From: Song Liu <songliubraving@fb.com>
To: Roman Gushchin <guro@fb.com>
Cc: bpf <bpf@vger.kernel.org>, Alexei Starovoitov <ast@kernel.org>,
"Daniel Borkmann" <daniel@iogearbox.net>,
"netdev@vger.kernel.org" <netdev@vger.kernel.org>,
Andrii Nakryiko <andrii@kernel.org>,
Shakeel Butt <shakeelb@google.com>,
"linux-mm@kvack.org" <linux-mm@kvack.org>,
"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
Kernel Team <Kernel-team@fb.com>
Subject: Re: [PATCH bpf-next v5 06/34] bpf: prepare for memcg-based memory accounting for bpf maps
Date: Fri, 13 Nov 2020 20:48:07 +0000 [thread overview]
Message-ID: <4E6A1738-4138-4F48-95ED-BD139A72B296@fb.com> (raw)
In-Reply-To: <20201113194023.GD2955309@carbon.dhcp.thefacebook.com>
> On Nov 13, 2020, at 11:40 AM, Roman Gushchin <guro@fb.com> wrote:
>
> On Fri, Nov 13, 2020 at 09:46:49AM -0800, Song Liu wrote:
>>
>>
>>> On Nov 12, 2020, at 2:15 PM, Roman Gushchin <guro@fb.com> wrote:
>>
>> [...]
>>
>>>
>>> +#ifdef CONFIG_MEMCG_KMEM
>>> +static __always_inline int __bpf_map_update_elem(struct bpf_map *map, void *key,
>>> + void *value, u64 flags)
>>> +{
>>> + struct mem_cgroup *old_memcg;
>>> + bool in_interrupt;
>>> + int ret;
>>> +
>>> + /*
>>> + * If update from an interrupt context results in a memory allocation,
>>> + * the memory cgroup to charge can't be determined from the context
>>> + * of the current task. Instead, we charge the memory cgroup, which
>>> + * contained a process created the map.
>>> + */
>>> + in_interrupt = in_interrupt();
>>> + if (in_interrupt)
>>> + old_memcg = set_active_memcg(map->memcg);
>>
>> set_active_memcg() checks in_interrupt() again. Maybe we can introduce another
>> helper to avoid checking it twice? Something like
>>
>> static inline struct mem_cgroup *
>> set_active_memcg_int(struct mem_cgroup *memcg)
>> {
>> struct mem_cgroup *old;
>>
>> old = this_cpu_read(int_active_memcg);
>> this_cpu_write(int_active_memcg, memcg);
>> return old;
>> }
>
> Yeah, it's a good idea!
>
> in_interrupt() check is very cheap (like checking some bits in a per-cpu variable),
> so I don't think there will be any measurable difference. So I suggest to implement
> it later as an enhancement on top (maybe in the next merge window), to avoid an another
> delay. Otherwise I'll need to send a patch to mm@, wait for reviews and an inclusion
> into the mm tree, etc). Does it work for you?
Yeah, that works.
Acked-by: Song Liu <songliubraving@fb.com>
next prev parent reply other threads:[~2020-11-13 20:48 UTC|newest]
Thread overview: 51+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-11-12 22:15 [PATCH bpf-next v5 00/34] bpf: switch to memcg-based memory accounting Roman Gushchin
2020-11-12 22:15 ` [PATCH bpf-next v5 05/34] bpf: memcg-based memory accounting for bpf progs Roman Gushchin
2020-11-13 17:31 ` Song Liu
2020-11-12 22:15 ` [PATCH bpf-next v5 06/34] bpf: prepare for memcg-based memory accounting for bpf maps Roman Gushchin
2020-11-13 17:46 ` Song Liu
2020-11-13 19:40 ` Roman Gushchin
2020-11-13 20:48 ` Song Liu [this message]
2020-11-12 22:15 ` [PATCH bpf-next v5 07/34] bpf: " Roman Gushchin
2020-11-13 18:04 ` Song Liu
2020-11-12 22:15 ` [PATCH bpf-next v5 08/34] bpf: refine memcg-based memory accounting for arraymap maps Roman Gushchin
2020-11-12 22:15 ` [PATCH bpf-next v5 09/34] bpf: refine memcg-based memory accounting for cpumap maps Roman Gushchin
2020-11-12 22:15 ` [PATCH bpf-next v5 10/34] bpf: memcg-based memory accounting for cgroup storage maps Roman Gushchin
2020-11-12 22:15 ` [PATCH bpf-next v5 11/34] bpf: refine memcg-based memory accounting for devmap maps Roman Gushchin
