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=-5.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS autolearn=no 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 10DD5C4320A for ; Sat, 24 Jul 2021 18:09:08 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id E959760E97 for ; Sat, 24 Jul 2021 18:09:07 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229947AbhGXR2d (ORCPT ); Sat, 24 Jul 2021 13:28:33 -0400 Received: from bedivere.hansenpartnership.com ([96.44.175.130]:52744 "EHLO bedivere.hansenpartnership.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229655AbhGXR2c (ORCPT ); Sat, 24 Jul 2021 13:28:32 -0400 Received: from localhost (localhost [127.0.0.1]) by bedivere.hansenpartnership.com (Postfix) with ESMTP id 182A21280193; Sat, 24 Jul 2021 11:09:04 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=hansenpartnership.com; s=20151216; t=1627150144; bh=OBdIbbICnlhWCgpUXqhBHIcAkWO2KhMxkOjYPmxy+rk=; h=Message-ID:Subject:From:To:Date:In-Reply-To:References:From; b=gcFzw40+mFqkGB0zVGYDDIcydpsBgO0E3sNonwKK7u/oLqfO4PUUERLX3/snLZRfC bf12atERrZw+QVmbt1qyzee4CXDJjDfr6HRI2l2dt1orUKzbF4dbwPWIlVP8QThiC+ 6Lr6Rnuel7fjYRMJF2S7+/zTFE7wNzXZ1SXUZzxE= Received: from bedivere.hansenpartnership.com ([127.0.0.1]) by localhost (bedivere.hansenpartnership.com [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id lxd24d0VwAYk; Sat, 24 Jul 2021 11:09:04 -0700 (PDT) Received: from jarvis.int.hansenpartnership.com (unknown [IPv6:2601:600:8280:66d1::527]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by bedivere.hansenpartnership.com (Postfix) with ESMTPSA id 761EC12800A0; Sat, 24 Jul 2021 11:09:03 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=hansenpartnership.com; s=20151216; t=1627150143; bh=OBdIbbICnlhWCgpUXqhBHIcAkWO2KhMxkOjYPmxy+rk=; h=Message-ID:Subject:From:To:Date:In-Reply-To:References:From; b=ptJWvvM7GD/9XKXB8DiWs9YTDWM/KfwqNNXZECbrVE7knJVp39uLW4ZXTii3+UJFj fgibyWkQGzmxVQHYKmIP/KUmRzICDL7hz7v4AaYmmx+GomDg84HgijyWKk/tSUB2f7 gmb8GXwr+qmtFhkOAp9JPshrsvV1IR3cuJGJV02M= Message-ID: <1e48f7edcb6d9a67e8b78823660939007e14bae1.camel@HansenPartnership.com> Subject: Re: Folios give an 80% performance win From: James Bottomley To: Matthew Wilcox , linux-kernel@vger.kernel.org Cc: linux-mm@kvack.org, linux-fsdevel@vger.kernel.org, Linus Torvalds , Andrew Morton , "Darrick J. Wong" , Christoph Hellwig , Andres Freund , Michael Larabel Date: Sat, 24 Jul 2021 11:09:02 -0700 In-Reply-To: References: <20210715033704.692967-1-willy@infradead.org> Content-Type: text/plain; charset="UTF-8" User-Agent: Evolution 3.34.4 MIME-Version: 1.0 Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Sat, 2021-07-24 at 18:27 +0100, Matthew Wilcox wrote: > What blows me away is the 80% performance improvement for PostgreSQL. > I know they use the page cache extensively, so it's plausibly real. > I'm a bit surprised that it has such good locality, and the size of > the win far exceeds my expectations. We should probably dive into it > and figure out exactly what's going on. Since none of the other tested databases showed more than a 3% improvement, this looks like an anomalous result specific to something in postgres ... although the next biggest db: mariadb wasn't part of the tests so I'm not sure that's definitive. Perhaps the next step should be to test mariadb? Since they're fairly similar in domain (both full SQL) if mariadb shows this type of improvement, you can safely assume it's something in the way SQL databases handle paging and if it doesn't, it's likely fixing a postgres inefficiency. James