On Mon, Jun 8, 2020 at 4:07 PM Roman Gushchin <guro@xxxxxx> wrote: > > Because the number of non-root kmem_caches doesn't depend on the > number of memory cgroups anymore and is generally not very big, > there is no more need for a dedicated workqueue. > > Also, as there is no more need to pass any arguments to the > memcg_create_kmem_cache() except the root kmem_cache, it's > possible to just embed the work structure into the kmem_cache > and avoid the dynamic allocation of the work structure. > > This will also simplify the synchronization: for each root kmem_cache > there is only one work. So there will be no more concurrent attempts > to create a non-root kmem_cache for a root kmem_cache: the second and > all following attempts to queue the work will fail. > > > On the kmem_cache destruction path there is no more need to call the > expensive flush_workqueue() and wait for all pending works to be > finished. Instead, cancel_work_sync() can be used to cancel/wait for > only one work. > > Signed-off-by: Roman Gushchin <guro@xxxxxx> > Reviewed-by: Vlastimil Babka <vbabka@xxxxxxx> Why not pre-allocate the non-root kmem_cache at the kmem_cache creation time? No need for work_struct, queue_work() or cancel_work_sync() at all.
