From patchwork Fri May 15 10:54:14 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Stefano Garzarella X-Patchwork-Id: 11551181 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 39477913 for ; Fri, 15 May 2020 10:54:31 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 23A952074D for ; Fri, 15 May 2020 10:54:31 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="Pjr5rGOD" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726521AbgEOKy1 (ORCPT ); Fri, 15 May 2020 06:54:27 -0400 Received: from us-smtp-1.mimecast.com ([207.211.31.81]:36624 "EHLO us-smtp-delivery-1.mimecast.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1726296AbgEOKyZ (ORCPT ); Fri, 15 May 2020 06:54:25 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1589540062; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=FAOMWx6OVu3YpynCtja6bREESlXthahEC6nREl9YhPo=; b=Pjr5rGODlNgTplhd2E10At0TOOkQGHA14iWNQ3M1rqTRdqTryPLFUUcRtEAqcjcW4zMHyi x3ioOd7n0V7XJwTUNMF4VoxZ+DDCRAZIWOEcClpiG6v8ze04MKD83sAKxTp6uX26HAZjU6 9QS1Rm6LyhAEQsgNX8qKbhDOBdm7MB4= Received: from mail-wm1-f72.google.com (mail-wm1-f72.google.com [209.85.128.72]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-471-0YXWjMUnM026SxeuLqbQnQ-1; Fri, 15 May 2020 06:54:21 -0400 X-MC-Unique: 0YXWjMUnM026SxeuLqbQnQ-1 Received: by mail-wm1-f72.google.com with SMTP id x11so815927wmc.9 for ; Fri, 15 May 2020 03:54:20 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references:mime-version:content-transfer-encoding; bh=FAOMWx6OVu3YpynCtja6bREESlXthahEC6nREl9YhPo=; b=Lyfs9Cgbfxb6rEjge3aZKMj62vtm/TDUciYyitIEmz1y5vQ835J3RKipVN+XzrgXe/ KFf7QKHDqUY/XZIrqaZmW7BRE0D7Oc1/rFp1eBa6/L6k2KCJb8hss5Rpq3h7BQYuZOsA EJ0hHvYNMX+WGfB1kz3oq93BPHonqvWUz1iAOYv/iOr6BZInsiFawSLgtw8pxs/G+Gid 3MBzvoDfnBfJnBVY9TdvlX9qCO+5zB0nQ0zKYpk80zVeRera4EwlZmfEWF3blaMFBA6M T+r6CrgpwaqtiMHem8CN7VPXCM+WvBO+iAHCXdXVTByPcJiR6RQKSOZsqjYz/0izgv9z EBDQ== X-Gm-Message-State: AOAM531YYjDCBzNhws4HiPPhM/41InopjMfomJTepsx8vbeFftBTBAN0 zZbo+/9NQsqbPYWpcXZzQTwwbD5cr+6CnWQ+NOnCrg0tmTato95RfP4dW0iXoU6SwqCDboyjFEf D9REXG7MyysLPJunGsijIhETfnA== X-Received: by 2002:adf:a1d7:: with SMTP id v23mr3623541wrv.155.1589540059926; Fri, 15 May 2020 03:54:19 -0700 (PDT) X-Google-Smtp-Source: ABdhPJz4HCg1+ZO2PPPCFOjhk551z/9enVbNA+X4sgmGqe+RDc8hyFQZev92P69lM/DpFfkAbRAVQw== X-Received: by 2002:adf:a1d7:: with SMTP id v23mr3623519wrv.155.1589540059653; Fri, 15 May 2020 03:54:19 -0700 (PDT) Received: from steredhat.redhat.com ([79.49.207.108]) by smtp.gmail.com with ESMTPSA id u74sm3081713wmu.13.2020.05.15.03.54.18 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 15 May 2020 03:54:18 -0700 (PDT) From: Stefano Garzarella To: Jens Axboe Cc: io-uring@vger.kernel.org, linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org, Alexander Viro Subject: [PATCH 2/2] io_uring: add IORING_CQ_NEED_WAKEUP to the CQ ring flags Date: Fri, 15 May 2020 12:54:14 +0200 Message-Id: <20200515105414.68683-3-sgarzare@redhat.com> X-Mailer: git-send-email 2.25.4 In-Reply-To: <20200515105414.68683-1-sgarzare@redhat.com> References: <20200515105414.68683-1-sgarzare@redhat.com> MIME-Version: 1.0 Sender: linux-fsdevel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org This new flag should be set/clear from the application to enable/disable eventfd notifications when a request is completed and queued to the CQ ring. Before this patch, notifications were always sent if an eventfd is registered, so to remain backwards compatible we enable them during initialization. It will be up to the application to disable them after initialization if no notifications are required at the beginning. Signed-off-by: Stefano Garzarella --- fs/io_uring.c | 7 +++++++ include/uapi/linux/io_uring.h | 5 +++++ 2 files changed, 12 insertions(+) diff --git a/fs/io_uring.c b/fs/io_uring.c index 6e8158269f3c..7c9486ea5aa3 100644 --- a/fs/io_uring.c +++ b/fs/io_uring.c @@ -1152,6 +1152,8 @@ static inline bool io_should_trigger_evfd(struct io_ring_ctx *ctx) { if (!ctx->cq_ev_fd) return false; + if (!(READ_ONCE(ctx->rings->cq_flags) & IORING_CQ_NEED_WAKEUP)) + return false; if (!ctx->eventfd_async) return true; return io_wq_current_is_worker(); @@ -7684,6 +7686,11 @@ static int io_allocate_scq_urings(struct io_ring_ctx *ctx, rings->cq_ring_mask = p->cq_entries - 1; rings->sq_ring_entries = p->sq_entries; rings->cq_ring_entries = p->cq_entries; + /* + * For backward compatibility we start with eventfd notification + * enabled. + */ + rings->cq_flags |= IORING_CQ_NEED_WAKEUP; ctx->sq_mask = rings->sq_ring_mask; ctx->cq_mask = rings->cq_ring_mask; ctx->sq_entries = rings->sq_ring_entries; diff --git a/include/uapi/linux/io_uring.h b/include/uapi/linux/io_uring.h index 602bb0ece607..1d20dc61779e 100644 --- a/include/uapi/linux/io_uring.h +++ b/include/uapi/linux/io_uring.h @@ -209,6 +209,11 @@ struct io_cqring_offsets { __u64 resv2; }; +/* + * cq_ring->flags + */ +#define IORING_CQ_NEED_WAKEUP (1U << 0) /* needs wakeup through eventfd */ + /* * io_uring_enter(2) flags */