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 29E43214A9B for ; Tue, 11 Aug 2026 14:52:06 +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=1786459928; cv=none; b=fYKEO1War16BhWC3t0+KeydfoGTANfYD1x3gEAyDAIGx09IpYls//7ZDS98eKNkYD59LD7cw3BGDqWRp9KxlmMRqMVj2E8wdOnK6OjEIN8SR6fY79/xZS4V2JNQoUa2bH7vAlILPOwPoV5m9atDgSgtc77+o3MOBu2XjSlT2aHA= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1786459928; c=relaxed/simple; bh=BDbCWx89JgtcFCUkuIxHgI00Q8in63pWpmBnIx582Ws=; h=Message-ID:Subject:From:To:Cc:Date:In-Reply-To:References: Content-Type:MIME-Version; b=gb0ev4YB9y1djeuvLL6h+P9xo1mHn7ssF6/QIO2bA89YMhbzboXW9GIuXFxJS1P79O1XRJ6/xub9if523UglVNRpgA86aJeEG+OE82w86imB+dPKYL7QOlI5hkyk60JXEkm3kvbirctYFWJ+a+EFvIvdcsr22qoS4MyjgSeZKkM= 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=V8GSuDwq; 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="V8GSuDwq" 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=xDhehgrrAOSRIdcwgmYMsgv1I5rPT085cxMqoCOwSbU=; b=V8GSuDwqveAqI2bqQieqG7EtHg eEEnasEdiZliXbP7agGL3h0BTexorRppTEp1vvgcYKNWcQPKxAE+aj6r2kqxu5qt/dCIkReEDkGfk Mv39k2CrHgvirJviGuUmpI0rl5In8PV6s/MzvXA6w407ZEF8rImshyHYqTLstwADLO15oulaVOYpa k/2Al6fKhV2KN5Y9uc3ST9gqZoUbA7TVvF12pppLqhZxWWIgV8niqXkX3KZ33dryOP8retFs8ljAi lD12KJ6b9+T+lsWTYBB9iUdCmdJ1ZXHmnk8KqQEI7u/mrZLS3tcxSF9fzosVw2ITsHnrk/QfPc4Es IfcuYK0Q==; Received: from [96.67.55.146] by shelob.surriel.com with esmtpsa (TLS1.2) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (Exim 4.97.1) (envelope-from ) id 1wtnp0-000000001Gy-1SI4; Tue, 11 Aug 2026 10:51:18 -0400 Message-ID: Subject: Re: [PATCH v5] kexec: keep the next kernel off hardware-poisoned pages From: Rik van Riel To: Kiryl Shutsemau , Mike Rapoport Cc: Breno Leitao , Andrew Morton , David Hildenbrand , Lorenzo Stoakes , "Liam R. Howlett" , Vlastimil Babka , Suren Baghdasaryan , Michal Hocko , Baoquan He , Pasha Tatashin , Pratyush Yadav , Miaohe Lin , Naoya Horiguchi , linux-mm@kvack.org, linux-kernel@vger.kernel.org, kexec@lists.infradead.org, rmikey@meta.com, kernel-team@meta.com Date: Tue, 11 Aug 2026 10:51:18 -0400 In-Reply-To: References: <20260810-kexec_posioned-v5-1-95e1b5e2e656@debian.org> 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 3.60.2 (3.60.2-1.fc44) Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 On Tue, 2026-08-11 at 15:21 +0100, Kiryl Shutsemau wrote: > On Tue, Aug 11, 2026 at 04:34:02PM +0300, Mike Rapoport wrote: > > On Tue, Aug 11, 2026 at 04:17:41AM -0700, Breno Leitao wrote: > > > > >=20 > > > But I honestly don't have a strong opinion here, though, happy to > > > batch > > > it if you prefer. Would this one look better?: > > >=20 > > > if (!(pfn % MAX_ORDER_NR_PAGES)) > > > cond_resched(); > >=20 > > Can't say I know the magic number here, but I think it's better to > > batch. >=20 > Hm. I thought cond_resched() deal with this internally, no? >=20 > We call it in pretty tight loops, like clear_contig_highpages() or > copy_folio_from_user(). >=20 > I think adding external batching might be a bad move. >=20 cond_resched() should be really cheap, indeed. It gets compiled out completely with PREEMPT_LAZY or PREEMPT_FULL. --=20 All Rights Reversed.