From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from out5-smtp.messagingengine.com (out5-smtp.messagingengine.com [66.111.4.29]) (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 82F09B660 for ; Tue, 6 Feb 2024 17:03:44 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=66.111.4.29 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1707239026; cv=none; b=QNWMdnfIhZq3CZVS7MI+knujM6dYgf5OyJXRqGcs+SPkF7z2MZGAOdjyrtfBYDPZ3wOMxGbwThwoIqyww/9lGaLse+VvwvT9EFSuMpScubjoVmJW2IGn/cn2c9wteIjbSPt4QVsoLgDRMA6+UF7eseHisdoWtvuY1gogHs+uQGg= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1707239026; c=relaxed/simple; bh=Pi2bQyjd4JrcnKiKXNf22cV4BhWExRbLQiYFOeF0mQg=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=P2Y3vq/LcaZhl9e6zTenuiiEyzGwPvyozKd3t21/8ASUyDk4X1TI2ZRhtJJoCr23ej4n1PcyxlIduaOPZddUKMoqeiYMCmIh714a8RtdkdGzK8LumZ+IrydMKowocJYGF3/PBbTdkEuhgnffNijp50SRLUt9DknWrka2pm6hqCk= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=tycho.pizza; spf=pass smtp.mailfrom=tycho.pizza; dkim=pass (2048-bit key) header.d=tycho.pizza header.i=@tycho.pizza header.b=RzH+usjA; dkim=pass (2048-bit key) header.d=messagingengine.com header.i=@messagingengine.com header.b=XjRWJj1P; arc=none smtp.client-ip=66.111.4.29 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=tycho.pizza Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=tycho.pizza Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=tycho.pizza header.i=@tycho.pizza header.b="RzH+usjA"; dkim=pass (2048-bit key) header.d=messagingengine.com header.i=@messagingengine.com header.b="XjRWJj1P" Received: from compute6.internal (compute6.nyi.internal [10.202.2.47]) by mailout.nyi.internal (Postfix) with ESMTP id 7F13D5C01DF; Tue, 6 Feb 2024 12:03:43 -0500 (EST) Received: from mailfrontend1 ([10.202.2.162]) by compute6.internal (MEProxy); Tue, 06 Feb 2024 12:03:43 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=tycho.pizza; h= cc:cc:content-type:content-type:date:date:from:from:in-reply-to :in-reply-to:message-id:mime-version:references:reply-to:subject :subject:to:to; s=fm2; t=1707239023; x=1707325423; bh=rncCsbijlK W5bm+uOCXcgesm6PuvgxlxVPQRyDZ1S1c=; b=RzH+usjAWVRDh+Cti/pnzv9Pmr jqG5J6X0+aqdbqnl5jP/QeAhVR2cZ3rzV7PuvvC04IuefVFP5itdV/UbeeG19OnZ EhPTP7FxhPBqvVeTxnDzNaAZ+fkQw3ggBg0D212fPpn6jsFhH1Pg6cKCHHtoZxxK 35Z4fXk1NevZvnvXtvjLVXqG2eh2l0+d9m4V3Sn86ak33Ei5QXXNfltKXpFnvKTL gtyw2rdZQbyHooZj/xDrQ21yR6dupSYZ2jdGqs8w0tkvRs6CriI65S/+HC+HJ0Lx uYR+quUB1hMcNHrdMTrw4NPadie6yFfxYmKMFaAvxETTUpUQl9+Y/KhNrSow== DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d= messagingengine.com; h=cc:cc:content-type:content-type:date:date :feedback-id:feedback-id:from:from:in-reply-to:in-reply-to :message-id:mime-version:references:reply-to:subject:subject:to :to:x-me-proxy:x-me-proxy:x-me-sender:x-me-sender:x-sasl-enc; s= fm3; t=1707239023; x=1707325423; bh=rncCsbijlKW5bm+uOCXcgesm6Puv gxlxVPQRyDZ1S1c=; b=XjRWJj1P5dv9c6+k43wQ7sBpjgWKPTmR1+uMvYjlul8H j8tz4AH4rNkCQsm+i53EWf6j2J/xMsOVeJrABQ7M3fnXLE99gjHsUYzYq7CzxZVs XVfxDqB1oWOWKTLq1AUczai70MkcK5umrDqfxFao03Vm26SwzUVfR9uFdCPyAHTK z91vYIkHRaKhF0z68doHY9NuovW4noBHSYmDOG2htfoL3bCX7TxPekbdIcPCiO8h TkIhkmzBTZD3MvZEUDpsbcs9Pz0XOF7UQbMKF0pihkPAzpRpgFCkvE2dPjW56U5J cpW3QhCNBwmxja33Tgj4i4T6LzE3BIm7XB0IYitGwg== X-ME-Sender: X-ME-Received: X-ME-Proxy-Cause: gggruggvucftvghtrhhoucdtuddrgedvledrtddtgdeiiecutefuodetggdotefrodftvf curfhrohhfihhlvgemucfhrghsthforghilhdpqfgfvfdpuffrtefokffrpgfnqfghnecu uegrihhlohhuthemuceftddtnecusecvtfgvtghiphhivghnthhsucdlqddutddtmdenuc fjughrpeffhffvvefukfhfgggtuggjsehttdertddttddvnecuhfhrohhmpefvhigthhho ucetnhguvghrshgvnhcuoehthigthhhosehthigthhhordhpihiiiigrqeenucggtffrrg htthgvrhhnpeelveduteeghfehkeeukefhudfftefhheetfedthfevgfetleevvdduveet ueefheenucffohhmrghinhepkhgvrhhnvghlrdhorhhgnecuvehluhhsthgvrhfuihiivg eptdenucfrrghrrghmpehmrghilhhfrhhomhepthihtghhohesthihtghhohdrphhiiiii rg X-ME-Proxy: Feedback-ID: i21f147d5:Fastmail Received: by mail.messagingengine.com (Postfix) with ESMTPA; Tue, 6 Feb 2024 12:03:42 -0500 (EST) Date: Tue, 6 Feb 2024 10:03:41 -0700 From: Tycho Andersen To: Oleg Nesterov Cc: Christian Brauner , Andy Lutomirski , "Eric W. Biederman" , linux-kernel@vger.kernel.org Subject: Re: [PATCH] pidfd: change do_notify_pidfd() to use __wake_up(poll_to_key(EPOLLIN)) Message-ID: References: <20240205141348.GA16539@redhat.com> 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=us-ascii Content-Disposition: inline In-Reply-To: <20240205141348.GA16539@redhat.com> On Mon, Feb 05, 2024 at 03:13:48PM +0100, Oleg Nesterov wrote: > rather than wake_up_all(). This way do_notify_pidfd() won't wakeup the > POLLHUP-only waiters which wait for pid_task() == NULL. > > TODO: > - as Christian pointed out, this asks for the new wake_up_all_poll() > helper, it can already have other users. > > - we can probably discriminate the PIDFD_THREAD and non-PIDFD_THREAD > waiters, but this needs more work. See > https://lore.kernel.org/all/20240205140848.GA15853@redhat.com/ > > Signed-off-by: Oleg Nesterov Reviewed-by: Tycho Andersen