2020-07-27 19:20:43

by Roman Gushchin

Subject: [PATCH bpf-next v2 01/35] bpf: memcg-based memory accounting for bpf progs

Include memory used by bpf programs into the memcg-based accounting.
This includes the memory used by programs itself, auxiliary data
and statistics.

Signed-off-by: Roman Gushchin <[email protected]>
---
kernel/bpf/core.c | 8 ++++----
1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/kernel/bpf/core.c b/kernel/bpf/core.c
index bde93344164d..daab8dcafbd4 100644
--- a/kernel/bpf/core.c
+++ b/kernel/bpf/core.c
@@ -77,7 +77,7 @@ void *bpf_internal_load_pointer_neg_helper(const struct sk_buff *skb, int k, uns

struct bpf_prog *bpf_prog_alloc_no_stats(unsigned int size, gfp_t gfp_extra_flags)
{
- gfp_t gfp_flags = GFP_KERNEL | __GFP_ZERO | gfp_extra_flags;
+ gfp_t gfp_flags = GFP_KERNEL_ACCOUNT | __GFP_ZERO | gfp_extra_flags;
struct bpf_prog_aux *aux;
struct bpf_prog *fp;

@@ -86,7 +86,7 @@ struct bpf_prog *bpf_prog_alloc_no_stats(unsigned int size, gfp_t gfp_extra_flag
if (fp == NULL)
return NULL;

- aux = kzalloc(sizeof(*aux), GFP_KERNEL | gfp_extra_flags);
+ aux = kzalloc(sizeof(*aux), GFP_KERNEL_ACCOUNT | gfp_extra_flags);
if (aux == NULL) {
vfree(fp);
return NULL;
@@ -104,7 +104,7 @@ struct bpf_prog *bpf_prog_alloc_no_stats(unsigned int size, gfp_t gfp_extra_flag

struct bpf_prog *bpf_prog_alloc(unsigned int size, gfp_t gfp_extra_flags)
{
- gfp_t gfp_flags = GFP_KERNEL | __GFP_ZERO | gfp_extra_flags;
+ gfp_t gfp_flags = GFP_KERNEL_ACCOUNT | __GFP_ZERO | gfp_extra_flags;
struct bpf_prog *prog;
int cpu;

@@ -217,7 +217,7 @@ void bpf_prog_free_linfo(struct bpf_prog *prog)
struct bpf_prog *bpf_prog_realloc(struct bpf_prog *fp_old, unsigned int size,
gfp_t gfp_extra_flags)
{
- gfp_t gfp_flags = GFP_KERNEL | __GFP_ZERO | gfp_extra_flags;
+ gfp_t gfp_flags = GFP_KERNEL_ACCOUNT | __GFP_ZERO | gfp_extra_flags;
struct bpf_prog *fp;
u32 pages, delta;
int ret;
--
2.26.2

2020-07-27 22:13:19

by Song Liu

Subject: Re: [PATCH bpf-next v2 01/35] bpf: memcg-based memory accounting for bpf progs

On Mon, Jul 27, 2020 at 12:20 PM Roman Gushchin <[email protected]> wrote:
>
> Include memory used by bpf programs into the memcg-based accounting.
> This includes the memory used by programs itself, auxiliary data
> and statistics.
>
> Signed-off-by: Roman Gushchin <[email protected]>
> ---
> kernel/bpf/core.c | 8 ++++----
> 1 file changed, 4 insertions(+), 4 deletions(-)
>
> diff --git a/kernel/bpf/core.c b/kernel/bpf/core.c
> index bde93344164d..daab8dcafbd4 100644
> --- a/kernel/bpf/core.c
> +++ b/kernel/bpf/core.c
> @@ -77,7 +77,7 @@ void *bpf_internal_load_pointer_neg_helper(const struct sk_buff *skb, int k, uns
>
> struct bpf_prog *bpf_prog_alloc_no_stats(unsigned int size, gfp_t gfp_extra_flags)
> {
> - gfp_t gfp_flags = GFP_KERNEL | __GFP_ZERO | gfp_extra_flags;
> + gfp_t gfp_flags = GFP_KERNEL_ACCOUNT | __GFP_ZERO | gfp_extra_flags;
> struct bpf_prog_aux *aux;
> struct bpf_prog *fp;
>
> @@ -86,7 +86,7 @@ struct bpf_prog *bpf_prog_alloc_no_stats(unsigned int size, gfp_t gfp_extra_flag
> if (fp == NULL)
> return NULL;
>
> - aux = kzalloc(sizeof(*aux), GFP_KERNEL | gfp_extra_flags);
> + aux = kzalloc(sizeof(*aux), GFP_KERNEL_ACCOUNT | gfp_extra_flags);
> if (aux == NULL) {
> vfree(fp);
> return NULL;
> @@ -104,7 +104,7 @@ struct bpf_prog *bpf_prog_alloc_no_stats(unsigned int size, gfp_t gfp_extra_flag
>
> struct bpf_prog *bpf_prog_alloc(unsigned int size, gfp_t gfp_extra_flags)
> {
> - gfp_t gfp_flags = GFP_KERNEL | __GFP_ZERO | gfp_extra_flags;
> + gfp_t gfp_flags = GFP_KERNEL_ACCOUNT | __GFP_ZERO | gfp_extra_flags;
> struct bpf_prog *prog;
> int cpu;
>
> @@ -217,7 +217,7 @@ void bpf_prog_free_linfo(struct bpf_prog *prog)
> struct bpf_prog *bpf_prog_realloc(struct bpf_prog *fp_old, unsigned int size,
> gfp_t gfp_extra_flags)
> {
> - gfp_t gfp_flags = GFP_KERNEL | __GFP_ZERO | gfp_extra_flags;
> + gfp_t gfp_flags = GFP_KERNEL_ACCOUNT | __GFP_ZERO | gfp_extra_flags;
> struct bpf_prog *fp;
> u32 pages, delta;
> int ret;
> --

