From patchwork Fri May 15 16:38:05 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Stefano Garzarella X-Patchwork-Id: 11552533 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 E42FF739 for ; Fri, 15 May 2020 16:38:16 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id CD8F92076A for ; Fri, 15 May 2020 16:38:16 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="XIjfRydh" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726233AbgEOQiP (ORCPT ); Fri, 15 May 2020 12:38:15 -0400 Received: from us-smtp-2.mimecast.com ([205.139.110.61]:30428 "EHLO us-smtp-delivery-1.mimecast.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1726294AbgEOQiO (ORCPT ); Fri, 15 May 2020 12:38:14 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1589560693; 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=YZmrRZSpZSImU0ZWw6sQoh3piuQw6gdHG9URSW684/o=; b=XIjfRydhU0zefeOxzx4Cq1p9jYq3vcNMShDMZAOeCjJuOCEtGOWhHalu+s9UGULUdM9Uo8 pJ29HaSuQ3h4zQjarTffc6cdVpPxeUZvoaBKdCvLmm4tI1WAsG8UbezBuH3xhZcTGdSc3e AbBr8RlM4beXYACQzMZDjQ83kiamabM= Received: from mail-wr1-f69.google.com (mail-wr1-f69.google.com [209.85.221.69]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-284-fKT5OynBMg25p2NPVNr1Ow-1; Fri, 15 May 2020 12:38:11 -0400 X-MC-Unique: fKT5OynBMg25p2NPVNr1Ow-1 Received: by mail-wr1-f69.google.com with SMTP id e14so1434967wrv.11 for ; Fri, 15 May 2020 09:38:11 -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=YZmrRZSpZSImU0ZWw6sQoh3piuQw6gdHG9URSW684/o=; b=FhFh1+DSFPs9ST5IB6+gm3a+0WZ9PwXB4kNtre+H124KId++dTg8U5cVPzbpnZmb5j 8yDx1wYb7KlqO+fgk5juJFtdeweEhCnjFWjhbOP3/A0kEDBbdnOoc4EZ1bM1CF84AowP DTzSFaZ1JKQ+2+cKqjPNqNVAr9fmV7x07qaRCkjAONTDSmDfE34DzTSp0RPA4EcR3oPA jZl8MCUocLlINiLb7bejjbP0NbrhktUAbDLnFG3asYl7DCHcj3KH+fs/QVgObxxv/0I7 pDBBq94JQkeiShDqmAcRD8Er3SMWVhqai7pZcB/ggWpsDXBJZ6c68IsocIU07pZ/CELC kf4g== X-Gm-Message-State: AOAM531NGtJctSmcRDcZNCWFDYjxE7adsDjfvDEuUdmuj8eQSEwvKCNK TN++sy9jogtdiViZ+6TlmHcZ/QgcXX3Y0ExKGj6OCE0llO5QkOWGBzXmS/R60TiTWJMAlYHcuxy gHVDOABOmDVYP0K4RmyQiUKiGaA== X-Received: by 2002:adf:ed82:: with SMTP id c2mr5379928wro.255.1589560690177; Fri, 15 May 2020 09:38:10 -0700 (PDT) X-Google-Smtp-Source: ABdhPJwHkK+pYRdkGRoBHu7DvxKUQxjk5W5DN2qukBf2VTAqpWYC92WZ6RC31kIRR64YG+MD9jnxcw== X-Received: by 2002:adf:ed82:: with SMTP id c2mr5379900wro.255.1589560689927; Fri, 15 May 2020 09:38:09 -0700 (PDT) Received: from steredhat.redhat.com ([79.49.207.108]) by smtp.gmail.com with ESMTPSA id b145sm4680274wme.41.2020.05.15.09.38.08 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 15 May 2020 09:38:09 -0700 (PDT) From: Stefano Garzarella To: Jens Axboe Cc: linux-kernel@vger.kernel.org, Alexander Viro , io-uring@vger.kernel.org, linux-fsdevel@vger.kernel.org Subject: [PATCH v2 2/2] io_uring: add IORING_CQ_EVENTFD_DISABLED to the CQ ring flags Date: Fri, 15 May 2020 18:38:05 +0200 Message-Id: <20200515163805.235098-3-sgarzare@redhat.com> X-Mailer: git-send-email 2.25.4 In-Reply-To: <20200515163805.235098-1-sgarzare@redhat.com> References: <20200515163805.235098-1-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 disable/enable 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 IORING_CQ_EVENTFD_DISABLED is not set during the initialization. It will be up to the application to set the flag after initialization if no notifications are required at the beginning. Signed-off-by: Stefano Garzarella --- v1 -> v2: - changed the flag name and behaviour from IORING_CQ_NEED_EVENT to IORING_CQ_EVENTFD_DISABLED [Jens] --- fs/io_uring.c | 2 ++ include/uapi/linux/io_uring.h | 7 +++++++ 2 files changed, 9 insertions(+) diff --git a/fs/io_uring.c b/fs/io_uring.c index 6e8158269f3c..a9b194e9b5bd 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_EVENTFD_DISABLED) + return false; if (!ctx->eventfd_async) return true; return io_wq_current_is_worker(); diff --git a/include/uapi/linux/io_uring.h b/include/uapi/linux/io_uring.h index 602bb0ece607..8c5775df08b8 100644 --- a/include/uapi/linux/io_uring.h +++ b/include/uapi/linux/io_uring.h @@ -209,6 +209,13 @@ struct io_cqring_offsets { __u64 resv2; }; +/* + * cq_ring->flags + */ + +/* disable eventfd notifications */ +#define IORING_CQ_EVENTFD_DISABLED (1U << 0) + /* * io_uring_enter(2) flags */