| Message ID | 20240628003253.1694510-12-almasrymina@google.com (mailing list archive) |
|---|---|
| State | New |
| Headers | show |
| Series | Device Memory TCP | expand |
On Fri, Jun 28, 2024 at 2:33 AM Mina Almasry <almasrymina@google.com> wrote: > > Add an interface for the user to notify the kernel that it is done > reading the devmem dmabuf frags returned as cmsg. The kernel will > drop the reference on the frags to make them available for reuse. > > Signed-off-by: Willem de Bruijn <willemb@google.com> > Signed-off-by: Kaiyuan Zhang <kaiyuanz@google.com> > Signed-off-by: Mina Almasry <almasrymina@google.com> > > --- > > v10: > - Fix leak of tokens (Nikolay). > > v7: > - Updated SO_DEVMEM_* uapi to use the next available entry (Arnd). > > v6: > - Squash in locking optimizations from edumazet@google.com. With his > changes we lock the xarray once per sock_devmem_dontneed operation > rather than once per frag. > > Changes in v1: > - devmemtoken -> dmabuf_token (David). > - Use napi_pp_put_page() for refcounting (Yunsheng). > - Fix build error with missing socket options on other asms. > > --- > arch/alpha/include/uapi/asm/socket.h | 1 + > arch/mips/include/uapi/asm/socket.h | 1 + > arch/parisc/include/uapi/asm/socket.h | 1 + > arch/sparc/include/uapi/asm/socket.h | 1 + > include/uapi/asm-generic/socket.h | 1 + > include/uapi/linux/uio.h | 4 ++ > net/core/sock.c | 61 +++++++++++++++++++++++++++ > 7 files changed, 70 insertions(+) > > > +struct dmabuf_token { > + __u32 token_start; > + __u32 token_count; > +}; > /* > * UIO_MAXIOV shall be at least 16 1003.1g (5.4.1.1) > */ > diff --git a/net/core/sock.c b/net/core/sock.c > index 9abc4fe259535..040c66ac26244 100644 > --- a/net/core/sock.c > +++ b/net/core/sock.c > @@ -124,6 +124,7 @@ > #include <linux/netdevice.h> > #include <net/protocol.h> > #include <linux/skbuff.h> > +#include <linux/skbuff_ref.h> > #include <net/net_namespace.h> > #include <net/request_sock.h> > #include <net/sock.h> > @@ -1049,6 +1050,62 @@ static int sock_reserve_memory(struct sock *sk, int bytes) > return 0; > } > > +#ifdef CONFIG_PAGE_POOL > +static noinline_for_stack int > +sock_devmem_dontneed(struct sock *sk, sockptr_t optval, unsigned int optlen) > +{ > + unsigned int num_tokens, i, j, k, netmem_num = 0; > + struct dmabuf_token *tokens; > + netmem_ref netmems[16]; > + int ret = 0; > + > + if (sk->sk_type != SOCK_STREAM || sk->sk_protocol != IPPROTO_TCP) > + return -EBADF; This might use sk_is_tcp() helper. > + > + if (optlen % sizeof(struct dmabuf_token) || > + optlen > sizeof(*tokens) * 128) > + return -EINVAL; > + > + tokens = kvmalloc_array(128, sizeof(*tokens), GFP_KERNEL); This allocates 8192 bytes even for small optlen ? Probably no big deal, no need to send a new version. Reviewed-by: Eric Dumazet <edumazet@google.com>
On 6/28/24 01:32, Mina Almasry wrote: > Add an interface for the user to notify the kernel that it is done > reading the devmem dmabuf frags returned as cmsg. The kernel will > drop the reference on the frags to make them available for reuse. > > Signed-off-by: Willem de Bruijn <willemb@google.com> > Signed-off-by: Kaiyuan Zhang <kaiyuanz@google.com> > Signed-off-by: Mina Almasry <almasrymina@google.com> Same, lost tag from v13 Reviewed-by: Pavel Begunkov <asml.silence@gmail.com> And, as a follow up, would be great to clean up the loop. Helper functions and "continue" should help to bring the indention down.
