Re: [PATCH bpf-next v2 27/35] bpf: eliminate rlimit-based memory accounting infra for bpf maps
From: Song Liu <song@kernel.org>
Date: 2020-07-28 06:06:58
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On Mon, Jul 27, 2020 at 10:58 PM Andrii Nakryiko [off-list ref] wrote:
On Mon, Jul 27, 2020 at 10:47 PM Song Liu [off-list ref] wrote:quoted
On Mon, Jul 27, 2020 at 12:26 PM Roman Gushchin [off-list ref] wrote:quoted
Remove rlimit-based accounting infrastructure code, which is not used anymore. Signed-off-by: Roman Gushchin <redacted>[...]quoted
static void bpf_map_put_uref(struct bpf_map *map)@@ -541,7 +484,7 @@ 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 */I am not sure whether we can deprecate this one.. How difficult is it to keep this statistics?It's factually correct now, that BPF map doesn't use any memlock memory, no?
I am not sure whether memlock really means memlock for all users... I bet there are users who use memlock to check total memory used by the map.
This is actually one way to detect whether RLIMIT_MEMLOCK is necessary or not: create a small map, check if it's fdinfo has memlock: 0 or not :)
If we do show memlock=0, this is a good check... Thanks, Song