From mboxrd@z Thu Jan 1 00:00:00 1970 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 AC8D2C433EF for ; Thu, 21 Apr 2022 19:45:11 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1392068AbiDUTsA (ORCPT ); Thu, 21 Apr 2022 15:48:00 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:51718 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1392057AbiDUTr7 (ORCPT ); Thu, 21 Apr 2022 15:47:59 -0400 Received: from mail-io1-xd34.google.com (mail-io1-xd34.google.com [IPv6:2607:f8b0:4864:20::d34]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 422B9140F9 for ; Thu, 21 Apr 2022 12:45:08 -0700 (PDT) Received: by mail-io1-xd34.google.com with SMTP id q22so6467922iod.2 for ; Thu, 21 Apr 2022 12:45:08 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel-dk.20210112.gappssmtp.com; s=20210112; h=from:to:cc:in-reply-to:references:subject:message-id:date :mime-version:content-transfer-encoding; bh=1tgz+X24f6XnX4f1yXTxoEYQUjnBY33NG2UKa/wMACk=; b=rfKqO1m+RUvn+rJMgR7Xk6wcQBoywjMk4RP/njbPPdsig4lYlb7gHyIDwktnpEBIiC U+GpNV25/elY5gDks9t3mgjdkykIrlpzvzr6SFQYmYbWwVCHfe3u0+tJHnE6gRZwXgVe xWmvaXHPpH4OFMDVHHjqFhZ80+TWUbEihGCReMIxAlloOoVAUWw4pilRllile6vNoguJ zwUkUdBrpPf0OiupMaiDcuKkNMTsTIJnE0nCi8ncYulFEpayJTO9OV5or3gOEk1exOiK JmnEIqhOuTUdr3w9OuKOCyesCopz0Y7RQjX0Kp/sc7w2scwxXE507YgGrmQEXQBlrBqe 5nzA== 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:in-reply-to:references:subject :message-id:date:mime-version:content-transfer-encoding; bh=1tgz+X24f6XnX4f1yXTxoEYQUjnBY33NG2UKa/wMACk=; b=iRA0eI2+Kjk9zJ2IhUw5HqP8Kzwejg9hTaQtWLsVZq+WMQf7PGHHaVbhaYJINyBEfU 93rh/VY9wkTMd/Itl52OfZLYV+bjuLkLq0JieiJheFJt770dA0lLElko9rFMQt7hbdrc orjM1IOWpnzDna/0RtgdT4xBQBDV3ZOfyMdWcovCulI8zduXhThcfoNbvb2JsO3wfV2Y iTE+GbY+86+Npy7TjJaNY4Ht7XL3fZuz3rv0J40DQSatgXbjFCyFr427PfK6dOJY9+Nu PE3yzQewO9lT/5cNZVwoNH5v0WRwVM/gFMXu0k8EOrFdUUI+29YyM7jzegoCjHeIFhBD K9ow== X-Gm-Message-State: AOAM533sSDd5uuwXQaCtvoOOcf+A7lb6/jY+cA7RtA/nVOoPfyyz8xUt IWSqQke5RH4Llh+izn3CCLuYFg== X-Google-Smtp-Source: ABdhPJxnmjYyEBvl3tBa4XmCQ75rxDL2W5WvAVzWXw/AvNBhlAe7CyRBsApwpMMayd0C/pfomXn15Q== X-Received: by 2002:a05:6602:2dcf:b0:656:d2f8:9dee with SMTP id l15-20020a0566022dcf00b00656d2f89deemr576107iow.29.1650570307512; Thu, 21 Apr 2022 12:45:07 -0700 (PDT) Received: from [127.0.1.1] ([207.135.234.126]) by smtp.gmail.com with ESMTPSA id z18-20020a05660229d200b0064c719946a8sm15215671ioq.34.2022.04.21.12.45.06 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 21 Apr 2022 12:45:06 -0700 (PDT) From: Jens Axboe To: dylany@fb.com, io-uring@vger.kernel.org Cc: asml.silence@gmail.com, linux-kernel@vger.kernel.org, kernel-team@fb.com In-Reply-To: <20220421091345.2115755-1-dylany@fb.com> References: <20220421091345.2115755-1-dylany@fb.com> Subject: Re: [PATCH 0/6] return an error when cqe is dropped Message-Id: <165057030672.167153.10167028049673775527.b4-ty@kernel.dk> Date: Thu, 21 Apr 2022 13:45:06 -0600 MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, 21 Apr 2022 02:13:39 -0700, Dylan Yudaken wrote: > This series addresses a rare but real error condition when a CQE is > dropped. Many applications rely on 1 SQE resulting in 1 CQE and may even > block waiting for the CQE. In overflow conditions if the GFP_ATOMIC > allocation fails, the CQE is dropped and a counter is incremented. However > the application is not actively signalled that something bad has > happened. We would like to indicate this error condition to the > application but in a way that does not rely on the application doing > invasive changes such as checking a flag before each wait. > > [...] Applied, thanks! [1/6] io_uring: add trace support for CQE overflow commit: f457ab8deb017140aef05be3027a00a18a7d16b7 [2/6] io_uring: trace cqe overflows commit: 2a847e6faf76810ae68a6e81bd9ac3a7c81534d0 [3/6] io_uring: rework io_uring_enter to simplify return value commit: db9bb58b391c9e62da68bc139598e8470d892c77 [4/6] io_uring: use constants for cq_overflow bitfield commit: b293240e2634b2100196d7314aeeb84299ce6d5b [5/6] io_uring: return an error when cqe is dropped commit: 34a7ee8a42c8496632465f3f0b444b3a7b908c46 [6/6] io_uring: allow NOP opcode in IOPOLL mode commit: ebbe59f49556822b9bcc7b0d4d96bae31f522905 Best regards, -- Jens Axboe