Commit 72f31889 authored by Linus Torvalds's avatar Linus Torvalds
Browse files

Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux 

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux: (31 commits)
  [S390] disassembler: mark exception causing instructions
  [S390] Enable exception traces by default
  [S390] return address of compat signals
  [S390] sysctl: get rid of dead declaration
  [S390] dasd: fix fixpoint divide exception in define_extent
  [S390] dasd: add sanity check to detect path connection error
  [S390] qdio: fix kernel panic for zfcp 31-bit
  [S390] Add s390x description to Documentation/kdump/kdump.txt
  [S390] Add VMCOREINFO_SYMBOL(high_memory) to vmcoreinfo
  [S390] dasd: fix expiration handling for recovery requests
  [S390] outstanding interrupts vs. smp_send_stop
  [S390] ipc: call generic sys_ipc demultiplexer
  [S390] zcrypt: Fix error return codes.
  [S390] zcrypt: Rework length parameter checking.
  [S390] cleanup trap handling
  [S390] Remove Kerntypes leftovers
  [S390] topology: increase poll frequency if change is anticipated
  [S390] entry[64].S improvements
  [S390] make arch/s390 subdirectories depend on config option
  [S390] kvm: move cmf host id constant out of lowcore
  ...

Fix up conflicts in arch/s390/kernel/{smp.c,topology.c} due to the
sysdev removal clashing with "topology: get rid of ifdefs" which moved
some of that code around.
parents a0e86bd4 2fa1d4fc

Documentation/dontdiff

+0 −1
Original line number Diff line number Diff line
@@ -66,7 +66,6 @@ GRTAGS 
GSYMS

GTAGS

Image

Kerntypes

Module.markers

Module.symvers

PENDING

Documentation/kdump/kdump.txt

+32 −3
Original line number Diff line number Diff line
@@ -17,8 +17,8 @@ You can use common commands, such as cp and scp, to copy the 
memory image to a dump file on the local disk, or across the network to

a remote system.



Kdump and kexec are currently supported on the x86, x86_64, ppc64 and ia64

architectures.

Kdump and kexec are currently supported on the x86, x86_64, ppc64, ia64,

and s390x architectures.



When the system kernel boots, it reserves a small section of memory for

the dump-capture kernel. This ensures that ongoing Direct Memory Access
@@ -34,11 +34,18 @@ Similarly on PPC64 machines first 32KB of physical memory is needed for 
booting regardless of where the kernel is loaded and to support 64K page

size kexec backs up the first 64KB memory.



For s390x, when kdump is triggered, the crashkernel region is exchanged

with the region [0, crashkernel region size] and then the kdump kernel

runs in [0, crashkernel region size]. Therefore no relocatable kernel is

needed for s390x.



All of the necessary information about the system kernel's core image is

encoded in the ELF format, and stored in a reserved area of memory

before a crash. The physical address of the start of the ELF header is

passed to the dump-capture kernel through the elfcorehdr= boot

parameter.

parameter. Optionally the size of the ELF header can also be passed

when using the elfcorehdr=[size[KMG]@]offset[KMG] syntax.





With the dump-capture kernel, you can access the memory image, or "old

memory," in two ways:
@@ -291,6 +298,10 @@ Boot into System Kernel 
   The region may be automatically placed on ia64, see the

   dump-capture kernel config option notes above.



   On s390x, typically use "crashkernel=xxM". The value of xx is dependent

   on the memory consumption of the kdump system. In general this is not

   dependent on the memory size of the production system.



Load the Dump-capture Kernel

============================
@@ -308,6 +319,8 @@ For ppc64: 
	- Use vmlinux

For ia64:

	- Use vmlinux or vmlinuz.gz

For s390x:

	- Use image or bzImage





If you are using a uncompressed vmlinux image then use following command
@@ -337,6 +350,8 @@ For i386, x86_64 and ia64: 
For ppc64:

	"1 maxcpus=1 noirqdistrib reset_devices"



For s390x:

	"1 maxcpus=1 cgroup_disable=memory"



Notes on loading the dump-capture kernel:
@@ -362,6 +377,20 @@ Notes on loading the dump-capture kernel: 
  dump. Hence generally it is useful either to build a UP dump-capture

  kernel or specify maxcpus=1 option while loading dump-capture kernel.



