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]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id ED829E668B1 for ; Sat, 20 Dec 2025 15:12:14 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 600216B0089; Sat, 20 Dec 2025 10:12:14 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id 5AAEC6B008A; Sat, 20 Dec 2025 10:12:14 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 4D7166B008C; Sat, 20 Dec 2025 10:12:14 -0500 (EST) 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 3CAF96B0089 for ; Sat, 20 Dec 2025 10:12:14 -0500 (EST) Received: from smtpin28.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay03.hostedemail.com (Postfix) with ESMTP id CD9ECBA613 for ; Sat, 20 Dec 2025 15:12:13 +0000 (UTC) X-FDA: 84240190146.28.EC5CDA6 Received: from mail-ed1-f51.google.com (mail-ed1-f51.google.com [209.85.208.51]) by imf08.hostedemail.com (Postfix) with ESMTP id E430916000A for ; Sat, 20 Dec 2025 15:12:11 +0000 (UTC) Authentication-Results: imf08.hostedemail.com; dkim=pass header.d=soleen.com header.s=google header.b=cwPBHw3+; dmarc=pass (policy=reject) header.from=soleen.com; spf=pass (imf08.hostedemail.com: domain of pasha.tatashin@soleen.com designates 209.85.208.51 as permitted sender) smtp.mailfrom=pasha.tatashin@soleen.com ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1766243532; a=rsa-sha256; cv=none; b=5bhMhWwbZhBrvkZty/XADNWRBWVHJ9bbV4M86o3LgpjRR4xZSYQ7s6otMN4wAU3adj6CGz 4l9n8bRdw4OS9hmmgA3BN4YB0woG1+GbU67glb+OPxxr3SVsWPgBF55GfOFXHr0cUNTWZD 03rX0juf6YpqGEhv0bX3T+nW6ZRsC+o= ARC-Authentication-Results: i=1; imf08.hostedemail.com; dkim=pass header.d=soleen.com header.s=google header.b=cwPBHw3+; dmarc=pass (policy=reject) header.from=soleen.com; spf=pass (imf08.hostedemail.com: domain of pasha.tatashin@soleen.com designates 209.85.208.51 as permitted sender) smtp.mailfrom=pasha.tatashin@soleen.com ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1766243532; 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=NirtzK3cSKP6Dn8RC3SUqGY+8QtbdDa8PCdCAnfz/Ds=; b=Yu0iwh0owiybIffjkhqpLi1hvKFbY2B1P4L2ioou//SZR2WDcZT33Z/kQ82kIxNOR0eqcJ y6zDzQjcf2Ua7+UvT6+RX+ZOHwqlXsQ/0tuNxGswAKMq+xMjBc96P8cnq+f52UKR0u2BUb W/2T1j+25AO0A8UyuGkaARkWyD69hPE= Received: by mail-ed1-f51.google.com with SMTP id 4fb4d7f45d1cf-64b9b0b4d5dso2895036a12.1 for ; Sat, 20 Dec 2025 07:12:11 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=soleen.com; s=google; t=1766243530; x=1766848330; darn=kvack.org; h=cc:to:subject:message-id:date:from:in-reply-to:references :mime-version:from:to:cc:subject:date:message-id:reply-to; bh=NirtzK3cSKP6Dn8RC3SUqGY+8QtbdDa8PCdCAnfz/Ds=; b=cwPBHw3+Lav8bYeEoCEFXeWfa5qnw8LTXbx+F5uSCWjYG94JZTcLPRmpwbLAiI05mC YFjO/ChbBHjPjBdW1ODZ/k/aXM19089+9nh5lwRqGVp8Ld8k3gcyI1ag/t/ujynXrKLa GYhQvp6knXntvJjTb+wnRiv2i8+2OT7r9ctvMVzMK0E3e7y+tU0peUjfra0LbXx0RKqU iKW+mSpVKeJ6Q0aQSH+Hpa2+h3vL7hhP14CrRdvCPZ4MZyjaK7OGzl3IBG6jAXE6QoIR WZ5r1ZV6tMpGykKAauqhKYAtsh3XlmXkKk88WT+9ChcgWRtaStupQmIc4CwGk0hUjpwJ U9YQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1766243530; x=1766848330; h=cc:to:subject:message-id:date:from:in-reply-to:references :mime-version:x-gm-gg:x-gm-message-state:from:to:cc:subject:date :message-id:reply-to; bh=NirtzK3cSKP6Dn8RC3SUqGY+8QtbdDa8PCdCAnfz/Ds=; b=QBvDvwDt9YEhLG71JjcDgBkKMexw6f7KU7d9tpSQ9i77LYvSARHfzkTVsEriI/DMaZ obxCzSrFlZe+FqpY+/nip4cBw/0H+be3oXLTPxn8PQdYB36k2oRdBc6af0dd6LTGsGwK X5xCouhhnSKdnNYddet7J3op1jrZsZKjF7aexVlXsTR475xC4lDXoKkaN38seyHz2f3W ocnZyLIN5+Doi7EODujXx1yDadOtAA3CSxU0eeoq0fnPp0Kd6u7Fg+8tvL/+vY5I2CDn 7t0qo4oJPHTVhF0F5+2q8efk7zBTXYJcQjdL08947dDjltGEAI0BjC0hsXl5XbJ1lLYU