpu.c)
are flagged as __cpuinit  -- so if we remove the __cpuinit from
arch specific callers, we will also get section mismatch warnings.
As an intermediate step, we intend to turn the linux/init.h cpuinit
content into no-ops as early as possible, since that will get rid
of these warnings.  In any case, they are temporary and harmless.

This removes all the arch/x86 uses of the __cpuinit macros from
all C files.  x86 only had the one __CPUINIT used in assembly files,
and it wasn't paired off with a .previous or a __FINIT, so we can
delete it directly w/o any corresponding additional change there.

[1] https://lkml.org/lkml/2013/5/20/589



Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: x86@kernel.org
Acked-by: default avatarIngo Molnar <mingo@kernel.org>
Acked-by: default avatarThomas Gleixner <tglx@linutronix.de>
Acked-by: default avatarH. Peter Anvin <hpa@linux.intel.com>
Signed-off-by: default avatarPaul Gortmaker <paul.gortmaker@windriver.com>
      148f9bb8
  17. Jul 12, 2013
  19. Jul 11, 2013
  21. Jul 09, 2013
  23. Jul 05, 2013
  25. Jul 04, 2013
    • Dave Hansen's avatar
      consolidate per-arch stack overflow debugging options · d1a1dc0b
      Dave Hansen authored 
      Original posting:

	http://lkml.kernel.org/r/20121214184202.F54094D9@kernel.stglabs.ibm.com



Several architectures have similar stack debugging config options.
They all pretty much do the same thing, some with slightly
differing help text.

This patch changes the architectures to instead enable a Kconfig
boolean, and then use that boolean in the generic Kconfig.debug
to present the actual menu option.  This removes a bunch of
duplication and adds consistency across arches.

Signed-off-by: default avatarDave Hansen <dave@linux.vnet.ibm.com>
Reviewed-by: default avatarH. Peter Anvin <hpa@zytor.com>
Reviewed-by: default avatarJames Hogan <james.hogan@imgtec.com>
Acked-by: Chris Metcalf <cmetcalf@tilera.com> [for tile]
Signed-off-by: default avatarDave Hansen <dave.hansen@linux.intel.com>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      d1a1dc0b
    • Gleb Natapov's avatar
      KVM: VMX: mark unusable segment as nonpresent · 03617c18
      Gleb Natapov authored 
      
Some userspaces do not preserve unusable property. Since usable
segment has to be present according to VMX spec we can use present
property to amend userspace bug by making unusable segment always
nonpresent. vmx_segment_access_rights() already marks nonpresent segment
as unusable.

Cc: stable@vger.kernel.org # 3.9+
Reported-by: default avatarStefan Pietsch <stefan.pietsch@lsexperts.de>
Tested-by: default avatarStefan Pietsch <stefan.pietsch@lsexperts.de>
Signed-off-by: default avatarGleb Natapov <gleb@redhat.com>
Signed-off-by: default avatarPaolo Bonzini <pbonzini@redhat.com>
      03617c18
    • Alexandre Bounine's avatar
      rapidio: add modular build option for the subsystem core · fdf90abc
      Alexandre Bounine authored 
      
Add a configuration option to build RapidIO subsystem core code as a
loadable kernel module.  Currently this option is available only for
x86-based platforms, with the additional patch for PowerPC planned to be
provided later.

This patch replaces kernel command line parameter "riohdid=" with its
module-specific analog "rapidio.hdid=".

Signed-off-by: default avatarAlexandre Bounine <alexandre.bounine@idt.com>
Cc: Matt Porter <mporter@kernel.crashing.org>
Cc: Li Yang <leoli@freescale.com>
Cc: Kumar Gala <galak@kernel.crashing.org>
Cc: Andre van Herk <andre.van.herk@Prodrive.nl>
Cc: Micha Nelissen <micha.nelissen@Prodrive.nl>
Cc: Stef van Os <stef.van.os@Prodrive.nl>
Cc: Jean Delvare <jdelvare@suse.de>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      fdf90abc
    • Oleg Nesterov's avatar
      x86: kill TIF_DEBUG · 37f07655
      Oleg Nesterov authored 
      
Because it is not used.