On 6/27/24 6:32 PM, Mina Almasry wrote: > @@ -1049,6 +1050,62 @@ static int sock_reserve_memory(struct sock *sk, int bytes) > return 0; > } > > +#ifdef CONFIG_PAGE_POOL > +static noinline_for_stack int > +sock_devmem_dontneed(struct sock *sk, sockptr_t optval, unsigned int optlen) > +{ > + unsigned int num_tokens, i, j, k, netmem_num = 0; > + struct dmabuf_token *tokens; > + netmem_ref netmems[16]; > + int ret = 0; > + > + if (sk->sk_type != SOCK_STREAM || sk->sk_protocol != IPPROTO_TCP) > + return -EBADF; > + > + if (optlen % sizeof(struct dmabuf_token) || > + optlen > sizeof(*tokens) * 128) > + return -EINVAL; > + > + tokens = kvmalloc_array(128, sizeof(*tokens), GFP_KERNEL); The '128' should be a named macro with a comment on why that value.
diff --git a/arch/alpha/include/uapi/asm/socket.h b/arch/alpha/include/uapi/asm/socket.h index ef4656a41058a..251b73c5481ea 100644 --- a/arch/alpha/include/uapi/asm/socket.h +++ b/arch/alpha/include/uapi/asm/socket.h @@ -144,6 +144,7 @@ #define SCM_DEVMEM_LINEAR SO_DEVMEM_LINEAR #define SO_DEVMEM_DMABUF 79 #define SCM_DEVMEM_DMABUF SO_DEVMEM_DMABUF +#define SO_DEVMEM_DONTNEED 80 #if !defined(__KERNEL__) diff --git a/arch/mips/include/uapi/asm/socket.h b/arch/mips/include/uapi/asm/socket.h index 414807d55e33f..8ab7582291abf 100644 --- a/arch/mips/include/uapi/asm/socket.h +++ b/arch/mips/include/uapi/asm/socket.h @@ -155,6 +155,7 @@ #define SCM_DEVMEM_LINEAR SO_DEVMEM_LINEAR #define SO_DEVMEM_DMABUF 79 #define SCM_DEVMEM_DMABUF SO_DEVMEM_DMABUF +#define SO_DEVMEM_DONTNEED 80 #if !defined(__KERNEL__) diff --git a/arch/parisc/include/uapi/asm/socket.h b/arch/parisc/include/uapi/asm/socket.h index 2b817efd45444..38fc0b188e084 100644 --- a/arch/parisc/include/uapi/asm/socket.h +++ b/arch/parisc/include/uapi/asm/socket.h @@ -136,6 +136,7 @@ #define SCM_DEVMEM_LINEAR SO_DEVMEM_LINEAR #define SO_DEVMEM_DMABUF 79 #define SCM_DEVMEM_DMABUF SO_DEVMEM_DMABUF +#define SO_DEVMEM_DONTNEED 80 #if !defined(__KERNEL__) diff --git a/arch/sparc/include/uapi/asm/socket.h b/arch/sparc/include/uapi/asm/socket.h index 00248fc689773..57084ed2f3c4e 100644 --- a/arch/sparc/include/uapi/asm/socket.h +++ b/arch/sparc/include/uapi/asm/socket.h @@ -137,6 +137,7 @@ #define SCM_DEVMEM_LINEAR SO_DEVMEM_LINEAR #define SO_DEVMEM_DMABUF 0x0058 #define SCM_DEVMEM_DMABUF SO_DEVMEM_DMABUF +#define SO_DEVMEM_DONTNEED 0x0059 #if !defined(__KERNEL__) diff --git a/include/uapi/asm-generic/socket.h b/include/uapi/asm-generic/socket.h index 25a2f5255f523..1acb77780f103 100644 --- a/include/uapi/asm-generic/socket.h +++ b/include/uapi/asm-generic/socket.h @@ -135,6 +135,7 @@ #define SO_PASSPIDFD 76 #define SO_PEERPIDFD 77 +#define