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Message-ID: <YkX200lPSHpw8rt8@carbon.dhcp.thefacebook.com>
Date: Thu, 31 Mar 2022 11:45:39 -0700
From: Roman Gushchin <roman.gushchin@...ux.dev>
To: Vasily Averin <vasily.averin@...ux.dev>
Cc: Pablo Neira Ayuso <pablo@...filter.org>, kernel@...nvz.org,
Jozsef Kadlecsik <kadlec@...filter.org>,
Florian Westphal <fw@...len.de>,
netfilter-devel@...r.kernel.org, linux-kernel@...r.kernel.org
Subject: Re: [PATCH nft] nft: memcg accounting for dynamically allocated
objects
On Thu, Mar 31, 2022 at 11:40:23AM +0300, Vasily Averin wrote:
> nft_*.c files whose NFT_EXPR_STATEFUL flag is set on need to
> use __GFP_ACCOUNT flag for objects that are dynamically
> allocated from the packet path.
>
> Such objects are allocated inside .init() or .clone() callbacks
> of struct nft_expr_ops executed in task context while processing
> netlink messages.
>
> In addition, this patch adds accounting to nft_set_elem_expr_clone()
> used for the same purposes.
The patch looks good to me. The only concern I have is a potential
performance regression. Are any of these allocations happening on really
hot paths? From a very brief look it seems like the answer is no,
but I'm not well familiar with the netfilter code. Would be nice to
have a confirmation from somebody working on the netfilter.
We are roughly talking about x2 slower memory allocations, which
is usually not a problem at all, given that allocations are still
very cheap.
Please, feel free to add my
Acked-by: Roman Gushchin <roman.gushchin@...ux.dev>
Thanks!
>
> Signed-off-by: Vasily Averin <vvs@...nvz.org>
> ---
> net/netfilter/nf_tables_api.c | 2 +-
> net/netfilter/nft_connlimit.c | 4 ++--
> net/netfilter/nft_counter.c | 4 ++--
> net/netfilter/nft_last.c | 4 ++--
> net/netfilter/nft_limit.c | 4 ++--
> net/netfilter/nft_quota.c | 4 ++--
> 6 files changed, 11 insertions(+), 11 deletions(-)
>
> diff --git a/net/netfilter/nf_tables_api.c b/net/netfilter/nf_tables_api.c
> index 04be94236a34..e01241151ef7 100644
> --- a/net/netfilter/nf_tables_api.c
> +++ b/net/netfilter/nf_tables_api.c
> @@ -5447,7 +5447,7 @@ int nft_set_elem_expr_clone(const struct nft_ctx *ctx, struct nft_set *set,
> int err, i, k;
>
> for (i = 0; i < set->num_exprs; i++) {
> - expr = kzalloc(set->exprs[i]->ops->size, GFP_KERNEL);
> + expr = kzalloc(set->exprs[i]->ops->size, GFP_KERNEL_ACCOUNT);
> if (!expr)
> goto err_expr;
>
> diff --git a/net/netfilter/nft_connlimit.c b/net/netfilter/nft_connlimit.c
> index 3362417ebfdb..9c2146aac59e 100644
> --- a/net/netfilter/nft_connlimit.c
> +++ b/net/netfilter/nft_connlimit.c
> @@ -77,7 +77,7 @@ static int nft_connlimit_do_init(const struct nft_ctx *ctx,
> invert = true;
> }
>
> - priv->list = kmalloc(sizeof(*priv->list), GFP_KERNEL);
> + priv->list = kmalloc(sizeof(*priv->list), GFP_KERNEL_ACCOUNT);
> if (!priv->list)
> return -ENOMEM;
>
> @@ -214,7 +214,7 @@ static int nft_connlimit_clone(struct nft_expr *dst, const struct nft_expr *src)
> struct nft_connlimit *priv_dst = nft_expr_priv(dst);
> struct nft_connlimit *priv_src = nft_expr_priv(src);
>
> - priv_dst->list = kmalloc(sizeof(*priv_dst->list), GFP_ATOMIC);
> + priv_dst->list = kmalloc(sizeof(*priv_dst->list), GFP_ATOMIC | __GFP_ACCOUNT);
> if (!priv_dst->list)
> return -ENOMEM;
>
> diff --git a/net/netfilter/nft_counter.c b/net/netfilter/nft_counter.c