Signed-off-by: default avatarOleg Nesterov <oleg@redhat.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Jan Kratochvil <jan.kratochvil@redhat.com>
Cc: Michael Neuling <mikey@neuling.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Paul Mundt <lethal@linux-sh.org>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Prasad <prasad@linux.vnet.ibm.com>
Cc: Russell King <linux@arm.linux.org.uk>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      37f07655
    • Jiang Liu's avatar
      mm/x86: prepare for removing num_physpages and simplify mem_init() · 46a84132
      Jiang Liu authored 
      
Prepare for removing num_physpages and simplify mem_init().

Signed-off-by: default avatarJiang Liu <jiang.liu@huawei.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Andreas Herrmann <andreas.herrmann3@amd.com>
Cc: Tang Chen <tangchen@cn.fujitsu.com>
Cc: Wen Congyang <wency@cn.fujitsu.com>
Cc: Jianguo Wu <wujianguo@huawei.com>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      46a84132
    • Jiang Liu's avatar
      mm: concentrate modification of totalram_pages into the mm core · 0c988534
      Jiang Liu authored 
      
Concentrate code to modify totalram_pages into the mm core, so the arch
memory initialized code doesn't need to take care of it.  With these
changes applied, only following functions from mm core modify global
variable totalram_pages: free_bootmem_late(), free_all_bootmem(),
free_all_bootmem_node(), adjust_managed_page_count().

With this patch applied, it will be much more easier for us to keep
totalram_pages and zone->managed_pages in consistence.

Signed-off-by: default avatarJiang Liu <jiang.liu@huawei.com>
Acked-by: default avatarDavid Howells <dhowells@redhat.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: "Michael S. Tsirkin" <mst@redhat.com>
Cc: <sworddragon2@aol.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Chris Metcalf <cmetcalf@tilera.com>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jeremy Fitzhardinge <jeremy@goop.org>
Cc: Jianguo Wu <wujianguo@huawei.com>
Cc: Joonsoo Kim <js1304@gmail.com>
Cc: Kamezawa Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Cc: Marek Szyprowski <m.szyprowski@samsung.com>
Cc: Mel Gorman <mel@csn.ul.ie>
Cc: Michel Lespinasse <walken@google.com>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Rik van Riel <riel@redhat.com>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: Tang Chen <tangchen@cn.fujitsu.com>
Cc: Tejun Heo <tj@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Wen Congyang <wency@cn.fujitsu.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com>
Cc: Yinghai Lu <yinghai@kernel.org>
Cc: Russell King <rmk@arm.linux.org.uk>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      0c988534
    • Jiang Liu's avatar
      mm: make __free_pages_bootmem() only available at boot time · 170a5a7e
      Jiang Liu authored 
      
In order to simpilify management of totalram_pages and
zone->managed_pages, make __free_pages_bootmem() only available at boot
time.  With this change applied, __free_pages_bootmem() will only be
used by bootmem.c and nobootmem.c at boot time, so mark it as __init.
Other callers of __free_pages_bootmem() have been converted to use
free_reserved_page(), which handles totalram_pages and
zone->managed_pages in a safer way.

This patch also fix a bug in free_pagetable() for x86_64, which should
increase zone->managed_pages instead of zone->present_pages when freeing
reserved pages.

And now we have managed_pages_count_lock to protect totalram_pages and
zone->managed_pages, so remove the redundant ppb_lock lock in
put_page_bootmem().  This greatly simplifies the locking rules.