2020-11-12 22:15 ` [PATCH bpf-next v5 12/34] bpf: refine memcg-based memory accounting for hashtab maps Roman Gushchin
2020-11-12 22:15 ` [PATCH bpf-next v5 13/34] bpf: memcg-based memory accounting for lpm_trie maps Roman Gushchin
2020-11-12 22:15 ` [PATCH bpf-next v5 14/34] bpf: memcg-based memory accounting for bpf ringbuffer Roman Gushchin
2020-11-12 22:15 ` [PATCH bpf-next v5 15/34] bpf: memcg-based memory accounting for bpf local storage maps Roman Gushchin
2020-11-13 18:07 ` Song Liu
2020-11-12 22:15 ` [PATCH bpf-next v5 16/34] bpf: refine memcg-based memory accounting for sockmap and sockhash maps Roman Gushchin
2020-11-12 22:15 ` [PATCH bpf-next v5 17/34] bpf: refine memcg-based memory accounting for xskmap maps Roman Gushchin
2020-11-12 22:15 ` [PATCH bpf-next v5 18/34] bpf: eliminate rlimit-based memory accounting for arraymap maps Roman Gushchin
2020-11-12 22:15 ` [PATCH bpf-next v5 19/34] bpf: eliminate rlimit-based memory accounting for bpf_struct_ops maps Roman Gushchin
2020-11-12 22:15 ` [PATCH bpf-next v5 20/34] bpf: eliminate rlimit-based memory accounting for cpumap maps Roman Gushchin
2020-11-12 22:15 ` [PATCH bpf-next v5 21/34] bpf: eliminate rlimit-based memory accounting for cgroup storage maps Roman Gushchin
2020-11-12 22:15 ` [PATCH bpf-next v5 22/34] bpf: eliminate rlimit-based memory accounting for devmap maps Roman Gushchin
2020-11-12 22:15 ` [PATCH bpf-next v5 23/34] bpf: eliminate rlimit-based memory accounting for hashtab maps Roman Gushchin
2020-11-12 22:15 ` [PATCH bpf-next v5 24/34] bpf: eliminate rlimit-based memory accounting for lpm_trie maps Roman Gushchin
2020-11-12 22:15 ` [PATCH bpf-next v5 25/34] bpf: eliminate rlimit-based memory accounting for queue_stack_maps maps Roman Gushchin
2020-11-12 22:15 ` [PATCH bpf-next v5 26/34] bpf: eliminate rlimit-based memory accounting for reuseport_array maps Roman Gushchin
2020-11-12 22:15 ` [PATCH bpf-next v5 27/34] bpf: eliminate rlimit-based memory accounting for bpf ringbuffer Roman Gushchin
2020-11-12 22:15 ` [PATCH bpf-next v5 28/34] bpf: eliminate rlimit-based memory accounting for sockmap and sockhash maps Roman Gushchin
2020-11-12 22:15 ` [PATCH bpf-next v5 29/34] bpf: eliminate rlimit-based memory accounting for stackmap maps Roman Gushchin
2020-11-12 22:15 ` [PATCH bpf-next v5 30/34] bpf: eliminate rlimit-based memory accounting for xskmap maps Roman Gushchin
2020-11-12 22:15 ` [PATCH bpf-next v5 31/34] bpf: eliminate rlimit-based memory accounting for bpf local storage maps Roman Gushchin
2020-11-13 18:14 ` Song Liu
2020-11-13 19:33 ` Roman Gushchin
2020-11-13 20:53 ` Song Liu
2020-11-12 22:15 ` [PATCH bpf-next v5 32/34] bpf: eliminate rlimit-based memory accounting infra for bpf maps Roman Gushchin
2020-11-13 18:17 ` Song Liu
2020-11-12 22:15 ` [PATCH bpf-next v5 33/34] bpf: eliminate rlimit-based memory accounting for bpf progs Roman Gushchin
2020-11-12 22:15 ` [PATCH bpf-next v5 34/34] bpf: samples: do not touch RLIMIT_MEMLOCK Roman Gushchin
[not found] ` <20201112221543.3621014-2-guro@fb.com>
2020-11-12 22:56 ` [PATCH bpf-next v5 01/34] mm: memcontrol: use helpers to read page's memcg data Stephen Rothwell
2020-11-13 0:26 ` Roman Gushchin
2020-11-13 3:04 ` Alexei Starovoitov
2020-11-13 3:18 ` Andrew Morton
2020-11-13 3:25 ` Alexei Starovoitov
2020-11-13 3:40 ` Andrew Morton
2020-11-13 4:08 ` Alexei Starovoitov
2020-11-13 4:01 ` Roman Gushchin
2020-11-13 14:25 ` Shakeel Butt
2020-11-13 17:18 ` Roman Gushchin
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