From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from shelob.surriel.com (shelob.surriel.com [96.67.55.147]) (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 397321DF980; Fri, 19 Jun 2026 18:55:22 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=96.67.55.147 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1781895323; cv=none; b=eS8DLDUdL8zIc+8P+Xra0GLDLZemmmMW+qmUhRtLCT8xxluFODZwCiBvlyn6c4/CrAe2ETI+U5M/vjuyYvxMb9wZGOy8WzfZfVAJDkRYOVEaNtwJu76RowZ8Ybn4e2RpQpVkLVjE4TAkm0S6r7mfa1cqzfnrimyLj5p+4EuLaIs= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1781895323; c=relaxed/simple; bh=lWGmWLHBkxB+j0p3dxSqyRjenJ6errj2YxoYMUe4EFM=; h=Message-ID:Subject:From:To:Cc:Date:In-Reply-To:References: Content-Type:MIME-Version; b=Kkce9VxNvJFi7HzvrmE/v6P77zfVW404ZIuvz45NXHQPf1N/shefNNONYDsJB7/Ok9ZObdchg8XaQm8s5GbHOe/feS/F7ZkeIrqjQpgsF1ITAZ3dXoDIw14lW0ErZb0eVlrrOnVdSVZV+plY2DSr8DScpUTr90AaeP8yKVRRNsU= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=surriel.com; spf=pass smtp.mailfrom=surriel.com; dkim=pass (2048-bit key) header.d=surriel.com header.i=@surriel.com header.b=JxZIrA69; arc=none smtp.client-ip=96.67.55.147 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=surriel.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=surriel.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=surriel.com header.i=@surriel.com header.b="JxZIrA69" DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=surriel.com ; s=mail; h=MIME-Version:Content-Transfer-Encoding:Content-Type:References: In-Reply-To:Date:Cc:To:From:Subject:Message-ID:Sender:Reply-To:Content-ID: Content-Description:Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc :Resent-Message-ID:List-Id:List-Help:List-Unsubscribe:List-Subscribe: List-Post:List-Owner:List-Archive; bh=lWGmWLHBkxB+j0p3dxSqyRjenJ6errj2YxoYMUe4EFM=; b=JxZIrA69mCqmFaUlRfDsiTz+2Q RsJUVizMo5yCkGs9tcei9Ax+CAltcDESIPm5f0emvrT3pmE2+08sY7UZLLRw7osnziH/7i2iLuhhq RkxuDnmsjjk65XXoqcFeuz6k9cEShpE4aqfFpjzCYBfCSFDuCt1hBYl0yrLLSv/s4jH3a4IDb2Zq8 yu58g7U1DOiYIHYYJwlPlr44NbWOXP/Vy0KwvSbK6Gk5efUoDShb/A0rJT5LzxCTtiOCf9dWKAKab CSJ4Ypf6b3HJDxLt2RyqIDeQdWTVa7uIExOiNqJL9Qq8eyAWh5eVdg1AVIhiELpPsHHgr2xh3qt3Y ejG9favg==; Received: from fangorn.home.surriel.com ([10.0.13.7]) by shelob.surriel.com with esmtpsa (TLS1.2) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (Exim 4.97.1) (envelope-from ) id 1waeMf-000000001cy-3JKu; Fri, 19 Jun 2026 14:54:53 -0400 Message-ID: Subject: Re: [PATCH v3 3/3] iova: defer maple tree erase on GFP_ATOMIC failure From: Rik van Riel To: Jason Gunthorpe , "Liam R. Howlett" Cc: linux-kernel@vger.kernel.org, kernel-team@meta.com, robin.murphy@arm.com, joro@8bytes.org, will@kernel.org, iommu@lists.linux.dev, kyle@mcmartin.ca, Rik van Riel , maple-tree@lists.infradead.org Date: Fri, 19 Jun 2026 14:54:53 -0400 In-Reply-To: <20260619121319.GK231643@ziepe.ca> References: <20260612180303.GO1066031@ziepe.ca> <20260615115633.GQ1066031@ziepe.ca> <20260617180419.GA231643@ziepe.ca> <20260618152451.GE231643@ziepe.ca> <76xtcbn5hxv3z2w6zbbudr5exjqdgjan4dkcsvrpgagdfpc45x@7prb5j6ivh4w> <20260619121319.GK231643@ziepe.ca> Autocrypt: addr=riel@surriel.com; prefer-encrypt=mutual; keydata=mQENBFIt3aUBCADCK0LicyCYyMa0E1lodCDUBf6G+6C5UXKG1jEYwQu49cc/gUBTTk33A eo2hjn4JinVaPF3zfZprnKMEGGv4dHvEOCPWiNhlz5RtqH3SKJllq2dpeMS9RqbMvDA36rlJIIo47 Z/nl6IA8MDhSqyqdnTY8z7LnQHqq16jAqwo7Ll9qALXz4yG1ZdSCmo80VPetBZZPw7WMjo+1hByv/ lvdFnLfiQ52tayuuC1r9x2qZ/SYWd2M4p/f5CLmvG9UcnkbYFsKWz8bwOBWKg1PQcaYHLx06sHGdY dIDaeVvkIfMFwAprSo5EFU+aes2VB2ZjugOTbkkW2aPSWTRsBhPHhV6dABEBAAG0HlJpayB2YW4gU mllbCA8cmllbEByZWRoYXQuY29tPokBHwQwAQIACQUCW5LcVgIdIAAKCRDOed6ShMTeg05SB/986o gEgdq4byrtaBQKFg5LWfd8e+h+QzLOg/T8mSS3dJzFXe5JBOfvYg7Bj47xXi9I5sM+I9Lu9+1XVb/ r2rGJrU1DwA09TnmyFtK76bgMF0sBEh1ECILYNQTEIemzNFwOWLZZlEhZFRJsZyX+mtEp/WQIygHV WjwuP69VJw+fPQvLOGn4j8W9QXuvhha7u1QJ7mYx4dLGHrZlHdwDsqpvWsW+3rsIqs1BBe5/Itz9o 6y9gLNtQzwmSDioV8KhF85VmYInslhv5tUtMEppfdTLyX4SUKh8ftNIVmH9mXyRCZclSoa6IMd635 Jq1Pj2/Lp64tOzSvN5Y9zaiCc5FucXtB9SaWsgdmFuIFJpZWwgPHJpZWxAc3VycmllbC5jb20+iQE +BBMBAgAoBQJSLd2lAhsjBQkSzAMABgsJCAcDAgYVCAIJCgsEFgIDAQIeAQIXgAAKCRDOed6ShMTe g4PpB/0ZivKYFt0LaB22ssWUrBoeNWCP1NY/lkq2QbPhR3agLB7ZXI97PF2z/5QD9Fuy/FD/jddPx KRTvFCtHcEzTOcFjBmf52uqgt3U40H9GM++0IM0yHusd9EzlaWsbp09vsAV2DwdqS69x9RPbvE/Ne fO5subhocH76okcF/aQiQ+oj2j6LJZGBJBVigOHg+4zyzdDgKM+jp0bvDI51KQ4XfxV593OhvkS3z 3FPx0CE7l62WhWrieHyBblqvkTYgJ6dq4bsYpqxxGJOkQ47WpEUx6onH+rImWmPJbSYGhwBzTo0Mm G1Nb1qGPG+mTrSmJjDRxrwf1zjmYqQreWVSFEt26tBpSaWsgdmFuIFJpZWwgPHJpZWxAZmIuY29tP okBPgQTAQIAKAUCW5LbiAIbIwUJEswDAAYLCQgHAwIGFQgCCQoLBBYCAwECHgECF4AACgkQznneko TE3oOUEQgAsrGxjTC1bGtZyuvyQPcXclap11Ogib6rQywGYu6/Mnkbd6hbyY3wpdyQii/cas2S44N cQj8HkGv91JLVE24/Wt0gITPCH3rLVJJDGQxprHTVDs1t1RAbsbp0XTksZPCNWDGYIBo2aHDwErhI omYQ0Xluo1WBtH/UmHgirHvclsou1Ks9jyTxiPyUKRfae7GNOFiX99+ZlB27P3t8CjtSO831Ij0Ip QrfooZ21YVlUKw0Wy6Ll8EyefyrEYSh8KTm8dQj4O7xxvdg865TLeLpho5PwDRF+/mR3qi8CdGbkE c4pYZQO8UDXUN4S+pe0aTeTqlYw8rRHWF9TnvtpcNzZw== Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable User-Agent: Evolution 3.56.2 (3.56.2-2.fc42) Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 On Fri, 2026-06-19 at 09:13 -0300, Jason Gunthorpe wrote: > On Fri, Jun 19, 2026 at 12:54:13AM -0400, Liam R. Howlett wrote: > >=20 > > no, but how often is there a failure?=C2=A0 Would walking the list and > > writing NULLs be out of the question (I really don't know, sorry if > > it's > > a dumb one)? >=20 > Yeah, this is what I was thinking. Should never happen? I wouldn't > burn memory in each node to make an emergency recovery run faster. >=20 > The idea of keeping track of the high/low along with the flag makes > sense, it will narrow the IOVA range to search. >=20 I've got this in v4 of the tree now. One open question is whether cleanup should happen from the next allocation, or whether we should move that into a work item that runs in a sleepable context. --=20 All Rights Reversed.