From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org 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.lore.kernel.org (Postfix) with ESMTPS id 5CB39C282DC for ; Tue, 4 Mar 2025 19:49:50 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:List-Subscribe:List-Help :List-Post:List-Archive:List-Unsubscribe:List-Id:Subject:Content-Type: MIME-Version:Message-ID:In-Reply-To:Date:References:Cc:To:From:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=5TCsW9XHfUCO29/pSg3et6o21s2sj6bi4Wbc2rT3bmI=; b=cvasfNkuN6ScKr+dB93neJPMCw a+Mzjkmy5x2OsN1aVnByNX0P9BDYHKLBGaD0ecM0CGYMkLlFmp9jwsq7Yx6FS/4fSKgWaehQD0g6u ffPwhDdWBDd4gzNM7JkcpXbBwhY2MtSVKnDukB8waAMBuL6MI6rdrzb1/CuLcS+Buydn6VqaoMEK1 ZEFG52YSeLWqk+rxp/cVVYF+1//hJCz5PEKFRCWv9BzHP8f8CtdJCEaCMr67v97yycpEJqs9aaQIM +kzuczUFsxkooHPylsiYzvucyzBoi75NaN57dMUCCAh5gYp1/iRPZAhM+OGibgqjd2kdgpq+7jDr9 TuCkyy5g==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.98 #2 (Red Hat Linux)) id 1tpYGz-0000000669r-03Cb; Tue, 04 Mar 2025 19:49:49 +0000 Received: from out02.mta.xmission.com ([166.70.13.232]) by bombadil.infradead.org with esmtps (Exim 4.98 #2 (Red Hat Linux)) id 1tpXLM-00000005u5v-0o6G for kexec@lists.infradead.org; Tue, 04 Mar 2025 18:50:17 +0000 Received: from in02.mta.xmission.com ([166.70.13.52]:41330) by out02.mta.xmission.com with esmtps (TLS1.3) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (Exim 4.93) (envelope-from ) id 1tpXL4-003CrC-Sf; Tue, 04 Mar 2025 11:49:58 -0700 Received: from ip72-198-198-28.om.om.cox.net ([72.198.198.28]:43810 helo=email.froward.int.ebiederm.org.xmission.com) by in02.mta.xmission.com with esmtpsa (TLS1.3) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (Exim 4.93) (envelope-from ) id 1tpXL3-009qdL-OE; Tue, 04 Mar 2025 11:49:58 -0700 From: "Eric W. Biederman" To: "Kirill A. Shutemov" Cc: akpm@linux-foundation.org, Dave Hansen , Baoquan He , "Kirill A. Shutemov" , kexec@lists.infradead.org, Yan Zhao , linux-kernel@vger.kernel.org, linux-coco@lists.linux.dev, x86@kernel.org, rick.p.edgecombe@intel.com, security@kernel.org References: <20241213094930.748-1-yan.y.zhao@intel.com> <87zfjuoj3i.fsf@email.froward.int.ebiederm.org> <4599571f-804b-40d8-b5c8-e19478a3ad18@intel.com> Date: Tue, 04 Mar 2025 12:49:15 -0600 In-Reply-To: (Kirill A. Shutemov's message of "Tue, 4 Mar 2025 10:41:56 +0200") Message-ID: <87o6ygskb8.fsf@email.froward.int.ebiederm.org> User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/28.2 (gnu/linux) MIME-Version: 1.0 Content-Type: text/plain X-XM-SPF: eid=1tpXL3-009qdL-OE;;;mid=<87o6ygskb8.fsf@email.froward.int.ebiederm.org>;;;hst=in02.mta.xmission.com;;;ip=72.198.198.28;;;frm=ebiederm@xmission.com;;;spf=pass X-XM-AID: U2FsdGVkX1+GBcBx8IrnL69HP7CI9T5d+uij0wQ3VeY= Subject: Re: [PATCH v2 0/1] Accept unaccepted kexec segments' destination addresses X-SA-Exim-Connect-IP: 166.70.13.52 X-SA-Exim-Rcpt-To: security@kernel.org, rick.p.edgecombe@intel.com, x86@kernel.org, linux-coco@lists.linux.dev, linux-kernel@vger.kernel.org, yan.y.zhao@intel.com, kexec@lists.infradead.org, kirill@shutemov.name, bhe@redhat.com, dave.hansen@intel.com, akpm@linux-foundation.org, kirill.shutemov@linux.intel.com X-SA-Exim-Mail-From: ebiederm@xmission.com X-SA-Exim-Scanned: No (on out02.mta.xmission.com); SAEximRunCond expanded to false X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20250304_105016_223566_B33CD9EB X-CRM114-Status: GOOD ( 22.50 ) X-BeenThere: kexec@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "kexec" Errors-To: kexec-bounces+kexec=archiver.kernel.org@lists.infradead.org "Kirill A. Shutemov" writes: > On Fri, Feb 14, 2025 at 08:20:07AM -0800, Dave Hansen wrote: >> On 2/14/25 05:46, Kirill A. Shutemov wrote: >> >> It sounds like you're advocating for the "slow guest boot" option. >> >> Kirill, can you remind us how fast a guest boots to the shell for >> >> modestly-sized (say 256GB) memory with "accept_memory=eager" versus >> >> "accept_memory=lazy"? IIRC, it was a pretty remarkable difference. >> > I only have 128GB machine readily available and posted some number on >> > other thread[1]: >> > >> > On single vCPU it takes about a minute to accept 90GiB of memory. >> > >> > It improves a bit with number of vCPUs. It is 40 seconds with 4 vCPU, but >> > it doesn't scale past that in my setup. >> > >> > I've mentioned it before in other thread: >> > >> > [1] https://lore.kernel.org/all/ihzvi5pwn5hrn4ky2ehjqztjxoixaiaby4igmeihqfehy2vrii@tsg6j5qvmyrm >> >> Oh, wow, from that other thread, you've been trying to get this crash >> fix accepted since November? >> >> From the looks of it, Eric stopped responding to that thread. I _think_ >> you gave a reasonable explanation of why memory acceptance is slow. He >> then popped back up last month raising security concerns. But I don't >> see anyone that shares those concerns. >> >> The unaccepted memory stuff is also _already_ touching the page >> allocator. If it's a dumb idea, then we should be gleefully ripping it >> out of the page allocator, not rejecting a 2-line kexec patch. >> >> Baoquan has also said this looks good to him. >> >> I'm happy to give Eric another week to respond in case he's on vacation >> or something, but I'm honestly not seeing a good reason to hold this bug >> fix up. >> >> Andrew, is this the kind of thing you can stick into mm and hold on to >> for a bit while we give Eric time to respond? > > Andrew, Eric, can we get this patch in? How goes the work to fix this horrifically slow firmware interface? Eric