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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id BFB18EB64DC for ; Tue, 11 Jul 2023 05:49:48 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229585AbjGKFtr convert rfc822-to-8bit (ORCPT ); Tue, 11 Jul 2023 01:49:47 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:34786 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229479AbjGKFtr (ORCPT ); Tue, 11 Jul 2023 01:49:47 -0400 Received: from mail.lichtvoll.de (luna.lichtvoll.de [194.150.191.11]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 23504195 for ; Mon, 10 Jul 2023 22:49:45 -0700 (PDT) Received: from 127.0.0.1 (localhost [127.0.0.1]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (secp384r1) server-digest SHA384) (No client certificate requested) by mail.lichtvoll.de (Postfix) with ESMTPSA id 6399E73B037; Tue, 11 Jul 2023 07:49:43 +0200 (CEST) Authentication-Results: mail.lichtvoll.de; auth=pass smtp.auth=martin smtp.mailfrom=martin@lichtvoll.de From: Martin Steigerwald To: linux-btrfs@vger.kernel.org, Tim Cuthbertson Subject: Re: Scrub of my nvme SSD has slowed by about 2/3 Date: Tue, 11 Jul 2023 07:49:43 +0200 Message-ID: <2149714.irdbgypaU6@lichtvoll.de> In-Reply-To: <5690570.DvuYhMxLoT@lichtvoll.de> References: <5690570.DvuYhMxLoT@lichtvoll.de> MIME-Version: 1.0 Content-Transfer-Encoding: 8BIT Content-Type: text/plain; charset="iso-8859-1" Precedence: bulk List-ID: X-Mailing-List: linux-btrfs@vger.kernel.org Martin Steigerwald - 11.07.23, 07:33:36 CEST: > This is with ThinkPad T14 AMD Gen 1 with AMD Ryzen 7 PRO 4750U and 32 > GiB RAM on Samsung 980 Pro 2TB NVME SSD connected via PCIe 3. The > hardware can definitely do more throughput even with "just" PCIe 3. I forgot to add that BTRFS is on top LVM inside LUKS. I see about 180000 reads in 10 seconds in atop. I have seen latency values from 55 to 85 µs which is highly unusual for NVME SSD ("avio" in atop¹). [1] according to man page atop(1) from atop 2.9: the average number of milliseconds needed by a request ('avio') for seek, latency and data transfer -- Martin