Signed-off-by: default avatarJiang Liu <jiang.liu@huawei.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Yinghai Lu <yinghai@kernel.org>
Cc: Wen Congyang <wency@cn.fujitsu.com>
Cc: Tang Chen <tangchen@cn.fujitsu.com>
Cc: Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com>
Cc: Mel Gorman <mel@csn.ul.ie>
Cc: Minchan Kim <minchan@kernel.org>
Cc: "Michael S. Tsirkin" <mst@redhat.com>
Cc: <sworddragon2@aol.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Chris Metcalf <cmetcalf@tilera.com>
Cc: David Howells <dhowells@redhat.com>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Jeremy Fitzhardinge <jeremy@goop.org>
Cc: Jianguo Wu <wujianguo@huawei.com>
Cc: Joonsoo Kim <js1304@gmail.com>
Cc: Kamezawa Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Cc: Marek Szyprowski <m.szyprowski@samsung.com>
Cc: Michel Lespinasse <walken@google.com>
Cc: Rik van Riel <riel@redhat.com>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: Tejun Heo <tj@kernel.org>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Russell King <rmk@arm.linux.org.uk>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      170a5a7e
    • Jiang Liu's avatar
      mm: accurately calculate zone->managed_pages for highmem zones · 7b4b2a0d
      Jiang Liu authored 
      
Commit "mm: introduce new field 'managed_pages' to struct zone" assumes
that all highmem pages will be freed into the buddy system by function
mem_init().  But that's not always true, some architectures may reserve
some highmem pages during boot.  For example PPC may allocate highmem
pages for giagant HugeTLB pages, and several architectures have code to
check PageReserved flag to exclude highmem pages allocated during boot
when freeing highmem pages into the buddy system.

So treat highmem pages in the same way as normal pages, that is to:
1) reset zone->managed_pages to zero in mem_init().
2) recalculate managed_pages when freeing pages into the buddy system.

Signed-off-by: default avatarJiang Liu <jiang.liu@huawei.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Tejun Heo <tj@kernel.org>
Cc: Joonsoo Kim <js1304@gmail.com>
Cc: Yinghai Lu <yinghai@kernel.org>
Cc: Mel Gorman <mel@csn.ul.ie>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Kamezawa Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Marek Szyprowski <m.szyprowski@samsung.com>
Cc: "Michael S. Tsirkin" <mst@redhat.com>
Cc: <sworddragon2@aol.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Chris Metcalf <cmetcalf@tilera.com>
Cc: David Howells <dhowells@redhat.com>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jeremy Fitzhardinge <jeremy@goop.org>
Cc: Jianguo Wu <wujianguo@huawei.com>
Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Cc: Michel Lespinasse <walken@google.com>
Cc: Rik van Riel <riel@redhat.com>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: Tang Chen <tangchen@cn.fujitsu.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Wen Congyang <wency@cn.fujitsu.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com>
Cc: Russell King <rmk@arm.linux.org.uk>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      7b4b2a0d
    • Jiang Liu's avatar
      mm/x86: use free_reserved_area() to simplify code · c88442ec
      Jiang Liu authored 
      
Use common help function free_reserved_area() to simplify code.

Signed-off-by: default avatarJiang Liu <jiang.liu@huawei.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Yinghai Lu <yinghai@kernel.org>
Cc: Tang Chen <tangchen@cn.fujitsu.com>
Cc: Wen Congyang <wency@cn.fujitsu.com>
Cc: Jianguo Wu <wujianguo@huawei.com>
Cc: "Michael S. Tsirkin" <mst@redhat.com>
Cc: <sworddragon2@aol.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Chris Metcalf <cmetcalf@tilera.com>
Cc: David Howells <dhowells@redhat.com>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Jeremy Fitzhardinge <jeremy@goop.org>
Cc: Joonsoo Kim <js1304@gmail.com>
Cc: Kamezawa Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Cc: Marek Szyprowski <m.szyprowski@samsung.com>
Cc: Mel Gorman <mel@csn.ul.ie>
Cc: Michel Lespinasse <walken@google.com>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Rik van Riel <riel@redhat.com>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: Tejun Heo <tj@kernel.org>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com>
Cc: Russell King <rmk@arm.linux.org.uk>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      c88442ec
    • Pavel Emelyanov's avatar
      mm: soft-dirty bits for user memory changes tracking · 0f8975ec
      Pavel Emelyanov authored 
      
