From patchwork Mon Jan 29 20:23:46 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jens Axboe X-Patchwork-Id: 13536352 Received: from mail-io1-f49.google.com (mail-io1-f49.google.com [209.85.166.49]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id D6460241E9 for ; Mon, 29 Jan 2024 20:30:33 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.166.49 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1706560235; cv=none; b=J+OV3uG/Y8gITtx700Gnlwtd/ijuG+s0Cqu5dysdopZ1PZw8n6VHlUll7Tim7pe+gcAs20Mz1FpXaklv2jwvA/v02cS8Vnx5S05B1NCshaEfbLLqqf0pm+uLt1tzO1rEdJgsfCe3IfkiUSBfRiEMfib+LHby0xM7/ZgZruNUAqE= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1706560235; c=relaxed/simple; bh=0+Rd3c+2VrjAHvhG2SXGTxJvV0LNchhXjiL1XoN1hYA=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=cwQJuveLzh0b8x0dPFom9NL6VrfBSdwsh/xvsHfTkJkGMC3aaNj0O8NGsdVK2gnD4cfreLGgoFTqDDbjrweHEcx/h6ZdhzSL5TevaBpR9Z0PAHOnSBbV1ZVPHybvEG6Rg6YEVJmIewZBh5ifK2eNCBvJLCLvfyQ5Js69wsgZRLs= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=kernel.dk; spf=pass smtp.mailfrom=kernel.dk; dkim=pass (2048-bit key) header.d=kernel-dk.20230601.gappssmtp.com header.i=@kernel-dk.20230601.gappssmtp.com header.b=g79Wba8k; arc=none smtp.client-ip=209.85.166.49 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=kernel.dk Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=kernel.dk Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel-dk.20230601.gappssmtp.com header.i=@kernel-dk.20230601.gappssmtp.com header.b="g79Wba8k" Received: by mail-io1-f49.google.com with SMTP id ca18e2360f4ac-7beeeb1ba87so49128939f.0 for ; Mon, 29 Jan 2024 12:30:33 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel-dk.20230601.gappssmtp.com; s=20230601; t=1706560232; x=1707165032; darn=vger.kernel.org; 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=6Uq6s8O+pYHZy+YqyeW9aGwqRrlELW919jI2ZvhUwBE=; b=g79Wba8krWHgWUkmqXySe4oo9o+vRUuaYWY/csaO3wprde+CEZL2+5Bl1evgNwFK9p P52vyeY5M2+ZlZTHM9Cm5AtOPL975xWNMSkzte3D1r39cfYJ/tVZTyOv+/3fI5B23ddQ 4Hay+JenYL6EDG7DPJ3rMEoARuVbNKXgjzASoIsf0cJ+67O7Gqy4J7aB00SBxJJ29ZgY Z7CN/RV8qw72VySOm83DwkWLGnB0GjTOKANzV6+QRrd5Yy714pp5t9Oo9YW/t5xP5ExU 6HQrR52r1qvkVAk/ib9qabiApI4NcgFGLnAUvz7RUL3M4ah8sSVwqE+bKoQacNLp4KtG eXJQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1706560232; x=1707165032; 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=6Uq6s8O+pYHZy+YqyeW9aGwqRrlELW919jI2ZvhUwBE=; b=MWQLrZvMVgm/jmVwJUIlDGqAyHramERUQ3j5NZG73jBBZetTWeP8kyWwvW9L+52mz0 QFu544mNjKzs5vb8XFzeP0YfczzMrK3VOQ17ZMm7K23fMTbfWav+0pyT8WkFjQ1aCVhG cxcoRKWbqEoJkHLhEIpOv5QRCsVZjy2HuizWhjPNRcUhgQF7J6pR6v1+F9FERjmvv8Dx hTr8Bca6ajrnQ3bYfoGE0nx+6CGx7XOEEOuXi3gaSan+IYuaiFiZgZUW0N2dibMpT/I5 8dYKN4HiTcc0RkiuUiYu5WMdep7KUb8zddoa+QWqoclGWu+cvIs3MbdqOftjUe4+t+0l 4Fgg== X-Gm-Message-State: AOJu0Yxa1Jkp+Nl4etxOqWOup+4tZZEgev4nhau3GaC+jeEuIvh6SBbp 0yFfoyW/Sm4LmR/6aWrJgD7ZmLYOJ4Jm6eqUUTJieiAk0c/rYebaowXhL18k/xMj6LomFseuGvj ah3I= X-Google-Smtp-Source: AGHT+IFI9DGTXsdE+TE2omu5IVWlSJ8jTtoDnY7xieNFXkdniHwWsNW+nz2DK80hHJLKG3RGXcU2UQ== X-Received: by 2002:a05:6602:1508:b0:7bf:f336:8032 with SMTP