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=-1.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_PASS 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 DB203C43381 for ; Fri, 22 Feb 2019 06:20:47 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id B0420207E0 for ; Fri, 22 Feb 2019 06:20:47 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726019AbfBVGUp (ORCPT ); Fri, 22 Feb 2019 01:20:45 -0500 Received: from len.romanrm.net ([91.121.75.85]:57978 "EHLO len.romanrm.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725873AbfBVGUp (ORCPT ); Fri, 22 Feb 2019 01:20:45 -0500 X-Greylist: delayed 310 seconds by postgrey-1.27 at vger.kernel.org; Fri, 22 Feb 2019 01:20:44 EST Received: from natsu (unknown [IPv6:fd39::e99e:8f1b:cfc9:ccb8]) by len.romanrm.net (Postfix) with SMTP id E3CCB203F0; Fri, 22 Feb 2019 06:15:32 +0000 (UTC) Date: Fri, 22 Feb 2019 11:15:32 +0500 From: Roman Mamedov To: "Martin K. Petersen" Cc: Jeff Mahoney , Keith Busch , Ric Wheeler , Dave Chinner , lsf-pc@lists.linux-foundation.org, linux-xfs , linux-fsdevel , linux-ext4 , linux-btrfs , linux-block@vger.kernel.org Subject: Re: [LSF/MM TOPIC] More async operations for file systems - async discard? Message-ID: <20190222111532.4ead81dc@natsu> In-Reply-To: References: <92ab41f7-35bc-0f56-056f-ed88526b8ea4@gmail.com> <20190217210948.GB14116@dastard> <46540876-c222-0889-ddce-44815dcaad04@gmail.com> <20190220234723.GA5999@localhost.localdomain> <45c27fea-6d74-2adc-fe9d-e314ce4f3672@suse.com> MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-block-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-block@vger.kernel.org On Thu, 21 Feb 2019 22:01:24 -0500 "Martin K. Petersen" wrote: > Consequently, many of the modern devices that claim to support discard > to make us software folks happy (or to satisfy a purchase order > requirements) complete the commands without doing anything at all. > We're simply wasting queue slots. Any example of such devices? Let alone "many"? Where you would issue a full-device blkdiscard, but then just read back old data. I know only one model(PLEXTOR PX-512M6M) of dozens tested, which is peculiar that it ignores trim specifically for the 1st sector of the entire disk. But implying there are "many" which no-op it entirely, seems like imagining the world already works like you would assume it to. -- With respect, Roman