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=-5.1 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE, SPF_PASS,USER_AGENT_SANE_1 autolearn=ham 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 01041C432C0 for ; Sun, 24 Nov 2019 01:20:07 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id C0CE120679 for ; Sun, 24 Nov 2019 01:20:06 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="IrEhRwuB" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726752AbfKXBUF (ORCPT ); Sat, 23 Nov 2019 20:20:05 -0500 Received: from mail-io1-f66.google.com ([209.85.166.66]:40623 "EHLO mail-io1-f66.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726676AbfKXBUF (ORCPT ); Sat, 23 Nov 2019 20:20:05 -0500 Received: by mail-io1-f66.google.com with SMTP id b26so10338870ion.7 for ; Sat, 23 Nov 2019 17:20:05 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=subject:from:to:cc:references:message-id:date:user-agent :mime-version:in-reply-to:content-language:content-transfer-encoding; bh=IcN7qN/axiT/anQqvUgOgObBoJ7jeG1dmpaltuOnysE=; b=IrEhRwuBNYpjmtDK0lprN6TSaevfI0yd5Uqy5xCVgZsSXhSFvKGLvufHTfkE+HQpUU LE01IYoO8/Zatpzb+T2kZo+uMISMCymCHIumy8DjSvv7sD+Al6YifbLMp+/IMmanHA8F WqfEu/kZ0Eqhnk65wH50hjU4IRZRpNn0gsVOEb2IGUaBXWW+fWzKHiiI8WkIQjrZZ7jH oKDupDTkDG2RepohJYgrDeHPQ5CA+TELaqf/FSFnYASgqvSO5gHxzWn2SymQD7wML7rO aduU8VJ2PGunwgdQuFy01fdcQ/3t7bapOLdSo+ALLqEFnCK5wPJtRQxLCmGBmMa+tC4A kKww== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:subject:from:to:cc:references:message-id:date :user-agent:mime-version:in-reply-to:content-language :content-transfer-encoding; bh=IcN7qN/axiT/anQqvUgOgObBoJ7jeG1dmpaltuOnysE=; b=JpoOcvkMtbFv0ULuJuBa1frcgde/opAckWoHhb4RlAJGP+Jz2RplMLEZMba1XyIlE+ i4MN4ryYgIi3cENn+pz1s0cU1JarQfEzlQvK97/x5e08yV2+W2OYnvAfuuiAEs0n0uYD NnSz3lQK8cTFBIX9LlqXmwG5dvWGlFpbveTMByfytbwqSGP25U9CtmCZ0j4aDql1rFIj eDBYu2uB/q3exJOSXQaIPVWOhNMxznP9fYnQerQjQZljV7MajNQOLM2OgQ1RLMylTFEN nviLSKQgajzybeRf63F/c3t7jmGK26f0HAQMpK9+4j9AQez7Ll1MD48J7izNKop+2ZUy LYng== X-Gm-Message-State: APjAAAXyHcuA3g/nfvyb2d8SvjW3oL2PIuV7RcQWfaeq9c0TGQD13w22 SbQTib16wvNm63aM+cbg67A= X-Google-Smtp-Source: APXvYqzptq12AFk58e5pes1fbOwD6X1J/1Y9lOTKoVx5uI2Ev1BQoaAaVz8zBXvx9gwpzLikstaTQQ== X-Received: by 2002:a6b:cf0f:: with SMTP id o15mr4152558ioa.229.1574558404640; Sat, 23 Nov 2019 17:20:04 -0800 (PST) Received: from dahern-DO-MB.local ([2601:282:800:fd80:c435:ff27:4396:2f9f]) by smtp.googlemail.com with ESMTPSA id w2sm774131ilg.51.2019.11.23.17.20.03 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Sat, 23 Nov 2019 17:20:03 -0800 (PST) Subject: Re: [PATCH V2 net-next 1/6] netlink: Convert extack msg to a formattable buffer From: David Ahern To: Jakub Kicinski , Saeed Mahameed Cc: "David S. Miller" , "netdev@vger.kernel.org" , Jiri Pirko , Johannes Berg References: <20191122224126.24847-1-saeedm@mellanox.com> <20191122224126.24847-2-saeedm@mellanox.com> <20191123165655.5a9b8877@cakuba.netronome.com> Message-ID: <9d46e1e4-aa34-01a0-b0ad-712bbb372746@gmail.com> Date: Sat, 23 Nov 2019 18:20:02 -0700 User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.14; rv:68.0) Gecko/20100101 Thunderbird/68.2.2 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org On 11/23/19 6:10 PM, David Ahern wrote: > On 11/23/19 5:56 PM, Jakub Kicinski wrote: >>> diff --git a/include/linux/netlink.h b/include/linux/netlink.h >>> index 205fa7b1f07a..de9004da0288 100644 >>> --- a/include/linux/netlink.h >>> +++ b/include/linux/netlink.h >>> @@ -62,6 +62,7 @@ netlink_kernel_create(struct net *net, int unit, struct netlink_kernel_cfg *cfg) >>> >>> /* this can be increased when necessary - don't expose to userland */ >>> #define NETLINK_MAX_COOKIE_LEN 20 >>> +#define NL_EXTACK_MAX_MSG_SZ 128 > > This makes extack use a lot of stack. There are a number of places that > are already emitting warnings about high stack usage. > It also adds unnecessary overhead since initialization 0's out the entire buffer (most sites declare with {}; a few use memset).