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 1EA5AC0015E for ; Fri, 28 Jul 2023 12:38:51 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S235084AbjG1Miu (ORCPT ); Fri, 28 Jul 2023 08:38:50 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:51960 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233765AbjG1Mit (ORCPT ); Fri, 28 Jul 2023 08:38:49 -0400 Received: from mail.lichtvoll.de (luna.lichtvoll.de [194.150.191.11]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 2D89C187 for ; Fri, 28 Jul 2023 05:38:48 -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 5020C75AF95; Fri, 28 Jul 2023 14:38:35 +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, Qu Wenruo Subject: Re: [PATCH 0/5] btrfs: scrub: improve the scrub performance Date: Fri, 28 Jul 2023 14:38:35 +0200 Message-ID: <6543972.G0QQBjFxQf@lichtvoll.de> In-Reply-To: References: MIME-Version: 1.0 Content-Transfer-Encoding: 7Bit Content-Type: text/plain; charset="us-ascii" Precedence: bulk List-ID: X-Mailing-List: linux-btrfs@vger.kernel.org Qu Wenruo - 28.07.23, 13:14:03 CEST: > The first 3 patches would greately improve the scrub read performance, > but unfortunately it's still not as fast as the pre-6.4 kernels. > (2.2GiB/s vs 3.0GiB/s), but still much better than 6.4 kernels > (2.2GiB vs 1.0GiB/s). Thanks for the patch set. What is the reason for not going back to the performance of the pre-6.4 kernel? Isn't it possible with the new scrubbing method? In that case what improvements does the new scrubbing code have that warrant to have a lower performance? Just like to understand the background of this a bit more. I do not mind a bit lower performance too much, especially in case it is outweighed by other benefits. -- Martin