Mailing List Archive

[PATCH net-next v2 13/15] net: replace page_frag with page_frag_cache
Use the newly introduced prepare/commit API to replace
page_frag with page_frag_cache for sk_page_frag().

Signed-off-by: Yunsheng Lin <linyunsheng@huawei.com>
---
.../chelsio/inline_crypto/chtls/chtls.h | 3 -
.../chelsio/inline_crypto/chtls/chtls_io.c | 101 ++++---------
.../chelsio/inline_crypto/chtls/chtls_main.c | 3 -
drivers/net/tun.c | 34 ++---
include/linux/sched.h | 4 +-
include/net/sock.h | 14 +-
kernel/exit.c | 3 +-
kernel/fork.c | 2 +-
net/core/skbuff.c | 32 ++--
net/core/skmsg.c | 22 +--
net/core/sock.c | 46 ++++--
net/ipv4/ip_output.c | 35 +++--
net/ipv4/tcp.c | 35 ++---
net/ipv4/tcp_output.c | 28 ++--
net/ipv6/ip6_output.c | 35 +++--
net/kcm/kcmsock.c | 30 ++--
net/mptcp/protocol.c | 74 ++++++----
net/tls/tls_device.c | 139 ++++++++++--------
18 files changed, 342 insertions(+), 298 deletions(-)

diff --git a/drivers/net/ethernet/chelsio/inline_crypto/chtls/chtls.h b/drivers/net/ethernet/chelsio/inline_crypto/chtls/chtls.h
index 7ff82b6778ba..fe2b6a8ef718 100644
--- a/drivers/net/ethernet/chelsio/inline_crypto/chtls/chtls.h
+++ b/drivers/net/ethernet/chelsio/inline_crypto/chtls/chtls.h
@@ -234,7 +234,6 @@ struct chtls_dev {
struct list_head list_node;
struct list_head rcu_node;
struct list_head na_node;
- unsigned int send_page_order;
int max_host_sndbuf;
u32 round_robin_cnt;
struct key_map kmap;
@@ -453,8 +452,6 @@ enum {

/* The ULP mode/submode of an skbuff */
#define skb_ulp_mode(skb) (ULP_SKB_CB(skb)->ulp_mode)
-#define TCP_PAGE(sk) (sk->sk_frag.page)
-#define TCP_OFF(sk) (sk->sk_frag.offset)

static inline struct chtls_dev *to_chtls_dev(struct tls_toe_device *tlsdev)
{
diff --git a/drivers/net/ethernet/chelsio/inline_crypto/chtls/chtls_io.c b/drivers/net/ethernet/chelsio/inline_crypto/chtls/chtls_io.c
index d567e42e1760..8f2dfbe9d3a4 100644
--- a/drivers/net/ethernet/chelsio/inline_crypto/chtls/chtls_io.c
+++ b/drivers/net/ethernet/chelsio/inline_crypto/chtls/chtls_io.c
@@ -825,12 +825,6 @@ void skb_entail(struct sock *sk, struct sk_buff *skb, int flags)
ULP_SKB_CB(skb)->flags = flags;
__skb_queue_tail(&csk->txq, skb);
sk->sk_wmem_queued += skb->truesize;
-
- if (TCP_PAGE(sk) && TCP_OFF(sk)) {
- put_page(TCP_PAGE(sk));
- TCP_PAGE(sk) = NULL;
- TCP_OFF(sk) = 0;
- }
}

static struct sk_buff *get_tx_skb(struct sock *sk, int size)
@@ -882,16 +876,12 @@ static void push_frames_if_head(struct sock *sk)
chtls_push_frames(csk, 1);
}

-static int chtls_skb_copy_to_page_nocache(struct sock *sk,
- struct iov_iter *from,
- struct sk_buff *skb,
- struct page *page,
- int off, int copy)
+static int chtls_skb_copy_to_va_nocache(struct sock *sk, struct iov_iter *from,
+ struct sk_buff *skb, char *va, int copy)
{
int err;

- err = skb_do_copy_data_nocache(sk, skb, from, page_address(page) +
- off, copy, skb->len);
+ err = skb_do_copy_data_nocache(sk, skb, from, va, copy, skb->len);
if (err)
return err;

@@ -1114,82 +1104,45 @@ int chtls_sendmsg(struct sock *sk, struct msghdr *msg, size_t size)
if (err)
goto do_fault;
} else {
+ struct page_frag_cache *pfrag = &sk->sk_frag;
int i = skb_shinfo(skb)->nr_frags;
- struct page *page = TCP_PAGE(sk);
- int pg_size = PAGE_SIZE;
- int off = TCP_OFF(sk);
- bool merge;
-
- if (page)
- pg_size = page_size(page);
- if (off < pg_size &&
- skb_can_coalesce(skb, i, page, off)) {
+ unsigned int offset, size;
+ bool merge = false;
+ struct page *page;
+ void *va;
+
+ size = 32U;
+ page = page_frag_alloc_prepare(pfrag, &offset, &size,
+ &va, sk->sk_allocation);
+ if (unlikely(!page))
+ goto wait_for_memory;
+
+ if (skb_can_coalesce(skb, i, page, offset))
merge = true;
- goto copy;
- }
- merge = false;
- if (i == (is_tls_tx(csk) ? (MAX_SKB_FRAGS - 1) :
- MAX_SKB_FRAGS))
+ else if (i == (is_tls_tx(csk) ? (MAX_SKB_FRAGS - 1) :
+ MAX_SKB_FRAGS))
goto new_buf;

- if (page && off == pg_size) {
- put_page(page);
- TCP_PAGE(sk) = page = NULL;
- pg_size = PAGE_SIZE;
- }
-
- if (!page) {
- gfp_t gfp = sk->sk_allocation;
- int order = cdev->send_page_order;
-
- if (order) {
- page = alloc_pages(gfp | __GFP_COMP |
- __GFP_NOWARN |
- __GFP_NORETRY,
- order);
- if (page)
- pg_size <<= order;
- }
- if (!page) {
- page = alloc_page(gfp);
- pg_size = PAGE_SIZE;
- }
- if (!page)
- goto wait_for_memory;
- off = 0;
- }
-copy:
- if (copy > pg_size - off)
- copy = pg_size - off;
+ copy = min_t(int, copy, size);
if (is_tls_tx(csk))
copy = min_t(int, copy, csk->tlshws.txleft);

- err = chtls_skb_copy_to_page_nocache(sk, &msg->msg_iter,
- skb, page,
- off, copy);
- if (unlikely(err)) {
- if (!TCP_PAGE(sk)) {
- TCP_PAGE(sk) = page;
- TCP_OFF(sk) = 0;
- }
+ err = chtls_skb_copy_to_va_nocache(sk, &msg->msg_iter,
+ skb, va, copy);
+ if (unlikely(err))
goto do_fault;
- }
+
/* Update the skb. */
if (merge) {
skb_frag_size_add(
&skb_shinfo(skb)->frags[i - 1],
copy);
+ page_frag_alloc_commit_noref(pfrag, offset,
+ copy);
} else {
- skb_fill_page_desc(skb, i, page, off, copy);
- if (off + copy < pg_size) {
- /* space left keep page */
- get_page(page);
- TCP_PAGE(sk) = page;
- } else {
- TCP_PAGE(sk) = NULL;
- }
+ skb_fill_page_desc(skb, i, page, offset, copy);
+ page_frag_alloc_commit(pfrag, offset, copy);
}
- TCP_OFF(sk) = off + copy;
}
if (unlikely(skb->len == mss))
tx_skb_finalize(skb);
diff --git a/drivers/net/ethernet/chelsio/inline_crypto/chtls/chtls_main.c b/drivers/net/ethernet/chelsio/inline_crypto/chtls/chtls_main.c
index 455a54708be4..ba88b2fc7cd8 100644
--- a/drivers/net/ethernet/chelsio/inline_crypto/chtls/chtls_main.c
+++ b/drivers/net/ethernet/chelsio/inline_crypto/chtls/chtls_main.c
@@ -34,7 +34,6 @@ static DEFINE_MUTEX(notify_mutex);
static RAW_NOTIFIER_HEAD(listen_notify_list);
static struct proto chtls_cpl_prot, chtls_cpl_protv6;
struct request_sock_ops chtls_rsk_ops, chtls_rsk_opsv6;
-static uint send_page_order = (14 - PAGE_SHIFT < 0) ? 0 : 14 - PAGE_SHIFT;

static void register_listen_notifier(struct notifier_block *nb)
{
@@ -273,8 +272,6 @@ static void *chtls_uld_add(const struct cxgb4_lld_info *info)
INIT_WORK(&cdev->deferq_task, process_deferq);
spin_lock_init(&cdev->listen_lock);
spin_lock_init(&cdev->idr_lock);
- cdev->send_page_order = min_t(uint, get_order(32768),
- send_page_order);
cdev->max_host_sndbuf = 48 * 1024;

if (lldi->vr->key.size)
diff --git a/drivers/net/tun.c b/drivers/net/tun.c
index 0b3f21cba552..5939dfacb6e2 100644
--- a/drivers/net/tun.c
+++ b/drivers/net/tun.c
@@ -1598,7 +1598,8 @@ static bool tun_can_build_skb(struct tun_struct *tun, struct tun_file *tfile,
}

static struct sk_buff *__tun_build_skb(struct tun_file *tfile,
- struct page_frag *alloc_frag, char *buf,
+ struct page_frag_cache *alloc_frag,
+ char *buf, unsigned int offset,
int buflen, int len, int pad)
{
struct sk_buff *skb = build_skb(buf, buflen);
@@ -1609,9 +1610,7 @@ static struct sk_buff *__tun_build_skb(struct tun_file *tfile,
skb_reserve(skb, pad);
skb_put(skb, len);
skb_set_owner_w(skb, tfile->socket.sk);
-
- get_page(alloc_frag->page);
- alloc_frag->offset += buflen;
+ page_frag_alloc_commit(alloc_frag, offset, buflen);

return skb;
}
@@ -1660,9 +1659,10 @@ static struct sk_buff *tun_build_skb(struct tun_struct *tun,
struct virtio_net_hdr *hdr,
int len, int *skb_xdp)
{
- struct page_frag *alloc_frag = &current->task_frag;
+ struct page_frag_cache *alloc_frag = &current->task_frag;
struct bpf_prog *xdp_prog;
int buflen = SKB_DATA_ALIGN(sizeof(struct skb_shared_info));
+ unsigned int offset, size;
char *buf;
size_t copied;
int pad = TUN_RX_PAD;
@@ -1675,14 +1675,13 @@ static struct sk_buff *tun_build_skb(struct tun_struct *tun,
buflen += SKB_DATA_ALIGN(len + pad);
rcu_read_unlock();

