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 kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by smtp.lore.kernel.org (Postfix) with ESMTP id 5FF4DC25B74 for ; Thu, 9 May 2024 08:32:19 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id EF9996B0095; Thu, 9 May 2024 04:32:18 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id EA9AD6B0096; Thu, 9 May 2024 04:32:18 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id D70FF6B0098; Thu, 9 May 2024 04:32:18 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0011.hostedemail.com [216.40.44.11]) by kanga.kvack.org (Postfix) with ESMTP id BA1AD6B0095 for ; Thu, 9 May 2024 04:32:18 -0400 (EDT) Received: from smtpin05.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay08.hostedemail.com (Postfix) with ESMTP id 5A05A141302 for ; Thu, 9 May 2024 08:32:18 +0000 (UTC) X-FDA: 82098190356.05.CA79DC9 Received: from mail-vk1-f179.google.com (mail-vk1-f179.google.com [209.85.221.179]) by imf24.hostedemail.com (Postfix) with ESMTP id 96E9918000F for ; Thu, 9 May 2024 08:32:16 +0000 (UTC) Authentication-Results: imf24.hostedemail.com; dkim=pass header.d=gmail.com header.s=20230601 header.b=KshekTWQ; spf=pass (imf24.hostedemail.com: domain of 21cnbao@gmail.com designates 209.85.221.179 as permitted sender) smtp.mailfrom=21cnbao@gmail.com; dmarc=pass (policy=none) header.from=gmail.com ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1715243536; a=rsa-sha256; cv=none; b=aBoQEize9l+a9I9JU9p9Wp+/UNjmNe6NkltNvFp58X8lVTvrtPQ2EvpUZThGUepV3FZN81 IuClM2W9kiypWjVvO4xI1g0YJvtnhKOb/0HdTn8OITkA0k/9gKWdyNwcRlq5PymoEPhcxr qLts1WnjQ5+GPvXtYMvJuUxqqclvTQM= ARC-Authentication-Results: i=1; imf24.hostedemail.com; dkim=pass header.d=gmail.com header.s=20230601 header.b=KshekTWQ; spf=pass (imf24.hostedemail.com: domain of 21cnbao@gmail.com designates 209.85.221.179 as permitted sender) smtp.mailfrom=21cnbao@gmail.com; dmarc=pass (policy=none) header.from=gmail.com ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1715243536; h=from:from:sender:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references:dkim-signature; bh=Vex5Pnrbj6pXdLB6wrqH+dw5zwsnYQyV11tpN7ZxBo0=; b=jelczvD/eAu05JY/qhAj0UWG/z1MX/Oss2duOZ/9ROX3EO3VZt1GfC7i2mn4ZYuvVFBewf 2N1GcnDfG6sVgrl7YogsJunjzPvT7itBYLpn7IeKavtOng+bkBA4KO72hjp3UIOSGKmG5j iMZxAATI8k0OdaLT1Kb1Hka2gPY6KYU= Received: by mail-vk1-f179.google.com with SMTP id 71dfb90a1353d-4df3e3c674fso246694e0c.2 for ; Thu, 09 May 2024 01:32:16 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20230601; t=1715243535; x=1715848335; darn=kvack.org; h=content-transfer-encoding:cc:to:subject:message-id:date:from :in-reply-to:references:mime-version:from:to:cc:subject:date :message-id:reply-to; bh=Vex5Pnrbj6pXdLB6wrqH+dw5zwsnYQyV11tpN7ZxBo0=; b=KshekTWQmfSstAdT1X2ZhMpVXB59UGONAapNleDeE4vioQNzVmVm0FaIccSG3cJO2/ ryYO2OjkAL7e2HomShYx8n6agz8CQRGlCJ9WtC6Pjh/x5KDwkh0xA7Rw4ktuLDfPxotd SJijzUhho106tPJmvsc+3SyVRCwH5K58zGrcjLoeWXH4A3oLXehzJ1XyfYvJ3BxG4Vma NoC/6BQ/SZYRW0lnZsWFEScpJmkN/vxHzs8EjoT6frmFihEyQ/hPz7YAa63oHWJpFjbz FoLnDSdDgW0mA3U7O4H/pHpjKL6SL0D8vk7eZbpL01L7gXPEXfNLC/1FPAm00ob+z4R3 m8zA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1715243535; x=1715848335; h=content-transfer-encoding:cc:to:subject:message-id:date:from :in-reply-to:references:mime-version:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=Vex5Pnrbj6pXdLB6wrqH+dw5zwsnYQyV11tpN7ZxBo0=; b=Osi06qCxEpw0Ljo29LotPXrHd1mIYvDUot81ot97H7spesOmxumxE0GBoSzLdOEVWb SlkjMBT8QEgEhq9EnXPF7BL0LP+zEiiYqo2TV6abnnSV2DVBuFcN0yHvCc6Vifn740T4 rw9RMwNUcVOp4HYELBrDAld8n+aIQwIdoxBfOmnQDUw/ilYXeNqTRuQ7SsRbtP1YfsrL VETNWBou7LwwcVMD67RnnSgxn8/6iHm8qUS7L+04kpV0mw7KppVm7AFwdaCsfIk+oRAA nMrzHao2kpHw1v+gIl8VON4tAxj1hbokjkBm67Ce4ceVfkCr7fLyFhomTkzSnzGRFGEw ok9Q== X-Forwarded-Encrypted: i=1; AJvYcCVL4ucb8gf5tywkMyOIZmKglQO5fKL995a+/DMA1upBu7H6dlisCM6PPHuxj59d9YtnwjcyVVGYzG3L9h3/GOIu0dM= X-Gm-Message-State: AOJu0YzCg5U325jzY8dAiEHZPM0fMG7ry/n3SKiLOBlmnwGMhRXHkbfH tQCWE823D+D+WX0NHpgwEoYWY2cbw/d4L7gG2OL9Kd+h1da/QvnBaP8wyAdkWZSJQgu0iNiwGzD