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 X-Spam-Level: X-Spam-Status: No, score=-2.2 required=3.0 tests=DKIM_INVALID,DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_PASS,USER_AGENT_MUTT autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 6E38DC04A6B for ; Fri, 10 May 2019 17:02:57 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 38BAD2084E for ; Fri, 10 May 2019 17:02:57 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b="hU+E15uc" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727820AbfEJRCv (ORCPT ); Fri, 10 May 2019 13:02:51 -0400 Received: from bombadil.infradead.org ([198.137.202.133]:56950 "EHLO bombadil.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727796AbfEJRCu (ORCPT ); Fri, 10 May 2019 13:02:50 -0400 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=bombadil.20170209; 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:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Id: List-Help:List-Unsubscribe:List-Subscribe:List-Post:List-Owner:List-Archive; bh=IziTW291S7TLrX5c1nQ0BR6rD/rA9YRqzUixUHiWrsw=; b=hU+E15ucag7QN44PBHizLVV+U YXBduJaryBgxzFbdCxi9XhgPyJRVvEzVMQ/L5/jwaE4UEAkz6dSTizK6H0XZ9BbixaAny2raeA0PM GZYiMpAozs0jHE1ySlNQIY5IG9iXJwSy9pKxHAJt+HnwZLcQMvSbogXQfrPr9LJSsj1ZSbpCzIhUU yXlcyUMdz1fK5kA9fkEB2DIbEofpBepyZE1ld9ii5xkEKJ4mzvbRujLu74uneoNe0SJGdG4GRhCpX Mr0/e16oFwaTFLjYwBe4LBu+3c2VCErCTZxx3WbSij1Vo7+HWzZaAT7zHUz0EXtqOOb47KJ2SrKwB 7t+EeHnRw==; Received: from hch by bombadil.infradead.org with local (Exim 4.90_1 #2 (Red Hat Linux)) id 1hP8v3-00075G-R8; Fri, 10 May 2019 17:02:49 +0000 Date: Fri, 10 May 2019 10:02:49 -0700 From: Christoph Hellwig To: Kanchan Joshi Cc: linux-kernel@vger.kernel.org, linux-block@vger.kernel.org, linux-nvme@lists.infradead.org, linux-fsdevel@vger.kernel.org, linux-ext4@vger.kernel.org, prakash.v@samsung.com, anshul@samsung.com Subject: Re: [PATCH v5 0/7] Extend write-hint framework, and add write-hint for Ext4 journal Message-ID: <20190510170249.GA26907@infradead.org> References: <1556191202-3245-1-git-send-email-joshi.k@samsung.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1556191202-3245-1-git-send-email-joshi.k@samsung.com> User-Agent: Mutt/1.9.2 (2017-12-15) X-SRS-Rewrite: SMTP reverse-path rewritten from by bombadil.infradead.org. See http://www.infradead.org/rpr.html Sender: linux-block-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-block@vger.kernel.org I think this fundamentally goes in the wrong direction. We explicitly designed the block layer infrastructure around life time hints and not the not fish not flesh streams interface, which causes all kinds of problems. Including the one this model causes on at least some SSDs where you now statically allocate resources to a stream that is now not globally available. All for the little log with very short date lifetime that any half decent hot/cold partitioning algorithm in the SSD should be able to detect.