From patchwork Fri Jan 20 16:38:07 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Pavel Begunkov X-Patchwork-Id: 13110207 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 290D4C38141 for ; Fri, 20 Jan 2023 16:39:08 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229495AbjATQjH (ORCPT ); Fri, 20 Jan 2023 11:39:07 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:49088 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229843AbjATQjG (ORCPT ); Fri, 20 Jan 2023 11:39:06 -0500 Received: from mail-ej1-x629.google.com (mail-ej1-x629.google.com [IPv6:2a00:1450:4864:20::629]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id DD8BECDF9 for ; Fri, 20 Jan 2023 08:39:03 -0800 (PST) Received: by mail-ej1-x629.google.com with SMTP id ud5so15402185ejc.4 for ; Fri, 20 Jan 2023 08:39:03 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:from:to:cc:subject:date :message-id:reply-to; bh=gE9MO3GkkyiofAW2y8qFay5Pv9XYefZ9N3l0wWOfkt8=; b=BYDJioRHr86x2BWXEu/ZAp85zapovJfGmjqEI/GC+6LqhhLZI5LmtdPmOeX2uyZqlh oE9fgGE93nuACkZIZzf3c81Kb6doWsFOtO0C0v5c8X3DV7DzKXT/VBR6S1lHxj//Ijev i0bOGvsTUfpHN4hCQRaT3PmGZWiymTz2duw1wXQHXAMy5HMPHnnSlhZZfAVTgAT4M1ey YDzgyiyf93y5CFnrlksojRluUiFVLfxzFzJZ+FssvgnzIIa+WfMfcTwdM0uDoXoP95Z4 P68/O50rqrqFN8dEC6GLPVrogCpQgfhn9I3xmtgam++AWrezecuOyhPGWfCcIJLFYRaR 1Y7g== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=gE9MO3GkkyiofAW2y8qFay5Pv9XYefZ9N3l0wWOfkt8=; b=tSsWZM96oVH+BNrUxF0Rzwfl5MeDB0gRS63BBuhK8P2kb4ON1ZYrsftS5K3dTtjdev CA1sT3aegwXWkNDlG8m9jaUiP/hDjDb3k62yBZSyOyjwNsBwiMr0TdJlhCOHXtQrsRgx AfcSbLpGDCcj57teb+h8BPuZ7C7sWTOCJrJJTJQkGCHGXn0UNHo0EbkEWIh6wxoPEOlm EzPxSx6qs3AycycNJSwdGPRPVi41G1VuMf74lXcnPDpcoOFIFmJXuUkx3pt1SCblhSCB p/OD03IW2lCbDnW915OaP9jKGuyE4B4iesVUeqYfRSEUI27eyAuXM1qkQ8ZCU0DcjL4w h9kA== X-Gm-Message-State: AFqh2krUtIAl7dO71Q3fHGPYmSku7k47Jp8+OL9AgPPw+x3IitUiZ3BR 7N46TaKBcXnwsT5+CiSA0gXrVJ/m/No= X-Google-Smtp-Source: AMrXdXtr3IrdDVepPo/qE+Jk7zkMGrsCm9j1Fs9+W+qv4VR6GzsekKYYozuV390x8/lPRZhJzHrzTQ== X-Received: by 2002:a17:907:6e05:b0:871:dd2:4afb with SMTP id sd5-20020a1709076e0500b008710dd24afbmr25165736ejc.42.1674232742183; Fri, 20 Jan 2023 08:39:02 -0800 (PST) Received: from 127.com ([2620:10d:c092:600::2:4670]) by smtp.gmail.com with ESMTPSA id t27-20020a170906179b00b008762e2b7004sm4702124eje.208.2023.01.20.08.39.01 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 20 Jan 2023 08:39:01 -0800 (PST) From: Pavel Begunkov To: io-uring@vger.kernel.org Cc: Jens Axboe , asml.silence@gmail.com Subject: [PATCH for-6.2 v2 3/3] io_uring/msg_ring: optimise with correct tw notify method Date: Fri, 20 Jan 2023 16:38:07 +0000 Message-Id: <018a3d4ce4d8653dd6a6710b959c597b9f98f87e.1674232514.git.asml.silence@gmail.com> X-Mailer: git-send-email 2.38.1 In-Reply-To: References: MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: io-uring@vger.kernel.org We may want to use TWA_SIGNAL_NO_IPI instead of TWA_SIGNAL if the target ring is configured with IORING_SETUP_COOP_TASKRUN, change io_msg_exec_remote() to use the target ring's ->notify_method. The caveat is that we have to set IORING_SQ_TASKRUN if the rings asks for it. However, once task_work_add() succeeds the target ring might go away and so we grab a ctx reference to pin the ring until we set IORING_SQ_TASKRUN. Signed-off-by: Pavel Begunkov --- io_uring/msg_ring.c | 15 +++++++++++---- 1 file changed, 11 insertions(+), 4 deletions(-) diff --git a/io_uring/msg_ring.c b/io_uring/msg_ring.c index 15602a136821..af802cd645b4 100644 --- a/io_uring/msg_ring.c +++ b/io_uring/msg_ring.c @@ -70,15 +70,22 @@ static int io_msg_exec_remote(struct io_kiocb *req, task_work_func_t func) struct io_ring_ctx *ctx = req->file->private_data; struct io_msg *msg = io_kiocb_to_cmd(req, struct io_msg); struct task_struct *task = READ_ONCE(ctx->submitter_task); + int ret = IOU_ISSUE_SKIP_COMPLETE; if (unlikely(!task)) return -EOWNERDEAD; + percpu_ref_get(&ctx->refs); init_task_work(&msg->tw, func); - if (task_work_add(ctx->submitter_task, &msg->tw, TWA_SIGNAL)) - return -EOWNERDEAD; - - return IOU_ISSUE_SKIP_COMPLETE; + if (task_work_add(ctx->submitter_task, &msg->tw, ctx->notify_method)) { + ret = -EOWNERDEAD; + goto out; + } + if (ctx->flags & IORING_SETUP_TASKRUN_FLAG) + atomic_or(IORING_SQ_TASKRUN, &ctx->rings->sq_flags); +out: + percpu_ref_put(&ctx->refs); + return ret; } static void io_msg_tw_complete(struct callback_head *head)