From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on gnuweeb.org X-Spam-Level: * X-Spam-Status: No, score=1.9 required=5.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_PASS, SPF_SOFTFAIL autolearn=no autolearn_force=no version=3.4.6 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 157DEC43334 for ; Tue, 28 Jun 2022 19:01:24 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231464AbiF1TBV (ORCPT ); Tue, 28 Jun 2022 15:01:21 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:55748 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234445AbiF1TAa (ORCPT ); Tue, 28 Jun 2022 15:00:30 -0400 Received: from mail-ej1-x62d.google.com (mail-ej1-x62d.google.com [IPv6:2a00:1450:4864:20::62d]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 7FB4A193E7; Tue, 28 Jun 2022 12:00:14 -0700 (PDT) Received: by mail-ej1-x62d.google.com with SMTP id h23so27614715ejj.12; Tue, 28 Jun 2022 12:00:14 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; h=from:to:cc:subject:date:message-id:in-reply-to:references :mime-version:content-transfer-encoding; bh=i0MO0fedUqWqU6OS3v8noUO6m7kPGB9OwseLoBpuluo=; b=FxAG96JzN9Cevq47mDhXQKg6CoCJp6Ik7+LjtZfbWvdsLQnX4N4VtaFK1K5TqTCHUJ irgc+0Fcsm9yk31Zrx6if98iy+1fssmDIFeHtq8g/UXqgSemeDhl00kCRKyAC8oyPsL/ MjyujfaEq5rC8cPbcxpvErGctVJWNrkFcnCLVWwHcj30xpCNQDWS3hTJLkpiTrQfHlDy E0bcuQYfIAcNGe+9VPHwMjrCRVpSYBqw6LXIZjWbU1NVEHrDdH1uNYP2NWm/Dc4okbrZ yuPQ8J/ovQ180r61dzHVBvGcSu+C1B9qqYLH1QmDLj7GlQeQRyLedrQZB5PmgBl1nJex nyVw== 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:in-reply-to :references:mime-version:content-transfer-encoding; bh=i0MO0fedUqWqU6OS3v8noUO6m7kPGB9OwseLoBpuluo=; b=u39+5xybBiM9TPjVjVBNDb4MHLGYLYr+p6JzjEY6U/AU2eJuK/32IOL27TOtcMn+wd gdYuM3olQzYZj+rzB9qR75SuhHYIzIXsvsS0b9PftfBVa9AYtDS24cnFiD2bi7GzrOrr WNnqOLPTNMAWU++6WwnZnXMRV+rrbK2ItNcpmhKf47oxhhvM2GJL94ODopaQb6bZ93kf taNtzAE5YJ5VhsXwOmYlEnS1HoVT4riTOSh0Ha/rehR/uaqzpEugAryf6GV53T82zusw aj/TLHXigA5IOKiJ3EAyI0ObGOtH27zsO3Eq9IH2FXh9yoid4YaS7d0Gd7JL2mDjfg6O 9Eyw== X-Gm-Message-State: AJIora/QBy9Aatp5SAkCsBPhMU/2O0aHTzn2Jo+C045eDJmScdv03PB1 ilTs+zxpCpQ0Mt6iKnZFvC6E90fPg1pU2g== X-Google-Smtp-Source: AGRyM1tAMSUMslAPyxoH+0wzXDKJtb027MJYgfXn00t1CGulBpfPU7dB3FymrXO1iaawk8utfe/udQ== X-Received: by 2002:a17:907:94d4:b0:722:e4b8:c2f2 with SMTP id dn20-20020a17090794d400b00722e4b8c2f2mr19166869ejc.527.1656442812700; Tue, 28 Jun 2022 12:00:12 -0700 (PDT) Received: from 127.0.0.1localhost (188.28.125.106.threembb.co.uk. [188.28.125.106]) by smtp.gmail.com with ESMTPSA id t21-20020a05640203d500b0043573c59ea0sm9758451edw.90.2022.06.28.12.00.11 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 28 Jun 2022 12:00:12 -0700 (PDT) From: Pavel Begunkov To: io-uring@vger.kernel.org, netdev@vger.kernel.org, linux-kernel@vger.kernel.org Cc: "David S . Miller" , Jakub Kicinski , Jonathan Lemon , Willem de Bruijn , Jens Axboe , kernel-team@fb.com, Pavel Begunkov Subject: [RFC net-next v3 17/29] io_uring: complete notifiers in tw Date: Tue, 28 Jun 2022 19:56:39 +0100 Message-Id: X-Mailer: git-send-email 2.36.1 In-Reply-To: References: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: io-uring@vger.kernel.org We need a task context to post CQEs but using wq is too expensive. Try to complete notifiers using task_work and fall back to wq if fails. Signed-off-by: Pavel Begunkov --- fs/io_uring.c | 21 ++++++++++++++++++++- 1 file changed, 20 insertions(+), 1 deletion(-) diff --git a/fs/io_uring.c b/fs/io_uring.c index 422ff835bf36..9ade0ea8552b 100644 --- a/fs/io_uring.c +++ b/fs/io_uring.c @@ -384,6 +384,8 @@ struct io_notif { /* hook into ctx->notif_list and ctx->notif_list_locked */ struct list_head cache_node; + /* complete via tw if ->task is non-NULL, fallback to wq otherwise */ + struct task_struct *task; union { struct callback_head task_work; struct work_struct commit_work; @@ -2802,6 +2804,11 @@ static void __io_notif_complete_tw(struct callback_head *cb) struct io_notif *notif = container_of(cb, struct io_notif, task_work); struct io_ring_ctx *ctx = notif->ctx; + if (likely(notif->task)) { + io_put_task(notif->task, 1); + notif->task = NULL; + } + spin_lock(&ctx->completion_lock); io_fill_cqe_aux(ctx, notif->tag, 0, notif->seq); @@ -2835,6 +2842,14 @@ static void io_uring_tx_zerocopy_callback(struct sk_buff *skb, if (!refcount_dec_and_test(&uarg->refcnt)) return; + + if (likely(notif->task)) { + init_task_work(¬if->task_work, __io_notif_complete_tw); + if (likely(!task_work_add(notif->task, ¬if->task_work, + TWA_SIGNAL))) + return; + } + INIT_WORK(¬if->commit_work, io_notif_complete_wq); queue_work(system_unbound_wq, ¬if->commit_work); } @@ -2946,8 +2961,12 @@ static __cold int io_notif_unregister(struct io_ring_ctx *ctx) for (i = 0; i < ctx->nr_notif_slots; i++) { struct io_notif_slot *slot = &ctx->notif_slots[i]; - if (slot->notif) + if (slot->notif) { + WARN_ON_ONCE(slot->notif->task); + + slot->notif->task = NULL; io_notif_slot_flush(slot); + } } kvfree(ctx->notif_slots); -- 2.36.1