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 CBE451F63C4; Tue, 17 Dec 2024 15:34:11 +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=1734449651; cv=none; b=ctMDSzvrcAfpRlXaluV5S4Z+5xhDt4HjOASDs3LQrwhppcszEVxXQPG0HowjTXHgSzmRT3uYobiavkd28p0sGMTMPLNs0dsIAEIaieGnDSA1+eDz4NN/HwL+wVG1XNRJaOQJKU9pUqj58UY6xpY0AkPJEqAxSSKeaWLWBCYBgB8= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1734449651; c=relaxed/simple; bh=PBoHMl/vjbrkDJJdW06HoXGpU5J3Rsz5cWS1b6kINrg=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=ccMX2tgEKSPD13zkM4OE4F1A6dM9uCM5lUm5eV1XksJ2Fmsv2hfrPY9hPqCNkLDGN+7VKtZCwiaLRg7Aa8Py6HqhyjxXLLlwftwLqaYrhFHajNmH1pIuRrYAWYTQpMnslFJ2eVFLed57wISYu8T/TgowiNfVGm+YpkP5A2K4Urk= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=PgxMTbsQ; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="PgxMTbsQ" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 88250C4CED6; Tue, 17 Dec 2024 15:34:10 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1734449651; bh=PBoHMl/vjbrkDJJdW06HoXGpU5J3Rsz5cWS1b6kINrg=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=PgxMTbsQ+h5iOtpVU533vBud9w8343J2e+egHvICld0hUFr7LqxFtVeYlLphnKieJ N78IZnvUhMe1HsMoT2itUg4Q7eUWthMde7Xa9fG2Tx2SDp3YnYHMNcpXsEYq1zItU+ BrU3612buMIwn28Ei1PSJ4/stU+D7LUZN8ad01wg= Date: Tue, 17 Dec 2024 16:34:08 +0100 From: Greg KH To: Brian Geffon Cc: "# v4 . 10+" , Xuewen Yan , Christian Brauner , jack@suse.cz, dietmar.eggemann@arm.com, rostedt@goodmis.org, bsegall@google.com, mgorman@suse.de, bristot@redhat.com, vschneid@redhat.com, cmllamas@google.com, linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org, ke.wang@unisoc.com, jing.xia@unisoc.com, xuewen.yan94@gmail.com, viro@zeniv.linux.org.uk, mingo@redhat.com, peterz@infradead.org, juri.lelli@redhat.com, vincent.guittot@linaro.org, lizeb@google.com Subject: Re: [RFC PATCH] epoll: Add synchronous wakeup support for ep_poll_callback Message-ID: <2024121705-unrigged-sanitary-7b19@gregkh> References: <20240426080548.8203-1-xuewen.yan@unisoc.com> <20241016-kurieren-intellektuell-50bd02f377e4@brauner> 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 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: On Tue, Dec 17, 2024 at 09:30:51AM -0500, Brian Geffon wrote: > On Thu, Dec 12, 2024 at 12:14 PM Brian Geffon wrote: > > > > On Wed, Oct 16, 2024 at 03:05:38PM -0400, Brian Geffon wrote: > > > On Wed, Oct 16, 2024 at 03:10:34PM +0200, Christian Brauner wrote: > > > > On Fri, 26 Apr 2024 16:05:48 +0800, Xuewen Yan wrote: > > > > > Now, the epoll only use wake_up() interface to wake up task. > > > > > However, sometimes, there are epoll users which want to use > > > > > the synchronous wakeup flag to hint the scheduler, such as > > > > > Android binder driver. > > > > > So add a wake_up_sync() define, and use the wake_up_sync() > > > > > when the sync is true in ep_poll_callback(). > > > > > > > > > > [...] > > > > > > > > Applied to the vfs.misc branch of the vfs/vfs.git tree. > > > > Patches in the vfs.misc 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.misc > > > > > > This is a bug that's been present for all of time, so I think we should: > > > > > > Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") > > > Cc: stable@vger.kernel.org > > > > This is in as 900bbaae ("epoll: Add synchronous wakeup support for > > ep_poll_callback"). How do maintainers feel about: > > > > Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") > > Cc: stable@vger.kernel.org > > Dear stable maintainers, this fixes a bug goes all the way back and > beyond Linux 2.6.12-rc2. Can you please add this commit to the stable > releases? > > commit 900bbaae67e980945dec74d36f8afe0de7556d5a upstream. How is this a bugfix? It looks like it is just a new feature being added to epoll, what bug does it "fix"? confused, greg k-h