* For s390x there are two kdump modes: If a ELF header is specified with

  the elfcorehdr= kernel parameter, it is used by the kdump kernel as it

  is done on all other architectures. If no elfcorehdr= kernel parameter is

  specified, the s390x kdump kernel dynamically creates the header. The

  second mode has the advantage that for CPU and memory hotplug, kdump has

  not to be reloaded with kexec_load().



* For s390x systems with many attached devices the "cio_ignore" kernel

  parameter should be used for the kdump kernel in order to prevent allocation

  of kernel memory for devices that are not relevant for kdump. The same

  applies to systems that use SCSI/FCP devices. In that case the

  "allow_lun_scan" zfcp module parameter should be set to zero before

  setting FCP devices online.



Kernel Panic

============

Documentation/s390/Debugging390.txt

+0 −34
Original line number Diff line number Diff line
@@ -41,7 +41,6 @@ ldd 
Debugging modules

The proc file system

Starting points for debugging scripting languages etc.

Dumptool & Lcrash

SysRq

References

Special Thanks
@@ -2455,39 +2454,6 @@ jdb <filename> another fully interactive gdb style debugger. 






Dumptool & Lcrash ( lkcd )

==========================

Michael Holzheu & others here at IBM have a fairly mature port of 

SGI's lcrash tool which allows one to look at kernel structures in a

running kernel.



It also complements a tool called dumptool which dumps all the kernel's

memory pages & registers to either a tape or a disk.

This can be used by tech support or an ambitious end user do

post mortem debugging of a machine like gdb core dumps.



Going into how to use this tool in detail will be explained

in other documentation supplied by IBM with the patches & the 

lcrash homepage http://oss.sgi.com/projects/lkcd/ & the lcrash manpage.



How they work

-------------

Lcrash is a perfectly normal program,however, it requires 2 

additional files, Kerntypes which is built using a patch to the 

linux kernel sources in the linux root directory & the System.map.



Kerntypes is an objectfile whose sole purpose in life

is to provide stabs debug info to lcrash, to do this

Kerntypes is built from kerntypes.c which just includes the most commonly

referenced header files used when debugging, lcrash can then read the

.stabs section of this file.



Debugging a live system it uses /dev/mem

alternatively for post mortem debugging it uses the data 

collected by dumptool.







SysRq

=====

This is now supported by linux for s/390 & z/Architecture.

arch/s390/Kbuild

+7 −6
Original line number Diff line number Diff line 
obj-y				+= kernel/

obj-y				+= mm/

obj-y += crypto/

obj-y += appldata/

obj-y += hypfs/

obj-y += kvm/
 
obj-$(CONFIG_KVM)		+= kvm/

obj-$(CONFIG_CRYPTO_HW)		+= crypto/

obj-$(CONFIG_S390_HYPFS_FS)	+= hypfs/

obj-$(CONFIG_APPLDATA_BASE)	+= appldata/

obj-$(CONFIG_MATHEMU)		+= math-emu/

arch/s390/Kconfig

+3 −8
Original line number Diff line number Diff line
@@ -193,18 +193,13 @@ config HOTPLUG_CPU 
	  Say N if you want to disable CPU hotplug.



config SCHED_MC

	def_bool y

	prompt "Multi-core scheduler support"

	depends on SMP

	help

	  Multi-core scheduler support improves the CPU scheduler's decision

	  making when dealing with multi-core CPU chips at a cost of slightly

	  increased overhead in some places.

	def_bool n



config SCHED_BOOK

	def_bool y

	prompt "Book scheduler support"

	depends on SMP && SCHED_MC

	depends on SMP

	select SCHED_MC

	help

	  Book scheduler support improves the CPU scheduler's decision making

	  when dealing with machines that have several books.

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