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 22608C25B75 for ; Thu, 6 Jun 2024 14:50:15 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id A9E6C6B0088; Thu, 6 Jun 2024 10:50:14 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id A4CCA6B00A1; Thu, 6 Jun 2024 10:50:14 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 914746B00A2; Thu, 6 Jun 2024 10:50:14 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0014.hostedemail.com [216.40.44.14]) by kanga.kvack.org (Postfix) with ESMTP id 751076B0088 for ; Thu, 6 Jun 2024 10:50:14 -0400 (EDT) Received: from smtpin20.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay03.hostedemail.com (Postfix) with ESMTP id 8D9E7A0373 for ; Thu, 6 Jun 2024 14:50:13 +0000 (UTC) X-FDA: 82200749106.20.8AB1583 Received: from sin.source.kernel.org (sin.source.kernel.org [145.40.73.55]) by imf14.hostedemail.com (Postfix) with ESMTP id 60D7010000A for ; Thu, 6 Jun 2024 14:50:10 +0000 (UTC) Authentication-Results: imf14.hostedemail.com; dkim=none; spf=pass (imf14.hostedemail.com: domain of "SRS0=WH+2=NI=goodmis.org=rostedt@kernel.org" designates 145.40.73.55 as permitted sender) smtp.mailfrom="SRS0=WH+2=NI=goodmis.org=rostedt@kernel.org"; dmarc=none ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1717685411; 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:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=2LFd3jR6qDR3QS+EWz1+ZCxOS3hIWTjnrGXktTWYyHY=; b=1LX3Ngd1HskpmFq2eBXm6SGTjxWiZbxZLsKlF6wVSThO8U5dRhVI5bERNczNmVmlXYcsSK DW4eRzKiRCm3XYrdXUyyAm4NBXjpOoRgqc8WjYOLv/J7KTM+rVj8nBs/GtreuskRdwx1Pm ZUG7l1Dsbu+rH7ylNGmJPBSpqHg1VkI= ARC-Authentication-Results: i=1; imf14.hostedemail.com; dkim=none; spf=pass (imf14.hostedemail.com: domain of "SRS0=WH+2=NI=goodmis.org=rostedt@kernel.org" designates 145.40.73.55 as permitted sender) smtp.mailfrom="SRS0=WH+2=NI=goodmis.org=rostedt@kernel.org"; dmarc=none ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1717685411; a=rsa-sha256; cv=none; b=dXq2nZ5u/QzQo9YpCeXiNDFte5V5VbOpU3OkX+EtnzlCwnGr74ncxgXnY39z4vJSPv108+ KOIOavfNGBsC+uyAFzrNg+Hf6BmtSFc4fTmkf+usfy5of7BZisRh+iVaJ+jr43JdW/PU6T 4FTspvBfIyZA33etnI6MBTrbh77T7Hg= Received: from smtp.kernel.org (transwarp.subspace.kernel.org [100.75.92.58]) by sin.source.kernel.org (Postfix) with ESMTP id 4EE80CE1B9C; Thu, 6 Jun 2024 14:50:07 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 4942DC2BD10; Thu, 6 Jun 2024 14:50:02 +0000 (UTC) Date: Thu, 6 Jun 2024 10:50:13 -0400 From: Steven Rostedt To: "Luck, Tony" Cc: Ard Biesheuvel , "linux-kernel@vger.kernel.org" , "linux-trace-kernel@vger.kernel.org" , Masami Hiramatsu , Mark Rutland , Mathieu Desnoyers , Andrew Morton , "Liam R. Howlett" , Vlastimil Babka , Lorenzo Stoakes , "linux-mm@kvack.org" , Thomas Gleixner , Ingo Molnar , Borislav Petkov , Dave Hansen , "x86@kernel.org" , "H. Peter Anvin" , Peter Zijlstra , Kees Cook , "Guilherme G. Piccoli" , "linux-hardening@vger.kernel.org" , Guenter Roeck , "Ross Zwisler" , "wklin@google.com" , "Vineeth Remanan Pillai" , Joel Fernandes , Suleiman Souhlal , "Linus Torvalds" , Catalin Marinas , Will Deacon , Mike Rapoport Subject: Re: [PATCH 1/2] mm/memblock: Add "reserve_mem" to reserved named memory at boot up Message-ID: <20240606105013.6435d553@rorschach.local.home> In-Reply-To: References: <20240603233330.801075898@goodmis.org> <20240603233631.452433539@goodmis.org> <20240604070826.030c5202@gandalf.local.home> X-Mailer: Claws Mail 3.17.8 (GTK+ 2.24.33; x86_64-pc-linux-gnu) MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit X-Rspam-User: X-Rspamd-Server: rspam09 X-Rspamd-Queue-Id: 60D7010000A X-Stat-Signature: aq9fcuwax88oq1gau413p3pkzce81ce8 X-HE-Tag: 1717685410-233972 X-HE-Meta: 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 PZXx72SP FP1aMP91SyW3AETY2QUDIVMPOCFxLASv2bqnUH2ikqQj1kLGOvVGSlCDt1M8vMBFeP9ot/sMgub1ckaa/2OW9VHZgLalX+BxIq4rMeDsN5vNmLXqUltctGIqb1SG1+Ef1dOWiFz8iHta2j9ZxkvpojdPyfNTzP57/ocFjWsXTMTCKgnVUuNZ/f+E3H6QzgH6RK+dgXv5GNZHdnT+NurNDCimtpoP21hy+85sl84HnSood8aLBPke61T7oGoirqlcZ9bf4jTtVaEEezzEh2xYSy4WA4bi/j9ox5IVrVL1k3S7dAXiCLChkktbhnXYNs7r/jOxOq3d22LJ3/OSnLbGq+CTvZibNA0TwmubKCazZLTK8R3I= 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 Tue, 4 Jun 2024 16:05:04 +0000 "Luck, Tony" wrote: > > I have been using this on two different test machines, as well as a > > chromebook, and it appears to work on all ofthem. As well as for VMs. I > > plan on adding this to my workstation and server too (they use EFI). > > I think that BIOS on Intel servers with ECC memory will stomp on all > memory (to ensure that ECC bits are all set to good values). There > might be a "fast boot" BIOS option to skip this (but using it leaves you > vulnerable after a crash due to ECC fail to hit the same error again). > Talking with some people that are interested in this, they told me that those servers (the ones that take several minutes to boot up) usually use kexec to reboot. Even after a crash (with or without kdump). In those cases, they said this would likely work for them. Again, this isn't fool proof nor guaranteed. It's a best effort approach that, at least for my use case, works most of the time. -- Steve