SO_DEVMEM_DONTNEED 97 #define SO_DEVMEM_LINEAR 98 #define SCM_DEVMEM_LINEAR SO_DEVMEM_LINEAR #define SO_DEVMEM_DMABUF 99 diff --git a/include/uapi/linux/uio.h b/include/uapi/linux/uio.h index 3a22ddae376a2..d17f8fcd93ec9 100644 --- a/include/uapi/linux/uio.h +++ b/include/uapi/linux/uio.h @@ -33,6 +33,10 @@ struct dmabuf_cmsg { */ }; +struct dmabuf_token { + __u32 token_start; + __u32 token_count; +}; /* * UIO_MAXIOV shall be at least 16 1003.1g (5.4.1.1) */ diff --git a/net/core/sock.c b/net/core/sock.c index 9abc4fe259535..040c66ac26244 100644 --- a/net/core/sock.c +++ b/net/core/sock.c @@ -124,6 +124,7 @@ #include <linux/netdevice.h> #include <net/protocol.h> #include <linux/skbuff.h> +#include <linux/skbuff_ref.h> #include <net/net_namespace.h> #include <net/request_sock.h> #include <net/sock.h> @@ -1049,6 +1050,62 @@ static int sock_reserve_memory(struct sock *sk, int bytes) return 0; } +#ifdef CONFIG_PAGE_POOL +static noinline_for_stack int +sock_devmem_dontneed(struct sock *sk, sockptr_t optval, unsigned int optlen) +{ + unsigned int num_tokens, i, j, k, netmem_num = 0; + struct dmabuf_token *tokens; + netmem_ref netmems[16]; + int ret = 0; + + if (sk->sk_type != SOCK_STREAM || sk->sk_protocol != IPPROTO_TCP) + return -EBADF; + + if (optlen % sizeof(struct dmabuf_token) || + optlen > sizeof(*tokens) * 128) + return -EINVAL; + + tokens = kvmalloc_array(128, sizeof(*tokens), GFP_KERNEL); + if (!tokens) + return -ENOMEM; + + num_tokens = optlen / sizeof(struct dmabuf_token); + if (copy_from_sockptr(tokens, optval, optlen)) { + kvfree(tokens); + return -EFAULT; + } + + xa_lock_bh(&sk->sk_user_frags); + for (i = 0; i < num_tokens; i++) { + for (j = 0; j < tokens[i].token_count; j++) { + netmem_ref netmem = (__force netmem_ref)__xa_erase( + &sk->sk_user_frags, tokens[i].token_start + j); + + if (netmem && + !WARN_ON_ONCE(!netmem_is_net_iov(netmem))) { + netmems[netmem_num++] = netmem; + if (netmem_num == ARRAY_SIZE(netmems)) { + xa_unlock_bh(&sk->sk_user_frags); + for (k = 0; k < netmem_num; k++) + WARN_ON_ONCE(!napi_pp_put_page(netmems[k])); + netmem_num = 0; + xa_lock_bh(&sk->sk_user_frags); + } + ret++; + } + } + } + + xa_unlock_bh(&sk->sk_user_frags); + for (k = 0; k < netmem_num; k++) + WARN_ON_ONCE(!napi_pp_put_page(netmems[k])); + + kvfree(tokens); + return ret; +} +#endif + void sockopt_lock_sock(struct sock *sk) { /* When current->bpf_ctx is set, the setsockopt is called from @@ -1211,6 +1268,10 @@ int sk_setsockopt(struct sock *sk, int level, int optname, ret = -EOPNOTSUPP; return ret; } +#ifdef CONFIG_PAGE_POOL + case SO_DEVMEM_DONTNEED: + return sock_devmem_dontneed(sk, optval, optlen); +#endif } sockopt_lock_sock(sk);