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=-5.6 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE, SPF_PASS,USER_AGENT_SANE_1 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 1048BC433E0 for ; Wed, 17 Jun 2020 23:46:12 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id E3C2D21548 for ; Wed, 17 Jun 2020 23:46:11 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1592437571; bh=M7bG+rSHSEDHF2Qry9Zk4SV+gGKCbl4sGRVOdFojW+4=; h=Date:From:To:Cc:Subject:Reply-To:References:In-Reply-To:List-ID: From; b=r6N4WxiVGl6v3LXw6VrMdvIQHmTxcCCUhxjHOnT/WdAi/wB/EGeR1OqkJ7AWhWidB NR9l4pwR2DYPNOi8KtyiLju2d6dNMEMR4dZ/IZmk8kqKzUi++Zxwz6udPd2uHHe/l5 c2SDFcAL2NzYdglWDjBnW0ZdM9LTbIIECBEvtz4s= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726909AbgFQXqK (ORCPT ); Wed, 17 Jun 2020 19:46:10 -0400 Received: from mail.kernel.org ([198.145.29.99]:46262 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726815AbgFQXqK (ORCPT ); Wed, 17 Jun 2020 19:46:10 -0400 Received: from paulmck-ThinkPad-P72.home (50-39-105-78.bvtn.or.frontiernet.net [50.39.105.78]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 83F23207E8; Wed, 17 Jun 2020 23:46:09 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1592437569; bh=M7bG+rSHSEDHF2Qry9Zk4SV+gGKCbl4sGRVOdFojW+4=; h=Date:From:To:Cc:Subject:Reply-To:References:In-Reply-To:From; b=HUfgpYwyNBOTeYNYb/UuaWuV4M7LYIjs+fIVd5OF+TCaLqEQK6a+xaIbb50JIhdB0 4X7NuWBSpb4wZVP5UmBhN27cOT0A7G0HYtfTZVvGhv+4D/SC7XlLxcI+022GMzRi0c mesUzHw/QEVJ9z3YjRh+D1v2du+ew+W9r2Xz6iWY= Received: by paulmck-ThinkPad-P72.home (Postfix, from userid 1000) id 6B8B03523551; Wed, 17 Jun 2020 16:46:09 -0700 (PDT) Date: Wed, 17 Jun 2020 16:46:09 -0700 From: "Paul E. McKenney" To: "Uladzislau Rezki (Sony)" Cc: LKML , linux-mm@kvack.org, Andrew Morton , "Theodore Y . Ts'o" , Matthew Wilcox , Joel Fernandes , RCU , Oleksiy Avramchenko Subject: Re: [PATCH v2 09/16] rcu/tree: Maintain separate array for vmalloc ptrs Message-ID: <20200617234609.GA10087@paulmck-ThinkPad-P72> Reply-To: paulmck@kernel.org References: <20200525214800.93072-1-urezki@gmail.com> <20200525214800.93072-10-urezki@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20200525214800.93072-10-urezki@gmail.com> User-Agent: Mutt/1.9.4 (2018-02-28) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, May 25, 2020 at 11:47:53PM +0200, Uladzislau Rezki (Sony) wrote: > To do so, we use an array of kvfree_rcu_bulk_data structures. > It consists of two elements: > - index number 0 corresponds to slab pointers. > - index number 1 corresponds to vmalloc pointers. > > Keeping vmalloc pointers separated from slab pointers makes > it possible to invoke the right freeing API for the right > kind of pointer. > > It also prepares us for future headless support for vmalloc > and SLAB objects. Such objects cannot be queued on a linked > list and are instead directly into an array. > > Signed-off-by: Uladzislau Rezki (Sony) > Signed-off-by: Joel Fernandes (Google) > Reviewed-by: Joel Fernandes (Google) > Co-developed-by: Joel Fernandes (Google) > --- [ . . . ] > + // Handle two first channels. > + for (i = 0; i < FREE_N_CHANNELS; i++) { > + for (; bkvhead[i]; bkvhead[i] = bnext) { > + bnext = bkvhead[i]->next; > + debug_rcu_bhead_unqueue(bkvhead[i]); > + > + rcu_lock_acquire(&rcu_callback_map); > + if (i == 0) { // kmalloc() / kfree(). > + trace_rcu_invoke_kfree_bulk_callback( > + rcu_state.name, bkvhead[i]->nr_records, > + bkvhead[i]->records); > + > + kfree_bulk(bkvhead[i]->nr_records, > + bkvhead[i]->records); > + } else { // vmalloc() / vfree(). > + for (j = 0; j < bkvhead[i]->nr_records; j++) { > + trace_rcu_invoke_kfree_callback( > + rcu_state.name, > + bkvhead[i]->records[j], 0); > + > + vfree(bkvhead[i]->records[j]); > + } > + } > + rcu_lock_release(&rcu_callback_map); Not an emergency, but did you look into replacing this "if" statement with an array of pointers to functions implementing the legs of the "if" statement? If nothing else, this would greatly reduced indentation. I am taking this as is, but if you have not already done so, could you please look into this for a follow-up patch? Thanx, Paul