On Mon, Jul 27, 2020 at 11:06:42PM -0700, Song Liu wrote: > On Mon, Jul 27, 2020 at 10:58 PM Andrii Nakryiko > <andrii.nakryiko@xxxxxxxxx> wrote: > > > > On Mon, Jul 27, 2020 at 10:47 PM Song Liu <song@xxxxxxxxxx> wrote: > > > > > > On Mon, Jul 27, 2020 at 12:26 PM Roman Gushchin <guro@xxxxxx> wrote: > > > > > > > > Remove rlimit-based accounting infrastructure code, which is not used > > > > anymore. > > > > > > > > Signed-off-by: Roman Gushchin <guro@xxxxxx> > > > [...] > > > > > > > > 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? Right. > > 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. But this is just the part of struct bpf_map, so I agree with Andrii, it's a safe check. > > > > > 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... The only question I have if it's worth checking at all? Bumping the rlimit is a way cheaper operation than creating a temporarily map and checking its properties. So is there any win in comparison to just leaving the userspace code* as it is for now? * except runqslower and samples
