From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (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 703602737F2; Tue, 1 Jul 2025 12:03:51 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1751371431; cv=none; b=pOxdYTP8Xtl2hlU5iCfIHgM2MicZk+vBxvPbbFY7hFVRBXyQDR/ELVEAmP5P5FNOwW/jqKNznvpo4E+XZWAqJIUCHmwnEl6feKGGd5DHB2Bq5NHeWIu4pZSWSTp6mdVAtzTgpihbEN9ZbB6DIUBc4NSMYEFNAIYFaL3G2dFhhHk= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1751371431; c=relaxed/simple; bh=Q7QVc2qsYqqx0YXVW49AwV+9qD+1NySnWlFCXrePDPA=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=a1gjjiUSBIW6NZ+890JvOCQEfqRToXjCpRe6+YnTdwCW3ignTo/rNcVGbEFmGMNlxAj9fkf6grNjKnBHClnA3xKJJJf0PR4/MsdNfVZdSfBIKgM2btG86tRKHhYGVnZ1GngFBydPOwq7BZeClD+PUD/oKu3mcc5ioqNeat6in3o= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=RXJJcXUr; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="RXJJcXUr" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 39886C4CEEB; Tue, 1 Jul 2025 12:03:47 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1751371431; bh=Q7QVc2qsYqqx0YXVW49AwV+9qD+1NySnWlFCXrePDPA=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=RXJJcXUrvHSAIOPY2gI4XfjpcD2WMOoRpuEgtUiwLc9iKiaRf/krf8PhSdchunuJM 8u4WdXAy7Y0lAjuaqgCxhvE5mdRI/Z/Bhz6v7ZTq3DO5qFtAmvy+fZ79lilbCEO+zE DyC82eMXBFcVinxD0Bq1Zl/0D6OADwhCc9kl6BmvhVS6tqonauHkLcJAZQRR+nWS24 Ig9OwkHGHt3GJVFLkQxDVHQNy9mVlClJS2w92exPJHXe4GW1pms/B2EuiRgOh76FiT /QRyLz/jJ3FHlOtG54Y7wBA1O2+Tk4GI8Qj5vI7iIMD9uJ/MQyeLiWGQXzGig+olW3 w7BWS9u7aqa0Q== From: Christian Brauner To: Nam Cao Cc: Christian Brauner , Frederic Weisbecker , Valentin Schneider , Alexander Viro , Jan Kara , Sebastian Andrzej Siewior , John Ogness , Clark Williams , Steven Rostedt , linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org, linux-rt-devel@lists.linux.dev, linux-rt-users@vger.kernel.org, Joe Damato , Martin Karsten , Jens Axboe Subject: Re: [PATCH v3] eventpoll: Fix priority inversion problem Date: Tue, 1 Jul 2025 14:03:38 +0200 Message-ID: <20250701-wochen-bespannt-33e745d23ff6@brauner> X-Mailer: git-send-email 2.47.2 In-Reply-To: <20250527090836.1290532-1-namcao@linutronix.de> References: <20250527090836.1290532-1-namcao@linutronix.de> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" X-Developer-Signature: v=1; a=openpgp-sha256; l=1208; i=brauner@kernel.org; h=from:subject:message-id; bh=Q7QVc2qsYqqx0YXVW49AwV+9qD+1NySnWlFCXrePDPA=; b=owGbwMvMwCU28Zj0gdSKO4sYT6slMWQkn1sQnrzZI0ljcfwpHbZEDYcZy5wUhU6vDzAqev/T+ FMGi4RqRykLgxgXg6yYIotDu0m43HKeis1GmRowc1iZQIYwcHEKwERefGT47+I7r6lfRrx4SZPC gr1nvyx/+ETLa9GU1lkpywpdORRPzmFk2P41wiBiwnsBnxR1dl8pydePEwQ5opmTf1rcsdl8aU4 PCwA= X-Developer-Key: i=brauner@kernel.org; a=openpgp; fpr=4880B8C9BD0E5106FC070F4F7B3C391EFEA93624 Content-Transfer-Encoding: 8bit On Tue, 27 May 2025 11:08:36 +0200, Nam Cao wrote: > The ready event list of an epoll object is protected by read-write > semaphore: > > - The consumer (waiter) acquires the write lock and takes items. > - the producer (waker) takes the read lock and adds items. > > The point of this design is enabling epoll to scale well with large number > of producers, as multiple producers can hold the read lock at the same > time. > > [...] Applied to the vfs.fixes branch of the vfs/vfs.git tree. Patches in the vfs.fixes branch should appear in linux-next soon. Please report any outstanding bugs that were missed during review in a new review to the original patch series allowing us to drop it. It's encouraged to provide Acked-bys and Reviewed-bys even though the patch has now been applied. If possible patch trailers will be updated. Note that commit hashes shown below are subject to change due to rebase, trailer updates or similar. If in doubt, please check the listed branch. tree: https://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs.git branch: vfs.fixes [1/1] eventpoll: Fix priority inversion problem https://git.kernel.org/vfs/vfs/c/e73f3008405b