From patchwork Fri Jul 29 01:00:32 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Namjae Jeon X-Patchwork-Id: 12931855 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 EF139C00140 for ; Fri, 29 Jul 2022 01:01:40 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232005AbiG2BBj (ORCPT ); Thu, 28 Jul 2022 21:01:39 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:48046 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232976AbiG2BBU (ORCPT ); Thu, 28 Jul 2022 21:01:20 -0400 Received: from mail-pj1-f41.google.com (mail-pj1-f41.google.com [209.85.216.41]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 9FC5D42AEB for ; Thu, 28 Jul 2022 18:01:18 -0700 (PDT) Received: by mail-pj1-f41.google.com with SMTP id 15-20020a17090a098f00b001f305b453feso6922769pjo.1 for ; Thu, 28 Jul 2022 18:01:18 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:from:to:cc:subject:date:message-id:mime-version :content-transfer-encoding; bh=Z8uVhYLqAh5DklynNlwyMATmPnanaKzNb0Q2ljuGZrI=; b=LlcYadp5LvsOhATk5ncIGUCFC9UiD2Z4m0lI/Q8Nb4qj737cqWsuGoPzdh+ZDuFlvu 8z5ELXkph6jVzvefa+o1q7JKgTj0Au1fbB6hKgF3nN3Jt4IglhQ4qwE3dZeUou/GPd2M AJrIAwcqBVYb2i3zu5mBZM5v3fdX8zfolHjGZCTTfxiKj9K0MJGi7vsSW03IWDWvXqhA oVJ83JBxdBRsjH1gS4H/to2NT3aCsF1b+RC7fhPauZILOnitVYzshyPXovh3sD2HMUt2 RSyIc4rFJpCzZDzy6qk0yEoWYD3ptYmJWt6PIOsuIpWy6/QEEu8pBzKyzM8poxcrXjVs Sv/g== X-Gm-Message-State: ACgBeo0HNEEC/FXHqLOyhT4ydOE2H1CuaKuRyvknJw1JJK5cliKWu28K PamCk8jMjVvkzoJW2V3c6U+UF1ID9Zk= X-Google-Smtp-Source: AA6agR6GwfXxBQqch7kd9lY9iS5Yy7rMGXq6tHaSzDbZahPCVxoY7MPMCJhy0IIr2Vk1vTO6nLwE6Q== X-Received: by 2002:a17:90a:540c:b0:1f2:26f1:6a37 with SMTP id z12-20020a17090a540c00b001f226f16a37mr1394027pjh.68.1659056477773; Thu, 28 Jul 2022 18:01:17 -0700 (PDT) Received: from localhost.localdomain ([211.49.23.9]) by smtp.gmail.com with ESMTPSA id i11-20020a170902c94b00b0016d81098d9asm728354pla.34.2022.07.28.18.01.15 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 28 Jul 2022 18:01:17 -0700 (PDT) From: Namjae Jeon To: linux-cifs@vger.kernel.org Cc: smfrench@gmail.com, hyc.lee@gmail.com, senozhatsky@chromium.org, Namjae Jeon Subject: [PATCH v3] ksmbd: use wait_event instead of schedule_timeout() Date: Fri, 29 Jul 2022 10:00:32 +0900 Message-Id: <20220729010032.15226-1-linkinjeon@kernel.org> X-Mailer: git-send-email 2.25.1 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-cifs@vger.kernel.org ksmbd threads eating masses of cputime when connection is disconnected. If connection is disconnected, ksmbd thread waits for pending requests to be processed using schedule_timeout. schedule_timeout() incorrectly is used, and it is more efficient to use wait_event/wake_up than to check r_count every time with timeout. Signed-off-by: Namjae Jeon Reviewed-by: Hyunchul Lee --- v2: - When r_count is zero, call wake_up event. v3: - change wake_up_all with wake_up(). - add the comments to fix waitqueue_active() warnings from checkpatch.pl fs/ksmbd/connection.c | 6 +++--- fs/ksmbd/connection.h | 1 + fs/ksmbd/oplock.c | 35 ++++++++++++++++++++++------------- fs/ksmbd/server.c | 8 +++++++- 4 files changed, 33 insertions(+), 17 deletions(-) diff --git a/fs/ksmbd/connection.c b/fs/ksmbd/connection.c index ce23cc89046e..756ad631c019 100644 --- a/fs/ksmbd/connection.c +++ b/fs/ksmbd/connection.c @@ -66,6 +66,7 @@ struct ksmbd_conn *ksmbd_conn_alloc(void) conn->outstanding_credits = 0; init_waitqueue_head(&conn->req_running_q); + init_waitqueue_head(&conn->r_count_q); INIT_LIST_HEAD(&conn->conns_list); INIT_LIST_HEAD(&conn->requests); INIT_LIST_HEAD(&conn->async_requests); @@ -165,7 +166,6 @@ int ksmbd_conn_write(struct ksmbd_work *work) struct kvec iov[3]; int iov_idx = 0; - ksmbd_conn_try_dequeue_request(work); if (!work->response_buf) { pr_err("NULL response header\n"); return -EINVAL; @@ -347,8 +347,8 @@ int ksmbd_conn_handler_loop(void *p) out: /* Wait till all reference dropped to the Server object*/ - while (atomic_read(&conn->r_count) > 0) - schedule_timeout(HZ); + wait_event(conn->r_count_q, atomic_read(&conn->r_count) == 0); + unload_nls(conn->local_nls); if (default_conn_ops.terminate_fn) diff --git a/fs/ksmbd/connection.h b/fs/ksmbd/connection.h index 5b39f0bdeff8..2e4730457c92 100644 --- a/fs/ksmbd/connection.h +++ b/fs/ksmbd/connection.h @@ -65,6 +65,7 @@ struct ksmbd_conn { unsigned int outstanding_credits; spinlock_t credits_lock; wait_queue_head_t req_running_q; + wait_queue_head_t r_count_q; /* Lock to protect requests list*/ spinlock_t request_lock; struct list_head requests; diff --git a/fs/ksmbd/oplock.c b/fs/ksmbd/oplock.c index 8b5560574d4c..3ef33ed4cdba 100644 --- a/fs/ksmbd/oplock.c +++ b/fs/ksmbd/oplock.c @@ -615,18 +615,13 @@ static void __smb2_oplock_break_noti(struct work_struct *wk) struct ksmbd_file *fp; fp = ksmbd_lookup_durable_fd(br_info->fid); - if (!fp) { - atomic_dec(&conn->r_count); - ksmbd_free_work_struct(work); - return; - } + if (!fp) + goto out; if (allocate_oplock_break_buf(work)) { pr_err("smb2_allocate_rsp_buf failed! "); - atomic_dec(&conn->r_count); ksmbd_fd_put(work, fp); - ksmbd_free_work_struct(work); - return; + goto out; } rsp_hdr = smb2_get_msg(work->response_buf); @@ -667,8 +662,16 @@ static void __smb2_oplock_break_noti(struct work_struct *wk) ksmbd_fd_put(work, fp); ksmbd_conn_write(work); + +out: ksmbd_free_work_struct(work); - atomic_dec(&conn->r_count); + /* + * Checking waitqueue to dropping pending requests on + * disconnection. waitqueue_active is safe because it + * uses atomic operation for condition. + */ + if (!atomic_dec_return(&conn->r_count) && waitqueue_active(&conn->r_count_q)) + wake_up(&conn->r_count_q); } /** @@ -731,9 +734,7 @@ static void __smb2_lease_break_noti(struct work_struct *wk) if (allocate_oplock_break_buf(work)) { ksmbd_debug(OPLOCK, "smb2_allocate_rsp_buf failed! "); - ksmbd_free_work_struct(work); - atomic_dec(&conn->r_count); - return; + goto out; } rsp_hdr = smb2_get_msg(work->response_buf); @@ -771,8 +772,16 @@ static void __smb2_lease_break_noti(struct work_struct *wk) inc_rfc1001_len(work->response_buf, 44); ksmbd_conn_write(work); + +out: ksmbd_free_work_struct(work); - atomic_dec(&conn->r_count); + /* + * Checking waitqueue to dropping pending requests on + * disconnection. waitqueue_active is safe because it + * uses atomic operation for condition. + */ + if (!atomic_dec_return(&conn->r_count) && waitqueue_active(&conn->r_count_q)) + wake_up(&conn->r_count_q); } /** diff --git a/fs/ksmbd/server.c b/fs/ksmbd/server.c index 4cd03d661df0..ce42bff42ef9 100644 --- a/fs/ksmbd/server.c +++ b/fs/ksmbd/server.c @@ -261,7 +261,13 @@ static void handle_ksmbd_work(struct work_struct *wk) ksmbd_conn_try_dequeue_request(work); ksmbd_free_work_struct(work); - atomic_dec(&conn->r_count); + /* + * Checking waitqueue to dropping pending requests on + * disconnection. waitqueue_active is safe because it + * uses atomic operation for condition. + */ + if (!atomic_dec_return(&conn->r_count) && waitqueue_active(&conn->r_count_q)) + wake_up(&conn->r_count_q); } /**