From 3c74e59f30ccfb4937a9814631cc828f64427de3 Mon Sep 17 00:00:00 2001 From: Mathias Krause Date: Fri, 8 Sep 2017 20:57:11 +0200 Subject: padata: ensure padata_do_serial() runs on the correct CPU commit 350ef88e7e922354f82a931897ad4a4ce6c686ff upstream. If the algorithm we're parallelizing is asynchronous we might change CPUs between padata_do_parallel() and padata_do_serial(). However, we don't expect this to happen as we need to enqueue the padata object into the per-cpu reorder queue we took it from, i.e. the same-cpu's parallel queue. Ensure we're not switching CPUs for a given padata object by tracking the CPU within the padata object. If the serial callback gets called on the wrong CPU, defer invoking padata_reorder() via a kernel worker on the CPU we're expected to run on. Signed-off-by: Mathias Krause Signed-off-by: Herbert Xu Cc: Ben Hutchings Signed-off-by: Greg Kroah-Hartman --- include/linux/padata.h | 2 ++ 1 file changed, 2 insertions(+) (limited to 'include/linux') diff --git a/include/linux/padata.h b/include/linux/padata.h index 963e69ff4659..e74d61fa50fe 100644 --- a/include/linux/padata.h +++ b/include/linux/padata.h @@ -37,6 +37,7 @@ * @list: List entry, to attach to the padata lists. * @pd: Pointer to the internal control structure. * @cb_cpu: Callback cpu for serializatioon. + * @cpu: Cpu for parallelization. * @seq_nr: Sequence number of the parallelized data object. * @info: Used to pass information from the parallel to the serial function. * @parallel: Parallel execution function. @@ -46,6 +47,7 @@ struct padata_priv { struct list_head list; struct parallel_data *pd; int cb_cpu; + int cpu; int info; void (*parallel)(struct padata_priv *padata); void (*serial)(struct padata_priv *padata); -- cgit v1.2.3