From patchwork Fri Jan 20 16:21:01 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Pavel Begunkov X-Patchwork-Id: 13110156 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 33743C38141 for ; Fri, 20 Jan 2023 16:22:22 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229475AbjATQWV (ORCPT ); Fri, 20 Jan 2023 11:22:21 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:57924 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229966AbjATQWT (ORCPT ); Fri, 20 Jan 2023 11:22:19 -0500 Received: from mail-ej1-x635.google.com (mail-ej1-x635.google.com [IPv6:2a00:1450:4864:20::635]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 20C75E3B0 for ; Fri, 20 Jan 2023 08:22:15 -0800 (PST) Received: by mail-ej1-x635.google.com with SMTP id vw16so15189825ejc.12 for ; Fri, 20 Jan 2023 08:22:15 -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=VgfhYJXc6p1/AlgNYL1c0MKlj8csbE9UKF7fOgnyQxk=; b=lPB82oHib2j0TdeQIhpB15CFCYNCcmCe77NzlClq5GwU1DMtOGYg8C9FRAYJRGlqpv RCFDRXuf/TJdQuV8I3+O171ixMC/b25UwOZ75ZRi2mEtG/7yL4fdoiLWGpQ72u2oYQqW JTUNdMISRd/JRIya/iIVXsFLcilqmekVMytR+W7zEPPSlslPs+gDCEsLEsa7QOzVf5U1 VxA9hr847OX2CcA93Ysoj1ReEffiaD+A5bhaSH38iLk14vrLNdn2exrpicsUL0bQ6RQP urdcftECn5JJ7Et82mZqZ8P3xYnC3hdrqipxxsQHzQ3S2qAt0Vk1mUj3zE3X8ZLdf3kd /tuw== 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=VgfhYJXc6p1/AlgNYL1c0MKlj8csbE9UKF7fOgnyQxk=; b=ycJz0KaYZvAhfuVSdi5wwc8UTzgygtNyIpUc9rhbgwn4znGKBXmyUyTkawBXj8u7Pe PU/U2xIy2qBv5u16uWyKpWTOtuLy8O7xhZHx+Z2+4RM74JeEP3ymHInVIHSiT43CdShR MmJN8uEniQ9/XFCHKjKLg8VhO77iNX+GUNu9e3mgV2cJ+gUKwJVKT+bfxL/KewaPLbwm M09ZTCfM1q+WhRq/aoCnPBnMxGK8EQIOkx+k2z9XKBGc2gSEs9iQJLUC7rHGLkZpReFd ChJKDVHObllB/b9eLFitqAcSE8gP4QBaUz7Hgsi2ulkihWG/Dcy08GPFkO3td0Kc3Lie 7Pig== X-Gm-Message-State: AFqh2kpMYTQfTrZIKkiQ+0nG/A9WMh9YRpdWG++IwruxExz69ZnKXGn5 jLvvrrqQzeR4O+BYUtiYeN+3Ft6Mt28= X-Google-Smtp-Source: AMrXdXtTmLD82l4TOReZB+9E6HCHYq6rKwhE1YShP3ayB7jAO/jQoomBn4sm1tU9wYwhkCJyKlN/ng== X-Received: by 2002:a17:907:3e18:b0:84d:3403:f4f2 with SMTP id hp24-20020a1709073e1800b0084d3403f4f2mr21279103ejc.62.1674231733576; Fri, 20 Jan 2023 08:22:13 -0800 (PST) Received: from 127.com ([2620:10d:c092:600::2:4670]) by smtp.gmail.com with ESMTPSA id s12-20020a1709060c0c00b0086621d9d9b0sm11406040ejf.81.2023.01.20.08.22.13 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 20 Jan 2023 08:22:13 -0800 (PST) From: Pavel Begunkov To: io-uring@vger.kernel.org Cc: Jens Axboe , asml.silence@gmail.com Subject: [PATCH for-6.2 3/3] io_uring/msg_ring: optimise with correct tw notify method Date: Fri, 20 Jan 2023 16:21:01 +0000 Message-Id: <205404218a6f113709407d596bc5a97ecfabedf9.1674231554.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 c68cd3898035..12dc9ed3d062 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)