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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id C7D9EC433FE for ; Sat, 9 Apr 2022 11:43:57 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S240148AbiDILqC (ORCPT ); Sat, 9 Apr 2022 07:46:02 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:37386 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S238441AbiDILqB (ORCPT ); Sat, 9 Apr 2022 07:46:01 -0400 Received: from wp530.webpack.hosteurope.de (wp530.webpack.hosteurope.de [IPv6:2a01:488:42:1000:50ed:8234::]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 1EC1E635C; Sat, 9 Apr 2022 04:43:54 -0700 (PDT) Received: from ip4d144895.dynamic.kabel-deutschland.de ([77.20.72.149] helo=[192.168.66.200]); authenticated by wp530.webpack.hosteurope.de running ExIM with esmtpsa (TLS1.3:ECDHE_RSA_AES_128_GCM_SHA256:128) id 1nd9VP-0001NN-1u; Sat, 09 Apr 2022 13:43:51 +0200 Message-ID: <8665439b-e82e-65b8-ddb6-da6a41d6f6da@leemhuis.info> Date: Sat, 9 Apr 2022 13:43:49 +0200 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:91.0) Gecko/20100101 Thunderbird/91.7.0 Subject: Re: [PATCH bpf 0/2] vmalloc: bpf: introduce VM_ALLOW_HUGE_VMAP Content-Language: en-US To: Song Liu , bpf@vger.kernel.org, netdev@vger.kernel.org, linux-mm@kvack.org Cc: ast@kernel.org, daniel@iogearbox.net, andrii@kernel.org, kernel-team@fb.com, akpm@linux-foundation.org, rick.p.edgecombe@intel.com, hch@infradead.org, imbrenda@linux.ibm.com References: <20220408223443.3303509-1-song@kernel.org> From: Thorsten Leemhuis In-Reply-To: <20220408223443.3303509-1-song@kernel.org> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit X-bounce-key: webpack.hosteurope.de;regressions@leemhuis.info;1649504634;d031920e; X-HE-SMSGID: 1nd9VP-0001NN-1u Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org Hi, this is your Linux kernel regression tracker. On 09.04.22 00:34, Song Liu wrote: > Enabling HAVE_ARCH_HUGE_VMALLOC on x86_64 and use it for bpf_prog_pack has > caused some issues [1], as many users of vmalloc are not yet ready to > handle huge pages. To enable a more smooth transition to use huge page > backed vmalloc memory, this set replaces VM_NO_HUGE_VMAP flag with an new > opt-in flag, VM_ALLOW_HUGE_VMAP. More discussions about this topic can be > found at [2]. > > Patch 1 removes VM_NO_HUGE_VMAP and adds VM_ALLOW_HUGE_VMAP. > Patch 2 uses VM_ALLOW_HUGE_VMAP in bpf_prog_pack. > > [1] https://lore.kernel.org/lkml/20220204185742.271030-1-song@kernel.org/ > [2] https://lore.kernel.org/linux-mm/20220330225642.1163897-1-song@kernel.org/ These patches apparently fix a regression (one that's mentioned in your [2]) that I tracked. Hence in the next iteration of your patches could you please instead add a 'Link:' tag pointing to the report for anyone wanting to look into the backstory in the future, as explained in 'Documentation/process/submitting-patches.rst' and 'Documentation/process/5.Posting.rst'? E.g. like this: "Link: https://lore.kernel.org/netdev/14444103-d51b-0fb3-ee63-c3f182f0b546@molgen.mpg.de/" Not totally sure, but I guess it needs a Fixes tag as well specifying the change that cause this regression (that's "fac54e2bfb5b"). The documents mentioned above explain this, too. A "Reported-by" might be appropriate as well. In anyone wonders why I care: there are internal and publicly used tools and scripts out there that reply on proper "Link" tags. I don't known how many, but there is at least one public tool I'm running that cares: regzbot, my regression tracking bot, which I use to track Linux kernel regressions and generate the regression reports sent to Linus. Proper "Link:" tags allow the bot to automatically connect regression reports with fixes being posted or applied to resolve the particular regression -- which makes regression tracking a whole lot easier and feasible for the Linux kernel. That's why it's a great help for me if people set proper "Link" tags. While at it, let me tell regzbot about this thread: #regzbot ^backmonitor: https://lore.kernel.org/netdev/14444103-d51b-0fb3-ee63-c3f182f0b546@molgen.mpg.de/ Ciao, Thorsten (wearing his 'the Linux kernel's regression tracker' hat) P.S.: As the Linux kernel's regression tracker I'm getting a lot of reports on my table. I can only look briefly into most of them and lack knowledge about most of the areas they concern. I thus unfortunately will sometimes get things wrong or miss something important. I hope that's not the case here; if you think it is, don't hesitate to tell me in a public reply, it's in everyone's interest to set the public record straight.