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=-8.6 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,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 91452C433E0 for ; Sat, 27 Jun 2020 04:55:21 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 6E42720E65 for ; Sat, 27 Jun 2020 04:55:21 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="gsThSYYl" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726385AbgF0EzU (ORCPT ); Sat, 27 Jun 2020 00:55:20 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:35358 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725904AbgF0EzR (ORCPT ); Sat, 27 Jun 2020 00:55:17 -0400 Received: from mail-pj1-x1043.google.com (mail-pj1-x1043.google.com [IPv6:2607:f8b0:4864:20::1043]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 40B18C03E979 for ; Fri, 26 Jun 2020 21:55:17 -0700 (PDT) Received: by mail-pj1-x1043.google.com with SMTP id f6so1769552pjq.5 for ; Fri, 26 Jun 2020 21:55:17 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=date:from:to:cc:subject:message-id:mime-version:content-disposition :user-agent; bh=+gA6TTWkMdHm5W4oJu5q0X2lUIi1w6v+kFfwKgYQFdw=; b=gsThSYYldvqlflGoCnyy6zhApgX1N1u4QndX5Ni5Ms9mflGFUYO7UxSjcngrtpUogE J0AOVFtzY1BYqTfXflC1HZBj2Gins8ECuvRTjVm3TcTy0KiiJnSliEF6E5bPN/WxTFTO icLy4DOWwVq8Dz6CJCYJum7AbZUs25BigtbQKmwIm+F7lEhWl3liPLkv4pR1w8mmlBQ8 NcPiRSr3Wot1j4JQ2BWXYRLtEurhVrSz6w5SYxdnS0EHf7lW7gSqCI0aLGlgT8TfFbcz GBMm44neagmza+5UMkSC+kE0szE5T6SZsV8f82olXxckz04SFelkGHnkDT3790KSlk14 J+rw== 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:mime-version :content-disposition:user-agent; bh=+gA6TTWkMdHm5W4oJu5q0X2lUIi1w6v+kFfwKgYQFdw=; b=TVhhjqS2KVcMxNTWPvIVNGXWeSd/FlVp1Pc4Y1FB8wCOgmnTvZFiddi7rrkiveEKnp +sGx2pt8b28S1pnxk8G26fZWJsASTqDIHnnfYx/C+Lw/Q/ewwfwnxPm1KsrtQsEEdtDi MTHNWvy70VzWRjkn25krmuZBa5cHSdl+7DeQtkM1wCQn4i8z7cBkpegGE6KNlJ+zIudp T0plvqz/1+7IegLZ3rcbHdRHb5qx1JGO18MTHdJhPhDXMaO73hO0MJZaujuVh97Ojofx wSlZWhRrGpg5lCjJuhoixGYenjaA7i8FpCh8ebEP87dXHxfMhtXFaRWSggPRO3XxIegr jTGg== X-Gm-Message-State: AOAM532g1wO9gAZ8yUzZrlSYD5lwMKbotjMZ2hnUPCwr3mWmdpIsLxcw H5GWXjDd4smt2EJ2WELDieI= X-Google-Smtp-Source: ABdhPJx3mWKJGR86Eb7qOI9bQqp5l2FYg+gm5648darG2hlNHr2XfBF/bQlTYhbohm1zrtiHXTBoXA== X-Received: by 2002:a17:902:9a89:: with SMTP id w9mr5518433plp.30.1593233716796; Fri, 26 Jun 2020 21:55:16 -0700 (PDT) Received: from localhost ([144.34.187.180]) by smtp.gmail.com with ESMTPSA id u8sm26859976pfh.215.2020.06.26.21.55.14 (version=TLS1_2 cipher=ECDHE-ECDSA-CHACHA20-POLY1305 bits=256/256); Fri, 26 Jun 2020 21:55:16 -0700 (PDT) Date: Sat, 27 Jun 2020 04:55:07 +0000 From: Long Li To: cl@linux.com, penberg@kernel.org, rientjes@google.com, iamjoonsoo.kim@lge.com, akpm@linux-foundation.org Cc: linux-mm@kvack.org, linux-kernel@vger.kernel.org Subject: [PATCH v1] mm:free unused pages in kmalloc_order Message-ID: <20200627045507.GA57675@lilong> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline 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 Environment using the slub allocator, 1G memory in my ARM32. kmalloc(1024, GFP_HIGHUSER) can allocate memory normally, kmalloc(64*1024, GFP_HIGHUSER) will cause a memory leak, because alloc_pages returns highmem physical pages, but it cannot be directly converted into a virtual address and return NULL, the pages has not been released. Usually driver developers will not use the GFP_HIGHUSER flag to allocate memory in kmalloc, but I think this memory leak is not perfect, it is best to be fixed. This is the first time I have posted a patch, there may be something wrong. Signed-off-by: Long Li --- mm/slab_common.c | 8 ++++++-- 1 file changed, 6 insertions(+), 2 deletions(-) diff --git a/mm/slab_common.c b/mm/slab_common.c index a143a8c8f874..d2c53b980ab3 100644 --- a/mm/slab_common.c +++ b/mm/slab_common.c @@ -819,8 +819,12 @@ void *kmalloc_order(size_t size, gfp_t flags, unsigned int order) page = alloc_pages(flags, order); if (likely(page)) { ret = page_address(page); - mod_node_page_state(page_pgdat(page), NR_SLAB_UNRECLAIMABLE_B, - PAGE_SIZE << order); + if (ret) + mod_node_page_state(page_pgdat(page), + NR_SLAB_UNRECLAIMABLE_B, + PAGE_SIZE << order); + else + __free_pages(page, order); } ret = kasan_kmalloc_large(ret, size, flags); /* As ret might get tagged, call kmemleak hook after KASAN. */ -- 2.17.1