From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-lf0-f69.google.com (mail-lf0-f69.google.com [209.85.215.69]) by kanga.kvack.org (Postfix) with ESMTP id 182676B025E for ; Tue, 2 Aug 2016 06:27:28 -0400 (EDT) Received: by mail-lf0-f69.google.com with SMTP id e7so91449789lfe.0 for ; Tue, 02 Aug 2016 03:27:28 -0700 (PDT) Received: from mail-lf0-x22e.google.com (mail-lf0-x22e.google.com. [2a00:1450:4010:c07::22e]) by mx.google.com with ESMTPS id d199si775947lfg.254.2016.08.02.03.27.26 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Tue, 02 Aug 2016 03:27:26 -0700 (PDT) Received: by mail-lf0-x22e.google.com with SMTP id l69so134838931lfg.1 for ; Tue, 02 Aug 2016 03:27:26 -0700 (PDT) MIME-Version: 1.0 In-Reply-To: <57A074AF.3040505@virtuozzo.com> References: <1470063563-96266-1-git-send-email-glider@google.com> <57A06F23.9080804@virtuozzo.com> <57A074AF.3040505@virtuozzo.com> From: Alexander Potapenko Date: Tue, 2 Aug 2016 12:27:25 +0200 Message-ID: Subject: Re: [PATCH] kasan: avoid overflowing quarantine size on low memory systems Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: quoted-printable Sender: owner-linux-mm@kvack.org List-ID: To: Andrey Ryabinin Cc: Dmitry Vyukov , Kostya Serebryany , Andrey Konovalov , Christoph Lameter , Andrew Morton , Steven Rostedt , Joonsoo Kim , Joonsoo Kim , Kuthonuzo Luruo , kasan-dev , LKML , "linux-mm@kvack.org" On Tue, Aug 2, 2016 at 12:23 PM, Andrey Ryabinin wrote: > > > On 08/02/2016 01:07 PM, Alexander Potapenko wrote: >> On Tue, Aug 2, 2016 at 12:05 PM, Dmitry Vyukov wrot= e: >>> On Tue, Aug 2, 2016 at 12:00 PM, Andrey Ryabinin >>>> >>>> Why WARN? I'd suggest pr_warn_once(); >>> >>> >>> I would suggest to just do something useful. Setting quarantine >>> new_quarantine_size to 0 looks fine. >>> What would user do with this warning? Number of CPUs and amount of >>> memory are generally fixed. Why is it an issue for end user at all? We >>> still have some quarantine per-cpu. A WARNING means a [non-critical] >>> kernel bug. E.g. syzkaller will catch each and every boot of such >>> system as a bug. >> How about printk_once then? >> Silently setting the quarantine size to zero may puzzle the user. >> > > Nope, user will not notice anything. So keeping it silent would be better= . > Plus it's very unlikely that this will ever happen in real life. > Ok, I've sent out v2, please take a look. --=20 Alexander Potapenko Software Engineer Google Germany GmbH Erika-Mann-Stra=C3=9Fe, 33 80636 M=C3=BCnchen Gesch=C3=A4ftsf=C3=BChrer: Matthew Scott Sucherman, Paul Terence Manicle Registergericht und -nummer: Hamburg, HRB 86891 Sitz der Gesellschaft: Hamburg -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org