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 D979AC52D6F for ; Wed, 21 Aug 2024 12:37:38 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 575D36B0103; Wed, 21 Aug 2024 08:37:38 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 526526B0110; Wed, 21 Aug 2024 08:37:38 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 3C72B6B0111; Wed, 21 Aug 2024 08:37:38 -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 1FF0C6B0103 for ; Wed, 21 Aug 2024 08:37:38 -0400 (EDT) Received: from smtpin14.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay07.hostedemail.com (Postfix) with ESMTP id C3547160CB9 for ; Wed, 21 Aug 2024 12:37:37 +0000 (UTC) X-FDA: 82476203754.14.6FFD468 Received: from mail-ed1-f50.google.com (mail-ed1-f50.google.com [209.85.208.50]) by imf13.hostedemail.com (Postfix) with ESMTP id C6A6D20015 for ; Wed, 21 Aug 2024 12:37:35 +0000 (UTC) Authentication-Results: imf13.hostedemail.com; dkim=pass header.d=suse.com header.s=google header.b=gqoTqwm7; dmarc=pass (policy=quarantine) header.from=suse.com; spf=pass (imf13.hostedemail.com: domain of mhocko@suse.com designates 209.85.208.50 as permitted sender) smtp.mailfrom=mhocko@suse.com ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1724243839; a=rsa-sha256; cv=none; b=IUshmwJWt0t6D7w35Jk4fSRnaAkSzku++KRSYSCtOmwtLetyQ+nt74CGLFq4sFNEFZ5yIV ZxFvRenCpgh8ZKHiHG6IV1IHg7d4br3xqIbnYEiuI+QswOssjuxHqpH+wK9eS+/lYCPi4Z O3D1wGAEb0it1UbrompRzmkBsRboiN4= ARC-Authentication-Results: i=1; imf13.hostedemail.com; dkim=pass header.d=suse.com header.s=google header.b=gqoTqwm7; dmarc=pass (policy=quarantine) header.from=suse.com; spf=pass (imf13.hostedemail.com: domain of mhocko@suse.com designates 209.85.208.50 as permitted sender) smtp.mailfrom=mhocko@suse.com ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1724243839; 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=+z0tkmKXFuor3PJd/fzSsG2T/EzZytsYDXe7BHDYMiI=; b=Bs8xHYpesmMiURAEC2EEjr/Dzk3ghsBbzOqaOU9/jLzIfgA0boIyFltlqWqRBRLAcY4667 /ekgFH5Cd0Pjs2WxPcUHrlyprbWeNGUW6ITIHa77e+q4PBhtDo7IbJjhj55zBgU/nuKjGV z2OD0yOW/mwhSo+k22+ZnU07SvT0ow0= Received: by mail-ed1-f50.google.com with SMTP id 4fb4d7f45d1cf-5bf009cf4c0so3409477a12.1 for ; Wed, 21 Aug 2024 05:37:35 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.com; s=google; t=1724243854; x=1724848654; darn=kvack.org; h=in-reply-to:content-disposition:mime-version:references:message-id :subject:cc:to:from:date:from:to:cc:subject:date:message-id:reply-to; bh=+z0tkmKXFuor3PJd/fzSsG2T/EzZytsYDXe7BHDYMiI=; b=gqoTqwm7D9eZosDmduYCFV5hgDs/TsJ+g29lekUVVNhJVnhBb6VoRnBkHrcxPRSesR FEGpNqger2Rz6d3Ea9umw6CYXjfw6dnXHA1vlDDgrZruQHAfq6+/oP39xTAH6REVCLDh ywy/r1ONk/eUeIhSh9sggsn4mW9wVaQzWiUs6WtzA0DbNgbZkHsC9+Pt4g0w2FLOYfst 0tS01yu4Hbq1B/j9Xc4rySmw+ygRFipieaNp7zePNohL/grS/0GtB1kScEBv8y3xOaCS QDT8Tmen8hgiLy/ps6dCS1WRBROxbDSXaCLW4TO+TBMI2feNRiVRvbqar5s01lMGCCb0 FljQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1724243854; x=1724848654; h=in-reply-to:content-disposition:mime-version:references:message-id :subject:cc:to:from:date:x-gm-message-state:from:to:cc:subject:date :message-id:reply-to; bh=+z0tkmKXFuor3PJd/fzSsG2T/EzZytsYDXe7BHDYMiI=; b=BVgJ2qiZEVK/uXwYnB+QN609jMpm286uIiTONf4Dnq0eBFlOCye3qjDWz+IR8mTIlu +SAoV/1Kj8ldmN44ftCMViRAf7fcxYNB/I33AlDeX1+xMlmy6dQEfC1eHFvMz8cMxmwW