From: Roman Gushchin <guro@fb.com>
To: Alexei Starovoitov <alexei.starovoitov@gmail.com>
Cc: <bpf@vger.kernel.org>, <ast@kernel.org>, <daniel@iogearbox.net>,
<netdev@vger.kernel.org>, <andrii@kernel.org>,
<akpm@linux-foundation.org>, <linux-mm@kvack.org>,
<linux-kernel@vger.kernel.org>, <kernel-team@fb.com>
Subject: Re: [PATCH bpf-next v7 32/34] bpf: eliminate rlimit-based memory accounting infra for bpf maps
Date: Fri, 20 Nov 2020 18:59:04 -0800 [thread overview]
Message-ID: <20201121025904.GA478375@carbon.DHCP.thefacebook.com> (raw)
In-Reply-To: <20201121025227.dypweojhaz7elwb3@ast-mbp>
On Fri, Nov 20, 2020 at 06:52:27PM -0800, Alexei Starovoitov wrote:
> On Thu, Nov 19, 2020 at 09:37:52AM -0800, Roman Gushchin wrote:
> > static void bpf_map_put_uref(struct bpf_map *map)
> > @@ -619,7 +562,7 @@ static void bpf_map_show_fdinfo(struct seq_file *m, struct file *filp)
> > "value_size:\t%u\n"
> > "max_entries:\t%u\n"
> > "map_flags:\t%#x\n"
> > - "memlock:\t%llu\n"
> > + "memlock:\t%llu\n" /* deprecated */
> > "map_id:\t%u\n"
> > "frozen:\t%u\n",
> > map->map_type,
> > @@ -627,7 +570,7 @@ static void bpf_map_show_fdinfo(struct seq_file *m, struct file *filp)
> > map->value_size,
> > map->max_entries,
> > map->map_flags,
> > - map->memory.pages * 1ULL << PAGE_SHIFT,
> > + 0LLU,
>
> The set looks great to me overall, but above change is problematic.
> There are tools out there that read this value.
> Returning zero might cause oncall alarms to trigger.
> I think we can be more accurate here.
> Instead of zero the kernel can return
> round_up(max_entries * round_up(key_size + value_size, 8), PAGE_SIZE)
> It's not the same as before, but at least the numbers won't suddenly
> go to zero and comparison between maps is still relevant.
> Of course we can introduce a page size calculating callback per map type,
> but imo that would be overkill. These monitoring tools don't care about
> precise number, but rather about relative value and growth from one
> version of the application to another.
>
> If Daniel doesn't find other issues this can be fixed in the follow up.
Makes total sense. I'll prepare a follow-up patch.
Thanks!
next prev parent reply other threads:[~2020-11-21 2:59 UTC|newest]
Thread overview: 48+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-11-19 17:37 [PATCH bpf-next v7 00/34] bpf: switch to memcg-based memory accounting Roman Gushchin
2020-11-19 17:37 ` [PATCH bpf-next v7 01/34] mm: memcontrol: use helpers to read page's memcg data Roman Gushchin
2020-11-19 17:37 ` [PATCH bpf-next v7 02/34] mm: memcontrol/slab: use helpers to access slab page's memcg_data Roman Gushchin
2020-11-19 17:37 ` [PATCH bpf-next v7 03/34] mm: introduce page memcg flags Roman Gushchin
2020-11-19 17:37 ` [PATCH bpf-next v7 04/34] mm: convert page kmemcg type to a page memcg flag Roman Gushchin
2020-11-19 17:37 ` [PATCH bpf-next v7 05/34] bpf: memcg-based memory accounting for bpf progs Roman Gushchin
2020-11-19 17:37 ` [PATCH bpf-next v7 06/34] bpf: prepare for memcg-based memory accounting for bpf maps Roman Gushchin
2020-11-20 1:05 ` Song Liu
2020-11-19 17:37 ` [PATCH bpf-next v7 07/34] bpf: " Roman Gushchin
2020-11-19 17:37 ` [PATCH bpf-next v7 08/34] bpf: refine memcg-based memory accounting for arraymap maps Roman Gushchin
2020-11-19 17:37 ` [PATCH bpf-next v7 09/34] bpf: refine memcg-based memory accounting for cpumap maps Roman Gushchin
2020-11-20 1:33 ` Song Liu
2020-11-19 17:37 ` [PATCH bpf-next v7 10/34] bpf: memcg-based memory accounting for cgroup storage maps Roman Gushchin
