* Vivek Goyal (vgo...@redhat.com) wrote:
> Right now we create a thread pool and main thread hands over the request
> to thread in thread pool to process. Number of threads in thread pool
> can be managed by option --thread-pool-size.
>
> In tests we have noted that many of the workloads are getting better
> performance if we don't use a thread pool at all and process all
> the requests in the context of a thread receiving the request.
>
> Hence give user an option to be able to run virtiofsd without using
> a thread pool.
>
> To implement this, I have used existing option --thread-pool-size. This
> option defines how many maximum threads can be in the thread pool.
> Thread pool size zero freezes thead pool. I can't see why will one
> start virtiofsd with a frozen thread pool (hence frozen file system).
> So I am redefining --thread-pool-size=0 to mean, don't use a thread pool.
> Instead process the request in the context of thread receiving request
> from the queue.
>
> Signed-off-by: Vivek Goyal <vgo...@redhat.com>
Reviewed-by: Dr. David Alan Gilbert <dgilb...@redhat.com>
> ---
> tools/virtiofsd/fuse_virtio.c | 36 ++++++++++++++++++++++++++---------
> 1 file changed, 27 insertions(+), 9 deletions(-)
>
> diff --git a/tools/virtiofsd/fuse_virtio.c b/tools/virtiofsd/fuse_virtio.c
> index 83ba07c6cd..944b9a577c 100644
> --- a/tools/virtiofsd/fuse_virtio.c
> +++ b/tools/virtiofsd/fuse_virtio.c
> @@ -588,13 +588,18 @@ static void *fv_queue_thread(void *opaque)
> struct VuDev *dev = &qi->virtio_dev->dev;
> struct VuVirtq *q = vu_get_queue(dev, qi->qidx);
> struct fuse_session *se = qi->virtio_dev->se;
> - GThreadPool *pool;
> -
> - pool = g_thread_pool_new(fv_queue_worker, qi, se->thread_pool_size,
> FALSE,
> - NULL);
> - if (!pool) {
> - fuse_log(FUSE_LOG_ERR, "%s: g_thread_pool_new failed\n", __func__);
> - return NULL;
> + GThreadPool *pool = NULL;
> + GList *req_list = NULL;
> +
> + if (se->thread_pool_size) {
> + fuse_log(FUSE_LOG_DEBUG, "%s: Creating thread pool for Queue %d\n",
> + __func__, qi->qidx);
> + pool = g_thread_pool_new(fv_queue_worker, qi, se->thread_pool_size,
> + FALSE, NULL);
> + if (!pool) {
> + fuse_log(FUSE_LOG_ERR, "%s: g_thread_pool_new failed\n",
> __func__);
> + return NULL;
> + }
> }
>
> fuse_log(FUSE_LOG_INFO, "%s: Start for queue %d kick_fd %d\n", __func__,
> @@ -669,14 +674,27 @@ static void *fv_queue_thread(void *opaque)
>
> req->reply_sent = false;
>
> - g_thread_pool_push(pool, req, NULL);
> + if (!se->thread_pool_size) {
> + req_list = g_list_prepend(req_list, req);
> + } else {
> + g_thread_pool_push(pool, req, NULL);
> + }
> }
>
> pthread_mutex_unlock(&qi->vq_lock);
> pthread_rwlock_unlock(&qi->virtio_dev->vu_dispatch_rwlock);
> +
> + /* Process all the requests. */
> + if (!se->thread_pool_size && req_list != NULL) {
> + g_list_foreach(req_list, fv_queue_worker, qi);
> + g_list_free(req_list);
> + req_list = NULL;
> + }
> }
>
> - g_thread_pool_free(pool, FALSE, TRUE);
> + if (pool) {
> + g_thread_pool_free(pool, FALSE, TRUE);
> + }
>
> return NULL;
> }
> --
> 2.25.4
>
--
Dr. David Alan Gilbert / dgilb...@redhat.com / Manchester, UK
