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path: root/include/linux/padata.h
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2012-03-14padata: Fix race on sequence number wrapSteffen Klassert
When padata_do_parallel() is called from multiple cpus for the same padata instance, we can get object reordering on sequence number wrap because testing for sequence number wrap and reseting the sequence number must happen atomically but is implemented with two atomic operations. This patch fixes this by converting the sequence number from atomic_t to an unsigned int and protect the access with a spin_lock. As a side effect, we get rid of the sequence number wrap handling because the seqence number wraps back to null now without the need to do anything. Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2010-09-03padata: add missing __percpu markup in include/linux/padata.hNamhyung Kim
parallel_data->queue is a percpu pointer but was missing __percpu markup. Add it. Signed-off-by: Namhyung Kim <namhyung@gmail.com> Acked-by: Steffen Klassert <steffen.klassert@secunet.com> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2010-07-31padata: Remove padata_get_cpumaskSteffen Klassert
A function that copies the padata cpumasks to a user buffer is a bit error prone. The cpumask can change any time so we can't be sure to have the right cpumask when using this function. A user who is interested in the padata cpumasks should register to the padata cpumask notifier chain instead. Users of padata_get_cpumask are already updated, so we can remove it. Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2010-07-31padata: Pass the padata cpumasks to the cpumask_change_notifier chainSteffen Klassert
We pass a pointer to the new padata cpumasks to the cpumask_change_notifier chain. So users can access the cpumasks without the need of an extra padata_get_cpumask function. Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2010-07-31padata: Rearrange set_cpumask functionsSteffen Klassert
padata_set_cpumask needs to be protected by a lock. We make __padata_set_cpumasks unlocked and static. So this function can be used by the exported and locked padata_set_cpumask and padata_set_cpumasks functions. Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2010-07-31padata: Rename padata_alloc functionsSteffen Klassert
We rename padata_alloc to padata_alloc_possible because this function allocates a padata_instance and uses the cpu_possible mask for parallel and serial workers. Also we rename __padata_alloc to padata_alloc to avoid to export underlined functions. Underlined functions are considered to be private to padata. Users are updated accordingly. Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2010-07-19padata: Added sysfs primitives to padata subsystemDan Kruchinin
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>
2010-07-19padata: Make two separate cpumasksDan Kruchinin
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>
2010-07-14padata: simplify serialization mechanismSteffen Klassert
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>
2010-07-14padata: Check for valid padata instance on startSteffen Klassert
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>
2010-05-19padata: Add some code commentsSteffen Klassert
Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2010-05-19padata: Use a timer to handle remaining objects in the reorder queues Steffen Klassert
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>
2010-01-06padata: Generic parallelization/serialization interfaceSteffen Klassert
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>