- alloc_frag->offset = ALIGN((u64)alloc_frag->offset, SMP_CACHE_BYTES);
- if (unlikely(!skb_page_frag_refill(buflen, alloc_frag, GFP_KERNEL)))
+ size = buflen;
+ buf = page_frag_alloc_va_prepare_align(alloc_frag, &offset, &size,
+ SMP_CACHE_BYTES, GFP_KERNEL);
+ if (unlikely(!buf))
return ERR_PTR(-ENOMEM);

- buf = (char *)page_address(alloc_frag->page) + alloc_frag->offset;
- copied = copy_page_from_iter(alloc_frag->page,
- alloc_frag->offset + pad,
- len, from);
+ copied = copy_from_iter(buf + pad, len, from);
if (copied != len)
return ERR_PTR(-EFAULT);

@@ -1692,8 +1691,8 @@ static struct sk_buff *tun_build_skb(struct tun_struct *tun,
*/
if (hdr->gso_type || !xdp_prog) {
*skb_xdp = 1;
- return __tun_build_skb(tfile, alloc_frag, buf, buflen, len,
- pad);
+ return __tun_build_skb(tfile, alloc_frag, buf, offset, buflen,
+ len, pad);
}

*skb_xdp = 0;
@@ -1710,13 +1709,12 @@ static struct sk_buff *tun_build_skb(struct tun_struct *tun,

act = bpf_prog_run_xdp(xdp_prog, &xdp);
if (act == XDP_REDIRECT || act == XDP_TX) {
- get_page(alloc_frag->page);
- alloc_frag->offset += buflen;
+ page_frag_alloc_commit(alloc_frag, offset, buflen);
}
err = tun_xdp_act(tun, xdp_prog, &xdp, act);
if (err < 0) {
if (act == XDP_REDIRECT || act == XDP_TX)
- put_page(alloc_frag->page);
+ page_frag_free_va(buf);
goto out;
}

@@ -1731,8 +1729,8 @@ static struct sk_buff *tun_build_skb(struct tun_struct *tun,
rcu_read_unlock();
local_bh_enable();

- return __tun_build_skb(tfile, alloc_frag, buf, buflen, len, pad);
-
+ return __tun_build_skb(tfile, alloc_frag, buf, offset, buflen, len,
+ pad);
out:
rcu_read_unlock();
local_bh_enable();
diff --git a/include/linux/sched.h b/include/linux/sched.h
index 3c2abbc587b4..55c4b5fbe845 100644
--- a/include/linux/sched.h
+++ b/include/linux/sched.h
@@ -35,7 +35,6 @@
#include <linux/sched/types.h>
#include <linux/signal_types.h>
#include <linux/syscall_user_dispatch_types.h>
-#include <linux/mm_types_task.h>
#include <linux/task_io_accounting.h>
#include <linux/posix-timers_types.h>
#include <linux/restart_block.h>
@@ -45,6 +44,7 @@
#include <linux/rv.h>
#include <linux/livepatch_sched.h>
#include <linux/uidgid_types.h>
+#include <linux/page_frag_cache.h>
#include <asm/kmap_size.h>

/* task_struct member predeclarations (sorted alphabetically): */
@@ -1338,7 +1338,7 @@ struct task_struct {
/* Cache last used pipe for splice(): */
struct pipe_inode_info *splice_pipe;

- struct page_frag task_frag;
+ struct page_frag_cache task_frag;

#ifdef CONFIG_TASK_DELAY_ACCT
struct task_delay_info *delays;
diff --git a/include/net/sock.h b/include/net/sock.h
index d214aeca72ad..a9c76fa623ce 100644
--- a/include/net/sock.h
+++ b/include/net/sock.h
@@ -461,7 +461,7 @@ struct sock {
struct sk_buff_head sk_write_queue;
u32 sk_dst_pending_confirm;
u32 sk_pacing_status; /* see enum sk_pacing */
- struct page_frag sk_frag;
+ struct page_frag_cache sk_frag;
struct timer_list sk_timer;

unsigned long sk_pacing_rate; /* bytes per second */
@@ -2573,7 +2573,7 @@ static inline void sk_stream_moderate_sndbuf(struct sock *sk)
* Return: a per task page_frag if context allows that,
* otherwise a per socket one.
*/
-static inline struct page_frag *sk_page_frag(struct sock *sk)
+static inline struct page_frag_cache *sk_page_frag(struct sock *sk)
{
if (sk->sk_use_task_frag)
return &current->task_frag;
@@ -2581,7 +2581,15 @@ static inline struct page_frag *sk_page_frag(struct sock *sk)
return &sk->sk_frag;
}

-bool sk_page_frag_refill(struct sock *sk, struct page_frag *pfrag);
+struct page *sk_page_frag_alloc_prepare(struct sock *sk,
+ struct page_frag_cache *pfrag,
+ unsigned int *size,
+ unsigned int *offset, void **va);
+
+struct page *sk_page_frag_alloc_pg_prepare(struct sock *sk,
+ struct page_frag_cache *pfrag,
+ unsigned int *size,
+ unsigned int *offset);

/*
* Default write policy as shown to user space via poll/select/SIGIO
diff --git a/kernel/exit.c b/kernel/exit.c
index 41a12630cbbc..8203275fd5ff 100644
--- a/kernel/exit.c
+++ b/kernel/exit.c
@@ -913,8 +913,7 @@ void __noreturn do_exit(long code)
if (tsk->splice_pipe)
free_pipe_info(tsk->splice_pipe);

- if (tsk->task_frag.page)
- put_page(tsk->task_frag.page);
+ page_frag_cache_drain(&tsk->task_frag);

exit_task_stack_account(tsk);

diff --git a/kernel/fork.c b/kernel/fork.c
index 39a5046c2f0b..8e5abc30c47a 100644
--- a/kernel/fork.c
+++ b/kernel/fork.c
@@ -1158,10 +1158,10 @@ static struct task_struct *dup_task_struct(struct task_struct *orig, int node)
tsk->btrace_seq = 0;
#endif
tsk->splice_pipe = NULL;
- tsk->task_frag.page = NULL;
tsk->wake_q.next = NULL;
tsk->worker_private = NULL;

+ page_frag_cache_init(&tsk->task_frag);
kcov_task_init(tsk);
kmsan_task_create(tsk);
kmap_local_fork(tsk);
diff --git a/net/core/skbuff.c b/net/core/skbuff.c
index cdbfdf651001..2b68f69bc1e9 100644
--- a/net/core/skbuff.c
+++ b/net/core/skbuff.c
@@ -2961,23 +2961,25 @@ static void sock_spd_release(struct splice_pipe_desc *spd, unsigned int i)
put_page(spd->pages[i]);
}

-static struct page *linear_to_page(struct page *page, unsigned int *len,
- unsigned int *offset,
- struct sock *sk)
+static struct page *linear_to_page(struct page_frag_cache *pfrag,
+ struct page *page, unsigned int *offset,
+ unsigned int *len, struct sock *sk)
{
- struct page_frag *pfrag = sk_page_frag(sk);
+ unsigned int new_len, new_offset;
+ struct page *frag_page;
+ void *va;

- if (!sk_page_frag_refill(sk, pfrag))
+ frag_page = sk_page_frag_alloc_prepare(sk, pfrag, &new_offset,
+ &new_len, &va);
+ if (!frag_page)
return NULL;

- *len = min_t(unsigned int, *len, pfrag->size - pfrag->offset);
+ *len = min_t(unsigned int, *len, new_len);

- memcpy(page_address(pfrag->page) + pfrag->offset,
- page_address(page) + *offset, *len);
- *offset = pfrag->offset;
- pfrag->offset += *len;
+ memcpy(va, page_address(page) + *offset, *len);
+ *offset = new_offset;

- return pfrag->page;
+ return frag_page;
}

static bool spd_can_coalesce(const struct splice_pipe_desc *spd,
@@ -2999,19 +3001,23 @@ static bool spd_fill_page(struct splice_pipe_desc *spd,
bool linear,
struct sock *sk)
{
+ struct page_frag_cache *pfrag = sk_page_frag(sk);
+
if (unlikely(spd->nr_pages == MAX_SKB_FRAGS))
return true;

if (linear) {
- page = linear_to_page(page, len, &offset, sk);
+ page = linear_to_page(pfrag, page, &offset, len, sk);
if (!page)
return true;
}
if (spd_can_coalesce(spd, page, offset)) {
spd->partial[spd->nr_pages - 1].len += *len;
+ page_frag_alloc_commit_noref(pfrag, offset, *len);
return false;
}
- get_page(page);
+
+ page_frag_alloc_commit(pfrag, offset, *len);
spd->pages[spd->nr_pages] = page;
spd->partial[spd->nr_pages].len = *len;
spd->partial[spd->nr_pages].offset = offset;
diff --git a/net/core/skmsg.c b/net/core/skmsg.c
index 4d75ef9d24bf..803f3903c019 100644
--- a/net/core/skmsg.c
+++ b/net/core/skmsg.c
@@ -27,23 +27,25 @@ static bool sk_msg_try_coalesce_ok(struct sk_msg *msg, int elem_first_coalesce)
int sk_msg_alloc(struct sock *sk, struct sk_msg *msg, int len,
int elem_first_coalesce)
{
- struct page_frag *pfrag = sk_page_frag(sk);
+ struct page_frag_cache *pfrag = sk_page_frag(sk);
u32 osize = msg->sg.size;
int ret = 0;

len -= msg->sg.size;
while (len > 0) {
+ unsigned int frag_offset, frag_len;
struct scatterlist *sge;
- u32 orig_offset;
+ struct page *page;
int use, i;

