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 68031C433EF for ; Thu, 28 Apr 2022 16:09:57 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1349579AbiD1QNJ (ORCPT ); Thu, 28 Apr 2022 12:13:09 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:53126 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232927AbiD1QNH (ORCPT ); Thu, 28 Apr 2022 12:13:07 -0400 Received: from mail-oa1-x31.google.com (mail-oa1-x31.google.com [IPv6:2001:4860:4864:20::31]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 49C034A3E0 for ; Thu, 28 Apr 2022 09:09:52 -0700 (PDT) Received: by mail-oa1-x31.google.com with SMTP id 586e51a60fabf-e2fa360f6dso5625489fac.2 for ; Thu, 28 Apr 2022 09:09:52 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; h=sender:date:from:to:cc:subject:message-id:references:mime-version :content-disposition:in-reply-to; bh=nT3t1w9TRCQTEHgFchj44IQlb1iT4EUgGpNoU9tkFsY=; b=gA7bjoCxWh92i/S1XF1eE2xn7QiKAkHhFHKC43aWKcdA7yJ14+7dncrlZhI9vRwUtl YLGV3y+wPDFF0sEqS5Cgc+enP8aoQiEjLPJjxtl3Y24SUc7qkk49DVu0/eOkKfmI/9gw C+2BgS5naRu3SyMowsXtMoq9pcj6EfDXWlvq2vG4g9FP8oiIKH3pKZPqCXTgW02KHwIj ZIMSTHHal5Wv0FGwumWUpnCfiR8FXVo49X2A/juFdw+e7XwNNmxppSxiCX349+WFviEh hgUNacOjrrUsyDGWLqjyfzKSvC2YUqPnJbB2zzwsRdQ0Rm70wcFwy9obpXs1zerbYO70 /jcQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:sender:date:from:to:cc:subject:message-id :references:mime-version:content-disposition:in-reply-to; bh=nT3t1w9TRCQTEHgFchj44IQlb1iT4EUgGpNoU9tkFsY=; b=4TXvTCJrNk10JlVKyiVrGqA+rtrB6KmcNWmqqG0e0N1aeS8uy7ipWN6TM57zW5x+3d Kcc3JAIa5pw1cNuaxNC9V99RCDAlby8wBpIxfd78rk187EmPaTN56FO+RaunnjdtqysU KM2zm4uGa+lDPXQDv10ZltYC0tJlHJS6IzQK734orB3Zi05U74iLjUEts2tSvyp0X3FW Nc2erco+VcCTxmLK3L2XqOhfzFgSbi50Pk7vpri7qtToSpNSPTwzHSBQiQJfRU8TP7Au bNa7gAvySrUz9oGMl6oXkoj/xm9h+WE3qWJYeDSEVviYke2i2q2BhVCsYuLc4Ptdhf5T 21pg== X-Gm-Message-State: AOAM531xFs0kQ8Pv5xWxHziTgqNX/+1MXnJajLJyOWFwLSt2LvCC2R2p yQ27R2S6MTrXs+cFgB48D9g= X-Google-Smtp-Source: ABdhPJy4QuxfXKo3x2RKwtWbQ7/VCsg7jnPYGdn94JBDr1/7gNQeWoBmW9i0Vii2BO1jjuiYtJxzGQ== X-Received: by 2002:a05:6870:e9a0:b0:e6:9d2:ff42 with SMTP id r32-20020a056870e9a000b000e609d2ff42mr14411601oao.7.1651162191312; Thu, 28 Apr 2022 09:09:51 -0700 (PDT) Received: from server.roeck-us.net ([2600:1700:e321:62f0:329c:23ff:fee3:9d7c]) by smtp.gmail.com with ESMTPSA id bt30-20020a0568201a9e00b0035ea84682b9sm181981oob.45.2022.04.28.09.09.50 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 28 Apr 2022 09:09:50 -0700 (PDT) Sender: Guenter Roeck Date: Thu, 28 Apr 2022 09:09:49 -0700 From: Guenter Roeck To: Liam Howlett Cc: "maple-tree@lists.infradead.org" , "linux-mm@kvack.org" , "linux-kernel@vger.kernel.org" , Andrew Morton , Yu Zhao Subject: Re: [PATCH v8 23/70] mm/mmap: change do_brk_flags() to expand existing VMA and add do_brk_munmap() Message-ID: <20220428160949.GA2923383@roeck-us.net> References: <20220426150616.3937571-1-Liam.Howlett@oracle.com> <20220426150616.3937571-24-Liam.Howlett@oracle.