From patchwork Wed Dec 27 20:38:23 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Rafael J. Wysocki" X-Patchwork-Id: 13505485 Received: from cloudserver094114.home.pl (cloudserver094114.home.pl [79.96.170.134]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id B56F747F64; Wed, 27 Dec 2023 20:41:45 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=rjwysocki.net Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=rjwysocki.net Received: from localhost (127.0.0.1) (HELO v370.home.net.pl) by /usr/run/smtp (/usr/run/postfix/private/idea_relay_lmtp) via UNIX with SMTP (IdeaSmtpServer 5.4.0) id de14cebbb85df213; Wed, 27 Dec 2023 21:41:43 +0100 Received: from kreacher.localnet (unknown [195.136.19.94]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by cloudserver094114.home.pl (Postfix) with ESMTPSA id 23511668E17; Wed, 27 Dec 2023 21:41:43 +0100 (CET) From: "Rafael J. Wysocki" To: Greg KH , linux-pm@vger.kernel.org Cc: Youngmin Nam , rafael@kernel.org, linux-kernel@vger.kernel.org, d7271.choe@samsung.com, janghyuck.kim@samsung.com, hyesoo.yu@samsung.com, Alan Stern , Ulf Hansson Subject: [PATCH v1 2/3] async: Introduce async_schedule_dev_nocall() Date: Wed, 27 Dec 2023 21:38:23 +0100 Message-ID: <4874693.GXAFRqVoOG@kreacher> In-Reply-To: <6019796.lOV4Wx5bFT@kreacher> References: <5754861.DvuYhMxLoT@kreacher> <6019796.lOV4Wx5bFT@kreacher> Precedence: bulk X-Mailing-List: linux-pm@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-CLIENT-IP: 195.136.19.94 X-CLIENT-HOSTNAME: 195.136.19.94 X-VADE-SPAMSTATE: clean X-VADE-SPAMCAUSE: gggruggvucftvghtrhhoucdtuddrgedvkedrvddvledgudegudcutefuodetggdotefrodftvfcurfhrohhfihhlvgemucfjqffogffrnfdpggftiffpkfenuceurghilhhouhhtmecuudehtdenucesvcftvggtihhpihgvnhhtshculddquddttddmnecujfgurhephffvvefufffkjghfggfgtgesthfuredttddtjeenucfhrhhomhepfdftrghfrggvlhculfdrucghhihsohgtkhhifdcuoehrjhifsehrjhifhihsohgtkhhirdhnvghtqeenucggtffrrghtthgvrhhnpedvffeuiedtgfdvtddugeeujedtffetteegfeekffdvfedttddtuefhgeefvdejhfenucfkphepudelhedrudefiedrudelrdelgeenucevlhhushhtvghrufhiiigvpedtnecurfgrrhgrmhepihhnvghtpeduleehrddufeeirdduledrleegpdhhvghlohepkhhrvggrtghhvghrrdhlohgtrghlnhgvthdpmhgrihhlfhhrohhmpedftfgrfhgrvghlucflrdcuhgihshhotghkihdfuceorhhjfiesrhhjfiihshhotghkihdrnhgvtheqpdhnsggprhgtphhtthhopedutddprhgtphhtthhopehgrhgvghhkhheslhhinhhugihfohhunhgurghtihhonhdrohhrghdprhgtphhtthhopehlihhnuhigqdhpmhesvhhgvghrrdhkvghrnhgvlhdrohhrghdprhgtphhtthhopeihohhunhhgmhhinhdrnhgrmhesshgrmhhsuhhnghdrtghomhdprhgtphhtthhopehrrghfrggvlheskhgvrhhnvghlrdhorhhgpdhrtghpthhtoheplhhinhhugidqkhgvrhhnvghlsehvghgvrhdrkhgvrhhnvghlrdhorhhgpdhrtghpthhtohepugejvdejuddrtghhohgvsehsrghmshhunhhgrdgtohhm X-DCC--Metrics: v370.home.net.pl 1024; Body=10 Fuz1=10 Fuz2=10 From: Rafael J. Wysocki In preparation for subsequent changes, introduce a specialized variant of async_schedule_dev() that will not invoke the argument function synchronously when it cannot be scheduled for asynchronous execution. The new function, async_schedule_dev_nocall(), will be used for fixing possible deadlocks in the system-wide power management core code. Signed-off-by: Rafael J. Wysocki Reviewed-by: Stanislaw Gruszka for the series. --- drivers/base/power/main.c | 12 ++++++++---- include/linux/async.h | 2 ++ kernel/async.c | 29 +++++++++++++++++++++++++++++ 3 files changed, 39 insertions(+), 4 deletions(-) Index: linux-pm/kernel/async.c =================================================================== --- linux-pm.orig/kernel/async.c +++ linux-pm/kernel/async.c @@ -244,6 +244,35 @@ async_cookie_t async_schedule_node(async EXPORT_SYMBOL_GPL(async_schedule_node); /** + * async_schedule_dev_nocall - A simplified variant of async_schedule_dev() + * @func: function to execute asynchronously + * @dev: device argument to be passed to function + * + * @dev is used as both the argument for the function and to provide NUMA + * context for where to run the function. + * + * If the asynchronous execution of @func is scheduled successfully, return + * true. Otherwise, do nothing and return false, unlike async_schedule_dev() + * that will run the function synchronously then. + */ +bool async_schedule_dev_nocall(async_func_t func, struct device *dev) +{ + struct async_entry *entry; + + entry = kzalloc(sizeof(struct async_entry), GFP_KERNEL); + + /* Give up if there is no memory or too much work. */ + if (!entry || atomic_read(&entry_count) > MAX_WORK) { + kfree(entry); + return false; + } + + __async_schedule_node_domain(func, dev, dev_to_node(dev), + &async_dfl_domain, entry); + return true; +} + +/** * async_synchronize_full - synchronize all asynchronous function calls * * This function waits until all asynchronous function calls have been done. Index: linux-pm/include/linux/async.h =================================================================== --- linux-pm.orig/include/linux/async.h +++ linux-pm/include/linux/async.h @@ -90,6 +90,8 @@ async_schedule_dev(async_func_t func, st return async_schedule_node(func, dev, dev_to_node(dev)); } +bool async_schedule_dev_nocall(async_func_t func, struct device *dev); + /** * async_schedule_dev_domain - A device specific version of async_schedule_domain * @func: function to execute asynchronously