Ming Lei <ming....@canonical.com> writes: > Hi Kevin, > > On Wed, Nov 26, 2014 at 10:46 PM, Kevin Wolf <kw...@redhat.com> wrote: >> This improves the performance of requests because an ACB doesn't need to >> be allocated on the heap any more. It also makes the code nicer and >> smaller. > > I am not sure it is good way for linux aio optimization: > > - for raw image with some constraint, coroutine can be avoided since > io_submit() won't sleep most of times > > - handling one time coroutine takes much time than handling malloc, > memset and free on small buffer, following the test data: > > -- 241ns per coroutine
What do you mean by "coroutine" here? Create + destroy? Yield? > -- 61ns per (malloc, memset, free for 128bytes) > > I still think we should figure out a fast path to avoid cocourinte > for linux-aio with raw image, otherwise it can't scale well for high > IOPS device. > > Also we can use simple buf pool to avoid the dynamic allocation > easily, can't we? [...]
