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Date:   Sat, 7 Mar 2020 17:58:02 -0800
From:   Matthew Wilcox <willy@infradead.org>
To:     Andrew Morton <akpm@linux-foundation.org>
Cc:     Jaewon Kim <jaewon31.kim@samsung.com>, walken@google.com,
        bp@suse.de, linux-mm@kvack.org, linux-kernel@vger.kernel.org,
        jaewon31.kim@gmail.com
Subject: Re: [PATCH] mm: mmap: show vm_unmapped_area error log
Message-ID: <20200308015802.GD31215@bombadil.infradead.org>
References: <CGME20200304030211epcas1p4da8cb569947aefb3aad1da039aaabce4@epcas1p4.samsung.com>
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 <20200305202443.8de3598558336b1d75afbba7@linux-foundation.org>
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On Sat, Mar 07, 2020 at 03:47:44PM -0800, Andrew Morton wrote:
> On Fri, 6 Mar 2020 15:16:22 +0900 Jaewon Kim <jaewon31.kim@samsung.com> wrote:
> > Even on 64 bit kernel, the mmap failure can happen for a 32 bit task.
> > Virtual memory space shortage of a task on mmap is reported to userspace
> > as -ENOMEM. It can be confused as physical memory shortage of overall
> > system.

But userspace can trigger this printk.  We don't usually allow printks
under those circumstances, even ratelimited.