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 48C288F6E for ; Mon, 23 Jun 2025 05:11:55 +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=1750655516; cv=none; b=a+k56i+nzYgCgWUbEcrj5fPXyLVmmWHJ79SiYx1+Me09n7c1YXTKgRmKPw9IwyIJQhDdjRdUCu5biuTBvKmSPMOp4LMbObbPXFB0koHvRasK83Sez7ZLVddop2CvoIGhz420ByZMR4qt8SXX38FmabpEQN3tSk7vgunl2+oNX8s= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1750655516; c=relaxed/simple; bh=imtjDLmHTyYtzjwOqDDYnnkmplPIv/la+cgpfPdQqqI=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=K//qgFpkeaWIaMxHFwSspQqTyjCtv1+gHdbMOH0vRoWQ22F3HH8JiwaycajMSoXTLbDu6H3+USQZtt4zfYjoHC3VDvXW1GlKfUOyM04dkONFw8nqoaV87jCGtz7DX84jWNPBlEBessnt7s/X0GLs9rL5JiT9uL/SffSMsiEZDo0= 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=eztFYiUC; 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="eztFYiUC" 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=Kld/uITGF/u1zNJ3lTXiAZxc7BUp8iDuyP9wy6UrYpU=; b=eztFYiUCB/mKUUKIq6PM0W7pBA 7ZBQowHztYmGRDKfXT6TOdxi635pfTP7NWCU9oGmtQFewK4rLoICSGUU2QrYbEJr7PCIYR6dF4wEy VoSyhbV6mDuFTQDiQ9nZKDmgrT/BLSujpl4rsh48DFTVTkHe7RfL9uG3k1/6VymcwGnnNhS25AHnY CxP9Bsxe+KlNHyYbSq/Ng6U+szBFk9GdiXFblyX1O1Dp3Dh1H3Jl8G0LM1qbtJMigJMzWHB3Ntr8E UJ/I5/4WabOq5esjTQGsdaOYKAA2A/af6qzmkGVj/mGegpQHBInSVXJtotWYJ68KMzKfgL/Y+HKp4 vd/A1EQA==; Received: from hch by bombadil.infradead.org with local (Exim 4.98.2 #2 (Red Hat Linux)) id 1uTZTD-00000001asl-3QLs; Mon, 23 Jun 2025 05:11:51 +0000 Date: Sun, 22 Jun 2025 22:11:51 -0700 From: Christoph Hellwig To: Vitaly Wool Cc: linux-mm@kvack.org, akpm@linux-foundation.org, linux-kernel@vger.kernel.org, Igor Belousov Subject: Re: [PATCH] mm/zswap: export zswap API to modules Message-ID: References: <20250620193552.2772125-1-vitaly.wool@konsulko.se> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20250620193552.2772125-1-vitaly.wool@konsulko.se> X-SRS-Rewrite: SMTP reverse-path rewritten from by bombadil.infradead.org. See http://www.infradead.org/rpr.html On Fri, Jun 20, 2025 at 09:35:52PM +0200, Vitaly Wool wrote: > There is no reason to not let modules use zswap capabilies to > densely store unused pages in RAM. This will allow to remove some > homebrew solutions for e.g. GPU drivers in favor of plainly using > zswap pool. Well, right now there very much is - there is no user of them. And any such user should first have a careful review on the list if they really should use zswap directly because that feels like a layering violation. (Maybe it's not, but without a proper review that is impossible to say) And this was the nice Monday morning after a long weekend reply. The short form is "don't add exports without a user", and everyone should really know that.