- if (!sk_page_frag_refill(sk, pfrag)) {
+ page = sk_page_frag_alloc_pg_prepare(sk, pfrag, &frag_offset,
+ &frag_len);
+ if (!page) {
ret = -ENOMEM;
goto msg_trim;
}

- orig_offset = pfrag->offset;
- use = min_t(int, len, pfrag->size - orig_offset);
+ use = min_t(int, len, frag_len);
if (!sk_wmem_schedule(sk, use)) {
ret = -ENOMEM;
goto msg_trim;
@@ -54,9 +56,10 @@ int sk_msg_alloc(struct sock *sk, struct sk_msg *msg, int len,
sge = &msg->sg.data[i];

if (sk_msg_try_coalesce_ok(msg, elem_first_coalesce) &&
- sg_page(sge) == pfrag->page &&
- sge->offset + sge->length == orig_offset) {
+ sg_page(sge) == page &&
+ sge->offset + sge->length == frag_offset) {
sge->length += use;
+ page_frag_alloc_commit_noref(pfrag, frag_offset, use);
} else {
if (sk_msg_full(msg)) {
ret = -ENOSPC;
@@ -65,14 +68,13 @@ int sk_msg_alloc(struct sock *sk, struct sk_msg *msg, int len,

sge = &msg->sg.data[msg->sg.end];
sg_unmark_end(sge);
- sg_set_page(sge, pfrag->page, use, orig_offset);
- get_page(pfrag->page);
+ sg_set_page(sge, page, use, frag_offset);
+ page_frag_alloc_commit(pfrag, frag_offset, use);
sk_msg_iter_next(msg, end);
}

sk_mem_charge(sk, use);
msg->sg.size += use;
- pfrag->offset += use;
len -= use;
}

diff --git a/net/core/sock.c b/net/core/sock.c
index fe9195186c13..a8318c7f6391 100644
--- a/net/core/sock.c
+++ b/net/core/sock.c
@@ -2191,10 +2191,7 @@ static void __sk_destruct(struct rcu_head *head)
pr_debug("%s: optmem leakage (%d bytes) detected\n",
__func__, atomic_read(&sk->sk_omem_alloc));

- if (sk->sk_frag.page) {
- put_page(sk->sk_frag.page);
- sk->sk_frag.page = NULL;
- }
+ page_frag_cache_drain(&sk->sk_frag);

/* We do not need to acquire sk->sk_peer_lock, we are the last user. */
put_cred(sk->sk_peer_cred);
@@ -2935,16 +2932,43 @@ bool skb_page_frag_refill(unsigned int sz, struct page_frag *pfrag, gfp_t gfp)
}
EXPORT_SYMBOL(skb_page_frag_refill);

-bool sk_page_frag_refill(struct sock *sk, struct page_frag *pfrag)
+struct page *sk_page_frag_alloc_prepare(struct sock *sk,
+ struct page_frag_cache *pfrag,
+ unsigned int *offset,
+ unsigned int *size, void **va)
{
- if (likely(skb_page_frag_refill(32U, pfrag, sk->sk_allocation)))
- return true;
+ struct page *page;
+
+ *size = 32U;
+ page = page_frag_alloc_prepare(pfrag, offset, size, va,
+ sk->sk_allocation);
+ if (likely(page))
+ return page;

sk_enter_memory_pressure(sk);
sk_stream_moderate_sndbuf(sk);
- return false;
+ return NULL;
+}
+EXPORT_SYMBOL(sk_page_frag_alloc_prepare);
+
+struct page *sk_page_frag_alloc_pg_prepare(struct sock *sk,
+ struct page_frag_cache *pfrag,
+ unsigned int *offset,
+ unsigned int *size)
+{
+ struct page *page;
+
+ *size = 32U;
+ page = page_frag_alloc_pg_prepare(pfrag, offset, size,
+ sk->sk_allocation);
+ if (likely(page))
+ return page;
+
+ sk_enter_memory_pressure(sk);
+ sk_stream_moderate_sndbuf(sk);
+ return NULL;
}
-EXPORT_SYMBOL(sk_page_frag_refill);
+EXPORT_SYMBOL(sk_page_frag_alloc_pg_prepare);

void __lock_sock(struct sock *sk)
__releases(&sk->sk_lock.slock)
@@ -3478,8 +3502,8 @@ void sock_init_data_uid(struct socket *sock, struct sock *sk, kuid_t uid)
sk->sk_error_report = sock_def_error_report;
sk->sk_destruct = sock_def_destruct;

- sk->sk_frag.page = NULL;
- sk->sk_frag.offset = 0;
+ page_frag_cache_init(&sk->sk_frag);
+
sk->sk_peek_off = -1;

sk->sk_peer_pid = NULL;
diff --git a/net/ipv4/ip_output.c b/net/ipv4/ip_output.c
index 1fe794967211..28b66922e298 100644
--- a/net/ipv4/ip_output.c
+++ b/net/ipv4/ip_output.c
@@ -952,7 +952,7 @@ static int __ip_append_data(struct sock *sk,
struct flowi4 *fl4,
struct sk_buff_head *queue,
struct inet_cork *cork,
- struct page_frag *pfrag,
+ struct page_frag_cache *pfrag,
int getfrag(void *from, char *to, int offset,
int len, int odd, struct sk_buff *skb),
void *from, int length, int transhdrlen,
@@ -1228,31 +1228,40 @@ static int __ip_append_data(struct sock *sk,
wmem_alloc_delta += copy;
} else if (!zc) {
int i = skb_shinfo(skb)->nr_frags;
+ unsigned int frag_offset, frag_size;
+ struct page *page;
+ void *va;

err = -ENOMEM;
- if (!sk_page_frag_refill(sk, pfrag))
+ page = sk_page_frag_alloc_prepare(sk, pfrag,
+ &frag_offset,
+ &frag_size, &va);
+ if (!page)
goto error;

skb_zcopy_downgrade_managed(skb);
- if (!skb_can_coalesce(skb, i, pfrag->page,
- pfrag->offset)) {
+ copy = min_t(int, copy, frag_size);
+
+ if (!skb_can_coalesce(skb, i, page, frag_offset)) {
err = -EMSGSIZE;
if (i == MAX_SKB_FRAGS)
goto error;

- __skb_fill_page_desc(skb, i, pfrag->page,
- pfrag->offset, 0);
+ __skb_fill_page_desc(skb, i, page, frag_offset,
+ copy);
skb_shinfo(skb)->nr_frags = ++i;
- get_page(pfrag->page);
+ page_frag_alloc_commit(pfrag, frag_offset,
+ copy);
+ } else {
+ skb_frag_size_add(
+ &skb_shinfo(skb)->frags[i - 1], copy);
+ page_frag_alloc_commit_noref(pfrag, frag_offset,
+ copy);
}
- copy = min_t(int, copy, pfrag->size - pfrag->offset);
- if (getfrag(from,
- page_address(pfrag->page) + pfrag->offset,
- offset, copy, skb->len, skb) < 0)
+
+ if (getfrag(from, va, offset, copy, skb->len, skb) < 0)
goto error_efault;

- pfrag->offset += copy;
- skb_frag_size_add(&skb_shinfo(skb)->frags[i - 1], copy);
skb_len_add(skb, copy);
wmem_alloc_delta += copy;
} else {
diff --git a/net/ipv4/tcp.c b/net/ipv4/tcp.c
index f23b97777ea5..53c66d6c886b 100644
--- a/net/ipv4/tcp.c
+++ b/net/ipv4/tcp.c
@@ -1180,13 +1180,17 @@ int tcp_sendmsg_locked(struct sock *sk, struct msghdr *msg, size_t size)
if (zc == 0) {
bool merge = true;
int i = skb_shinfo(skb)->nr_frags;
- struct page_frag *pfrag = sk_page_frag(sk);
-
- if (!sk_page_frag_refill(sk, pfrag))
+ struct page_frag_cache *pfrag = sk_page_frag(sk);
+ unsigned int offset, size;
+ struct page *page;
+ void *va;
+
+ page = sk_page_frag_alloc_prepare(sk, pfrag, &offset,
+ &size, &va);
+ if (!page)
goto wait_for_space;

- if (!skb_can_coalesce(skb, i, pfrag->page,
- pfrag->offset)) {
+ if (!skb_can_coalesce(skb, i, page, offset)) {
if (i >= READ_ONCE(sysctl_max_skb_frags)) {
tcp_mark_push(tp, skb);
goto new_segment;
@@ -1194,7 +1198,7 @@ int tcp_sendmsg_locked(struct sock *sk, struct msghdr *msg, size_t size)
merge = false;
}

- copy = min_t(int, copy, pfrag->size - pfrag->offset);
+ copy = min_t(int, copy, size);

if (unlikely(skb_zcopy_pure(skb) || skb_zcopy_managed(skb))) {
if (tcp_downgrade_zcopy_pure(sk, skb))
@@ -1206,22 +1210,19 @@ int tcp_sendmsg_locked(struct sock *sk, struct msghdr *msg, size_t size)
if (!copy)
goto wait_for_space;

- err = skb_copy_to_page_nocache(sk, &msg->msg_iter, skb,
- pfrag->page,
- pfrag->offset,
- copy);
+ err = skb_copy_to_va_nocache(sk, &msg->msg_iter, skb,
+ va, copy);
if (err)
goto do_error;

/* Update the skb. */
if (merge) {
skb_frag_size_add(&skb_shinfo(skb)->frags[i - 1], copy);
+ page_frag_alloc_commit_noref(pfrag, offset, copy);
} else {
- skb_fill_page_desc(skb, i, pfrag->page,
- pfrag->offset, copy);
- page_ref_inc(pfrag->page);
+ skb_fill_page_desc(skb, i, page, offset, copy);
+ page_frag_alloc_commit(pfrag, offset, copy);
}
- pfrag->offset += copy;
} else if (zc == MSG_ZEROCOPY) {
/* First append to a fragless skb builds initial
* pure zerocopy skb
@@ -3108,11 +3109,7 @@ int tcp_disconnect(struct sock *sk, int flags)

