linux.git/arch/s390/kernel/sysinfo.c, branch v3.11

s390: delete __cpuinit usage from all s390 files

2013-07-14T23:36:53+00:00

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 5e427ec2d0 ("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/s390 uses of the __cpuinit macros from
all C files.  Currently s390 does not have any __CPUINIT used in
assembly files.

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

Cc: Martin Schwidefsky 
Cc: Heiko Carstens 
Cc: linux390@de.ibm.com
Cc: linux-s390@vger.kernel.org
Signed-off-by: Paul Gortmaker

s390/sysinfo,stsi: change return code handling

2012-09-26T13:45:12+00:00

Change return code handling of the stsi() function:

In case function code 0 was specified the return value is the
current configuration level (already shifted). That way all
the code that actually copied the stsi_0() function can go
away.

Otherwise the return value is 0 (success) or negative to
indicate an error (currently only -EOPNOTSUPP).

Also stsi() is no longer an inline function. The function is
not performance critical, but every caller would generate an
exception table entry for this function.

Signed-off-by: Heiko Carstens 
Signed-off-by: Martin Schwidefsky

s390/sysinfo,topology: fix cpu topology maximum nesting detection

2012-09-26T13:45:08+00:00

The maximum nesting of the cpu topology is evaluated when /proc/sysinfo
is the first time read. This happens without a lock and a concurrent
reader on a different cpu can see and use an invalid intermediate value.
Besides the fact that this race is quite unlikely the worst thing that
could happen is that /proc/sysinfo would contain bogus information about
the machine's cpu topology.
Nevertheless this should be fixed. So move the detection code to the
early machine detection code and since now the value is early available
use it in the topology code as well.

Signed-off-by: Heiko Carstens 
Signed-off-by: Martin Schwidefsky

s390/sysinfo: add additional z196 fields to output

2012-09-26T13:45:07+00:00

Add a couple of missing fields that were introduced with z196.

Signed-off-by: Heiko Carstens 
Signed-off-by: Martin Schwidefsky

s390/sysinfo: convert /proc/sysinfo to seqfile

2012-09-26T13:45:07+00:00

The current proc implementation of the /proc/sysinfo file writes all
informations contained in all system information blocks to a single
page.
This is done by calling sprintf all the time in the expectation that
everything will fit into a single page. This however is not necessarily
true if the configuration of a machine is very large.
So convert /proc/sysinfo to avoid writing into random memory regions.

For readability reasons a couple of lines are longer than 80 characters.

Signed-off-by: Heiko Carstens 
Signed-off-by: Martin Schwidefsky

s390/cpu: remove cpu "capabilities" sysfs attribute

2012-05-30T07:07:30+00:00

It has been a big mistage to add the capabilities attribute to the
cpus in sysfs:
First the attribute only contains the cpu capability of primary cpus,
which however is not necessarily (or better: unlikely) the type of
cpu the kernel runs on, which is typically an IFL.
In addition all information that is necessary is available in
/proc/sysinfo already. So this attribute partially duplicated
informations.
So programs should look into the sysinfo file to retrieve all
informations they are interested in.

Since with this kernel release also the powersavings cpu attributes
are removed this seems to be a good opportunity to remove another
broken interface.

Signed-off-by: Heiko Carstens 
Signed-off-by: Martin Schwidefsky

[S390] sparse: fix sparse warnings in math-emu

2011-10-30T14:16:46+00:00

Fix three sparse warnings in math-emu / sysinfo:

arch/s390/kernel/sysinfo.c:448:17: error: return expression in void function
arch/s390/kernel/sysinfo.c:445:25: warning: shift too big (32) for type unsigned int
arch/s390/kernel/sysinfo.c:445:25: warning: shift too big (32) for type unsigned int

Signed-off-by: Martin Schwidefsky

[S390] topology: add SCHED_MC config option

2010-10-29T14:50:49+00:00

This allows us to easily check for performance differences seen with
!CONFIG_SCHED_MC and topology=off.
Actually there shouldn't be any (besides a small overhead because of
additional code).

Signed-off-by: Heiko Carstens 
Signed-off-by: Martin Schwidefsky

[S390] topology: export cpu topology via proc/sysinfo

2010-10-25T14:10:21+00:00

Export the cpu configuration topology via sysinfo. Two new lines are
introduced:

CPU Topology HW:      0 0 0 4 6 4
CPU Topology SW:      0 0 0 0 4 24

The HW line describes the cpu topology nesting levels when the maximum
nesting level is used to get the corresponding SYSIB.
The SW line describes what Linux is actually using. In this case it
supports only two levels (CONFIG_SCHED_BOOK off) and therefore the
hardware folded the two lower levels in the SYSIB response block.

Signed-off-by: Heiko Carstens 
Signed-off-by: Martin Schwidefsky

[S390] sysinfo: display capacity adjustment indicator

2010-10-25T14:10:15+00:00

Display machine capacity adjustment indicator and capacity
change reason if available in /proc/sysinfo.

Signed-off-by: Heiko Carstens 
Signed-off-by: Martin Schwidefsky