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 D799DC433EF for ; Tue, 21 Sep 2021 09:04:36 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id AE9F760EE4 for ; Tue, 21 Sep 2021 09:04:36 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231224AbhIUJGD (ORCPT ); Tue, 21 Sep 2021 05:06:03 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:46586 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229533AbhIUJGD (ORCPT ); Tue, 21 Sep 2021 05:06:03 -0400 Received: from casper.infradead.org (casper.infradead.org [IPv6:2001:8b0:10b:1236::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 6D4BDC061574 for ; Tue, 21 Sep 2021 02:04:35 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=casper.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; bh=jJDzcwRgsAVQLKWMuLUxhQ9IiQg5NJdlg47IJLyeYvI=; b=EV7XfRHbjwXQqGUjCe9SVjDpj2 XXxNUuoAbVqKvfHsPms3fvPmRzvp7mb/nuzrJkA8l1JvBYgfxmmYd4n70MKhw6rOd5mMVPLpsbWCq zTzTAyJsQ7IeatffGs01bpwHz9o5o8bVZz1gVvbAUR+/ntk5sehdVgn83eQa9BZHSlGD06nbOiRX1 8N5zi68qsZdd/EubzaXFEJHu7eJW2dW0hXXG9mK8N5jnCVd2QfJ5glMiuyN7E6O4bd8rqYbvktaEY OYLGjgvo4tlo/dHHyJ+XE5PqCZRtUVKpDcS5m2Lx8yMZ2g0l7oGApOCOtPCPZTPQ4oGZlBF34yuM7 zZB1Pw8g==; Received: from hch by casper.infradead.org with local (Exim 4.94.2 #2 (Red Hat Linux)) id 1mSbgr-003epn-J6; Tue, 21 Sep 2021 09:03:57 +0000 Date: Tue, 21 Sep 2021 10:03:49 +0100 From: Christoph Hellwig To: Dave Chinner Cc: "Darrick J. Wong" , chandan.babu@oracle.com, chandanrlinux@gmail.com, linux-xfs@vger.kernel.org Subject: Re: [PATCH 11/14] xfs: dynamically allocate cursors based on maxlevels Message-ID: References: <163192854958.416199.3396890438240296942.stgit@magnolia> <163192861018.416199.11733078081556457241.stgit@magnolia> <20210920230635.GM1756565@dread.disaster.area> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20210920230635.GM1756565@dread.disaster.area> X-SRS-Rewrite: SMTP reverse-path rewritten from by casper.infradead.org. See http://www.infradead.org/rpr.html Precedence: bulk List-ID: X-Mailing-List: linux-xfs@vger.kernel.org On Tue, Sep 21, 2021 at 09:06:35AM +1000, Dave Chinner wrote: > On Fri, Sep 17, 2021 at 06:30:10PM -0700, Darrick J. Wong wrote: > > From: Darrick J. Wong > > > > Replace the statically-sized btree cursor zone with dynamically sized > > allocations so that we can reduce the memory overhead for per-AG bt > > cursors while handling very tall btrees for rt metadata. > > Hmmmmm. We do a *lot* of btree cursor allocation and freeing under > load. Keeping that in a single slab rather than using heap memory is > a good idea for stuff like this for many reasons... Or rather a few slabs for the different kind of cursors. But otherwise agreed.