WARN_ON(inet->inet_num && !icsk->icsk_bind_hash);

- if (sk->sk_frag.page) {
- put_page(sk->sk_frag.page);
- sk->sk_frag.page = NULL;
- sk->sk_frag.offset = 0;
- }
+ page_frag_cache_drain(&sk->sk_frag);
sk_error_report(sk);
return 0;
}
diff --git a/net/ipv4/tcp_output.c b/net/ipv4/tcp_output.c
index 61119d42b0fd..dfc96a433481 100644
--- a/net/ipv4/tcp_output.c
+++ b/net/ipv4/tcp_output.c
@@ -3930,9 +3930,12 @@ static int tcp_send_syn_data(struct sock *sk, struct sk_buff *syn)
struct inet_connection_sock *icsk = inet_csk(sk);
struct tcp_sock *tp = tcp_sk(sk);
struct tcp_fastopen_request *fo = tp->fastopen_req;
- struct page_frag *pfrag = sk_page_frag(sk);
+ struct page_frag_cache *pfrag = sk_page_frag(sk);
+ unsigned int offset, size;
struct sk_buff *syn_data;
int space, err = 0;
+ struct page *page;
+ void *va;

tp->rx_opt.mss_clamp = tp->advmss; /* If MSS is not cached */
if (!tcp_fastopen_cookie_check(sk, &tp->rx_opt.mss_clamp, &fo->cookie))
@@ -3951,30 +3954,31 @@ static int tcp_send_syn_data(struct sock *sk, struct sk_buff *syn)

space = min_t(size_t, space, fo->size);

- if (space &&
- !skb_page_frag_refill(min_t(size_t, space, PAGE_SIZE),
- pfrag, sk->sk_allocation))
- goto fallback;
+ if (space) {
+ size = min_t(size_t, space, PAGE_SIZE);
+ page = page_frag_alloc_prepare(pfrag, &offset, &size, &va,
+ sk->sk_allocation);
+ if (!page)
+ goto fallback;
+ }
+
syn_data = tcp_stream_alloc_skb(sk, sk->sk_allocation, false);
if (!syn_data)
goto fallback;
memcpy(syn_data->cb, syn->cb, sizeof(syn->cb));
if (space) {
- space = min_t(size_t, space, pfrag->size - pfrag->offset);
+ space = min_t(size_t, space, size);
space = tcp_wmem_schedule(sk, space);
}
if (space) {
- space = copy_page_from_iter(pfrag->page, pfrag->offset,
- space, &fo->data->msg_iter);
+ space = _copy_from_iter(va, space, &fo->data->msg_iter);
if (unlikely(!space)) {
tcp_skb_tsorted_anchor_cleanup(syn_data);
kfree_skb(syn_data);
goto fallback;
}
- skb_fill_page_desc(syn_data, 0, pfrag->page,
- pfrag->offset, space);
- page_ref_inc(pfrag->page);
- pfrag->offset += space;
+ skb_fill_page_desc(syn_data, 0, page, offset, space);
+ page_frag_alloc_commit(pfrag, offset, space);
skb_len_add(syn_data, space);
skb_zcopy_set(syn_data, fo->uarg, NULL);
}
diff --git a/net/ipv6/ip6_output.c b/net/ipv6/ip6_output.c
index b9dd3a66e423..95a4dbf1a7b1 100644
--- a/net/ipv6/ip6_output.c
+++ b/net/ipv6/ip6_output.c
@@ -1404,7 +1404,7 @@ static int __ip6_append_data(struct sock *sk,
struct sk_buff_head *queue,
struct inet_cork_full *cork_full,
struct inet6_cork *v6_cork,
- struct page_frag *pfrag,
+ struct page_frag_cache *pfrag,
int getfrag(void *from, char *to, int offset,
int len, int odd, struct sk_buff *skb),
void *from, size_t length, int transhdrlen,
@@ -1745,32 +1745,41 @@ static int __ip6_append_data(struct sock *sk,
copy = err;
wmem_alloc_delta += copy;
} else if (!zc) {
+ unsigned int frag_offset, frag_size;
int i = skb_shinfo(skb)->nr_frags;
+ struct page *page;
+ void *va;

err = -ENOMEM;
- if (!sk_page_frag_refill(sk, pfrag))
+ page = sk_page_frag_alloc_prepare(sk, pfrag,
+ &frag_offset,
+ &frag_size, &va);
+ if (!page)
goto error;

skb_zcopy_downgrade_managed(skb);
- if (!skb_can_coalesce(skb, i, pfrag->page,
- pfrag->offset)) {
+ copy = min_t(int, copy, frag_size);
+
+ if (!skb_can_coalesce(skb, i, page, frag_offset)) {
err = -EMSGSIZE;
if (i == MAX_SKB_FRAGS)
goto error;

- __skb_fill_page_desc(skb, i, pfrag->page,
- pfrag->offset, 0);
+ __skb_fill_page_desc(skb, i, page, frag_offset,
+ copy);
skb_shinfo(skb)->nr_frags = ++i;
- get_page(pfrag->page);
+ page_frag_alloc_commit(pfrag, frag_offset,
+ copy);
+ } else {
+ skb_frag_size_add(
+ &skb_shinfo(skb)->frags[i - 1], copy);
+ page_frag_alloc_commit_noref(pfrag, frag_offset,
+ copy);
}
- copy = min_t(int, copy, pfrag->size - pfrag->offset);
- if (getfrag(from,
- page_address(pfrag->page) + pfrag->offset,
- offset, copy, skb->len, skb) < 0)
+
+ if (getfrag(from, va, offset, copy, skb->len, skb) < 0)
goto error_efault;

- pfrag->offset += copy;
- skb_frag_size_add(&skb_shinfo(skb)->frags[i - 1], copy);
skb->len += copy;
skb->data_len += copy;
skb->truesize += copy;
diff --git a/net/kcm/kcmsock.c b/net/kcm/kcmsock.c
index 2f191e50d4fc..6b837e85b683 100644
--- a/net/kcm/kcmsock.c
+++ b/net/kcm/kcmsock.c
@@ -803,13 +803,17 @@ static int kcm_sendmsg(struct socket *sock, struct msghdr *msg, size_t len)
while (msg_data_left(msg)) {
bool merge = true;
int i = skb_shinfo(skb)->nr_frags;
- struct page_frag *pfrag = sk_page_frag(sk);
-
- if (!sk_page_frag_refill(sk, pfrag))
+ struct page_frag_cache *pfrag = sk_page_frag(sk);
+ unsigned int offset, size;
+ struct page *page;
+ void *va;
+
+ page = sk_page_frag_alloc_prepare(sk, pfrag, &offset, &size,
+ &va);
+ if (!page)
goto wait_for_memory;

- if (!skb_can_coalesce(skb, i, pfrag->page,
- pfrag->offset)) {
+ if (!skb_can_coalesce(skb, i, page, offset)) {
if (i == MAX_SKB_FRAGS) {
struct sk_buff *tskb;

@@ -850,15 +854,12 @@ static int kcm_sendmsg(struct socket *sock, struct msghdr *msg, size_t len)
if (head != skb)
head->truesize += copy;
} else {
- copy = min_t(int, msg_data_left(msg),
- pfrag->size - pfrag->offset);
+ copy = min_t(int, msg_data_left(msg), size);
if (!sk_wmem_schedule(sk, copy))
goto wait_for_memory;

- err = skb_copy_to_page_nocache(sk, &msg->msg_iter, skb,
- pfrag->page,
- pfrag->offset,
- copy);
+ err = skb_copy_to_va_nocache(sk, &msg->msg_iter, skb,
+ va, copy);
if (err)
goto out_error;

@@ -866,13 +867,12 @@ static int kcm_sendmsg(struct socket *sock, struct msghdr *msg, size_t len)
if (merge) {
skb_frag_size_add(
&skb_shinfo(skb)->frags[i - 1], copy);
+ page_frag_alloc_commit_noref(pfrag, offset, copy);
} else {
- skb_fill_page_desc(skb, i, pfrag->page,
- pfrag->offset, copy);
- get_page(pfrag->page);
+ skb_fill_page_desc(skb, i, page, offset, copy);
+ page_frag_alloc_commit(pfrag, offset, copy);
}

- pfrag->offset += copy;
}

copied += copy;
diff --git a/net/mptcp/protocol.c b/net/mptcp/protocol.c
index f8bc34f0d973..368dd480c4cd 100644
--- a/net/mptcp/protocol.c
+++ b/net/mptcp/protocol.c
@@ -959,17 +959,16 @@ static bool mptcp_skb_can_collapse_to(u64 write_seq,
}

/* we can append data to the given data frag if:
- * - there is space available in the backing page_frag
- * - the data frag tail matches the current page_frag free offset
+ * - the data frag tail matches the current page and offset
* - the data frag end sequence number matches the current write seq
*/
static bool mptcp_frag_can_collapse_to(const struct mptcp_sock *msk,
- const struct page_frag *pfrag,
+ const struct page *page,
+ const unsigned int offset,
const struct mptcp_data_frag *df)
{
- return df && pfrag->page == df->page &&
- pfrag->size - pfrag->offset > 0 &&
- pfrag->offset == (df->offset + df->data_len) &&
+ return df && page == df->page &&
+ offset == (df->offset + df->data_len) &&
df->data_seq + df->data_len == msk->write_seq;
}