uYCA== X-Forwarded-Encrypted: i=1; AJvYcCUsCUpWToKIJh/hWbqh87tuXIGBzvRYNlW+uYZcVkwX4T4Po4uJ9HV7fAaYSGh21WE43JGsCA7oWA==@kvack.org X-Gm-Message-State: AOJu0Yyzi3Jl6VltMsr8d9gn98eXLMn3LbmZYzEbD6H0LAC3rDd4IGfN TUgjFyMbJ6XDwHZ752yK1sINjIJODWwGyTDmXEB24mf6Jw3iFDNJ81mgDl6JOrQVI/NuqhPH2ze CF3UobohhZwyM7FL1+WorLSuScs0584Eh4gzp081fW/0V7pz6bDUsMqs= X-Gm-Gg: AY/fxX5sr4hJXWz+an16o4s0IBG5f6iAECo7UQKmxWUJWJZ/xkTM/8KLDvPtQAt+Haf ZUDJ35ud9xrrXDHwAywH5W8YF5UDnpxGJiEoxB7x7yhtVh2q8r0sPUZttS6jfsv+zl8z6Z8pzmc bMeynioFkrJq60gY4A4A7ZkV2fgrSFZ5BGpeaXHVaDRB6Rsp+7VfFMXx04wbU0kRStDfIx9O/R0 GXfVGPP3TqWnFRIm0dRic+OaDOSTfpcx7RZybgjsSNqqq+AzGXzvnMS+DQIuHQWw4MMb5zOs53a 7RcO4NIM5tgMNIgwB+7tzc2V65jtpg1RyvRb64Woj/F+fixbeoyVlvIP2o99WA== X-Google-Smtp-Source: AGHT+IG2H0JMzpZ4Rw9d+GSeTdHtlvEwfcgulZM7WmjLKT/BwHOEpNubFax4Xm7riytdiegSHPUBkYePz2N2H5EqPpE= X-Received: by 2002:a05:6402:34c5:b0:649:230e:ec52 with SMTP id 4fb4d7f45d1cf-64b8e935a65mr4687631a12.1.1766243530490; Sat, 20 Dec 2025 07:12:10 -0800 (PST) MIME-Version: 1.0 References: <20251206230222.853493-1-pratyush@kernel.org> <20251206230222.853493-5-pratyush@kernel.org> <86wm2hj0ky.fsf@kernel.org> In-Reply-To: <86wm2hj0ky.fsf@kernel.org> From: Pasha Tatashin Date: Sat, 20 Dec 2025 10:11:34 -0500 X-Gm-Features: AQt7F2rkD8DzKJtnBrRBVjSiNOllvUXl1o05w5fOraa6mNPG1z2m3wrrR9PJQmQ Message-ID: Subject: Re: [RFC PATCH 04/10] liveupdate: flb: allow getting FLB data in early boot To: Pratyush Yadav Cc: Mike Rapoport , Andrew Morton , David Hildenbrand , Lorenzo Stoakes , "Liam R. Howlett" , Vlastimil Babka , Suren Baghdasaryan , Michal Hocko , Jonathan Corbet , Thomas Gleixner , Ingo Molnar , Borislav Petkov , Dave Hansen , x86@kernel.org, "H. Peter Anvin" , Muchun Song , Oscar Salvador , Alexander Graf , David Matlack , David Rientjes , Jason Gunthorpe , Samiullah Khawaja , Vipin Sharma , Zhu Yanjun , linux-kernel@vger.kernel.org, linux-mm@kvack.org, linux-doc@vger.kernel.org, kexec@lists.infradead.org Content-Type: text/plain; charset="UTF-8" X-Rspamd-Queue-Id: E430916000A X-Stat-Signature: ga69a1z1y63cbexn3wke1kxh3m4tyw9y X-Rspam-User: X-Rspamd-Server: rspam06 X-HE-Tag: 1766243531-866775 X-HE-Meta: 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 creNxPup oEIFKQZYrLAjfEcD6SjgfIQK7mQDC+mYvXTKEH/IPRXYUb1nGVmOD1oSR6Ib44IwtQLJK+60VCMAi+bpHv0Y39IYf61Ds5MSKVZG5G4tHlq8PgCDTyU8SP4FpC+OvwuOTlzJgfhFi3t3CiqZ8icGl0Pr7Yg== 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: > > [Follow-up from LPC discussion] > > > > This patch is not needed, you can use liveupdate_flb_get_incoming() > > directly in early boot. The main concern is that we take mutex in that > > function, but that I think is safe. The might_sleep() has the proper > > handling to be called early in boot, it has "system_state == > > SYSTEM_BOOTING" check to silence warning during boot. > > Right. I will give it a try. For hugetlb, this works fine since it > doesn't really need to do much in FLB retrieve anyway, it just needs to > parse some data structures. > > If other subsystems end up needing a two-part retrieve, one in early > boot and one later, then I think it would be a good idea to model that > properly instead of leaving it up to the subsystem to manage it. > > Anyway, that isn't a real problem today so let's look at it when it does > show up. FLB has exactly one .retrieve() lifecycle event. Once called, the data is considered fully available and cached in private->incoming.obj. If a subsystem has a requirement where it needs a specific state available very early and other state available much later, the clean solution is simply to register two separate FLBs. Pasha