On Wed, Jun 17, 2020 at 11:51:07PM -0700, Christoph Hellwig wrote: > Much better. Although if we touch all the callers we might as well > pass the csd as the argument to the callback, as with that we can > pretty trivially remove the private data field later.
My plan was to introduce a new function and type and convert smp_call_function_async() callers over to that. The csd as it exists is useful for the regular smp_call_function*() API. > Btw, it seems the callers that don't have the CSD embedded into the > containing structure seems to be of these two kinds: > > - reimplementing on_each_cpumask (mostly because they can be called > from irq context) These are fairly special purpose constructs; and they come at the cost of extra per-cpu storage and they have the limitiation that they must wait for completion of the first before they can be used again. > - reimplenenting smp_call_function_single because they want > to sleep instead of busy wait These are atrocious pieces of crap (the x86/msr ones), the reason it was done is because virt :/
