Re: [PATCH 7/7] aio-posix: remove idle poll handlers to improve scalability

[Paolo Bonzini]

On 05/03/20 18:08, Stefan Hajnoczi wrote:
> +    /*
> +     * List of handlers participating in userspace polling.  Accessed almost
> +     * exclusively from aio_poll() and therefore not an RCU list.  Protected 
> by
> +     * ctx->list_lock.
> +     */
> +    AioHandlerList poll_aio_handlers;
> +

Not sure I understand the "almost" part.  If it's accessed only from
aio_poll() it is protected via either AIO_WAIT_WHILE or the BQL, not by
ctx->list_lock; if it's protected by ctx->list_lock (using
qemu_lockcnt_inc in readers), it is an RCU list.

Paolo