The soft-dirty is a bit on a PTE which helps to track which pages a task
writes to.  In order to do this tracking one should

  1. Clear soft-dirty bits from PTEs ("echo 4 > /proc/PID/clear_refs)
  2. Wait some time.
  3. Read soft-dirty bits (55'th in /proc/PID/pagemap2 entries)

To do this tracking, the writable bit is cleared from PTEs when the
soft-dirty bit is.  Thus, after this, when the task tries to modify a
page at some virtual address the #PF occurs and the kernel sets the
soft-dirty bit on the respective PTE.

Note, that although all the task's address space is marked as r/o after
the soft-dirty bits clear, the #PF-s that occur after that are processed
fast.  This is so, since the pages are still mapped to physical memory,
and thus all the kernel does is finds this fact out and puts back
writable, dirty and soft-dirty bits on the PTE.

Another thing to note, is that when mremap moves PTEs they are marked
with soft-dirty as well, since from the user perspective mremap modifies
the virtual memory at mremap's new address.

Signed-off-by: default avatarPavel Emelyanov <xemul@parallels.com>
Cc: Matt Mackall <mpm@selenic.com>
Cc: Xiao Guangrong <xiaoguangrong@linux.vnet.ibm.com>
Cc: Glauber Costa <glommer@parallels.com>
Cc: Marcelo Tosatti <mtosatti@redhat.com>
Cc: KOSAKI Motohiro <kosaki.motohiro@gmail.com>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      0f8975ec
  27. Jul 02, 2013
    • Seiji Aguchi's avatar
      x86/tracing: Add irq_enter/exit() in smp_trace_reschedule_interrupt() · 4787c368
      Seiji Aguchi authored 
      
Reschedule vector tracepoints may be called in cpu idle state.
This causes lockdep check warning below.

The tracepoint requires rcu but for accuracy it also
requires irq_enter() (tracepoints record the irq context), thus,
the tracepoint interrupt handler should be calling irq_enter()
and not rcu_irq_enter() (irq_enter() calls rcu_irq_enter()).

So, add irq_enter/exit() to smp_trace_reschedule_interrupt()
with common pre/post processing functions, smp_entering_irq()
and exiting_irq() (exiting_irq() calls just irq_exit()
 in arch/x86/include/asm/apic.h),
because these can be shared among reschedule, call_function,
and call_function_single vectors.

[   50.720557] Testing event reschedule_exit:
[   50.721349]
[   50.721502] ===============================
[   50.721835] [ INFO: suspicious RCU usage. ]
[   50.722169] 3.10.0-rc6-00004-gcf910e8 #190 Not tainted
[   50.722582] -------------------------------
[   50.722915] /c/kernel-tests/src/linux/arch/x86/include/asm/trace/irq_vectors.h:50 suspicious rcu_dereference_check() usage!
[   50.723770]
[   50.723770] other info that might help us debug this:
[   50.723770]
[   50.724385]
[   50.724385] RCU used illegally from idle CPU!
[   50.724385] rcu_scheduler_active = 1, debug_locks = 0
[   50.725232] RCU used illegally from extended quiescent state!
[   50.725690] no locks held by swapper/0/0.
[   50.726010]
[   50.726010] stack backtrace:
[...]

Signed-off-by: default avatarSeiji Aguchi <seiji.aguchi@hds.com>
Reviewed-by: default avatarSteven Rostedt <rostedt@goodmis.org>
Link: http://lkml.kernel.org/r/51CDCFA3.9080101@hds.com


Signed-off-by: default avatarIngo Molnar <mingo@kernel.org>
      4787c368
  29. Jun 29, 2013
  31. Jun 28, 2013
    • David Vrabel's avatar
      x86: xen: Sync the CMOS RTC as well as the Xen wallclock · 47433b8c
      David Vrabel authored 
      
Adjustments to Xen's persistent clock via update_persistent_clock()
don't actually persist, as the Xen wallclock is a software only clock
and modifications to it do not modify the underlying CMOS RTC.

