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 <schwidefsky@de.ibm.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: linux390@de.ibm.com
Cc: linux-s390@vger.kernel.org
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
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 <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
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 <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Add a couple of missing fields that were introduced with z196.
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
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 <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
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 <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
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 <schwidefsky@de.ibm.com>
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 <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
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 <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Display machine capacity adjustment indicator and capacity
change reason if available in /proc/sysinfo.
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
percpu.h is included by sched.h and module.h and thus ends up being
included when building most .c files. percpu.h includes slab.h which
in turn includes gfp.h making everything defined by the two files
universally available and complicating inclusion dependencies.
percpu.h -> slab.h dependency is about to be removed. Prepare for
this change by updating users of gfp and slab facilities include those
headers directly instead of assuming availability. As this conversion
needs to touch large number of source files, the following script is
used as the basis of conversion.
http://userweb.kernel.org/~tj/misc/slabh-sweep.py
The script does the followings.
* Scan files for gfp and slab usages and update includes such that
only the necessary includes are there. ie. if only gfp is used,
gfp.h, if slab is used, slab.h.
* When the script inserts a new include, it looks at the include
blocks and try to put the new include such that its order conforms
to its surrounding. It's put in the include block which contains
core kernel includes, in the same order that the rest are ordered -
alphabetical, Christmas tree, rev-Xmas-tree or at the end if there
doesn't seem to be any matching order.
* If the script can't find a place to put a new include (mostly
because the file doesn't have fitting include block), it prints out
an error message indicating which .h file needs to be added to the
file.
The conversion was done in the following steps.
1. The initial automatic conversion of all .c files updated slightly
over 4000 files, deleting around 700 includes and adding ~480 gfp.h
and ~3000 slab.h inclusions. The script emitted errors for ~400
files.
2. Each error was manually checked. Some didn't need the inclusion,
some needed manual addition while adding it to implementation .h or
embedding .c file was more appropriate for others. This step added
inclusions to around 150 files.
3. The script was run again and the output was compared to the edits
from #2 to make sure no file was left behind.
4. Several build tests were done and a couple of problems were fixed.
e.g. lib/decompress_*.c used malloc/free() wrappers around slab
APIs requiring slab.h to be added manually.
5. The script was run on all .h files but without automatically
editing them as sprinkling gfp.h and slab.h inclusions around .h
files could easily lead to inclusion dependency hell. Most gfp.h
inclusion directives were ignored as stuff from gfp.h was usually
wildly available and often used in preprocessor macros. Each
slab.h inclusion directive was examined and added manually as
necessary.
6. percpu.h was updated not to include slab.h.
7. Build test were done on the following configurations and failures
were fixed. CONFIG_GCOV_KERNEL was turned off for all tests (as my
distributed build env didn't work with gcov compiles) and a few
more options had to be turned off depending on archs to make things
build (like ipr on powerpc/64 which failed due to missing writeq).
* x86 and x86_64 UP and SMP allmodconfig and a custom test config.
* powerpc and powerpc64 SMP allmodconfig
* sparc and sparc64 SMP allmodconfig
* ia64 SMP allmodconfig
* s390 SMP allmodconfig
* alpha SMP allmodconfig
* um on x86_64 SMP allmodconfig
8. percpu.h modifications were reverted so that it could be applied as
a separate patch and serve as bisection point.
Given the fact that I had only a couple of failures from tests on step
6, I'm fairly confident about the coverage of this conversion patch.
If there is a breakage, it's likely to be something in one of the arch
headers which should be easily discoverable easily on most builds of
the specific arch.
Signed-off-by: Tejun Heo <tj@kernel.org>
Guess-its-ok-by: Christoph Lameter <cl@linux-foundation.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>
All in sysinfo.c is core kernel code and not driver code. So move it
to arch/s390/kernel. Also includes some small cleanups.
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
