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 9F0E6383A9 for ; Wed, 24 Jul 2024 13:38:48 +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=1721828330; cv=none; b=VtiDCj75Evfd7EXgG+9PKzGq22HpxZRmyhDvWdOqAVsXFbK4fARQVvO3dhOvcnOS/qnEnLXRRCOzXissCL+VI7FRWnQZ0TwAjCIAcblNlOikicQ6GxKwMf6WnuNqQz/ojH1epiIjqg1cB2nIlairGG7WFmDZtf7aV1MSyC3On+0= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1721828330; c=relaxed/simple; bh=0v+CVxTYq3Gbd5r+G9NTqFSG5V3tl4pVOXjBLir2xY0=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=aTW1KQBavDjBlqesjyuiO1kKySmdvV58Jwj1gAU6pvYy9ZPtgN3kvd9D+zzA9T1RKuz+oZIrSZQ8EpJOLUT/XUMAErXyjXPR1djeRgjmFxaRm82t5xJfdt4JP+3FMuHgVGhxzJD7AYyA9UnhhlDYuryn3fbCNMwMEwwkbyg9LyY= 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=EN/3Ds8z; 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="EN/3Ds8z" 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=b/KEzmx1aMMGRJQpHAjdbVT5z73BzbBw+LIwhc43mRI=; b=EN/3Ds8zwhG6he2rQH2e04Bkq+ iUsMRkJH6sJWwWivU8LahkjYMU2RLUSIK5dSQJ1101Gcm4Cx9YuG6WTC/hgMg/0h1ydvh1DFB8FVq Ra5gjh9mhRQkTHVUNfZe6s/a2ggnwGB5LjNE48sXGyB8dODsMy5Y2JuPhays+uhf/nWuLJQf9n2Hw pAvCj+5xp9PqBBGGIIX+0joALiSxukDavmiHMCx83N3TIcjTXdjqveaJAd5RN9TYpMMpCvrOzZaD8 QTUWA3xWkfqjbVuq7/MdQkv2M5jUCt0PgtshZA1Mx4pq7kGb/al8Xv7Z1+P4V68IwtE21qNfm7xtO kuuIHyOA==; Received: from hch by bombadil.infradead.org with local (Exim 4.97.1 #2 (Red Hat Linux)) id 1sWcCX-0000000FTDi-29nF; Wed, 24 Jul 2024 13:38:41 +0000 Date: Wed, 24 Jul 2024 06:38:41 -0700 From: Christoph Hellwig To: Vlastimil Babka Cc: Michal Hocko , Christoph Hellwig , 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> <400b2f6f-f7f0-4888-99ee-7327faad7e5c@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: <400b2f6f-f7f0-4888-99ee-7327faad7e5c@suse.cz> 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 03:33:19PM +0200, Vlastimil Babka wrote: > > I do not see this a problem. There is no real reason to have a NOWAIT > > allocation down the stack that has a different fallback strategy. > > I am not saying that this is the current practice because I do not know > > that but I am saying that this is not impossible to imagine and it makes > > scoped NOFAIL context subtle and error prone. > > I don't think Christoph proposed scoped NOFAIL, just use scoped NOFS/NOIO > together with GFP_KERNEL_NOFAIL intead of introducing GFP_NOFS_NOFAIL. Yes, exactly. And I didn't think Michal thought I meant something different, maybe that's why it felt really confusing.