Do we need similar changes in

bpf_prog_array_copy()
bpf_prog_alloc_jited_linfo()
bpf_prog_clone_create()

and maybe a few more?

Thanks,
Song

2020-07-28 00:10:55

by Roman Gushchin

Subject: Re: [PATCH bpf-next v2 01/35] bpf: memcg-based memory accounting for bpf progs

On Mon, Jul 27, 2020 at 03:11:42PM -0700, Song Liu wrote:
> On Mon, Jul 27, 2020 at 12:20 PM Roman Gushchin <[email protected]> wrote:
> >
> > Include memory used by bpf programs into the memcg-based accounting.
> > This includes the memory used by programs itself, auxiliary data
> > and statistics.
> >
> > Signed-off-by: Roman Gushchin <[email protected]>
> > ---
> > kernel/bpf/core.c | 8 ++++----
> > 1 file changed, 4 insertions(+), 4 deletions(-)
> >
> > diff --git a/kernel/bpf/core.c b/kernel/bpf/core.c
> > index bde93344164d..daab8dcafbd4 100644
> > --- a/kernel/bpf/core.c
> > +++ b/kernel/bpf/core.c
> > @@ -77,7 +77,7 @@ void *bpf_internal_load_pointer_neg_helper(const struct sk_buff *skb, int k, uns
> >
> > struct bpf_prog *bpf_prog_alloc_no_stats(unsigned int size, gfp_t gfp_extra_flags)
> > {
> > - gfp_t gfp_flags = GFP_KERNEL | __GFP_ZERO | gfp_extra_flags;
> > + gfp_t gfp_flags = GFP_KERNEL_ACCOUNT | __GFP_ZERO | gfp_extra_flags;
> > struct bpf_prog_aux *aux;
> > struct bpf_prog *fp;
> >
> > @@ -86,7 +86,7 @@ struct bpf_prog *bpf_prog_alloc_no_stats(unsigned int size, gfp_t gfp_extra_flag
> > if (fp == NULL)
> > return NULL;
> >
> > - aux = kzalloc(sizeof(*aux), GFP_KERNEL | gfp_extra_flags);
> > + aux = kzalloc(sizeof(*aux), GFP_KERNEL_ACCOUNT | gfp_extra_flags);
> > if (aux == NULL) {
> > vfree(fp);
> > return NULL;
> > @@ -104,7 +104,7 @@ struct bpf_prog *bpf_prog_alloc_no_stats(unsigned int size, gfp_t gfp_extra_flag
> >
> > struct bpf_prog *bpf_prog_alloc(unsigned int size, gfp_t gfp_extra_flags)
> > {
> > - gfp_t gfp_flags = GFP_KERNEL | __GFP_ZERO | gfp_extra_flags;
> > + gfp_t gfp_flags = GFP_KERNEL_ACCOUNT | __GFP_ZERO | gfp_extra_flags;
> > struct bpf_prog *prog;
> > int cpu;
> >
> > @@ -217,7 +217,7 @@ void bpf_prog_free_linfo(struct bpf_prog *prog)
> > struct bpf_prog *bpf_prog_realloc(struct bpf_prog *fp_old, unsigned int size,
> > gfp_t gfp_extra_flags)
> > {
> > - gfp_t gfp_flags = GFP_KERNEL | __GFP_ZERO | gfp_extra_flags;
> > + gfp_t gfp_flags = GFP_KERNEL_ACCOUNT | __GFP_ZERO | gfp_extra_flags;
> > struct bpf_prog *fp;
> > u32 pages, delta;
> > int ret;
> > --

Hi Song!

Thank you for looking into the patchset!

>
> Do we need similar changes in
>
> bpf_prog_array_copy()
> bpf_prog_alloc_jited_linfo()
> bpf_prog_clone_create()
>
> and maybe a few more?

