From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-ed1-f42.google.com (mail-ed1-f42.google.com [209.85.208.42]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id C2D841494C8 for ; Wed, 24 Jul 2024 12:17:53 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.208.42 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1721823475; cv=none; b=ZZwFva4mg+I29XLDofoG2ezyB5Y98+O3PwaaBs/Lgm+a8CRNoYhguOpyH9vbsj3+eZv7BJlEY7iFk34h6UCUSuhuDRPiF/enKlm7ILVsAsyHaxp/ouns0S6p8Y06TNXB4hahnPGDKRQow38xjVrFlM8izLmlfz93FoZOsqNmMv8= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1721823475; c=relaxed/simple; bh=JK9JCXnNFA+Q88R0pI3Is57I6tUtCQ6aLilbZ+7avwQ=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=oElu4HWNDf51RVbK64M9TuX2jEhLLw+y8rWwFPIspEwTs3ykVPrkQjwz30yEwzMvNchXtxOD8O2qhLlg2iL5RoHU8t8Ml4kDA+BlNJidNd0KMzsX+GsohQ+ZdwtnJ1rYIpE6zVwW52bSP0gOvy1S7ZudCrJ4m+ti97dye89SC0I= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=suse.com; spf=pass smtp.mailfrom=suse.com; dkim=pass (2048-bit key) header.d=suse.com header.i=@suse.com header.b=fHoTy0ya; arc=none smtp.client-ip=209.85.208.42 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=suse.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=suse.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=suse.com header.i=@suse.com header.b="fHoTy0ya" Received: by mail-ed1-f42.google.com with SMTP id 4fb4d7f45d1cf-5a167b9df7eso6823725a12.3 for ; Wed, 24 Jul 2024 05:17:53 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.com; s=google; t=1721823472; x=1722428272; darn=lists.linux.dev; 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=AH6/60ilSqogotIa0Yn+76PK3sWEb69NY//2ZTuyhAE=; b=fHoTy0yaJGn7SN4D+jMnSrSfj6VmTqjp+raJoy2QqzNyolSIfOfY6yDHg1zMqqZlph 79FtWqmft+OMkUnaSLi3lLriBZvLLaKJ0Z28UH5+g/v4kCpKkw2QL7VcjiBTT/ajq+e8 IQtAPHZYVegSHLvArILBCQCWMokh3++PSFcigEoSrgLB2eihgpbI/c145n2vYv1BcoDT lCofnpk6bs6XUaPgP418HBs9/ph/uq7s8tocvMSX+n3KpZqkLV7sPN6jZV6Y+vZSTkVY 8Cr3jcw2slQ2OX7P9APaLtjgvs+wnocYd1MzDYHDNy4RqShCfts3UoaLnhgO6Zv8bi/e xLyQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1721823472; x=1722428272; 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=AH6/60ilSqogotIa0Yn+76PK3sWEb69NY//2ZTuyhAE=; b=t+0hc5g0HFcnq2g5W0xrLgZ90mWkVT9kfJVjsXlFz4tkjGYJsx2AZii+K3x9Mc3doL wuM9DDoGFctP6ueGouTVX3JzAyYboRQaouMgag0IdTTfOEHuEGr883o8II/FJ7o4KsG5 f5lKedy0AdozAlzR6MkM24P/ZVwm3QgWfHA3KU5ClT8F/Hj1J4tEJ7+h9Uu3+zacAGDn /z/YrP6NT9x7CU6PgJ/yvOuygucWiHkQUawWakvdqwFK7YsBQr/sV56YwZiVSf1ubmP8 1yzeXxrXka1zNovh7Et1kBUaJ7j8NCcxcq2Q95aPyGL5yQNdLJP/em/piUzEfgCXll3x +UYw== X-Forwarded-Encrypted: i=1; AJvYcCW69OxzOlFvuFvH9ktCGmVCXBYj48r7nqKlQGCVWNscjWaJ3A1xWpleaVJVsQVzz9MRy/zvQIrAOo2efYg9kp23nlk9W4oeV5QM7pcd8EE= X-Gm-Message-State: AOJu0Yy66mExaW3x1pOwyrDaJ2VHQp1K72bUGnJUZDUhLRwA2j0Kc5gT 4MtdIdSROYNWZJtwqSnpHynunZrkfoKODms0AfgamLREFkmUcEBICHx/HSTYpQA= X-Google-Smtp-Source: AGHT+IHfYQ0bvxc2iNBQgy+rvJ4GtEtz1AIw7oKDKgMgcbTYPs7bQokdfT3snYcXpjGEyw6Qamqg0g== X-Received: by 2002:a17:907:6d06:b0:a7a:9144:e254 with SMTP id a640c23a62f3a-a7ab0d081c8mr141848366b.10.1721823472048; Wed, 24 Jul 2024 05:17:52 -0700 (PDT) Received: from localhost (109-81-94-157.rct.o2.cz. [109.81.94.157]) by smtp.gmail.com with ESMTPSA id a640c23a62f3a-a7a3c786162sm647262166b.18.2024.07.24.05.17.51 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 24 Jul 2024 05:17:51 -0700 (PDT) Date: Wed, 24 Jul 2024 14:17:50 +0200 From: Michal Hocko To: Barry Song <21cnbao@gmail.com> Cc: akpm@linux-foundation.org, linux-mm@kvack.org, 42.hyeyoo@gmail.com, cl@linux.com, hch@infradead.org, iamjoonsoo.kim@lge.com, lstoakes@gmail.com, penberg@kernel.org, rientjes@google.com, roman.gushchin@linux.dev, urezki@gmail.com, v-songbaohua@oppo.com, vbabka@suse.cz, virtualization@lists.linux.dev, hailong.liu@oppo.com, torvalds@linux-foundation.org Subject: Re: [PATCH RFC 5/5] non-mm: discourage the usage of __GFP_NOFAIL and encourage GFP_NOFAIL Message-ID: References: <20240724085544.299090-1-21cnbao@gmail.com> <20240724085544.299090-6-21cnbao@gmail.com> Precedence: bulk X-Mailing-List: virtualization@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20240724085544.299090-6-21cnbao@gmail.com> On Wed 24-07-24 20:55:44, Barry Song wrote: > From: Barry Song > > GFP_NOFAIL includes the meaning of block and direct reclamation, which > is essential for a true no-fail allocation. We are gradually starting > to enforce this block semantics to prevent the potential misuse of > __GFP_NOFAIL in atomic contexts in the future. > > A typical example of incorrect usage is in VDPA, where GFP_ATOMIC > and __GFP_NOFAIL are used together. Ohh, so you have done the migration. Please squash those two patches. Also if we want to preserve clean __GFP_NOFAIL for internal MM use then it should be moved away from include/linux/gfp_types.h. But is there any real use for that? -- Michal Hocko SUSE Labs