2020-11-20 1:37 ` Song Liu
2020-11-19 17:37 ` [PATCH bpf-next v7 11/34] bpf: refine memcg-based memory accounting for devmap maps Roman Gushchin
2020-11-20 1:38 ` Song Liu
2020-11-19 17:37 ` [PATCH bpf-next v7 12/34] bpf: refine memcg-based memory accounting for hashtab maps Roman Gushchin
2020-11-20 1:39 ` Song Liu
2020-11-19 17:37 ` [PATCH bpf-next v7 13/34] bpf: memcg-based memory accounting for lpm_trie maps Roman Gushchin
2020-11-20 1:39 ` Song Liu
2020-11-19 17:37 ` [PATCH bpf-next v7 14/34] bpf: memcg-based memory accounting for bpf ringbuffer Roman Gushchin
2020-11-19 17:37 ` [PATCH bpf-next v7 15/34] bpf: memcg-based memory accounting for bpf local storage maps Roman Gushchin
2020-11-20 1:44 ` Song Liu
2020-11-19 17:37 ` [PATCH bpf-next v7 16/34] bpf: refine memcg-based memory accounting for sockmap and sockhash maps Roman Gushchin
2020-11-20 1:45 ` Song Liu
2020-11-19 17:37 ` [PATCH bpf-next v7 17/34] bpf: refine memcg-based memory accounting for xskmap maps Roman Gushchin
2020-11-20 1:45 ` Song Liu
2020-11-19 17:37 ` [PATCH bpf-next v7 18/34] bpf: eliminate rlimit-based memory accounting for arraymap maps Roman Gushchin
2020-11-19 17:37 ` [PATCH bpf-next v7 19/34] bpf: eliminate rlimit-based memory accounting for bpf_struct_ops maps Roman Gushchin
2020-11-19 17:37 ` [PATCH bpf-next v7 20/34] bpf: eliminate rlimit-based memory accounting for cpumap maps Roman Gushchin
2020-11-19 17:37 ` [PATCH bpf-next v7 21/34] bpf: eliminate rlimit-based memory accounting for cgroup storage maps Roman Gushchin
2020-11-19 17:37 ` [PATCH bpf-next v7 22/34] bpf: eliminate rlimit-based memory accounting for devmap maps Roman Gushchin
2020-11-19 17:37 ` [PATCH bpf-next v7 23/34] bpf: eliminate rlimit-based memory accounting for hashtab maps Roman Gushchin
2020-11-19 17:37 ` [PATCH bpf-next v7 24/34] bpf: eliminate rlimit-based memory accounting for lpm_trie maps Roman Gushchin
2020-11-19 17:37 ` [PATCH bpf-next v7 25/34] bpf: eliminate rlimit-based memory accounting for queue_stack_maps maps Roman Gushchin
2020-11-19 17:37 ` [PATCH bpf-next v7 26/34] bpf: eliminate rlimit-based memory accounting for reuseport_array maps Roman Gushchin
2020-11-19 17:37 ` [PATCH bpf-next v7 27/34] bpf: eliminate rlimit-based memory accounting for bpf ringbuffer Roman Gushchin
2020-11-19 17:37 ` [PATCH bpf-next v7 28/34] bpf: eliminate rlimit-based memory accounting for sockmap and sockhash maps Roman Gushchin
2020-11-19 17:37 ` [PATCH bpf-next v7 29/34] bpf: eliminate rlimit-based memory accounting for stackmap maps Roman Gushchin
2020-11-19 17:37 ` [PATCH bpf-next v7 30/34] bpf: eliminate rlimit-based memory accounting for xskmap maps Roman Gushchin
2020-11-19 17:37 ` [PATCH bpf-next v7 31/34] bpf: eliminate rlimit-based memory accounting for bpf local storage maps Roman Gushchin
2020-11-19 17:37 ` [PATCH bpf-next v7 32/34] bpf: eliminate rlimit-based memory accounting infra for bpf maps Roman Gushchin
2020-11-21 2:52 ` Alexei Starovoitov
2020-11-21 2:59 ` Roman Gushchin [this message]
2020-11-19 17:37 ` [PATCH bpf-next v7 33/34] bpf: eliminate rlimit-based memory accounting for bpf progs Roman Gushchin
2020-11-19 17:37 ` [PATCH bpf-next v7 34/34] bpf: samples: do not touch RLIMIT_MEMLOCK Roman Gushchin
2020-11-23 13:30 ` [PATCH bpf-next v7 00/34] bpf: switch to memcg-based memory accounting Daniel Borkmann
2020-11-24 0:05 ` Roman Gushchin
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