V6Y/kIvncgGjJ02aDFHCKxMTp0wA= X-Google-Smtp-Source: AGHT+IGQOakR1UQwRPkvNnKqUu7WsXnibCzsIFljlK/L8T8rvDRaWR+S2xPmwYnG/KM7tJ8xJOCxoqjMX8kj6N/DtCQ= X-Received: by 2002:a05:6122:411a:b0:4da:ced8:b09a with SMTP id 71dfb90a1353d-4df69001fbfmr5570961e0c.0.1715243535532; Thu, 09 May 2024 01:32:15 -0700 (PDT) MIME-Version: 1.0 References: <20240508125808.28882-1-hailong.liu@oppo.com> <20240509080636.bauxbgpqdluzpein@oppo.com> In-Reply-To: <20240509080636.bauxbgpqdluzpein@oppo.com> From: Barry Song <21cnbao@gmail.com> Date: Thu, 9 May 2024 20:32:04 +1200 Message-ID: Subject: Re: [RFC PATCH] mm/vmalloc: fix vmalloc which may return null if called with __GFP_NOFAIL To: Hailong Liu Cc: Michal Hocko , akpm@linux-foundation.org, urezki@gmail.com, hch@infradead.org, lstoakes@gmail.com, linux-mm@kvack.org, linux-kernel@vger.kernel.org, xiang@kernel.org, chao@kernel.org, Oven Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable X-Stat-Signature: wgeb4b7b8u917y7bjookpjneb33y6kir X-Rspam-User: X-Rspamd-Server: rspam02 X-Rspamd-Queue-Id: 96E9918000F X-HE-Tag: 1715243536-51950 X-HE-Meta: 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 lfhX+d9b 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 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000022, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: On Thu, May 9, 2024 at 8:21=E2=80=AFPM Hailong Liu w= rote: > > On Thu, 09. May 09:48, Michal Hocko wrote: > > On Wed 08-05-24 20:58:08, hailong.liu@oppo.com wrote: > > > From: "Hailong.Liu" > > > > > > Commit a421ef303008 ("mm: allow !GFP_KERNEL allocations for kvmalloc"= ) > > > includes support for __GFP_NOFAIL, but it presents a conflict with > > > commit dd544141b9eb ("vmalloc: back off when the current task is > > > OOM-killed"). A possible scenario is as belows: > > > > > > process-a > > > kvcalloc(n, m, GFP_KERNEL | __GFP_NOFAIL) > > > __vmalloc_node_range() > > > __vmalloc_area_node() > > > vm_area_alloc_pages() > > > --> oom-killer send SIGKILL to process-a > > > if (fatal_signal_pending(current)) break; > > > --> return NULL; > > > > > > to fix this, do not check fatal_signal_pending() in vm_area_alloc_pag= es() > > > if __GFP_NOFAIL set. > > > > > > Reported-by: Oven > > > Signed-off-by: Hailong.Liu > > > --- > > > mm/vmalloc.c | 2 +- > > > 1 file changed, 1 insertion(+), 1 deletion(-) > > > > > > diff --git a/mm/vmalloc.c b/mm/vmalloc.c > > > index 6641be0ca80b..2f359d08bf8d 100644 > > > --- a/mm/vmalloc.c > > > +++ b/mm/vmalloc.c > > > @@ -3560,7 +3560,7 @@ vm_area_alloc_pages(gfp_t gfp, int nid, > > > > > > /* High-order pages or fallback path if "bulk" fails. */ > > > while (nr_allocated < nr_pages) { > > > - if (fatal_signal_pending(current)) > > > + if (!(gfp & __GFP_NOFAIL) && fatal_signal_pending(current= )) > > > > Use nofail instead of gfp & __GFP_NOFAIL. > > > > Other than that looks good to me. After that is fixed, please feel free > > to add Acked-by: Michal Hocko > > > > I believe this should also have Fixes: 9376130c390a ("mm/vmalloc: add s= upport for __GFP_NOFAIL") > > -- > > Michal Hocko > > SUSE Labs > > Thanks for the review and the Ack! > > Add Fixes in V2 patch. > > IIUC, nofail could not used for this case. > > /* > * For order-0 pages we make use of bulk allocator, if > * the page array is partly or not at all populated due > * to fails, fallback to a single page allocator that is > * more permissive. > */ > if (!order) { > /* bulk allocator doesn't support nofail req. officially = */ > xxx > -> nofail =3D false; isn't it another bug that needs a fix? > } else if (gfp & __GFP_NOFAIL) { > /* > * Higher order nofail allocations are really expensive a= nd > * potentially dangerous (pre-mature OOM, disruptive recl= aim > * and compaction etc. > */ > alloc_gfp &=3D ~__GFP_NOFAIL; > nofail =3D true; > } > > /* High-order pages or fallback path if "bulk" fails. */ > while (nr_allocated < nr_pages) { > > -> nofail is false here if bulk allocator fails. > if (fatal_signal_pending(current)) > break; > > -- > > Best Regards, > Hailong.