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=-2.6 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE, SPF_PASS,URIBL_BLOCKED,USER_AGENT_SANE_1 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 DBADBC06513 for ; Tue, 2 Jul 2019 18:58:48 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id BC46E21850 for ; Tue, 2 Jul 2019 18:58:48 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=linaro.org header.i=@linaro.org header.b="RxycRGr5" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726861AbfGBS6q (ORCPT ); Tue, 2 Jul 2019 14:58:46 -0400 Received: from mail-lj1-f196.google.com ([209.85.208.196]:40704 "EHLO mail-lj1-f196.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726329AbfGBS6q (ORCPT ); Tue, 2 Jul 2019 14:58:46 -0400 Received: by mail-lj1-f196.google.com with SMTP id a21so18032393ljh.7 for ; Tue, 02 Jul 2019 11:58:44 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linaro.org; s=google; h=date:from:to:cc:subject:message-id:mail-followup-to:references :mime-version:content-disposition:in-reply-to:user-agent; bh=HJRRZ7xwVWKgrrchV3QbMX/wgWRGVLbHC2E+m6l+0/o=; b=RxycRGr5u5OwWuZ2gNevQdwgxs7WNYCcmy6MN0Xz79Q2tNLNs9oq+9T+GtYIaKou4x ApR0Uy9q0zxgvGzaYSBJKVvkIoXFr2fitP7amOqfsC1+gzDKM5svTDQXAnLJRSi6kRsI lK/ehsnPvFZW9qpq7sF5A7L+b0lAYwspjsHRHpiLcqhVBTr7D63JpIV+329tMpzh8b8p TxWQUv26+Xm5H7imex4kC2lwaVpHvj+tPooHa7MKHwF4ZTeQt1PL7nBQF8/WZ2STEOsc kjDlnPXKKR6HCmEvt2fYSEmuRWh39ix8wP0ttAcjK6Dw6L0e5zkxQOh8ocywsKapU8H5 +/Wg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:from:to:cc:subject:message-id :mail-followup-to:references:mime-version:content-disposition :in-reply-to:user-agent; bh=HJRRZ7xwVWKgrrchV3QbMX/wgWRGVLbHC2E+m6l+0/o=; b=jGrS2uoiv8FHu5KPu0fH5NPffK49aVUiujAyzl0EKac/yWgh9VcfbVNk5iLLqOlFvP GooFvhny78g4H5H56Z0b+K67pQR1qpZT5PsUURTtvv9EB9g2XhkVMcPznJmuhIZ1DHHD L3EqggvHtsu9iWG9g/On0MpjCaqTfGiUozji+0Yl8HlPo6b9UPGsYQv5IFWZ1fcOiQgb gbBGKHjtRMeWBElgvMVKIIbgSkT8Ul8fr08vyOMzZUg0sT3BnZVxk8ttQTwxmeiAHmEI gSWKvNEmGMNJFtGb8dPe5ZWrewh/YGbbEJEamycQQA4/C6cmYgKc/7vLsQCP25xG4eu2 FMUw== X-Gm-Message-State: APjAAAV2oPQtEGLjak5CNNlFZ1u9PZEJ3lkI1vbVBH4hjkb9PXZd/5+C ZeLzLM32OFmj/WwCVGsrtxQP4g== X-Google-Smtp-Source: APXvYqwOnRz12ZXWfwVkH3WodU4LhkeAYjXfGRaMtJWg1mdkdc5MbazZkwv/mQfmjb288oDC/euaTw== X-Received: by 2002:a2e:730d:: with SMTP id o13mr517630ljc.81.1562093923391; Tue, 02 Jul 2019 11:58:43 -0700 (PDT) Received: from khorivan (59-201-94-178.pool.ukrtel.net. [178.94.201.59]) by smtp.gmail.com with ESMTPSA id o8sm842315ljh.100.2019.07.02.11.58.42 (version=TLS1_2 cipher=ECDHE-RSA-CHACHA20-POLY1305 bits=256/256); Tue, 02 Jul 2019 11:58:42 -0700 (PDT) Date: Tue, 2 Jul 2019 21:58:40 +0300 From: Ivan Khoronzhuk To: Jesper Dangaard Brouer Cc: netdev@vger.kernel.org, Ilias Apalodimas , grygorii.strashko@ti.com, jakub.kicinski@netronome.com, daniel@iogearbox.net, john.fastabend@gmail.com, ast@kernel.org, linux-kernel@vger.kernel.org, linux-omap@vger.kernel.org Subject: Re: [PATCH] net: core: page_pool: add user refcnt and reintroduce page_pool_destroy Message-ID: <20190702185839.GH4510@khorivan> Mail-Followup-To: Jesper Dangaard Brouer , netdev@vger.kernel.org, Ilias Apalodimas , grygorii.strashko@ti.com, jakub.kicinski@netronome.com, daniel@iogearbox.net, john.fastabend@gmail.com, ast@kernel.org, linux-kernel@vger.kernel.org, linux-omap@vger.kernel.org References: <20190702153902.0e42b0b2@carbon> <156207778364.29180.5111562317930943530.stgit@firesoul> <20190702144426.GD4510@khorivan> <20190702165230.6caa36e3@carbon> <20190702145612.GF4510@khorivan> <20190702171029.76c60538@carbon> <20190702152112.GG4510@khorivan> <20190702202907.15fb30ce@carbon> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii; format=flowed Content-Disposition: inline In-Reply-To: <20190702202907.15fb30ce@carbon> User-Agent: Mutt/1.9.4 (2018-02-28) Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org On Tue, Jul 02, 2019 at 08:29:07PM +0200, Jesper Dangaard Brouer wrote: >On Tue, 2 Jul 2019 18:21:13 +0300 >Ivan Khoronzhuk wrote: > >> On Tue, Jul 02, 2019 at 05:10:29PM +0200, Jesper Dangaard Brouer wrote: >> >On Tue, 2 Jul 2019 17:56:13 +0300 >> >Ivan Khoronzhuk wrote: >> > >> >> On Tue, Jul 02, 2019 at 04:52:30PM +0200, Jesper Dangaard Brouer wrote: >> >> >On Tue, 2 Jul 2019 17:44:27 +0300 >> >> >Ivan Khoronzhuk wrote: >> >> > >> >> >> On Tue, Jul 02, 2019 at 04:31:39PM +0200, Jesper Dangaard Brouer wrote: >> >> >> >From: Ivan Khoronzhuk >> >> >> > >> >> >> >Jesper recently removed page_pool_destroy() (from driver invocation) and >> >> >> >moved shutdown and free of page_pool into xdp_rxq_info_unreg(), in-order to >> >> >> >handle in-flight packets/pages. This created an asymmetry in drivers >> >> >> >create/destroy pairs. >> >> >> > >> >> >> >This patch add page_pool user refcnt and reintroduce page_pool_destroy. >> >> >> >This serves two purposes, (1) simplify drivers error handling as driver now >> >> >> >drivers always calls page_pool_destroy() and don't need to track if >> >> >> >xdp_rxq_info_reg_mem_model() was unsuccessful. (2) allow special cases >> >> >> >where a single RX-queue (with a single page_pool) provides packets for two >> >> >> >net_device'es, and thus needs to register the same page_pool twice with two >> >> >> >xdp_rxq_info structures. >> >> >> >> >> >> As I tend to use xdp level patch there is no more reason to mention (2) case >> >> >> here. XDP patch serves it better and can prevent not only obj deletion but also >> >> >> pool flush, so, this one patch I could better leave only for (1) case. >> >> > >> >> >I don't understand what you are saying. >> >> > >> >> >Do you approve this patch, or do you reject this patch? >> >> > >> >> It's not reject, it's proposition to use both, XDP and page pool patches, >> >> each having its goal. >> > >> >Just to be clear, if you want this patch to get accepted you have to >> >reply with your Signed-off-by (as I wrote). >> > >> >Maybe we should discuss it in another thread, about why you want two >> >solutions to the same problem. >> >> If it solves same problem I propose to reject this one and use this: >> https://lkml.org/lkml/2019/7/2/651 > >No, I propose using this one, and rejecting the other one. There is at least several arguments against this one (related (2) purpose) It allows: - avoid changes to page_pool/mlx5/netsec - save not only allocator obj but allocator "page/buffer flush" - buffer flush can be present not only in page_pool but for other allocators that can behave differently and not so simple solution. - to not limit cpsw/(potentially others) to use "page_pool" allocator only .... This patch better leave also, as it simplifies error path for page_pool and have more error prone usage comparing with existent one. Please, don't limit cpsw and potentially other drivers to use only page_pool it can be zca or etc... I don't won't to modify each allocator. I propose to add both as by fact they solve different problems with common solution. -- Regards, Ivan Khoronzhuk