Re: [PATCH bpf-next v5 7/7] bpf: Use try_alloc_pages() to allocate pages for bpf needs.

[Alexei Starovoitov <alexei.starovoitov@gmail.com>]

On Wed, Jan 15, 2025 at 10:03 AM Vlastimil Babka <vbabka@suse.cz> wrote:
>
> On 1/15/25 03:17, Alexei Starovoitov wrote:
> > From: Alexei Starovoitov <ast@kernel.org>
> >
> > Use try_alloc_pages() and free_pages_nolock()
> >
> > Signed-off-by: Alexei Starovoitov <ast@kernel.org>
> > ---
> >  kernel/bpf/syscall.c | 4 ++--
> >  1 file changed, 2 insertions(+), 2 deletions(-)
> >
> > diff --git a/kernel/bpf/syscall.c b/kernel/bpf/syscall.c
> > index 0daf098e3207..8bcf48e31a5a 100644
> > --- a/kernel/bpf/syscall.c
> > +++ b/kernel/bpf/syscall.c
> > @@ -582,14 +582,14 @@ int bpf_map_alloc_pages(const struct bpf_map *map, gfp_t gfp, int nid,
>
> This makes the gfp parameter unused? And the callers are passing GFP_KERNEL
> anyway? Isn't try_alloc_pages() rather useful for some context that did not
> even try to allocate until now, but now it could?

Correct. gfp arg is unused and currently it's only called
from sleepable bpf kfunc with GFP_KERNEL.
I have more patches on top that change all that:
remove gfp argument, etc.
Just didn't send them as part of this set, since it's all bpf internal
stuff.