On 28/06/2016 11:01, Peter Lieven wrote:
the current coroutine freelist implementation has 2 kinds of pools.
One shared release pool between all threads and additionally one
allocation pool per thread. The release pool is especially necessary
if the coroutine is created in a different thread than it is released.
This is e.g. the case if an IDE interface is used.
But in times of virtio and dataplane the the release pool adds costs
which are not entirely necessary. At first if virtio is used the release
pool tends to fill up to 100% because all coroutines are first handed
back to the release pool. On coroutine create a thread can steal this
release pool and make it its local allocation pool, but during mixed
I/O pattern at the end the release pool is full of useless coroutines
and the alloc_pool has also filled to maximum size.
The cost is 2^16 bytes * 2^6 coroutines, that is 4 MB. I don't think
this is worth an extra knob that no one will use...