From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-11.1 required=3.0 tests=BAYES_00,DKIM_INVALID, DKIM_SIGNED,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id B025FC56201 for ; Mon, 9 Nov 2020 10:12:23 +0000 (UTC) Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 025F620684 for ; Mon, 9 Nov 2020 10:12:22 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="P8CniogT" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 025F620684 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=redhat.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Received: from localhost ([::1]:37252 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1kc49t-0000WP-Vd for qemu-devel@archiver.kernel.org; Mon, 09 Nov 2020 05:12:22 -0500 Received: from eggs.gnu.org ([2001:470:142:3::10]:38050) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1kc48s-0007bZ-Pv for qemu-devel@nongnu.org; Mon, 09 Nov 2020 05:11:18 -0500 Received: from us-smtp-delivery-124.mimecast.com ([216.205.24.124]:46236) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_CBC_SHA1:256) (Exim 4.90_1) (envelope-from ) id 1kc48q-0003e4-Tq for qemu-devel@nongnu.org; Mon, 09 Nov 2020 05:11:18 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1604916676; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=EbSFT4UQTx0TP7UQk3z6+DZ44LhApXMSvZhL50keook=; b=P8CniogTtof+Ju7mjCPntjcnmjQTsGY5QYxrqnu+zVzt9iBCzgIkwHwJHbwHFF7u2HZb7y f8ENMxbwZF1GV7YQ92Clpi1oX77J6qS2IAlNF3ocGLbAVa0exV+KQ7ElgWoKW0UJ8zQay2 vbKVA5qqsgiX7BoaKH/RMeGXNxUJZb0= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-151-ZvZzj-5BMEG6JslY4JbxGA-1; Mon, 09 Nov 2020 05:11:14 -0500 X-MC-Unique: ZvZzj-5BMEG6JslY4JbxGA-1 Received: from smtp.corp.redhat.com (int-mx03.intmail.prod.int.phx2.redhat.com [10.5.11.13]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 4F1121009E35; Mon, 9 Nov 2020 10:11:13 +0000 (UTC) Received: from work-vm (ovpn-114-198.ams2.redhat.com [10.36.114.198]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 60D746EF6B; Mon, 9 Nov 2020 10:11:05 +0000 (UTC) Date: Mon, 9 Nov 2020 10:11:02 +0000 From: "Dr. David Alan Gilbert" To: Vivek Goyal Subject: Re: [PATCH] virtiofsd: Use --thread-pool-size=0 to mean no thread pool Message-ID: <20201109101102.GE3024@work-vm> References: <20201105194416.GA1384085@redhat.com> MIME-Version: 1.0 In-Reply-To: <20201105194416.GA1384085@redhat.com> User-Agent: Mutt/1.14.6 (2020-07-11) X-Scanned-By: MIMEDefang 2.79 on 10.5.11.13 Authentication-Results: relay.mimecast.com; auth=pass smtp.auth=CUSA124A263 smtp.mailfrom=dgilbert@redhat.com X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Received-SPF: pass client-ip=216.205.24.124; envelope-from=dgilbert@redhat.com; helo=us-smtp-delivery-124.mimecast.com X-detected-operating-system: by eggs.gnu.org: First seen = 2020/11/09 00:04:29 X-ACL-Warn: Detected OS = Linux 2.2.x-3.x [generic] [fuzzy] X-Spam_score_int: -20 X-Spam_score: -2.1 X-Spam_bar: -- X-Spam_report: (-2.1 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-0.001, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, RCVD_IN_DNSWL_NONE=-0.0001, RCVD_IN_MSPIKE_H4=-0.01, RCVD_IN_MSPIKE_WL=-0.01, SPF_HELO_NONE=0.001, SPF_PASS=-0.001 autolearn=ham autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: virtio-fs-list , jose.carlos.venegas.munoz@intel.com, qemu-devel@nongnu.org, Stefan Hajnoczi Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" * Vivek Goyal (vgoyal@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. > > There is a chance that in case of some workloads, we might get better > performance if we don't handover the request to a different thread > and process in the context of thread receiving the request. > > To implement that, redefine the meaning of --thread-pool-size=0 to > mean that don't use a thread pool. Instead process the request in > the context of thread receiving request from the queue. > > I can't think how --thread-pool-size=0 is useful and hence using > that. If it is already useful somehow, I could look at defining > a new option say "--no-thread-pool". > > I think this patch will be used more as a debug help to do comparison > when it is more effecient to do not hand over the requests to a > thread pool. > > Signed-off-by: Vivek Goyal I think this is OK, but you need to fix the style to match qemu rather than kernel style. (See qemu's scripts/checpatch.pl) Dave > --- > tools/virtiofsd/fuse_virtio.c | 33 ++++++++++++++++++++++++--------- > 1 file changed, 24 insertions(+), 9 deletions(-) > > diff --git a/tools/virtiofsd/fuse_virtio.c b/tools/virtiofsd/fuse_virtio.c > index ff86f6d1ce..60aa7cd3e5 100644 > --- a/tools/virtiofsd/fuse_virtio.c > +++ b/tools/virtiofsd/fuse_virtio.c > @@ -695,13 +695,17 @@ 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__, > @@ -780,14 +784,25 @@ static void *fv_queue_thread(void *opaque) > req->bad_in_num = bad_in_num; > req->bad_out_num = bad_out_num; > > - 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 / dgilbert@redhat.com / Manchester, UK