@@ -1084,30 +1083,36 @@ static void mptcp_enter_memory_pressure(struct sock *sk)
/* ensure we get enough memory for the frag hdr, beyond some minimal amount of
* data
*/
-static bool mptcp_page_frag_refill(struct sock *sk, struct page_frag *pfrag)
+static struct page *mptcp_page_frag_alloc_prepare(struct sock *sk,
+ struct page_frag_cache *pfrag,
+ unsigned int *offset,
+ unsigned int *size, void **va)
{
- if (likely(skb_page_frag_refill(32U + sizeof(struct mptcp_data_frag),
- pfrag, sk->sk_allocation)))
- return true;
+ struct page *page;
+
+ page = page_frag_alloc_prepare(pfrag, offset, size, va,
+ sk->sk_allocation);
+ if (likely(page))
+ return page;

mptcp_enter_memory_pressure(sk);
- return false;
+ return NULL;
}

static struct mptcp_data_frag *
-mptcp_carve_data_frag(const struct mptcp_sock *msk, struct page_frag *pfrag,
- int orig_offset)
+mptcp_carve_data_frag(const struct mptcp_sock *msk, struct page *page,
+ unsigned int orig_offset)
{
int offset = ALIGN(orig_offset, sizeof(long));
struct mptcp_data_frag *dfrag;

- dfrag = (struct mptcp_data_frag *)(page_to_virt(pfrag->page) + offset);
+ dfrag = (struct mptcp_data_frag *)(page_to_virt(page) + offset);
dfrag->data_len = 0;
dfrag->data_seq = msk->write_seq;
dfrag->overhead = offset - orig_offset + sizeof(struct mptcp_data_frag);
dfrag->offset = offset + sizeof(struct mptcp_data_frag);
dfrag->already_sent = 0;
- dfrag->page = pfrag->page;
+ dfrag->page = page;

return dfrag;
}
@@ -1792,7 +1797,7 @@ static u32 mptcp_send_limit(const struct sock *sk)
static int mptcp_sendmsg(struct sock *sk, struct msghdr *msg, size_t len)
{
struct mptcp_sock *msk = mptcp_sk(sk);
- struct page_frag *pfrag;
+ struct page_frag_cache *pfrag;
size_t copied = 0;
int ret = 0;
long timeo;
@@ -1831,9 +1836,12 @@ static int mptcp_sendmsg(struct sock *sk, struct msghdr *msg, size_t len)
while (msg_data_left(msg)) {
int total_ts, frag_truesize = 0;
struct mptcp_data_frag *dfrag;
- bool dfrag_collapsed;
- size_t psize, offset;
+ bool dfrag_collapsed = false;
+ unsigned int offset, size;
+ struct page *page;
+ size_t psize;
u32 copy_limit;
+ void *va;

/* ensure fitting the notsent_lowat() constraint */
copy_limit = mptcp_send_limit(sk);
@@ -1844,21 +1852,31 @@ static int mptcp_sendmsg(struct sock *sk, struct msghdr *msg, size_t len)
* page allocator
*/
dfrag = mptcp_pending_tail(sk);
- dfrag_collapsed = mptcp_frag_can_collapse_to(msk, pfrag, dfrag);
+ size = 32U;
+ page = mptcp_page_frag_alloc_prepare(sk, pfrag, &offset, &size,
+ &va);
+ if (!page)
+ goto wait_for_memory;
+
+ dfrag_collapsed = mptcp_frag_can_collapse_to(msk, page, offset,
+ dfrag);
if (!dfrag_collapsed) {
- if (!mptcp_page_frag_refill(sk, pfrag))
+ size = 32U + sizeof(struct mptcp_data_frag);
+ page = mptcp_page_frag_alloc_prepare(sk, pfrag, &offset,
+ &size, &va);
+ if (!page)
goto wait_for_memory;

- dfrag = mptcp_carve_data_frag(msk, pfrag, pfrag->offset);
+ dfrag = mptcp_carve_data_frag(msk, page, offset);
frag_truesize = dfrag->overhead;
+ va += dfrag->overhead;
}

/* we do not bound vs wspace, to allow a single packet.
* memory accounting will prevent execessive memory usage
* anyway
*/
- offset = dfrag->offset + dfrag->data_len;
- psize = pfrag->size - offset;
+ psize = size - frag_truesize;
psize = min_t(size_t, psize, msg_data_left(msg));
psize = min_t(size_t, psize, copy_limit);
total_ts = psize + frag_truesize;
@@ -1866,8 +1884,7 @@ static int mptcp_sendmsg(struct sock *sk, struct msghdr *msg, size_t len)
if (!sk_wmem_schedule(sk, total_ts))
goto wait_for_memory;

- ret = do_copy_data_nocache(sk, psize, &msg->msg_iter,
- page_address(dfrag->page) + offset);
+ ret = do_copy_data_nocache(sk, psize, &msg->msg_iter, va);
if (ret)
goto do_error;

@@ -1876,7 +1893,6 @@ static int mptcp_sendmsg(struct sock *sk, struct msghdr *msg, size_t len)
copied += psize;
dfrag->data_len += psize;
frag_truesize += psize;
- pfrag->offset += frag_truesize;
WRITE_ONCE(msk->write_seq, msk->write_seq + psize);

/* charge data on mptcp pending queue to the msk socket
@@ -1884,11 +1900,15 @@ static int mptcp_sendmsg(struct sock *sk, struct msghdr *msg, size_t len)
*/
sk_wmem_queued_add(sk, frag_truesize);
if (!dfrag_collapsed) {
- get_page(dfrag->page);
+ page_frag_alloc_commit(pfrag, offset, frag_truesize);
list_add_tail(&dfrag->list, &msk->rtx_queue);
if (!msk->first_pending)
WRITE_ONCE(msk->first_pending, dfrag);
+ } else {
+ page_frag_alloc_commit_noref(pfrag, offset,
+ frag_truesize);
}
+
pr_debug("msk=%p dfrag at seq=%llu len=%u sent=%u new=%d", msk,
dfrag->data_seq, dfrag->data_len, dfrag->already_sent,
!dfrag_collapsed);
diff --git a/net/tls/tls_device.c b/net/tls/tls_device.c
index ab6e694f7bc2..47829f3b229e 100644
--- a/net/tls/tls_device.c
+++ b/net/tls/tls_device.c
@@ -256,25 +256,43 @@ static void tls_device_resync_tx(struct sock *sk, struct tls_context *tls_ctx,
clear_bit_unlock(TLS_TX_SYNC_SCHED, &tls_ctx->flags);
}

-static void tls_append_frag(struct tls_record_info *record,
- struct page_frag *pfrag,
- int size)
+static void tls_append_pfrag(struct tls_record_info *record,
+ struct page_frag_cache *pfrag, struct page *page,
+ unsigned int offset, unsigned int size)
{
skb_frag_t *frag;

frag = &record->frags[record->num_frags - 1];
- if (skb_frag_page(frag) == pfrag->page &&
- skb_frag_off(frag) + skb_frag_size(frag) == pfrag->offset) {
+ if (skb_frag_page(frag) == page &&
+ skb_frag_off(frag) + skb_frag_size(frag) == offset) {
skb_frag_size_add(frag, size);
+ page_frag_alloc_commit_noref(pfrag, offset, size);
} else {
++frag;
- skb_frag_fill_page_desc(frag, pfrag->page, pfrag->offset,
- size);
+ skb_frag_fill_page_desc(frag, page, offset, size);
++record->num_frags;
- get_page(pfrag->page);
+ page_frag_alloc_commit(pfrag, offset, size);
+ }
+
+ record->len += size;
+}
+
+static void tls_append_page(struct tls_record_info *record, struct page *page,
+ unsigned int offset, unsigned int size)
+{
+ skb_frag_t *frag;
+
+ frag = &record->frags[record->num_frags - 1];
+ if (skb_frag_page(frag) == page &&
+ skb_frag_off(frag) + skb_frag_size(frag) == offset) {
+ skb_frag_size_add(frag, size);
+ } else {
+ ++frag;
+ skb_frag_fill_page_desc(frag, page, offset, size);
+ ++record->num_frags;
+ get_page(page);
}

- pfrag->offset += size;
record->len += size;
}

@@ -315,11 +333,12 @@ static int tls_push_record(struct sock *sk,
static void tls_device_record_close(struct sock *sk,
struct tls_context *ctx,
struct tls_record_info *record,
- struct page_frag *pfrag,
+ struct page_frag_cache *pfrag,
unsigned char record_type)
{
struct tls_prot_info *prot = &ctx->prot_info;
- struct page_frag dummy_tag_frag;
+ unsigned int offset, size;
+ struct page *page;

/* append tag
* device will fill in the tag, we just need to append a placeholder
@@ -327,13 +346,14 @@ static void tls_device_record_close(struct sock *sk,
* increases frag count)
* if we can't allocate memory now use the dummy page
*/
- if (unlikely(pfrag->size - pfrag->offset < prot->tag_size) &&
- !skb_page_frag_refill(prot->tag_size, pfrag, sk->sk_allocation)) {
- dummy_tag_frag.page = dummy_page;
- dummy_tag_frag.offset = 0;
- pfrag = &dummy_tag_frag;
+ size = prot->tag_size;
+ page = page_frag_alloc_pg_prepare(pfrag, &offset, &size,
+ sk->sk_allocation);
+ if (unlikely(!page)) {
+ tls_append_page(record, dummy_page, 0, prot->tag_size);
+ } else {
+ tls_append_pfrag(record, pfrag, page, offset, prot->tag_size);
}
- tls_append_frag(record, pfrag, prot->tag_size);

/* fill prepend */
tls_fill_prepend(ctx, skb_frag_address(&record->frags[0]),
@@ -341,23 +361,33 @@ static void tls_device_record_close(struct sock *sk,
record_type);
}

-static int tls_create_new_record(struct tls_offload_context_tx *offload_ctx,
- struct page_frag *pfrag,
+static int tls_create_new_record(struct sock *sk,
+ struct tls_offload_context_tx *offload_ctx,
+ struct page_frag_cache *pfrag,
size_t prepend_size)
{
struct tls_record_info *record;
+ unsigned int offset, size;
+ struct page *page;
skb_frag_t *frag;

