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 kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by smtp.lore.kernel.org (Postfix) with ESMTP id 52FA4C3ABA4 for ; Tue, 29 Apr 2025 08:00:17 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 709F66B0005; Tue, 29 Apr 2025 04:00:15 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 6B8C36B0006; Tue, 29 Apr 2025 04:00:15 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 5804D6B0007; Tue, 29 Apr 2025 04:00:15 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0010.hostedemail.com [216.40.44.10]) by kanga.kvack.org (Postfix) with ESMTP id 39EB66B0005 for ; Tue, 29 Apr 2025 04:00:15 -0400 (EDT) Received: from smtpin14.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay01.hostedemail.com (Postfix) with ESMTP id 8FA761CCAD2 for ; Tue, 29 Apr 2025 08:00:15 +0000 (UTC) X-FDA: 83386333590.14.DF8181C Received: from tor.source.kernel.org (tor.source.kernel.org [172.105.4.254]) by imf30.hostedemail.com (Postfix) with ESMTP id CBA0180011 for ; Tue, 29 Apr 2025 08:00:13 +0000 (UTC) Authentication-Results: imf30.hostedemail.com; dkim=pass header.d=kernel.org header.s=k20201202 header.b=Uh6R5dPa; dmarc=pass (policy=quarantine) header.from=kernel.org; spf=pass (imf30.hostedemail.com: domain of rppt@kernel.org designates 172.105.4.254 as permitted sender) smtp.mailfrom=rppt@kernel.org ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1745913613; a=rsa-sha256; cv=none; b=y7AEq//Q9vbPkfi65IlT06mYfFzuP6LpuyaUrC5gkSFm60lZEyYMUJxcvc7TzJR4eqtN1t x+ADjlc3/lioCbikPRgHJ9K+0Jvhyqq3RixGSwThj527Z6UIVro3lfIkrd8MwfwfMUiBmJ /MrDyAv1y6V6qKKT62k013HA3oq9mWc= ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1745913613; h=from:from:sender:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type:content-transfer-encoding: in-reply-to:in-reply-to:references:references:dkim-signature; bh=iGig1JI54KemODVxGfaJgsaqsZGPE/6V6CkkITKo4rQ=; b=Y1tWVYO65G5FT58QyqlyvV/L3QgK1oVyvYYl4Manx223Tm30EUesBg4zJ0li1TeBgoph6Z j0HDgFO1lKgSc1WGRJiNlqXNEsTXgpB6mwmA8wxALDYUula3GF75MxCwZX4ld32cpkVQhw 5yLsHSgsJ6zZbamXl5gIqflD71REzD8= ARC-Authentication-Results: i=1; imf30.hostedemail.com; dkim=pass header.d=kernel.org header.s=k20201202 header.b=Uh6R5dPa; dmarc=pass (policy=quarantine) header.from=kernel.org; spf=pass (imf30.hostedemail.com: domain of rppt@kernel.org designates 172.105.4.254 as permitted sender) smtp.mailfrom=rppt@kernel.org Received: from smtp.kernel.org (transwarp.subspace.kernel.org [100.75.92.58]) by tor.source.kernel.org (Postfix) with ESMTP id 3E1EF61120; Tue, 29 Apr 2025 07:59:47 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 2A301C4CEE3; Tue, 29 Apr 2025 08:00:06 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1745913612; bh=5oCFwF0Xr4nHFTfMM2oRVPH/AlXCf2DmeqL2UB+IeqQ=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=Uh6R5dPacY/L3/s9YwwUL2+q2rt6fZJDJ0HT1A3+AvBAVWEaxk2rWkNeYW6qoZg1f u2AfIlpuPxgylzd/PejxTridyCE33nkOpw9o4vV1GHnwtluicKJSnIUUSmSra+Cb6A 5v1Qet43r43B3qrZOpVFYhfOtIKCnp1uPHMvEl2UZcSq9Xqe21OoeJiylb+rdbpMfq dZjRpHJlPXe0oxQcvGa0KFygzYxMDZSdrPd0CpixElOYIWOlaNnLI++4+2Ei4eWEpO TBxEnR66LNerk1+VmfJI2cCldVRGLuzApkoNtTUSYK9gU1SYaJi/iY0XL8XtFxba8U NhEZqhp/x98xg== Date: Tue, 29 Apr 2025 11:00:03 +0300 From: Mike Rapoport To: Dave Hansen Cc: David Rientjes , Alexander Graf , Anthony Yznaga , David Hildenbrand , Frank van der Linden , James Gowans , Jason Gunthorpe , Junaid Shahid , Pankaj Gupta , Pasha Tatashin , Pratyush Yadav , Vipin Sharma , Vishal Annapurve , "Woodhouse, David" , linux-mm@kvack.org, kexec@lists.infradead.org Subject: Re: [Hypervisor Live Update] Notes from April 21, 2025 Message-ID: References: <087a7b3b-a2d4-4596-af53-d0f850ea6aa2@intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <087a7b3b-a2d4-4596-af53-d0f850ea6aa2@intel.com> X-Rspamd-Server: rspam06 X-Rspamd-Queue-Id: CBA0180011 X-Stat-Signature: orebjj8w5w3tzwe3jp19kdpkwg1rdn3j X-Rspam-User: X-HE-Tag: 1745913613-467092 X-HE-Meta: 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 GaoS2PbI x7xY4lGDBrOM9puwCFlpUyB/9wsdT1Gei8EbDxdbRlyjyty8ck+TybKlOtN+DppGHoXah+Vxr6sHisZXRs+w+Ako/1n82tT8bD7Y5Vh0yBHF3IvvxbN++S7wMW4JpqFeQz9lW59CJgHz139KxnFKIVyd6Z5j6GnAvhmR6bZ00xHKkaDJDZKmdhurTnxEbFQSty9esR+ywQN497tCVYkZBMK6w787l5Fo1t7BMZNFu+am2op2woyYeQrLONPLpu1rWVKRhswTkWfKUWrc4eBvOTdVDhwrEGD/etoiSplQ/p54WBlsccRnWAiSvdHVND29ykEz1usY/fq481G4= X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: On Mon, Apr 28, 2025 at 05:35:07PM -0700, Dave Hansen wrote: > On 4/27/25 23:20, David Rientjes wrote: > > KHO v6 is now staged in Andrew's mm-new tree. We discussed what it will > > take for this series to be pushed to Linus, specifically around > > Reviewed-by tags. There is not a ton of x86 specific code, but it would > > likely be useful to have Reviewed-bys from some x86 maintainers. Dave > > Hansen, would you be the right person to take a look at this from an x86 > > perspective? > > It looks mostly OK. > > The one worry is the scratch reservation sizing, how folks will get that > right, and the implications if they get it wrong. For engineered cloud systems folks will get it right most of the time with explicit setting of the scrach size in the command line. There's also a way to let kernel estimate the scratch size by scaling early memory usage by user defined percentage (with 150% as the default). > If it's undersized because newer kernels need more space, what ends up > happening? Is it just an OOM during boot? It will OOM and panic during boot, yes. Potentially we can skip KHO if the scratch is undersized and continue to boot without restoring any of the previous state, but to start with OOM and panic are much simpler. -- Sincerely yours, Mike.