From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from out02.mta.xmission.com (out02.mta.xmission.com [166.70.13.232]) (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 2BFFC2376EC; Tue, 4 Mar 2025 19:16:48 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=166.70.13.232 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1741115810; cv=none; b=NOz7L9vrki8Iadqdan0HrIQUfFlDU2ky/D2NkLqa44UagQiZtUhqYgKCgW/yCDjuIYR9XAo3WTYn5fU3JZqjHwYLw+/Zb/H7o6jjhDkHIWn6Nzs8X6js0epPH6I1hx816o4V3O+NWHhTH99etjh+CDDzVMfL09MxtzOfgShcD+E= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1741115810; c=relaxed/simple; bh=pOWLXes4uWQgjfo1TJ9f6OtmzhBGnF2YDRXOGUxK9lo=; h=From:To:Cc:References:Date:In-Reply-To:Message-ID:MIME-Version: Content-Type:Subject; b=nm7NIl6n3Byh3gW2Vn5mMudj2mJRH1il953fokbd6wmyrspGj5YETbJixFsG7CcFOY7VCny2rmUwMW3D/ch3KvJVis+CE98SctxP+6Pgr8YNRtNB1mWNMtHb6CYSAZ6xHuNo9gVZgouiYWuNCTGX2XYE10Kb7xMhlkGYJvyrINQ= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=xmission.com; spf=pass smtp.mailfrom=xmission.com; arc=none smtp.client-ip=166.70.13.232 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=xmission.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=xmission.com 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) Precedence: bulk X-Mailing-List: linux-coco@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: 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= X-Spam-Level: * X-Spam-Report: * -1.0 ALL_TRUSTED Passed through trusted hosts only via SMTP * 0.8 BAYES_50 BODY: Bayes spam probability is 40 to 60% * [score: 0.4999] * 0.7 XMSubLong Long Subject * 0.0 T_TM2_M_HEADER_IN_MSG BODY: No description available. * -0.0 DCC_CHECK_NEGATIVE Not listed in DCC * [sa07 1397; Body=1 Fuz1=1 Fuz2=1] * 0.2 XM_B_SpammyWords One or more commonly used spammy words * 0.4 FVGT_m_MULTI_ODD Contains multiple odd letter combinations * 0.0 T_TooManySym_01 4+ unique symbols in subject X-Spam-DCC: XMission; sa07 1397; Body=1 Fuz1=1 Fuz2=1 X-Spam-Combo: *;"Kirill A. Shutemov" X-Spam-Relay-Country: X-Spam-Timing: total 480 ms - load_scoreonly_sql: 0.06 (0.0%), signal_user_changed: 10 (2.0%), b_tie_ro: 8 (1.7%), parse: 1.03 (0.2%), extract_message_metadata: 12 (2.6%), get_uri_detail_list: 1.67 (0.3%), tests_pri_-2000: 13 (2.6%), tests_pri_-1000: 2.7 (0.6%), tests_pri_-950: 1.26 (0.3%), tests_pri_-900: 1.02 (0.2%), tests_pri_-90: 166 (34.5%), check_bayes: 164 (34.1%), b_tokenize: 8 (1.6%), b_tok_get_all: 8 (1.7%), b_comp_prob: 3.1 (0.7%), b_tok_touch_all: 141 (29.4%), b_finish: 0.89 (0.2%), tests_pri_0: 258 (53.8%), check_dkim_signature: 0.53 (0.1%), check_dkim_adsp: 2.8 (0.6%), poll_dns_idle: 0.57 (0.1%), tests_pri_10: 2.2 (0.5%), tests_pri_500: 10 (2.0%), rewrite_mail: 0.00 (0.0%) 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 "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