From: Martynas Pumputis <m@lambda.lt>
To: Michal Hocko <mhocko@kernel.org>
Cc: bpf@vger.kernel.org, ast@kernel.org, daniel@iogearbox.net
Subject: Re: [PATCH] bpf: Try harder when allocating memory for maps
Date: Fri, 8 Mar 2019 21:02:41 +0100 [thread overview]
Message-ID: <2cbb3fe7-39a9-1b1e-e22f-4dffa20b9414@lambda.lt> (raw)
In-Reply-To: <20190308112000.GG5232@dhcp22.suse.cz>
On 3/8/19 12:20 PM, Michal Hocko wrote:
> On Fri 08-03-19 12:14:16, Martynas Pumputis wrote:
>>
>>
>> On 3/8/19 9:44 AM, Michal Hocko wrote:
>>> On Fri 08-03-19 09:08:57, Martynas Pumputis wrote:
>>>> It has been observed that sometimes memory allocation for BPF maps
>>>> fails when there is no obvious memory pressure in a system.
>>>>
>>>> E.g. the map (BPF_MAP_TYPE_LRU_HASH, key=38, value=56, max_elems=524288)
>>>> could not be created due to due to vmalloc unable to allocate 75497472B,
>>>> when the system's memory consumption (in MB) was the following:
>>>>
>>>> Total: 3942 Used: 837 (21.24%) Free: 138 Buffers: 239 Cached: 2727
>>>
>>> Hmm 75MB is quite large and much larger than the slab/page allocator
>>> cann provide so this is not really a fragmentation issue. Vmalloc does
>>> respect noretry but considering that there shouldn't be a large memory
>>> pressure I wonder how NORETRY managed to fail the allocation. Do you
>>> happen to have the allocation failure report?
>>
>> I got /proc/{meminfo,vmstat,vmallocinfo} just after the allocation has
>> failed:
>> https://gist.github.com/brb/62092c1d83daa6527271b88f0352e32d
>
> dmesg with the allocation failure report would be more helpful
https://gist.github.com/brb/2d7ac323d2e14cb7a38bacba301fe3af
>
> Thanks!
>
next prev parent reply other threads:[~2019-03-08 20:01 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-03-08 8:08 [PATCH] bpf: Try harder when allocating memory for maps Martynas Pumputis
2019-03-08 8:44 ` Michal Hocko
2019-03-08 10:33 ` Daniel Borkmann
2019-03-08 10:55 ` Michal Hocko
2019-03-08 11:30 ` Daniel Borkmann
2019-03-08 12:00 ` Michal Hocko
2019-03-08 11:14 ` Martynas Pumputis
2019-03-08 11:20 ` Michal Hocko
2019-03-08 20:02 ` Martynas Pumputis [this message]
2019-03-10 7:13 ` Michal Hocko
2019-03-11 19:33 ` Martynas Pumputis
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