From patchwork Tue Oct 18 19:16:02 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jonathan Lemon X-Patchwork-Id: 13010973 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 63C3AC433FE for ; Tue, 18 Oct 2022 19:16:26 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229682AbiJRTQZ convert rfc822-to-8bit (ORCPT ); Tue, 18 Oct 2022 15:16:25 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:53824 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229905AbiJRTQV (ORCPT ); Tue, 18 Oct 2022 15:16:21 -0400 Received: from mx0a-00082601.pphosted.com (mx0a-00082601.pphosted.com [67.231.145.42]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 2EC8E5A3DD for ; Tue, 18 Oct 2022 12:16:18 -0700 (PDT) Received: from pps.filterd (m0044010.ppops.net [127.0.0.1]) by mx0a-00082601.pphosted.com (8.17.1.5/8.17.1.5) with ESMTP id 29IDnw0E024815 for ; Tue, 18 Oct 2022 12:16:17 -0700 Received: from maileast.thefacebook.com ([163.114.130.16]) by mx0a-00082601.pphosted.com (PPS) with ESMTPS id 3k9gcnty5d-3 (version=TLSv1.2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128 verify=NOT) for ; Tue, 18 Oct 2022 12:16:17 -0700 Received: from twshared5252.09.ash9.facebook.com (2620:10d:c0a8:1b::d) by mail.thefacebook.com (2620:10d:c0a8:82::f) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2375.31; Tue, 18 Oct 2022 12:16:14 -0700 Received: by devvm2494.atn0.facebook.com (Postfix, from userid 172786) id 82185227F0534; Tue, 18 Oct 2022 12:16:02 -0700 (PDT) From: Jonathan Lemon To: CC: Subject: [RFC PATCH v2 13/13] io_uring: Make remove_ifq_region a delayed work call Date: Tue, 18 Oct 2022 12:16:02 -0700 Message-ID: <20221018191602.2112515-14-jonathan.lemon@gmail.com> X-Mailer: git-send-email 2.30.2 In-Reply-To: <20221018191602.2112515-1-jonathan.lemon@gmail.com> References: <20221018191602.2112515-1-jonathan.lemon@gmail.com> MIME-Version: 1.0 X-FB-Internal: Safe X-Proofpoint-GUID: ezX_kytenqNn_y_5JETmJtMGGDf9pqhB X-Proofpoint-ORIG-GUID: ezX_kytenqNn_y_5JETmJtMGGDf9pqhB X-Proofpoint-Virus-Version: vendor=baseguard engine=ICAP:2.0.205,Aquarius:18.0.895,Hydra:6.0.545,FMLib:17.11.122.1 definitions=2022-10-18_07,2022-10-18_01,2022-06-22_01 Precedence: bulk List-ID: X-Mailing-List: io-uring@vger.kernel.org Very much a WIP! The page backing store should not be removed until all ouststanding packets are returned. The packets may be inflight, owned by the driver or sitting in a socket buffer. This shows how the cleanup routine should check that there are no pending packets in flight, before cleaning up the buffers. Signed-off-by: Jonathan Lemon --- io_uring/zctap.c | 33 +++++++++++++++++++++++++-------- 1 file changed, 25 insertions(+), 8 deletions(-) diff --git a/io_uring/zctap.c b/io_uring/zctap.c index 4a551349b600..a1525a0b0245 100644 --- a/io_uring/zctap.c +++ b/io_uring/zctap.c @@ -25,6 +25,7 @@ struct ifq_region { u16 id; spinlock_t freelist_lock; + struct delayed_work release_work; struct io_zctap_buf *buf; struct io_zctap_buf *freelist[]; @@ -199,24 +200,38 @@ static void io_zctap_put_page(struct io_zctap_ifq *ifq, struct page *page) io_zctap_put_buf(ifq, &ifr->buf[pgid]); } -static void io_remove_ifq_region(struct ifq_region *ifr) +static void io_remove_ifq_region_work(struct work_struct *work) { - struct io_mapped_ubuf *imu; - struct page *page; - int i; + struct ifq_region *ifr = container_of( + to_delayed_work(work), struct ifq_region, release_work); + struct io_zctap_buf *buf; + int i, refs; - imu = ifr->imu; for (i = 0; i < ifr->nr_pages; i++) { - page = imu->bvec[i].bv_page; + buf = &ifr->buf[i]; + refs = atomic_read(&buf->refcount) & IO_ZCTAP_KREF_MASK; + if (refs) { + schedule_delayed_work(&ifr->release_work, HZ); + return; + } + } - ClearPagePrivate(page); - set_page_private(page, 0); + for (i = 0; i < ifr->nr_pages; i++) { + buf = &ifr->buf[i]; + set_page_private(buf->page, 0); + ClearPagePrivate(buf->page); } kvfree(ifr->buf); kvfree(ifr); } +static void io_remove_ifq_region(struct ifq_region *ifr) +{ + INIT_DELAYED_WORK(&ifr->release_work, io_remove_ifq_region_work); + schedule_delayed_work(&ifr->release_work, 0); +} + static inline struct device * netdev2device(struct net_device *dev) { @@ -403,6 +418,8 @@ static struct io_zctap_ifq *io_zctap_ifq_alloc(void) return &priv->ifq; } +/* XXX this seems to be called too late - MM is already torn down? */ +/* need to tear down sockets, then io_uring, then MM */ static void io_zctap_ifq_free(struct io_zctap_ifq *ifq) { if (ifq->queue_id != -1)