+ size = prepend_size;
+ page = page_frag_alloc_pg_prepare(pfrag, &offset, &size,
+ sk->sk_allocation);
+ if (!page) {
+ READ_ONCE(sk->sk_prot)->enter_memory_pressure(sk);
+ sk_stream_moderate_sndbuf(sk);
+ return -ENOMEM;
+ }
+
record = kmalloc(sizeof(*record), GFP_KERNEL);
if (!record)
return -ENOMEM;

frag = &record->frags[0];
- skb_frag_fill_page_desc(frag, pfrag->page, pfrag->offset,
- prepend_size);
+ skb_frag_fill_page_desc(frag, page, offset, prepend_size);

- get_page(pfrag->page);
- pfrag->offset += prepend_size;
+ page_frag_alloc_commit(pfrag, offset, prepend_size);

record->num_frags = 1;
record->len = prepend_size;
@@ -365,33 +395,21 @@ static int tls_create_new_record(struct tls_offload_context_tx *offload_ctx,
return 0;
}

-static int tls_do_allocation(struct sock *sk,
- struct tls_offload_context_tx *offload_ctx,
- struct page_frag *pfrag,
- size_t prepend_size)
+static struct page *tls_do_allocation(struct sock *sk,
+ struct tls_offload_context_tx *ctx,
+ struct page_frag_cache *pfrag,
+ size_t prepend_size, unsigned int *offset,
+ unsigned int *size, void **va)
{
- int ret;
-
- if (!offload_ctx->open_record) {
- if (unlikely(!skb_page_frag_refill(prepend_size, pfrag,
- sk->sk_allocation))) {
- READ_ONCE(sk->sk_prot)->enter_memory_pressure(sk);
- sk_stream_moderate_sndbuf(sk);
- return -ENOMEM;
- }
+ if (!ctx->open_record) {
+ int ret;

- ret = tls_create_new_record(offload_ctx, pfrag, prepend_size);
+ ret = tls_create_new_record(sk, ctx, pfrag, prepend_size);
if (ret)
- return ret;
-
- if (pfrag->size > pfrag->offset)
- return 0;
+ return NULL;
}

- if (!sk_page_frag_refill(sk, pfrag))
- return -ENOMEM;
-
- return 0;
+ return sk_page_frag_alloc_prepare(sk, pfrag, offset, size, va);
}

static int tls_device_copy_data(void *addr, size_t bytes, struct iov_iter *i)
@@ -428,8 +446,8 @@ static int tls_push_data(struct sock *sk,
struct tls_prot_info *prot = &tls_ctx->prot_info;
struct tls_offload_context_tx *ctx = tls_offload_ctx_tx(tls_ctx);
struct tls_record_info *record;
+ struct page_frag_cache *pfrag;
int tls_push_record_flags;
- struct page_frag *pfrag;
size_t orig_size = size;
u32 max_open_record_len;
bool more = false;
@@ -466,8 +484,13 @@ static int tls_push_data(struct sock *sk,
max_open_record_len = TLS_MAX_PAYLOAD_SIZE +
prot->prepend_size;
do {
- rc = tls_do_allocation(sk, ctx, pfrag, prot->prepend_size);
- if (unlikely(rc)) {
+ unsigned int frag_offset, frag_size;
+ struct page *page;
+ void *va;
+
+ page = tls_do_allocation(sk, ctx, pfrag, prot->prepend_size,
+ &frag_offset, &frag_size, &va);
+ if (unlikely(!page)) {
rc = sk_stream_wait_memory(sk, &timeo);
if (!rc)
continue;
@@ -495,8 +518,8 @@ static int tls_push_data(struct sock *sk,

copy = min_t(size_t, size, max_open_record_len - record->len);
if (copy && (flags & MSG_SPLICE_PAGES)) {
- struct page_frag zc_pfrag;
- struct page **pages = &zc_pfrag.page;
+ struct page *splice_page;
+ struct page **pages = &splice_page;
size_t off;

rc = iov_iter_extract_pages(iter, &pages,
@@ -508,24 +531,22 @@ static int tls_push_data(struct sock *sk,
}
copy = rc;

- if (WARN_ON_ONCE(!sendpage_ok(zc_pfrag.page))) {
+ if (WARN_ON_ONCE(!sendpage_ok(splice_page))) {
iov_iter_revert(iter, copy);
rc = -EIO;
goto handle_error;
}

- zc_pfrag.offset = off;
- zc_pfrag.size = copy;
- tls_append_frag(record, &zc_pfrag, copy);
+ tls_append_page(record, splice_page, off, copy);
} else if (copy) {
- copy = min_t(size_t, copy, pfrag->size - pfrag->offset);
+ copy = min_t(size_t, copy, frag_size);

- rc = tls_device_copy_data(page_address(pfrag->page) +
- pfrag->offset, copy,
- iter);
+ rc = tls_device_copy_data(va, copy, iter);
if (rc)
goto handle_error;
- tls_append_frag(record, pfrag, copy);
+
+ tls_append_pfrag(record, pfrag, page, frag_offset,
+ copy);
}

size -= copy;
--
2.33.0
Re: [PATCH net-next v2 13/15] net: replace page_frag with page_frag_cache [ In reply to ]
On Mon, 15 Apr 2024, Yunsheng Lin wrote:

> Use the newly introduced prepare/commit API to replace
> page_frag with page_frag_cache for sk_page_frag().
>
> Signed-off-by: Yunsheng Lin <linyunsheng@huawei.com>
> ---
> .../chelsio/inline_crypto/chtls/chtls.h | 3 -
> .../chelsio/inline_crypto/chtls/chtls_io.c | 101 ++++---------
> .../chelsio/inline_crypto/chtls/chtls_main.c | 3 -
> drivers/net/tun.c | 34 ++---
> include/linux/sched.h | 4 +-
> include/net/sock.h | 14 +-
> kernel/exit.c | 3 +-
> kernel/fork.c | 2 +-
> net/core/skbuff.c | 32 ++--
> net/core/skmsg.c | 22 +--
> net/core/sock.c | 46 ++++--
> net/ipv4/ip_output.c | 35 +++--
> net/ipv4/tcp.c | 35 ++---
> net/ipv4/tcp_output.c | 28 ++--
> net/ipv6/ip6_output.c | 35 +++--
> net/kcm/kcmsock.c | 30 ++--
> net/mptcp/protocol.c | 74 ++++++----
> net/tls/tls_device.c | 139 ++++++++++--------
> 18 files changed, 342 insertions(+), 298 deletions(-)

Hi Yunsheng,

Just focusing on mptcp:

> diff --git a/net/mptcp/protocol.c b/net/mptcp/protocol.c
> index f8bc34f0d973..368dd480c4cd 100644
> --- a/net/mptcp/protocol.c
> +++ b/net/mptcp/protocol.c
> @@ -959,17 +959,16 @@ static bool mptcp_skb_can_collapse_to(u64 write_seq,
> }
>
> /* we can append data to the given data frag if:
> - * - there is space available in the backing page_frag
> - * - the data frag tail matches the current page_frag free offset
> + * - the data frag tail matches the current page and offset
> * - the data frag end sequence number matches the current write seq
> */
> static bool mptcp_frag_can_collapse_to(const struct mptcp_sock *msk,
> - const struct page_frag *pfrag,
> + const struct page *page,
> + const unsigned int offset,
> const struct mptcp_data_frag *df)
> {
> - return df && pfrag->page == df->page &&
> - pfrag->size - pfrag->offset > 0 &&
> - pfrag->offset == (df->offset + df->data_len) &&
> + return df && page == df->page &&
> + offset == (df->offset + df->data_len) &&
> df->data_seq + df->data_len == msk->write_seq;
> }
>
> @@ -1084,30 +1083,36 @@ static void mptcp_enter_memory_pressure(struct sock *sk)
> /* ensure we get enough memory for the frag hdr, beyond some minimal amount of
> * data
> */
> -static bool mptcp_page_frag_refill(struct sock *sk, struct page_frag *pfrag)
> +static struct page *mptcp_page_frag_alloc_prepare(struct sock *sk,
> + struct page_frag_cache *pfrag,
> + unsigned int *offset,
> + unsigned int *size, void **va)
> {
> - if (likely(skb_page_frag_refill(32U + sizeof(struct mptcp_data_frag),
> - pfrag, sk->sk_allocation)))
> - return true;
> + struct page *page;
> +
> + page = page_frag_alloc_prepare(pfrag, offset, size, va,
> + sk->sk_allocation);
> + if (likely(page))
> + return page;
>
> mptcp_enter_memory_pressure(sk);
> - return false;
> + return NULL;
> }
>
> static struct mptcp_data_frag *
> -mptcp_carve_data_frag(const struct mptcp_sock *msk, struct page_frag *pfrag,
> - int orig_offset)
> +mptcp_carve_data_frag(const struct mptcp_sock *msk, struct page *page,
> + unsigned int orig_offset)
> {
> int offset = ALIGN(orig_offset, sizeof(long));
> struct mptcp_data_frag *dfrag;
>
> - dfrag = (struct mptcp_data_frag *)(page_to_virt(pfrag->page) + offset);
> + dfrag = (struct mptcp_data_frag *)(page_to_virt(page) + offset);
> dfrag->data_len = 0;
> dfrag->data_seq = msk->write_seq;
> dfrag->overhead = offset - orig_offset + sizeof(struct mptcp_data_frag);
> dfrag->offset = offset + sizeof(struct mptcp_data_frag);
> dfrag->already_sent = 0;
> - dfrag->page = pfrag->page;
> + dfrag->page = page;
>
> return dfrag;
> }
> @@ -1792,7 +1797,7 @@ static u32 mptcp_send_limit(const struct sock *sk)
> static int mptcp_sendmsg(struct sock *sk, struct msghdr *msg, size_t len)
> {
> struct mptcp_sock *msk = mptcp_sk(sk);
> - struct page_frag *pfrag;
> + struct page_frag_cache *pfrag;
> size_t copied = 0;
> int ret = 0;
> long timeo;
> @@ -1831,9 +1836,12 @@ static int mptcp_sendmsg(struct sock *sk, struct msghdr *msg, size_t len)
> while (msg_data_left(msg)) {
> int total_ts, frag_truesize = 0;
> struct mptcp_data_frag *dfrag;
> - bool dfrag_collapsed;
> - size_t psize, offset;
> + bool dfrag_collapsed = false;
> + unsigned int offset, size;
> + struct page *page;
> + size_t psize;
> u32 copy_limit;
> + void *va;
>
> /* ensure fitting the notsent_lowat() constraint */
> copy_limit = mptcp_send_limit(sk);
> @@ -1844,21 +1852,31 @@ static int mptcp_sendmsg(struct sock *sk, struct msghdr *msg, size_t len)
> * page allocator
> */
> dfrag = mptcp_pending_tail(sk);
> - dfrag_collapsed = mptcp_frag_can_collapse_to(msk, pfrag, dfrag);
> + size = 32U;
> + page = mptcp_page_frag_alloc_prepare(sk, pfrag, &offset, &size,
> + &va);
> + if (!page)
> + goto wait_for_memory;
> +
> + dfrag_collapsed = mptcp_frag_can_collapse_to(msk, page, offset,
> + dfrag);
> if (!dfrag_collapsed) {
> - if (!mptcp_page_frag_refill(sk, pfrag))
> + size = 32U + sizeof(struct mptcp_data_frag);
> + page = mptcp_page_frag_alloc_prepare(sk, pfrag, &offset,
> + &size, &va);

Since 'size' was updated to contain the maximum available space on the
first call to mptcp_page_frag_alloc_prepare(), is it necessary to call it
again instead of checking to see if 'size' is large enough for the
mptcp_data_frag struct?