The x86_platform.set_wallclock hook is there to keep the hardware RTC
synchronized. On a guest this is pointless.

On Dom0 we can use the native implementaion which actually updates the
hardware RTC, but we still need to keep the software emulation of RTC
for the guests up to date. The subscription to the pvclock_notifier
allows us to emulate this easily. The notifier is called at every tick
and when the clock was set.

Right now we only use that notifier when the clock was set, but due to
the fact that it is called periodically from the timekeeping update
code, we can utilize it to emulate the NTP driven drift compensation
of update_persistant_clock() for the Xen wall (software) clock.

Add a 11 minutes periodic update to the pvclock_gtod notifier callback
to achieve that. The static variable 'next' which maintains that 11
minutes update cycle is protected by the core code serialization so
there is no need to add a Xen specific serialization mechanism.

[ tglx: Massaged changelog and added a few comments ]

Signed-off-by: default avatarDavid Vrabel <david.vrabel@citrix.com>
Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Cc: John Stultz <john.stultz@linaro.org>
Cc: <xen-devel@lists.xen.org>
Link: http://lkml.kernel.org/r/1372329348-20841-6-git-send-email-david.vrabel@citrix.com


Signed-off-by: default avatarThomas Gleixner <tglx@linutronix.de>
      47433b8c
    • David Vrabel's avatar
      x86: xen: Sync the wallclock when the system time is set · 5584880e
      David Vrabel authored 
      
Currently the Xen wallclock is only updated every 11 minutes if NTP is
synchronized to its clock source (using the sync_cmos_clock() work).
If a guest is started before NTP is synchronized it may see an
incorrect wallclock time.

Use the pvclock_gtod notifier chain to receive a notification when the
system time has changed and update the wallclock to match.

This chain is called on every timer tick and we want to avoid an extra
(expensive) hypercall on every tick.  Because dom0 has historically
never provided a very accurate wallclock and guests do not expect one,
we can do this simply: the wallclock is only updated if the clock was
set.

Signed-off-by: default avatarDavid Vrabel <david.vrabel@citrix.com>
Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Cc: John Stultz <john.stultz@linaro.org>
Cc: <xen-devel@lists.xen.org>
Link: http://lkml.kernel.org/r/1372329348-20841-5-git-send-email-david.vrabel@citrix.com


Signed-off-by: default avatarThomas Gleixner <tglx@linutronix.de>
      5584880e
    • Laszlo Ersek's avatar
      xen/time: remove blocked time accounting from xen "clockchip" · 0b0c002c
      Laszlo Ersek authored 
      ... because the "clock_event_device framework" already accounts for idle
time through the "event_handler" function pointer in
xen_timer_interrupt().

The patch is intended as the completion of [1]. It should fix the double
idle times seen in PV guests' /proc/stat [2]. It should be orthogonal to
stolen time accounting (the removed code seems to be isolated).

The approach may be completely misguided.

[1] https://lkml.org/lkml/2011/10/6/10
[2] http://lists.xensource.com/archives/html/xen-devel/2010-08/msg01068.html



John took the time to retest this patch on top of v3.10 and reported:
"idle time is correctly incremented for pv and hvm for the normal
case, nohz=off and nohz=idle." so lets put this patch in.

CC: stable@vger.kernel.org
Signed-off-by: default avatarLaszlo Ersek <lersek@redhat.com>
Signed-off-by: default avatarJohn Haxby <john.haxby@oracle.com>
Signed-off-by: default avatarKonrad Rzeszutek Wilk <konrad.wilk@oracle.com>
      0b0c002c