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20220426150616.3937571-24-Liam.Howlett@oracle.com> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Apr 26, 2022 at 03:06:35PM +0000, Liam Howlett wrote: > From: "Liam R. Howlett" > > Avoid allocating a new VMA when it a vma modification can occur. When a > brk() can expand or contract a VMA, then the single store operation will > only modify one index of the maple tree instead of causing a node to split > or coalesce. This avoids unnecessary allocations/frees of maple tree > nodes and VMAs. > > Move some limit & flag verifications out of the do_brk_flags() function to > use only relevant checks in the code path of bkr() and vm_brk_flags(). > > Set the vma to check if it can expand in vm_brk_flags() if extra criteria > are met. > > Drop userfaultfd from do_brk_flags() path and only use it in > vm_brk_flags() path since that is the only place a munmap will happen. > > Signed-off-by: Liam R. Howlett This patch results in boot failures on alpha. Trying to revert it results in conflicts, so I was unable to cross-check. Bisect log attached. The failure is silent - boot simply stalls after "random: crng init done", so attaching a boot log doesn't add value. Guenter --- # bad: [bdc61aad77faf67187525028f1f355eff3849f22] Add linux-next specific files for 20220428 # good: [af2d861d4cd2a4da5137f795ee3509e6f944a25b] Linux 5.18-rc4 git bisect start 'HEAD' 'v5.18-rc4' # good: [a6ffa4aa7e81a54632f3370f4c93fce603160192] Merge branch 'master' of git://git.kernel.org/pub/scm/linux/kernel/git/herbert/cryptodev-2.6.git git bisect good a6ffa4aa7e81a54632f3370f4c93fce603160192 # good: [cd63f17e3bb63006f9f88bf7f5947b8e1601bcd9] Merge branch 'edac-for-next' of git://git.kernel.org/pub/scm/linux/kernel/git/ras/ras.git git bisect good cd63f17e3bb63006f9f88bf7f5947b8e1601bcd9 # good: [cee7bbed3e5cc089b5c364ac8ad4a186c2a28bb6] Merge branch 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/vkoul/dmaengine.git git bisect good cee7bbed3e5cc089b5c364ac8ad4a186c2a28bb6 # good: [d5a23156ea99f10b584221893a6a7d6f6554cde8] Merge branch 'for-next' of git://git.kernel.org/pub/scm/linux/kernel/git/vbabka/slab.git git bisect good d5a23156ea99f10b584221893a6a7d6f6554cde8 # good: [2f1fde90d983bc404503100c9c4bbbf1e191bcf4] selftests: cgroup: fix alloc_anon_noexit() instantly freeing memory git bisect good 2f1fde90d983bc404503100c9c4bbbf1e191bcf4 # good: [fca1db6ff251278c532231552e840c7dc36dfa76] Merge branch 'bitmap-for-next' of https://github.com/norov/linux.git git bisect good fca1db6ff251278c532231552e840c7dc36dfa76 # bad: [40b39116fe8e6fb66e3166ea40138eec506dfd91] perf: use VMA iterator git bisect bad 40b39116fe8e6fb66e3166ea40138eec506dfd91 # good: [3f2187cf9b93a58343dd01273afdab9df04b0ca3] proc: remove VMA rbtree use from nommu git bisect good 3f2187cf9b93a58343dd01273afdab9df04b0ca3 # bad: [7dbf1873ad5953d8cf732d5fd5a94c1b95c022b0] parisc: remove mmap linked list from cache handling git bisect bad 7dbf1873ad5953d8cf732d5fd5a94c1b95c022b0 # bad: [c6e0b59766907a73be6cb77683f3ba60d0115495] mm/mmap: use advanced maple tree API for mmap_region() git bisect bad c6e0b59766907a73be6cb77683f3ba60d0115495 # good: [f461d9862fdab8e6aea51094e7286f3ec1b25402] mm: optimize find_exact_vma() to use vma_lookup() git bisect good f461d9862fdab8e6aea51094e7286f3ec1b25402 # bad: [c19a5ccbcbc6fe2c422fd85b22b40abed96c6f6b] mm/mmap: change do_brk_flags() to expand existing VMA and add do_brk_munmap() git bisect bad c19a5ccbcbc6fe2c422fd85b22b40abed96c6f6b # good: [993adc76c4d7afb40133be90333b5303b02115b6] mm/khugepaged: optimize collapse_pte_mapped_thp() by using vma_lookup() git bisect good 993adc76c4d7afb40133be90333b5303b02115b6 # first bad commit: [c19a5ccbcbc6fe2c422fd85b22b40abed96c6f6b] mm/mmap: change do_brk_flags() to expand existing VMA and add do_brk_munmap()