I've tried to follow the rlimit-based accounting, so those objects which were
skipped are mostly skipped now and vice versa. The main reason for that is
simple: I don't know many parts of bpf code well enough to decide whether
we need accounting or not.

In general with memcg-based accounting we can easily cover places which were
not covered previously: e.g. the memory used by the verifier. But I guess it's
better to do it case-by-case.

But if you're aware of any big objects which should be accounted for sure,
please, let me know.

Thanks!

2020-07-28 04:46:13

by Song Liu

Subject: Re: [PATCH bpf-next v2 01/35] bpf: memcg-based memory accounting for bpf progs

On Mon, Jul 27, 2020 at 5:08 PM Roman Gushchin <[email protected]> wrote:
>
> On Mon, Jul 27, 2020 at 03:11:42PM -0700, Song Liu wrote:
> > On Mon, Jul 27, 2020 at 12:20 PM Roman Gushchin <[email protected]> wrote:
> > >
> > > Include memory used by bpf programs into the memcg-based accounting.
> > > This includes the memory used by programs itself, auxiliary data
> > > and statistics.
> > >
> > > Signed-off-by: Roman Gushchin <[email protected]>
> > > ---
> > > kernel/bpf/core.c | 8 ++++----
> > > 1 file changed, 4 insertions(+), 4 deletions(-)
> > >
> > > diff --git a/kernel/bpf/core.c b/kernel/bpf/core.c
> > > index bde93344164d..daab8dcafbd4 100644
> > > --- a/kernel/bpf/core.c
> > > +++ b/kernel/bpf/core.c
> > > @@ -77,7 +77,7 @@ void *bpf_internal_load_pointer_neg_helper(const struct sk_buff *skb, int k, uns
> > >
> > > struct bpf_prog *bpf_prog_alloc_no_stats(unsigned int size, gfp_t gfp_extra_flags)
> > > {
> > > - gfp_t gfp_flags = GFP_KERNEL | __GFP_ZERO | gfp_extra_flags;
> > > + gfp_t gfp_flags = GFP_KERNEL_ACCOUNT | __GFP_ZERO | gfp_extra_flags;
> > > struct bpf_prog_aux *aux;
> > > struct bpf_prog *fp;
> > >
> > > @@ -86,7 +86,7 @@ struct bpf_prog *bpf_prog_alloc_no_stats(unsigned int size, gfp_t gfp_extra_flag
> > > if (fp == NULL)
> > > return NULL;
> > >
> > > - aux = kzalloc(sizeof(*aux), GFP_KERNEL | gfp_extra_flags);
> > > + aux = kzalloc(sizeof(*aux), GFP_KERNEL_ACCOUNT | gfp_extra_flags);
> > > if (aux == NULL) {
> > > vfree(fp);
> > > return NULL;
> > > @@ -104,7 +104,7 @@ struct bpf_prog *bpf_prog_alloc_no_stats(unsigned int size, gfp_t gfp_extra_flag
> > >
> > > struct bpf_prog *bpf_prog_alloc(unsigned int size, gfp_t gfp_extra_flags)
> > > {
> > > - gfp_t gfp_flags = GFP_KERNEL | __GFP_ZERO | gfp_extra_flags;
> > > + gfp_t gfp_flags = GFP_KERNEL_ACCOUNT | __GFP_ZERO | gfp_extra_flags;
> > > struct bpf_prog *prog;
> > > int cpu;
> > >
> > > @@ -217,7 +217,7 @@ void bpf_prog_free_linfo(struct bpf_prog *prog)
> > > struct bpf_prog *bpf_prog_realloc(struct bpf_prog *fp_old, unsigned int size,
> > > gfp_t gfp_extra_flags)
> > > {
> > > - gfp_t gfp_flags = GFP_KERNEL | __GFP_ZERO | gfp_extra_flags;
> > > + gfp_t gfp_flags = GFP_KERNEL_ACCOUNT | __GFP_ZERO | gfp_extra_flags;
> > > struct bpf_prog *fp;
> > > u32 pages, delta;
> > > int ret;
> > > --
>
> Hi Song!
>
> Thank you for looking into the patchset!
>
> >
> > Do we need similar changes in
> >
> > bpf_prog_array_copy()
> > bpf_prog_alloc_jited_linfo()
> > bpf_prog_clone_create()
> >
> > and maybe a few more?
>
> I've tried to follow the rlimit-based accounting, so those objects which were
> skipped are mostly skipped now and vice versa. The main reason for that is
> simple: I don't know many parts of bpf code well enough to decide whether
> we need accounting or not.
>
> In general with memcg-based accounting we can easily cover places which were
> not covered previously: e.g. the memory used by the verifier. But I guess it's
> better to do it case-by-case.
>
> But if you're aware of any big objects which should be accounted for sure,
> please, let me know.

Thanks for the explanation. I think we can do one-to-one migration to
memcg-based accounting for now.

Song