> + if (!page)
> goto wait_for_memory;
>
> - dfrag = mptcp_carve_data_frag(msk, pfrag, pfrag->offset);
> + dfrag = mptcp_carve_data_frag(msk, page, offset);
> frag_truesize = dfrag->overhead;
> + va += dfrag->overhead;
> }
>
> /* we do not bound vs wspace, to allow a single packet.
> * memory accounting will prevent execessive memory usage
> * anyway
> */
> - offset = dfrag->offset + dfrag->data_len;
> - psize = pfrag->size - offset;
> + psize = size - frag_truesize;
> psize = min_t(size_t, psize, msg_data_left(msg));
> psize = min_t(size_t, psize, copy_limit);
> total_ts = psize + frag_truesize;
> @@ -1866,8 +1884,7 @@ static int mptcp_sendmsg(struct sock *sk, struct msghdr *msg, size_t len)
> if (!sk_wmem_schedule(sk, total_ts))
> goto wait_for_memory;
>
> - ret = do_copy_data_nocache(sk, psize, &msg->msg_iter,
> - page_address(dfrag->page) + offset);
> + ret = do_copy_data_nocache(sk, psize, &msg->msg_iter, va);
> if (ret)
> goto do_error;
>
> @@ -1876,7 +1893,6 @@ static int mptcp_sendmsg(struct sock *sk, struct msghdr *msg, size_t len)
> copied += psize;
> dfrag->data_len += psize;
> frag_truesize += psize;
> - pfrag->offset += frag_truesize;
> WRITE_ONCE(msk->write_seq, msk->write_seq + psize);
>
> /* charge data on mptcp pending queue to the msk socket
> @@ -1884,11 +1900,15 @@ static int mptcp_sendmsg(struct sock *sk, struct msghdr *msg, size_t len)
> */
> sk_wmem_queued_add(sk, frag_truesize);
> if (!dfrag_collapsed) {
> - get_page(dfrag->page);
> + page_frag_alloc_commit(pfrag, offset, frag_truesize);

It would be more efficient (but more complicated) to defer the commit
until the loop is done or the maximum frag size is reached. This would
perform more like the older code, which only had to call refill when
mptcp_frag_can_collapse_to() returned false.

- Mat

> list_add_tail(&dfrag->list, &msk->rtx_queue);
> if (!msk->first_pending)
> WRITE_ONCE(msk->first_pending, dfrag);
> + } else {
> + page_frag_alloc_commit_noref(pfrag, offset,
> + frag_truesize);
> }
> +
> pr_debug("msk=%p dfrag at seq=%llu len=%u sent=%u new=%d", msk,
> dfrag->data_seq, dfrag->data_len, dfrag->already_sent,
> !dfrag_collapsed);
Re: [PATCH net-next v2 13/15] net: replace page_frag with page_frag_cache [ In reply to ]
On 2024/4/16 9:37, Mat Martineau wrote:
> On Mon, 15 Apr 2024, Yunsheng Lin wrote:
>
>> Use the newly introduced prepare/commit API to replace
>> page_frag with page_frag_cache for sk_page_frag().
>>
>> Signed-off-by: Yunsheng Lin <linyunsheng@huawei.com>
>> ---
>> .../chelsio/inline_crypto/chtls/chtls.h | 3 -
>> .../chelsio/inline_crypto/chtls/chtls_io.c | 101 ++++---------
>> .../chelsio/inline_crypto/chtls/chtls_main.c | 3 -
>> drivers/net/tun.c | 34 ++---
>> include/linux/sched.h | 4 +-
>> include/net/sock.h | 14 +-
>> kernel/exit.c | 3 +-
>> kernel/fork.c | 2 +-
>> net/core/skbuff.c | 32 ++--
>> net/core/skmsg.c | 22 +--
>> net/core/sock.c | 46 ++++--
>> net/ipv4/ip_output.c | 35 +++--
>> net/ipv4/tcp.c | 35 ++---
>> net/ipv4/tcp_output.c | 28 ++--
>> net/ipv6/ip6_output.c | 35 +++--
>> net/kcm/kcmsock.c | 30 ++--
>> net/mptcp/protocol.c | 74 ++++++----
>> net/tls/tls_device.c | 139 ++++++++++--------
>> 18 files changed, 342 insertions(+), 298 deletions(-)
>
> Hi Yunsheng,
>
> Just focusing on mptcp:

Thanks for reviewing.

>
>> diff --git a/net/mptcp/protocol.c b/net/mptcp/protocol.c
>> index f8bc34f0d973..368dd480c4cd 100644
>> --- a/net/mptcp/protocol.c
>> +++ b/net/mptcp/protocol.c
>> @@ -959,17 +959,16 @@ static bool mptcp_skb_can_collapse_to(u64 write_seq,
>> }
>>
>> /* we can append data to the given data frag if:
>> - * - there is space available in the backing page_frag
>> - * - the data frag tail matches the current page_frag free offset
>> + * - the data frag tail matches the current page and offset
>> * - the data frag end sequence number matches the current write seq
>> */
>> static bool mptcp_frag_can_collapse_to(const struct mptcp_sock *msk,
>> - const struct page_frag *pfrag,
>> + const struct page *page,
>> + const unsigned int offset,
>> const struct mptcp_data_frag *df)
>> {
>> - return df && pfrag->page == df->page &&
>> - pfrag->size - pfrag->offset > 0 &&
>> - pfrag->offset == (df->offset + df->data_len) &&
>> + return df && page == df->page &&
>> + offset == (df->offset + df->data_len) &&
>> df->data_seq + df->data_len == msk->write_seq;
>> }
>>
>> @@ -1084,30 +1083,36 @@ static void mptcp_enter_memory_pressure(struct sock *sk)
>> /* ensure we get enough memory for the frag hdr, beyond some minimal amount of
>> * data
>> */
>> -static bool mptcp_page_frag_refill(struct sock *sk, struct page_frag *pfrag)
>> +static struct page *mptcp_page_frag_alloc_prepare(struct sock *sk,
>> + struct page_frag_cache *pfrag,
>> + unsigned int *offset,
>> + unsigned int *size, void **va)
>> {
>> - if (likely(skb_page_frag_refill(32U + sizeof(struct mptcp_data_frag),
>> - pfrag, sk->sk_allocation)))
>> - return true;
>> + struct page *page;
>> +
>> + page = page_frag_alloc_prepare(pfrag, offset, size, va,
>> + sk->sk_allocation);
>> + if (likely(page))
>> + return page;
>>
>> mptcp_enter_memory_pressure(sk);
>> - return false;
>> + return NULL;
>> }
>>
>> static struct mptcp_data_frag *
>> -mptcp_carve_data_frag(const struct mptcp_sock *msk, struct page_frag *pfrag,
>> - int orig_offset)
>> +mptcp_carve_data_frag(const struct mptcp_sock *msk, struct page *page,
>> + unsigned int orig_offset)
>> {
>> int offset = ALIGN(orig_offset, sizeof(long));
>> struct mptcp_data_frag *dfrag;
>>
>> - dfrag = (struct mptcp_data_frag *)(page_to_virt(pfrag->page) + offset);
>> + dfrag = (struct mptcp_data_frag *)(page_to_virt(page) + offset);
>> dfrag->data_len = 0;
>> dfrag->data_seq = msk->write_seq;
>> dfrag->overhead = offset - orig_offset + sizeof(struct mptcp_data_frag);
>> dfrag->offset = offset + sizeof(struct mptcp_data_frag);
>> dfrag->already_sent = 0;
>> - dfrag->page = pfrag->page;
>> + dfrag->page = page;
>>
>> return dfrag;
>> }
>> @@ -1792,7 +1797,7 @@ static u32 mptcp_send_limit(const struct sock *sk)
>> static int mptcp_sendmsg(struct sock *sk, struct msghdr *msg, size_t len)
>> {
>> struct mptcp_sock *msk = mptcp_sk(sk);
>> - struct page_frag *pfrag;
>> + struct page_frag_cache *pfrag;
>> size_t copied = 0;
>> int ret = 0;
>> long timeo;
>> @@ -1831,9 +1836,12 @@ static int mptcp_sendmsg(struct sock *sk, struct msghdr *msg, size_t len)
>> while (msg_data_left(msg)) {
>> int total_ts, frag_truesize = 0;
>> struct mptcp_data_frag *dfrag;
>> - bool dfrag_collapsed;
>> - size_t psize, offset;
>> + bool dfrag_collapsed = false;
>> + unsigned int offset, size;
>> + struct page *page;
>> + size_t psize;
>> u32 copy_limit;
>> + void *va;
>>
>> /* ensure fitting the notsent_lowat() constraint */
>> copy_limit = mptcp_send_limit(sk);
>> @@ -1844,21 +1852,31 @@ static int mptcp_sendmsg(struct sock *sk, struct msghdr *msg, size_t len)
>> * page allocator
>> */
>> dfrag = mptcp_pending_tail(sk);
>> - dfrag_collapsed = mptcp_frag_can_collapse_to(msk, pfrag, dfrag);
>> + size = 32U;
>> + page = mptcp_page_frag_alloc_prepare(sk, pfrag, &offset, &size,
>> + &va);
>> + if (!page)
>> + goto wait_for_memory;
>> +
>> + dfrag_collapsed = mptcp_frag_can_collapse_to(msk, page, offset,
>> + dfrag);
>> if (!dfrag_collapsed) {
>> - if (!mptcp_page_frag_refill(sk, pfrag))
>> + size = 32U + sizeof(struct mptcp_data_frag);
>> + page = mptcp_page_frag_alloc_prepare(sk, pfrag, &offset,
>> + &size, &va);
>
> Since 'size' was updated to contain the maximum available space on the first call to mptcp_page_frag_alloc_prepare(), is it necessary to call it again instead of checking to see if 'size' is large enough for the mptcp_data_frag struct?

