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[209.132.180.67]) by mx.google.com with ESMTP id e14si3514754pfj.86.2018.02.06.09.50.54; Tue, 06 Feb 2018 09:51:07 -0800 (PST) Received-SPF: pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) client-ip=209.132.180.67; Authentication-Results: mx.google.com; dkim=pass header.i=@gmail.com header.s=20161025 header.b=Mk6vwaIf; spf=pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org; dmarc=pass (p=NONE sp=NONE dis=NONE) header.from=gmail.com Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752759AbeBFRsy (ORCPT + 99 others); Tue, 6 Feb 2018 12:48:54 -0500 Received: from mail-lf0-f67.google.com ([209.85.215.67]:40975 "EHLO mail-lf0-f67.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752612AbeBFRss (ORCPT ); Tue, 6 Feb 2018 12:48:48 -0500 Received: by mail-lf0-f67.google.com with SMTP id f136so3933192lff.8 for ; Tue, 06 Feb 2018 09:48:47 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=mime-version:in-reply-to:references:from:date:message-id:subject:to :cc; bh=P3WehsMzpmkstzwOhQUzv6nlXec4a6ZpmDyNeWJBRCI=; b=Mk6vwaIfqVIlDK5e+XWWX6f5YdSaEiv2rTHbq10JELRvIOgzwR+tVfSITr/Bvo7Ozr Ejbhv/DG/rMdiLEyRu5U5ZO0Tao7RqtDhjaIhESnQ3vdHZ//oJKNEjzlwdmSLVOuJGoc vLah37EB1kgm0y6Kvr7AIq+sEGL+YzpsTr/zhF3T1KjoRs1WT/AnaRWpJs+c99BQhWcR Bjrb92242crlWjapFoM5bylXgrsDHPV1vrmBRqwAB+MZzz0kVEBAtieqT4FFATyRnvZh ntM59Em3fA28Mk9h+FbdWB2SE9NJTVf2o8ExrngNW/2OfdyvsG82vXIH6ovyb/Aoi++d 4/HQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:in-reply-to:references:from:date :message-id:subject:to:cc; bh=P3WehsMzpmkstzwOhQUzv6nlXec4a6ZpmDyNeWJBRCI=; b=Cqa5lcovSGd8mBmKoCGom6HlZLQiC8ezV0x5+fyNZSTwTQhvMX/X5PK3wPLzJgIWgK EWYx0eakXlT6MVNy4fc2eFWgDo7AMf2lRJsmUuX7RGkS8xJZqfAMbAQpzwgf+lQbJUIW HZ41PkpQkwXj1vGww5QBI3nVwpCW5dH+69vI91zA/WAdG6rMzmI/61bZeKlM6sr24LQn BpB5hugs5GN5KMB2wDezPk/uehZv151drWJHmcOgDm2VwezeUmK3cE2zVwippk1bkcZG IxObur8TukzH33x63e3n9EwcoMZDTsD18YIvv7Yn4Ta9bJx17Ryof6ylkNu1MyyEDbkE LAmA== X-Gm-Message-State: APf1xPDPORG1NYDeC5rQe+VkkTiT5+lhrdkRjIo9UceC68yUSXpf9O09 bM9isOh9akajwJkfimvS2xPMRBPa+Hp76oS0nOc= X-Received: by 10.46.99.220 with SMTP id s89mr2278928lje.17.1517939326520; Tue, 06 Feb 2018 09:48:46 -0800 (PST) MIME-Version: 1.0 Received: by 10.25.41.2 with HTTP; Tue, 6 Feb 2018 09:48:46 -0800 (PST) In-Reply-To: <1517935505-9321-1-git-send-email-dwmw@amazon.co.uk> References: <1517935505-9321-1-git-send-email-dwmw@amazon.co.uk> From: Konstantin Khlebnikov Date: Tue, 6 Feb 2018 20:48:46 +0300 Message-ID: Subject: Re: [PATCH] mm: Always print RLIMIT_DATA warning To: David Woodhouse Cc: Andrew Morton , Cyrill Gorcunov , Linus Torvalds , Vegard Nossum , Peter Zijlstra , Vladimir Davydov , Andy Lutomirski , Quentin Casasnovas , Kees Cook , Willy Tarreau , Pavel Emelyanov , Laura Abbott , Linux Kernel Mailing List , linux-mm@kvack.org Content-Type: text/plain; charset="UTF-8" Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Feb 6, 2018 at 7:45 PM, David Woodhouse wrote: > The documentation for ignore_rlimit_data says that it will print a warning > at first misuse. Yet it doesn't seem to do that. Fix the code to print > the warning even when we allow the process to continue. Ack. But I think this was a misprint in docs. Anyway, this knob is a kludge so we might warn once even if it is set. So, somebody still have problems with this change? I remember concerns about that "warn_once" isn't enough to detect what's going wrong. And probably we should invent "warn_sometimes". > > Signed-off-by: David Woodhouse > --- > We should probably also do what Linus suggested in > https://lkml.org/lkml/2016/9/16/585 > > mm/mmap.c | 14 ++++++++------ > 1 file changed, 8 insertions(+), 6 deletions(-) > > diff --git a/mm/mmap.c b/mm/mmap.c > index 9efdc021..dd76ea3 100644 > --- a/mm/mmap.c > +++ b/mm/mmap.c > @@ -3184,13 +3184,15 @@ bool may_expand_vm(struct mm_struct *mm, vm_flags_t flags, unsigned long npages) > if (rlimit(RLIMIT_DATA) == 0 && > mm->data_vm + npages <= rlimit_max(RLIMIT_DATA) >> PAGE_SHIFT) > return true; > - if (!ignore_rlimit_data) { > - pr_warn_once("%s (%d): VmData %lu exceed data ulimit %lu. Update limits or use boot option ignore_rlimit_data.\n", > - current->comm, current->pid, > - (mm->data_vm + npages) << PAGE_SHIFT, > - rlimit(RLIMIT_DATA)); > + > + pr_warn_once("%s (%d): VmData %lu exceed data ulimit %lu. Update limits%s.\n", > + current->comm, current->pid, > + (mm->data_vm + npages) << PAGE_SHIFT, > + rlimit(RLIMIT_DATA), > + ignore_rlimit_data ? "" : " or use boot option ignore_rlimit_data"); > + > + if (!ignore_rlimit_data) > return false; > - } > } > > return true; > -- > 2.7.4 >