id g8-20020a056602150800b007bff3368032mr5204169iow.2.1706560232543; Mon, 29 Jan 2024 12:30:32 -0800 (PST) Received: from localhost.localdomain ([96.43.243.2]) by smtp.gmail.com with ESMTPSA id i8-20020a05663815c800b0046e6a6482d2sm1952510jat.97.2024.01.29.12.30.31 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 29 Jan 2024 12:30:31 -0800 (PST) From: Jens Axboe To: io-uring@vger.kernel.org Cc: asml.silence@gmail.com, Jens Axboe Subject: [PATCH 3/4] io_uring/poll: add requeue return code from poll multishot handling Date: Mon, 29 Jan 2024 13:23:46 -0700 Message-ID: <20240129203025.3214152-4-axboe@kernel.dk> X-Mailer: git-send-email 2.43.0 In-Reply-To: <20240129203025.3214152-1-axboe@kernel.dk> References: <20240129203025.3214152-1-axboe@kernel.dk> Precedence: bulk X-Mailing-List: io-uring@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Since our poll handling is edge triggered, multishot handlers retry internally until they know that no more data is available. In preparation for limiting these retries, add an internal return code, IOU_REQUEUE, which can be used to inform the poll backend about the handler wanting to retry, but that this should happen through a normal task_work requeue rather than keep hammering on the issue side for this one request. No functional changes in this patch, nobody is using this return code just yet. Signed-off-by: Jens Axboe --- io_uring/io_uring.h | 8 +++++++- io_uring/poll.c | 9 ++++++++- 2 files changed, 15 insertions(+), 2 deletions(-) diff --git a/io_uring/io_uring.h b/io_uring/io_uring.h index 04e33f25919c..d5495710c178 100644 --- a/io_uring/io_uring.h +++ b/io_uring/io_uring.h @@ -15,11 +15,17 @@ #include #endif - enum { IOU_OK = 0, IOU_ISSUE_SKIP_COMPLETE = -EIOCBQUEUED, + /* + * Requeue the task_work to restart operations on this request. The + * actual value isn't important, should just be not an otherwise + * valid error code, yet less than -MAX_ERRNO and valid internally. + */ + IOU_REQUEUE = -3072, + /* * Intended only when both IO_URING_F_MULTISHOT is passed * to indicate to the poll runner that multishot should be diff --git a/io_uring/poll.c b/io_uring/poll.c index 785a5b191003..7513afc7b702 100644 --- a/io_uring/poll.c +++ b/io_uring/poll.c @@ -226,6 +226,7 @@ enum { IOU_POLL_NO_ACTION = 1, IOU_POLL_REMOVE_POLL_USE_RES = 2, IOU_POLL_REISSUE = 3, + IOU_POLL_REQUEUE = 4, }; static void __io_poll_execute(struct io_kiocb *req, int mask) @@ -329,6 +330,8 @@ static int io_poll_check_events(struct io_kiocb *req, struct io_tw_state *ts) int ret = io_poll_issue(req, ts); if (ret == IOU_STOP_MULTISHOT) return IOU_POLL_REMOVE_POLL_USE_RES; + else if (ret == IOU_REQUEUE) + return IOU_POLL_REQUEUE; if (ret < 0) return ret; } @@ -351,8 +354,12 @@ void io_poll_task_func(struct io_kiocb *req, struct io_tw_state *ts) int ret; ret = io_poll_check_events(req, ts); - if (ret == IOU_POLL_NO_ACTION) + if (ret == IOU_POLL_NO_ACTION) { return; + } else if (ret == IOU_POLL_REQUEUE) { + __io_poll_execute(req, 0); + return; + } io_poll_remove_entries(req); io_poll_tw_hash_eject(req, ts);