From patchwork Wed May 24 08:18:40 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jason Wang X-Patchwork-Id: 13253444 Received: from lindbergh.monkeyblade.net (lindbergh.monkeyblade.net [23.128.96.19]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 9064D8480 for ; Wed, 24 May 2023 08:18:55 +0000 (UTC) Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.129.124]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 51B22C0 for ; Wed, 24 May 2023 01:18:54 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1684916333; 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: content-transfer-encoding:content-transfer-encoding; bh=tr17fslrkCiphsGkEGKeZVhavScCHFO7w1RXhH4sGc0=; b=WxxqVTlATJ40JI/7vB9FNakcabu+r6NOM57ShygFbQN2CKBM5o7c+fi+j/n38BPMws613V 4NPjyk8Gjesm1fDrYIthtbvd1502Os9MO/FGFARKyMluBPQrAFYZ1k4z9S3jwBGsPyPe0P pBHLmwhUd6WZr813H+Dnp7yQTP1Pk8c= Received: from mimecast-mx02.redhat.com (mx3-rdu2.redhat.com [66.187.233.73]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-193-2JRr0exkNyGTgTbJbqvnjw-1; Wed, 24 May 2023 04:18:50 -0400 X-MC-Unique: 2JRr0exkNyGTgTbJbqvnjw-1 Received: from smtp.corp.redhat.com (int-mx07.intmail.prod.int.rdu2.redhat.com [10.11.54.7]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id AD9EC3C02B62; Wed, 24 May 2023 08:18:49 +0000 (UTC) Received: from localhost.localdomain (ovpn-13-76.pek2.redhat.com [10.72.13.76]) by smtp.corp.redhat.com (Postfix) with ESMTP id 356C6140EBD7; Wed, 24 May 2023 08:18:44 +0000 (UTC) From: Jason Wang To: mst@redhat.com, jasowang@redhat.com, xuanzhuo@linux.alibaba.com, davem@davemloft.net, edumazet@google.com, kuba@kernel.org, pabeni@redhat.com Cc: virtualization@lists.linux-foundation.org, netdev@vger.kernel.org, linux-kernel@vger.kernel.org, alvaro.karsz@solid-run.com Subject: [PATCH V3 net-next 0/2] virtio-net: don't busy poll for cvq command Date: Wed, 24 May 2023 16:18:40 +0800 Message-Id: <20230524081842.3060-1-jasowang@redhat.com> Precedence: bulk X-Mailing-List: netdev@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-type: text/plain X-Scanned-By: MIMEDefang 3.1 on 10.11.54.7 X-Spam-Status: No, score=-2.1 required=5.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,DKIM_VALID_EF,RCVD_IN_DNSWL_NONE, RCVD_IN_MSPIKE_H2,SPF_HELO_NONE,SPF_NONE,T_SCC_BODY_TEXT_LINE autolearn=ham autolearn_force=no version=3.4.6 X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on lindbergh.monkeyblade.net X-Patchwork-Delegate: kuba@kernel.org Hi all: The code used to busy poll for cvq command which turns out to have several side effects: 1) infinite poll for buggy devices 2) bad interaction with scheduler So this series tries to use cond_resched() in the waiting loop. Before doing this we need first make sure the cvq command is not executed in atomic environment, so we need first convert rx mode handling to a workqueue. Please review. Thanks Changes since V2: - Don't use interrupt but cond_resched() Changes since V1: - use RTNL to synchronize rx mode worker - use completion for simplicity - don't try to harden CVQ command Changes since RFC: - switch to use BAD_RING in virtio_break_device() - check virtqueue_is_broken() after being woken up - use more_used() instead of virtqueue_get_buf() to allow caller to get buffers afterwards - break the virtio-net device when timeout - get buffer manually since the virtio core check more_used() instead Jason Wang (2): virtio-net: convert rx mode setting to use workqueue virtio-net: add cond_resched() to the command waiting loop drivers/net/virtio_net.c | 59 +++++++++++++++++++++++++++++++++++++--- 1 file changed, 55 insertions(+), 4 deletions(-)