From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id D047D158A01 for ; Wed, 24 Jul 2024 13:23:34 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=198.137.202.133 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1721827415; cv=none; b=fFzG66kaekfzpVJzHdZo/dTGgBrvyR5ytL4dW/6z3nI4ea8lSBSMcmXgulBAP6ZMEBROrbpKskiUUvP9qWwkg8LxDrjtA0+rr2kLt63GQSiby0FtDEHTta4Rj6cI+5UvmKPjZsP9Nc0HX2ohBMMPrCr/ma25/cWgRQccWuxx14A= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1721827415; c=relaxed/simple; bh=kJmSUyWHhaALt3X8CM3M5BPxurv+/4DKWnjHf/hw45Y=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=nCONsJPAoEAqxBQ4VJh+iEU4f41JVwNSZEqYONcyaSoeiXeWGeDRhvuWZpMqANOWyQoYz5EEcTlR3wpVPdq9smOueiI9jIE99rtKcgqIHhYS0YOjVojm/J/vC0BJyKxvqgmOAoVFd5iDQTBq8X2nBssFVpAsL/tVnY3jd60x6hw= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=infradead.org; spf=none smtp.mailfrom=bombadil.srs.infradead.org; dkim=pass (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b=T6EKofbh; arc=none smtp.client-ip=198.137.202.133 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=infradead.org Authentication-Results: smtp.subspace.kernel.org; spf=none smtp.mailfrom=bombadil.srs.infradead.org Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b="T6EKofbh" DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=bombadil.20210309; h=In-Reply-To:Content-Type:MIME-Version :References:Message-ID:Subject:Cc:To:From:Date:Sender:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description; bh=aGDmrf70xonv6Qm91bhRo10OdhYvaEykAIZYXVPLJ8w=; b=T6EKofbhHAV0bXikVRXIvzascT JLhhFq6JmRbVL4FEZWPnF3KmN9egpn/MLIznUPvYW0FPL45+dnJ7bP65/vjNKq8bKvoiQShdEklKO 4o9F37RzB9UXMEBMJpRgEoXBDgOL7aFOhY6XITr6GOZmQ/r55u15i6Y07FAbJ3b6P+ng6ev99fSTm IsojksZSOczxUCn5ZCVkPSYIUuujhd2VTfXCE6ns7od/dNBgCECWR1OdXp8zhkTZCv0Ymo+kyZcyN NYCuBVGzywsHFEIFOjOXpy26okIsTUJr6a1gT8nSiJUEBC4mSUtgQStNoLff3LWu35p4xMmt6dxTT sApTpSbQ==; Received: from hch by bombadil.infradead.org with local (Exim 4.97.1 #2 (Red Hat Linux)) id 1sWbxp-0000000FQlv-0NY5; Wed, 24 Jul 2024 13:23:29 +0000 Date: Wed, 24 Jul 2024 06:23:29 -0700 From: Christoph Hellwig To: Michal Hocko Cc: Christoph Hellwig , Vlastimil Babka , Barry Song <21cnbao@gmail.com>, akpm@linux-foundation.org, linux-mm@kvack.org, 42.hyeyoo@gmail.com, cl@linux.com, iamjoonsoo.kim@lge.com, lstoakes@gmail.com, penberg@kernel.org, rientjes@google.com, roman.gushchin@linux.dev, urezki@gmail.com, v-songbaohua@oppo.com, 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> <68ee812b-3b96-4c8b-9a54-70d4742488bb@suse.cz> 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: X-SRS-Rewrite: SMTP reverse-path rewritten from by bombadil.infradead.org. See http://www.infradead.org/rpr.html On Wed, Jul 24, 2024 at 03:21:13PM +0200, Michal Hocko wrote: > Scope API is tricky here. Exactly because the scope itself could have > opportunistic GFP_NOWAIT allocations. Really, where? That just sounds f**cked up as callers using any kind of nofail API can be broken by a caller higher in the stack. And that's totally independ of adding a NOFS/NOIO helper, so it'll need to be fixed. Adding more NOFS/NOIO wrappers while we're trying to kill the flag just is not helpful going forward.