From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (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 AD3B03F9D2; Wed, 14 Aug 2024 04:26:56 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=198.137.202.133 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1723609618; cv=none; b=GLzgb+l16R42tBWNgWo3+YkQIVg9d8YDZvK1idHdPlmcKJyCoQFeYZ8j6PEMjYrp/ajUAAoq7920eqQwmx1UWKq+T1LJ2MAk5oOlTxUKmzD+J+b1vgkpqr2JFpRz3vvjwK4XVEdMrAdOgwv6cPHJGspAKCg5etheGJHpnY84/NQ= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1723609618; c=relaxed/simple; bh=PLb67pVSsndcRI1y+KjrOGjJp6540cHeBGACcgBee8M=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=Fu6jS5yAk9kun9+PKbTMAc0SZ2AMA+o8K1SD2Oy1XTw7nO8WQvWfuxQKU9LkAKcfNT0saZQkI8Vncw9SYc7eQRq2TFQ/j+L5K5h3vMO314u9gcvDq+NVRBii0twNCIIuxTwdZIXn9tiTAwju+OaMmYUZyi5NsF55UyEiOtNuTx4= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=infradead.org; spf=none smtp.mailfrom=bombadil.srs.infradead.org; dkim=pass (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b=uh2JpD5Q; arc=none smtp.client-ip=198.137.202.133 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=infradead.org Authentication-Results: smtp.subspace.kernel.org; spf=none smtp.mailfrom=bombadil.srs.infradead.org Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b="uh2JpD5Q" DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=bombadil.20210309; h=In-Reply-To:Content-Type:MIME-Version :References:Message-ID:Subject:Cc:To:From:Date:Sender:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description; bh=LLpJw7phUcutr01b12qv/qpETaOvy+zBcX+/75hkvbs=; b=uh2JpD5QvJXwqoGwxpzEwHpoFa CGMYHrX7qJBCL2dDDtAlj0zdNDORRfH8/0OoO+ounA//ihfJ1GQewiXVrDZk1yQxBEPkw23ad+yOj 18+AKDzpJB/MGHbOq/LBuDgp0BRYM1+td2BrXODCaY2BYF17M+hdHArGCs2+KRxS63AhuKPrG1md0 8VkG46a5ftMHdpYXkyLQ+4p0swHOD81TJfaPne1dGD2DKhG9OpqX/psWhwQVKS4LtrLIxEB5gKgU7 DlL9e/q8XqXsyZDaSVwVF2Zy/TdA/bJtzQQuQE4oOiU8bAYUEy/xT2KFvoTBf4f2hW+OdGUF0leo2 ISRtmz9A==; Received: from hch by bombadil.infradead.org with local (Exim 4.97.1 #2 (Red Hat Linux)) id 1se5b5-00000005gyt-2c07; Wed, 14 Aug 2024 04:26:55 +0000 Date: Tue, 13 Aug 2024 21:26:55 -0700 From: Christoph Hellwig To: Jason Gunthorpe Cc: Christoph Hellwig , Martin Oliveira , linux-rdma@vger.kernel.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org, Andrew Morton , Artemy Kovalyov , Greg Kroah-Hartman , Leon Romanovsky , Logan Gunthorpe , Michael Guralnik , Mike Marciniszyn , Shiraz Saleem , Tejun Heo , John Hubbard , Dan Williams , David Sloan Subject: Re: [PATCH v5 3/4] mm/gup: allow FOLL_LONGTERM & FOLL_PCI_P2PDMA Message-ID: References: <20240808183340.483468-1-martin.oliveira@eideticom.com> <20240808183340.483468-4-martin.oliveira@eideticom.com> <20240812231249.GG1985367@ziepe.ca> <20240813160502.GH1985367@ziepe.ca> Precedence: bulk X-Mailing-List: linux-rdma@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: <20240813160502.GH1985367@ziepe.ca> X-SRS-Rewrite: SMTP reverse-path rewritten from by bombadil.infradead.org. See http://www.infradead.org/rpr.html On Tue, Aug 13, 2024 at 01:05:02PM -0300, Jason Gunthorpe wrote: > > Where do we block driver unbind with an open resource? > > I keep seeing it in different subsystems, safe driver unbind is really > hard. :\ eg I think VFIO has some waits in it Well, waits for what? Usuaully an unbind has to wait for something, but waiting for unbound references is always a bug. And I can't think of any sensible subsystem doing this.