> index f179e8c3b0ca..040a697d96b3 100644
> --- a/net/netfilter/nft_counter.c
> +++ b/net/netfilter/nft_counter.c
> @@ -62,7 +62,7 @@ static int nft_counter_do_init(const struct nlattr * const tb[],
> struct nft_counter __percpu *cpu_stats;
> struct nft_counter *this_cpu;
>
> - cpu_stats = alloc_percpu(struct nft_counter);
> + cpu_stats = alloc_percpu_gfp(struct nft_counter, GFP_KERNEL_ACCOUNT);
> if (cpu_stats == NULL)
> return -ENOMEM;
>
> @@ -235,7 +235,7 @@ static int nft_counter_clone(struct nft_expr *dst, const struct nft_expr *src)
>
> nft_counter_fetch(priv, &total);
>
> - cpu_stats = alloc_percpu_gfp(struct nft_counter, GFP_ATOMIC);
> + cpu_stats = alloc_percpu_gfp(struct nft_counter, GFP_ATOMIC | __GFP_ACCOUNT);
> if (cpu_stats == NULL)
> return -ENOMEM;
>
> diff --git a/net/netfilter/nft_last.c b/net/netfilter/nft_last.c
> index 4f745a409d34..4cf4f6349855 100644
> --- a/net/netfilter/nft_last.c
> +++ b/net/netfilter/nft_last.c
> @@ -30,7 +30,7 @@ static int nft_last_init(const struct nft_ctx *ctx, const struct nft_expr *expr,
> u64 last_jiffies;
> int err;
>
> - last = kzalloc(sizeof(*last), GFP_KERNEL);
> + last = kzalloc(sizeof(*last), GFP_KERNEL_ACCOUNT);
> if (!last)
> return -ENOMEM;
>
> @@ -105,7 +105,7 @@ static int nft_last_clone(struct nft_expr *dst, const struct nft_expr *src)
> {
> struct nft_last_priv *priv_dst = nft_expr_priv(dst);
>
> - priv_dst->last = kzalloc(sizeof(*priv_dst->last), GFP_ATOMIC);
> + priv_dst->last = kzalloc(sizeof(*priv_dst->last), GFP_ATOMIC | __GFP_ACCOUNT);
> if (!priv_dst->last)
> return -ENOMEM;
>
> diff --git a/net/netfilter/nft_limit.c b/net/netfilter/nft_limit.c
> index a726b623963d..d7779d5f3cbb 100644
> --- a/net/netfilter/nft_limit.c
> +++ b/net/netfilter/nft_limit.c
> @@ -90,7 +90,7 @@ static int nft_limit_init(struct nft_limit_priv *priv,
> priv->rate);
> }
>
> - priv->limit = kmalloc(sizeof(*priv->limit), GFP_KERNEL);
> + priv->limit = kmalloc(sizeof(*priv->limit), GFP_KERNEL_ACCOUNT);
> if (!priv->limit)
> return -ENOMEM;
>
> @@ -144,7 +144,7 @@ static int nft_limit_clone(struct nft_limit_priv *priv_dst,
> priv_dst->burst = priv_src->burst;
> priv_dst->invert = priv_src->invert;
>
> - priv_dst->limit = kmalloc(sizeof(*priv_dst->limit), GFP_ATOMIC);
> + priv_dst->limit = kmalloc(sizeof(*priv_dst->limit), GFP_ATOMIC | __GFP_ACCOUNT);
> if (!priv_dst->limit)
> return -ENOMEM;
>
> diff --git a/net/netfilter/nft_quota.c b/net/netfilter/nft_quota.c
> index f394a0b562f6..2def4d92a170 100644
> --- a/net/netfilter/nft_quota.c
> +++ b/net/netfilter/nft_quota.c
> @@ -90,7 +90,7 @@ static int nft_quota_do_init(const struct nlattr * const tb[],
> return -EOPNOTSUPP;
> }
>
> - priv->consumed = kmalloc(sizeof(*priv->consumed), GFP_KERNEL);
> + priv->consumed = kmalloc(sizeof(*priv->consumed), GFP_KERNEL_ACCOUNT);
> if (!priv->consumed)
> return -ENOMEM;
>
> @@ -236,7 +236,7 @@ static int nft_quota_clone(struct nft_expr *dst, const struct nft_expr *src)
> {
> struct nft_quota *priv_dst = nft_expr_priv(dst);
>
> - priv_dst->consumed = kmalloc(sizeof(*priv_dst->consumed), GFP_ATOMIC);
> + priv_dst->consumed = kmalloc(sizeof(*priv_dst->consumed), GFP_ATOMIC | __GFP_ACCOUNT);
> if (!priv_dst->consumed)
> return -ENOMEM;
>
> --
> 2.31.1
>
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