From: Qian Cai <cai@gmx.us>
To: Catalin Marinas <catalin.marinas@arm.com>
Cc: linux-kernel@vger.kernel.org, linux-mm@kvack.org,
kasan-dev@googlegroups.com,
Andrey Ryabinin <aryabinin@virtuozzo.com>,
Alexander Potapenko <glider@google.com>,
Dmitry Vyukov <dvyukov@google.com>,
Will Deacon <will.deacon@arm.com>,
linux-arm-kernel@lists.infradead.org
Subject: Re: kmemleak: Early log buffer exceeded (525980) during boot
Date: Tue, 27 Nov 2018 23:21:51 -0500 [thread overview]
Message-ID: <a2a9180f-32cf-a0fa-3829-f36133e3b924@gmx.us> (raw)
In-Reply-To: <20181110165938.lbt6dfamk2ljafcv@localhost>
On 11/10/18 11:59 AM, Catalin Marinas wrote:
> On Sat, Nov 10, 2018 at 10:08:10AM -0500, Qian Cai wrote:
>> On Nov 8, 2018, at 4:23 PM, Qian Cai <cai@gmx.us> wrote:
>>> The maximum value for DEBUG_KMEMLEAK_EARLY_LOG_SIZE is only 40000, so it
>>> disables kmemleak every time on this aarch64 server running the latest mainline
>>> (b00d209).
>>>
>>> # echo scan > /sys/kernel/debug/kmemleak
>>> -bash: echo: write error: Device or resource busy
>>>
>>> Any idea on how to enable kmemleak there?
>>
>> I have managed to hard-code DEBUG_KMEMLEAK_EARLY_LOG_SIZE to 600000,
>
> That's quite a high number, I wouldn't have thought it is needed.
> Basically the early log buffer is only used until the slub allocator
> gets initialised and kmemleak_init() is called from start_kernel(). I
> don't know what allocates that much memory so early.
>
It turned out that kmemleak does not play well with KASAN on those aarch64 (HPE
Apollo 70 and Huawei TaiShan 2280) servers.
After calling start_kernel()->setup_arch()->kasan_init(), kmemleak early log
buffer went from something like from 280 to 260000. The multitude of
kmemleak_alloc() calls is,
for_each_memblock(memory, reg) x \
while (pgdp++, addr = next, addr != end) x \
while (ptep++, addr = next, addr != end && \ pte_none(READ_ONCE(*ptep)))
Is this expected?
next prev parent reply other threads:[~2018-11-28 4:21 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <1541712198.12945.12.camel@gmx.us>
2018-11-10 15:08 ` kmemleak: Early log buffer exceeded (525980) during boot Qian Cai
2018-11-10 16:59 ` Catalin Marinas
2018-11-10 17:42 ` Qian Cai
2018-11-14 2:31 ` Qian Cai
2018-11-28 4:21 ` Qian Cai [this message]
2018-12-05 14:38 ` Dmitry Vyukov
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