RE: [PATCH v3 1/1] util: adjust coroutine pool size to virtio block queue

[Hiroki Narukawa]

> Coroutine pool size was 64 from long ago, and the basis was organized in the
> commit message in c740ad92.

Sorry, I noticed that commit ID mentioning here was incorrect.
The correct one is 4d68e86b.

https://gitlab.com/qemu-project/qemu/-/commit/4d68e86bb10159099da0798f74e7512955f15eec

I have resent this patch as v4 with exactly the same code as v3, just changing 
this commit message.

> 
> At that time, virtio-blk queue-size and num-queue were not configuable, and
> equivalent values were 128 and 1.
> 
> Coroutine pool size 64 was fine then.
> 
> Later queue-size and num-queue got configuable, and default values were
> increased.
> 
> Coroutine pool with size 64 exhausts frequently with random disk IO in new 
> size,
> and slows down.
> 
> This commit adjusts coroutine pool size adaptively with new values.
> 
> This commit adds 64 by default, but now coroutine is not only for block 
> devices,
> 
> and is not too much burdon comparing with new default.
> 
> pool size of 128 * vCPUs.
> 
> Signed-off-by: Hiroki Narukawa <hnarukaw@yahoo-corp.jp>
> ---
>  hw/block/virtio-blk.c    |  5 +++++
>  include/qemu/coroutine.h | 10 ++++++++++
>  util/qemu-coroutine.c    | 20 ++++++++++++++++----
>  3 files changed, 31 insertions(+), 4 deletions(-)
>