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=-7.5 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,NICE_REPLY_A,SPF_HELO_NONE,SPF_PASS,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 B498AC48BCF for ; Wed, 9 Jun 2021 11:19:35 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id A123E6139A for ; Wed, 9 Jun 2021 11:19:35 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S238871AbhFILV2 (ORCPT ); Wed, 9 Jun 2021 07:21:28 -0400 Received: from us-smtp-delivery-124.mimecast.com ([216.205.24.124]:41630 "EHLO us-smtp-delivery-124.mimecast.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S238815AbhFILV0 (ORCPT ); Wed, 9 Jun 2021 07:21:26 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1623237572; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=HXqVwTnASpC+nIzC1ZP9Vkwf/4P5Ctyk3R0WhAf1tMM=; b=NQXcl1rs9zgP5a3IY+S/jiBkWk5hmI0VsaWcJRqkG4vp//lH+mKwq0GwRrWhH8ktQ1grZx UwCqCWFR9BK5x76F+7i4y93x1HGHkFY3uSv222UuV/XQSskOJs9wpTJqiVemUxWlVd31ZO PNGGzuNHy4YhiVid708/7wcCiDkTSD0= Received: from mail-wr1-f72.google.com (mail-wr1-f72.google.com [209.85.221.72]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-517-6V9Xgfd6NWGZzNZhnSiq-Q-1; Wed, 09 Jun 2021 07:19:31 -0400 X-MC-Unique: 6V9Xgfd6NWGZzNZhnSiq-Q-1 Received: by mail-wr1-f72.google.com with SMTP id e11-20020a056000178bb0290119c11bd29eso5769344wrg.2 for ; Wed, 09 Jun 2021 04:19:30 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:subject:to:references:from:organization :message-id:date:user-agent:mime-version:in-reply-to :content-language:content-transfer-encoding; bh=HXqVwTnASpC+nIzC1ZP9Vkwf/4P5Ctyk3R0WhAf1tMM=; b=K4+i9lAaYvzkujj9TO43vvTrhX11jGMhz/v7eW1moEZuSo46TfNLl1+09pcO+m5Vmt 6k0ZmtbqY2frr44JFlkLPgQMG69KPqeDNaFL1OY022YYPMFAW8L/0cWhi/tCP/HwRsqw ENdLX6M2RNEYB/12TcS0oviYQo3ViWs+Q1M+CN32F1bVYxstI3JZn9X8oH1K3UQ7/twN eW1iIOfaH3GCwrhym1dnKja/4USM2eDl+697TuuQGP6NrdYLcHIddeQkGODeB0wf0tkM hv6lK5/YR7L5nOHnm7JXgF//bos4Jt3H0PYQYKBdM77qoO2GQ5NHnGvAkXtFiNDQipF6 FppQ== X-Gm-Message-State: AOAM532rvpPC3bqq35fCoVDgfW9QXNbHv94twtV9uQtMs2f50LJO/il3 1fVM0GZ10IPFLKaPaPhK1j9xiG/QSwMEHVkbwUYyOL/KkrpRgG6k/eFTURGw6tK58BLOTH5kGH9 nYo8MA9rsZ2f/T15SUbpsZg6L X-Received: by 2002:a7b:c4d0:: with SMTP id g16mr9269543wmk.147.1623237570011; Wed, 09 Jun 2021 04:19:30 -0700 (PDT) X-Google-Smtp-Source: ABdhPJxxkQ4yaJtDvcqAOFQCE+NtOTgjEw4SoDiwEa4p8GZrxX++FSnSA2ZvZ0jnJ+v5Fcx7Ma1E2A== X-Received: by 2002:a7b:c4d0:: with SMTP id g16mr9269528wmk.147.1623237569795; Wed, 09 Jun 2021 04:19:29 -0700 (PDT) Received: from [192.168.3.132] (p5b0c611d.dip0.t-ipconnect.de. [91.12.97.29]) by smtp.gmail.com with ESMTPSA id h6sm14828393wrt.20.2021.06.09.04.19.29 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Wed, 09 Jun 2021 04:19:29 -0700 (PDT) Subject: Re: how to return a chunk of kernel .data to free mem ? To: jim.cromie@gmail.com, LKML , Linux Memory Management List , Jason Baron References: From: David Hildenbrand Organization: Red Hat Message-ID: <196e42a7-d50f-48e0-b4bd-e7f3701bfc6d@redhat.com> Date: Wed, 9 Jun 2021 13:19:29 +0200 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:78.0) Gecko/20100101 Thunderbird/78.10.1 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 05.06.21 16:50, jim.cromie@gmail.com wrote: > I have convinced DYNAMIC_DEBUG code to not need > about 15% of its __dyndbg section, about 30kb on my test kernel. > > This memory is not kmalloc'd, so krealloc wont work. > (I tried anyway, on a loaded module, it panicd) > > Is there a way to return a chunk of init .data memory to general use ? > > heres the patchset; > https://lore.kernel.org/lkml/20210529200029.205306-1-jim.cromie@gmail.com/ > Hm, you could try free_reserved_page(). But obviously, only full pages can be handed to the buddy. -- Thanks, David / dhildenb