From e49393a349925567cb83cfe810bc595e42a17883 Mon Sep 17 00:00:00 2001 From: Vivek Goyal Date: Mon, 9 Nov 2020 09:35:48 -0500 Subject: [PATCH] virtiofsd: Use --thread-pool-size=0 to mean no thread pool 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 Message-Id: <20201109143548.GA1479853@redhat.com> Reviewed-by: Dr. David Alan Gilbert Reviewed-by: Stefan Hajnoczi Signed-off-by: Dr. David Alan Gilbert --- tools/virtiofsd/fuse_virtio.c | 34 ++++++++++++++++++++++++++-------- 1 file changed, 26 insertions(+), 8 deletions(-) diff --git a/tools/virtiofsd/fuse_virtio.c b/tools/virtiofsd/fuse_virtio.c index b264dcbd18..ddcefee427 100644 --- a/tools/virtiofsd/fuse_virtio.c +++ b/tools/virtiofsd/fuse_virtio.c @@ -578,13 +578,18 @@ 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; + GThreadPool *pool = NULL; + GList *req_list = NULL; - 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; + 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__, @@ -659,14 +664,27 @@ 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; }