Now that we allow to change the cpumasks from userspace, we have
to check for valid cpumasks in padata_do_parallel. This patch adds
the necessary check. This fixes a division by zero crash if the
parallel cpumask contains no active cpu.
Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
The cpumask separation work assumes the cpumask dependend recources
present regardless of valid or invalid cpumasks. With this patch
we allocate the cpumask dependend recources in any case. This fixes
two NULL pointer dereference crashes in padata_replace and in
padata_get_cpumask.
Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
The counting of the cpu index got lost with a recent commit.
This patch restores it. This fixes a hang of the parallel worker
threads on cpu hotplug.
Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Added sysfs primitives to padata subsystem. Now API user may
embedded kobject each padata instance contains into any sysfs
hierarchy. For now padata sysfs interface provides only
two objects:
serial_cpumask [RW] - cpumask for serial workers
parallel_cpumask [RW] - cpumask for parallel workers
Signed-off-by: Dan Kruchinin <dkruchinin@acm.org>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
The aim of this patch is to make two separate cpumasks
for padata parallel and serial workers respectively.
It allows user to make more thin and sophisticated configurations
of padata framework. For example user may bind parallel and serial workers to non-intersecting
CPU groups to gain better performance. Also each padata instance has notifiers chain for its
cpumasks now. If either parallel or serial or both masks were changed all
interested subsystems will get notification about that. It's especially useful
if padata user uses algorithm for callback CPU selection according to serial cpumask.
Signed-off-by: Dan Kruchinin <dkruchinin@acm.org>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
We count the number of processed objects on a percpu basis,
so we need to go through all the percpu reorder queues to calculate
the sequence number of the next object that needs serialization.
This patch changes this to count the number of processed objects
global. So we can calculate the sequence number and the percpu
reorder queue of the next object that needs serialization without
searching through the percpu reorder queues. This avoids some
accesses to memory of foreign cpus.
Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
To return -EINPROGRESS on success in padata_do_parallel was
considered to be odd. This patch changes this to return zero
on success. Also the only user of padata, pcrypt is adapted to
convert a return of zero to -EINPROGRESS within the crypto layer.
This also removes the pcrypt fallback if padata_do_parallel
was called on a not running padata instance as we can't handle it
anymore. This fallback was unused, so it's save to remove it.
Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
This patch fixes a bug when the padata cpumask does not
intersect with the active cpumask. In this case we get a
division by zero in padata_alloc_pd and we end up with a
useless padata instance. Padata can end up with an empty
cpumask for two reasons:
1. A user removed the last cpu that belongs to the padata
cpumask and the active cpumask.
2. The last cpu that belongs to the padata cpumask and the
active cpumask goes offline.
We introduce a function padata_validate_cpumask to check if the padata
cpumask does intersect with the active cpumask. If the cpumasks do not
intersect we mark the instance as invalid, so it can't be used. We do not
allocate the cpumask dependend recources in this case. This fixes the
division by zero and keeps the padate instance in a consistent state.
It's not possible to trigger this bug by now because the only padata user,
pcrypt uses always the possible cpumask.
Reported-by: Dan Kruchinin <dkruchinin@acm.org>
Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
This patch makes padata_stop to block until the padata
instance is unused. Also we split padata_stop to a locked
and a unlocked version. This is in preparation to be able
to change the cpumask after a call to patata stop.
Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
This patch introduces the PADATA_INVALID flag which is
checked on padata start. This will be used to mark a padata
instance as invalid, if the padata cpumask does not intersect
with the active cpumask. we change padata_start to return an
error if the PADATA_INVALID is set. Also we adapt the only
padata user, pcrypt to this change.
Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
MAX_SEQ_NR is used in padata_alloc_pd() like this:
pd->max_seq_nr = (MAX_SEQ_NR / num_cpus) * num_cpus - 1;
It needs parenthesis or the divide by num_cpus takes precedence over the
subtraction.
Signed-off-by: Dan Carpenter <error27@gmail.com>
Acked-by: Steffen Klassert <steffen.klassert@secunet.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Add get_online_cpus/put_online_cpus to ensure that no cpu goes
offline during the flushing of the padata percpu queues.
Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
yield was used to wait until all references of the internal control
structure in use are dropped before it is freed. This patch implements
padata_flush_queues which actively flushes the padata percpu queues
in this case.
Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
padata_get_next needs to check whether the next object that
need serialization must be parallel processed by the local cpu.
This check was wrong implemented and returned always true,
so the try_again loop in padata_reorder was never taken. This
can lead to object leaks in some rare cases due to a race that
appears with the trylock in padata_reorder. The try_again loop
was not a good idea after all, because a cpu could take that
loop frequently, so we handle this with a timer instead.
This patch adds a timer to handle the race that appears with
the trylock. If cpu1 queues an object to the reorder queue while
cpu2 holds the pd->lock but left the while loop in padata_reorder
already, cpu2 can't care for this object and cpu1 exits because
it can't get the lock. Usually the next cpu that takes the lock
cares for this object too. We need the timer just if this object
was the last one that arrives to the reorder queues. The timer
function sends it out in this case.
Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
This patch puts get_online_cpus/put_online_cpus around the places
we modify the padata cpumask to ensure that no cpu goes offline
during this operation.
Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
padata_alloc_pd set up queues for all possible cpus.
This patch changes this to set up the queues just for
the used cpus.
Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
might_sleep() was placed before mutex_lock() in some places.
We remove them because mutex_lock() does might_sleep() too.
Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
This patch makes the padata cpu hotplug code dependend on CONFIG_HOTPLUG_CPU.
Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Scaling the maximum number of objects in the parallel
codepath can lead to out of memory problems on bigsmp
machines.
Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
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>
This patch removes the __cupinit from padata_cpu_callback(),
which is refered by the exportet function padata_alloc().
This could lead to problems if CONFIG_HOTPLUG_CPU is disabled,
which should happen very often.
WARNING: kernel/built-in.o(.text+0x7ffcb): Section mismatch in reference from the function padata_alloc() to the function .cpuinit.text:padata_cpu_callback()
The function padata_alloc() references
the function __cpuinit padata_cpu_callback().
This is often because padata_alloc lacks a __cpuinit
annotation or the annotation of padata_cpu_callback is wrong.
Signed-off-by: Henrik Kretzschmar <henne@nachtwindheim.de>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
The cpumask of the padata instance was used without allocated.
This caused boot crashes if CONFIG_CPUMASK_OFFSTACK is enabled.
This patch fixes this by doing proper allocation for this cpumask.
Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
This patch introduces an interface to process data objects
in parallel. The parallelized objects return after serialization
in the same order as they were before the parallelization.
Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Steffen Klassert