sdum4PAhAVJNJmUwdTQceewb0yjlRGYhUUQ49Va7G3ZflsKPVpT5haXHPNahC+7rSLmX Ej9AQ3W9dsROS3WFz3J3F9cByoizuC7zf7/PzSW1NR+7izR9HfrD2JGhSCJiUGMtzvJl 9b1JE0N5/9iWs+ySB6EAxXj0PZELVzQKctUL/QVw/lFZz/5fdFgXqBRNc+t6NhsPKGP7 pc1w== X-Forwarded-Encrypted: i=1; AJvYcCUb8wlrNaA9S84YU0fFvWjc2sbKvtTv6GJNW2GFtKPOD3co/6vkwTedmD8qvu/w1T9h/nQ8AOISbw==@kvack.org X-Gm-Message-State: AOJu0Yx5Qjt3rna+IL6XIq7v0XOEvEiCcOkJS2SPvTY4OhWU3oWu8QTK is+E2bcnVRt0J0HNyAwZOz+iElZ01LSxJcV4OTVPPGPb859u9kTnlNcEwY8yKp8= X-Google-Smtp-Source: AGHT+IFet+ZD+ZG5UYlF6HZaloNtjZmJNvxbYWC/Q0UrbM+pJa4I2BB6pLCsLtQOrrm0QxUkoBAEZw== X-Received: by 2002:a17:907:9483:b0:a7a:8e98:890d with SMTP id a640c23a62f3a-a866f2fe311mr183761166b.16.1724243853995; Wed, 21 Aug 2024 05:37:33 -0700 (PDT) Received: from localhost ([193.86.92.181]) by smtp.gmail.com with ESMTPSA id a640c23a62f3a-a8681c106aasm27698966b.216.2024.08.21.05.37.33 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 21 Aug 2024 05:37:33 -0700 (PDT) Date: Wed, 21 Aug 2024 14:37:33 +0200 From: Michal Hocko To: Christoph Hellwig Cc: Yafang Shao , Andrew Morton , viro@zeniv.linux.org.uk, brauner@kernel.org, jack@suse.cz, david@fromorbit.com, linux-fsdevel@vger.kernel.org, linux-mm@kvack.org, Kent Overstreet Subject: Re: [PATCH] mm: document risk of PF_MEMALLOC_NORECLAIM Message-ID: References: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: X-Rspam-User: X-Rspamd-Queue-Id: C6A6D20015 X-Rspamd-Server: rspam01 X-Stat-Signature: zun8h1tibmxx5k76uyraiuzit86gdmt5 X-HE-Tag: 1724243855-353137 X-HE-Meta: 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 lv03Tvmu APFPO8Br/9E8kv1BvptDqM+0k3gHW0ri/QwYSnvM/jRGLl6jNngpsmoHUKyehrJ7p9kWM8V+4u/FKYqhKjxcogGYYRhbg53sC/1rpvdoZj6BIKR2cxh22aW8y90WJIfuNzNLm3tE+8YF+Rmh3lnz0LsYVvTxo0WEPjgfdC1rj7tKzUv1nUDqwnS2AaL9bTm7i+u5d4HBy0eZ7zRtdjQ9GVBt2yVj8Ssvv9CnNkgyOxHN9x6n1vExmhUjGkF5cVM1VS3dxaTdoY6tCSY1yOUC2fQaro66KFp8LHyqxvAGHoVXqs9exwrylyXRYHXdPu2MfQR76Yq+mbv8FacCUx/o5/RAqkexRWevYGA1t7PvN5P/na4peO7XKfqk05tbBl7Vdp3FZ/cDp8zEu5dVwAtdqGlUaKA== 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 Wed 21-08-24 04:44:03, Christoph Hellwig wrote: > On Fri, Aug 16, 2024 at 10:54:37AM +0200, Michal Hocko wrote: > > Yes, I think we should kill it before it spreads even more but I would > > not like to make the existing user just broken. I have zero visibility > > and understanding of the bcachefs code but from a quick look at __bch2_new_inode > > it shouldn't be really terribly hard to push GFP_NOWAIT flag there > > directly. > > > I don't understand that sentence. You're adding the gfp_t argument to > it, which to mean counts as pushing it there directly. Sorry, what I meant to say is that pushing GFP_NOWAIT directly seem fine unless I have missed some hidden corners down the call path which would require a scope flag to override a hardcoded gfp flag. > > It would require inode_init_always_gfp variant as well (to not > > touch all existing callers that do not have any locking requirements but > > I do not see any other nested allocations. > > inode_init_always only has 4 callers, so I'd just add the gfp_t > argument. Otherwise this looks good modulo the fix your posted: > > Acked-by: Christoph Hellwig Thanks. I will wait for more review and post this as a real patch. I would really appreciate any help with actual testing. -- Michal Hocko SUSE Labs