As the first call to the mptcp_page_frag_alloc_prepare() with the size
being 32U, the maximum available space might less than '32U +
sizeof(struct mptcp_data_frag)', in that case we need to call the
mptcp_page_frag_alloc_prepare() with the size being '32U +
sizeof(struct mptcp_data_frag)' anyway, so I am not sure if checking
the maximum available space on the first call to
mptcp_page_frag_alloc_prepare() before making the second call will
make the thing simpler.

>
>> + if (!page)
>> goto wait_for_memory;
>>
>> - dfrag = mptcp_carve_data_frag(msk, pfrag, pfrag->offset);
>> + dfrag = mptcp_carve_data_frag(msk, page, offset);
>> frag_truesize = dfrag->overhead;
>> + va += dfrag->overhead;
>> }
>>
>> /* we do not bound vs wspace, to allow a single packet.
>> * memory accounting will prevent execessive memory usage
>> * anyway
>> */
>> - offset = dfrag->offset + dfrag->data_len;
>> - psize = pfrag->size - offset;
>> + psize = size - frag_truesize;
>> psize = min_t(size_t, psize, msg_data_left(msg));
>> psize = min_t(size_t, psize, copy_limit);
>> total_ts = psize + frag_truesize;
>> @@ -1866,8 +1884,7 @@ static int mptcp_sendmsg(struct sock *sk, struct msghdr *msg, size_t len)
>> if (!sk_wmem_schedule(sk, total_ts))
>> goto wait_for_memory;
>>
>> - ret = do_copy_data_nocache(sk, psize, &msg->msg_iter,
>> - page_address(dfrag->page) + offset);
>> + ret = do_copy_data_nocache(sk, psize, &msg->msg_iter, va);
>> if (ret)
>> goto do_error;
>>
>> @@ -1876,7 +1893,6 @@ static int mptcp_sendmsg(struct sock *sk, struct msghdr *msg, size_t len)
>> copied += psize;
>> dfrag->data_len += psize;
>> frag_truesize += psize;
>> - pfrag->offset += frag_truesize;
>> WRITE_ONCE(msk->write_seq, msk->write_seq + psize);
>>
>> /* charge data on mptcp pending queue to the msk socket
>> @@ -1884,11 +1900,15 @@ static int mptcp_sendmsg(struct sock *sk, struct msghdr *msg, size_t len)
>> */
>> sk_wmem_queued_add(sk, frag_truesize);
>> if (!dfrag_collapsed) {
>> - get_page(dfrag->page);
>> + page_frag_alloc_commit(pfrag, offset, frag_truesize);
>
> It would be more efficient (but more complicated) to defer the commit until the loop is done or the maximum frag size is reached. This would perform more like the older code, which only had to call refill when mptcp_frag_can_collapse_to() returned false.

page_frag_alloc_commit() is a inlined helper, it does not seems
to be an issue here as it is updating the reference counting
and offset as the old code does with less overhead.

Maybe what we could do is to do the prepare in the inline
helper instead of a function when cache is enough, so that
we can avoid a function call as the old code does, as an
inlined function requires less overhead and is generally
faster than a function call.

But that requires more refactoring, as this patchset is bigger
enough now, I guess we try it later if it is possible.


>
> - Mat
>
Re: [PATCH net-next v2 13/15] net: replace page_frag with page_frag_cache [ In reply to ]
On Tue, 16 Apr 2024, Yunsheng Lin wrote:

> On 2024/4/16 9:37, Mat Martineau wrote:
>> On Mon, 15 Apr 2024, Yunsheng Lin wrote:
>>
>>> Use the newly introduced prepare/commit API to replace
>>> page_frag with page_frag_cache for sk_page_frag().
>>>
>>> Signed-off-by: Yunsheng Lin <linyunsheng@huawei.com>
>>> ---
>>> .../chelsio/inline_crypto/chtls/chtls.h | 3 -
>>> .../chelsio/inline_crypto/chtls/chtls_io.c | 101 ++++---------
>>> .../chelsio/inline_crypto/chtls/chtls_main.c | 3 -
>>> drivers/net/tun.c | 34 ++---
>>> include/linux/sched.h | 4 +-
>>> include/net/sock.h | 14 +-
>>> kernel/exit.c | 3 +-
>>> kernel/fork.c | 2 +-
>>> net/core/skbuff.c | 32 ++--
>>> net/core/skmsg.c | 22 +--
>>> net/core/sock.c | 46 ++++--
>>> net/ipv4/ip_output.c | 35 +++--
>>> net/ipv4/tcp.c | 35 ++---
>>> net/ipv4/tcp_output.c | 28 ++--
>>> net/ipv6/ip6_output.c | 35 +++--
>>> net/kcm/kcmsock.c | 30 ++--
>>> net/mptcp/protocol.c | 74 ++++++----
>>> net/tls/tls_device.c | 139 ++++++++++--------
>>> 18 files changed, 342 insertions(+), 298 deletions(-)
>>
>> Hi Yunsheng,
>>
>> Just focusing on mptcp:
>
> Thanks for reviewing.
>
>>
>>> diff --git a/net/mptcp/protocol.c b/net/mptcp/protocol.c
>>> index f8bc34f0d973..368dd480c4cd 100644
>>> --- a/net/mptcp/protocol.c
>>> +++ b/net/mptcp/protocol.c
>>> @@ -959,17 +959,16 @@ static bool mptcp_skb_can_collapse_to(u64 write_seq,
>>> }
>>>
>>> /* we can append data to the given data frag if:
>>> - * - there is space available in the backing page_frag
>>> - * - the data frag tail matches the current page_frag free offset
>>> + * - the data frag tail matches the current page and offset
>>> * - the data frag end sequence number matches the current write seq
>>> */
>>> static bool mptcp_frag_can_collapse_to(const struct mptcp_sock *msk,
>>> - const struct page_frag *pfrag,
>>> + const struct page *page,
>>> + const unsigned int offset,
>>> const struct mptcp_data_frag *df)
>>> {
>>> - return df && pfrag->page == df->page &&
>>> - pfrag->size - pfrag->offset > 0 &&
>>> - pfrag->offset == (df->offset + df->data_len) &&
>>> + return df && page == df->page &&
>>> + offset == (df->offset + df->data_len) &&
>>> df->data_seq + df->data_len == msk->write_seq;
>>> }
>>>
>>> @@ -1084,30 +1083,36 @@ static void mptcp_enter_memory_pressure(struct sock *sk)
>>> /* ensure we get enough memory for the frag hdr, beyond some minimal amount of
>>> * data
>>> */
>>> -static bool mptcp_page_frag_refill(struct sock *sk, struct page_frag *pfrag)
>>> +static struct page *mptcp_page_frag_alloc_prepare(struct sock *sk,
>>> + struct page_frag_cache *pfrag,
>>> + unsigned int *offset,
>>> + unsigned int *size, void **va)
>>> {
>>> - if (likely(skb_page_frag_refill(32U + sizeof(struct mptcp_data_frag),
>>> - pfrag, sk->sk_allocation)))
>>> - return true;
>>> + struct page *page;
>>> +
>>> + page = page_frag_alloc_prepare(pfrag, offset, size, va,
>>> + sk->sk_allocation);
>>> + if (likely(page))
>>> + return page;
>>>
>>> mptcp_enter_memory_pressure(sk);
>>> - return false;
>>> + return NULL;
>>> }
>>>
>>> static struct mptcp_data_frag *
>>> -mptcp_carve_data_frag(const struct mptcp_sock *msk, struct page_frag *pfrag,
>>> - int orig_offset)
>>> +mptcp_carve_data_frag(const struct mptcp_sock *msk, struct page *page,
>>> + unsigned int orig_offset)
>>> {
>>> int offset = ALIGN(orig_offset, sizeof(long));
>>> struct mptcp_data_frag *dfrag;
>>>
>>> - dfrag = (struct mptcp_data_frag *)(page_to_virt(pfrag->page) + offset);
>>> + dfrag = (struct mptcp_data_frag *)(page_to_virt(page) + offset);
>>> dfrag->data_len = 0;
>>> dfrag->data_seq = msk->write_seq;
>>> dfrag->overhead = offset - orig_offset + sizeof(struct mptcp_data_frag);
>>> dfrag->offset = offset + sizeof(struct mptcp_data_frag);
>>> dfrag->already_sent = 0;
>>> - dfrag->page = pfrag->page;
>>> + dfrag->page = page;
>>>
>>> return dfrag;
>>> }
>>> @@ -1792,7 +1797,7 @@ static u32 mptcp_send_limit(const struct sock *sk)
>>> static int mptcp_sendmsg(struct sock *sk, struct msghdr *msg, size_t len)
>>> {
>>> struct mptcp_sock *msk = mptcp_sk(sk);
>>> - struct page_frag *pfrag;
>>> + struct page_frag_cache *pfrag;
>>> size_t copied = 0;
>>> int ret = 0;
>>> long timeo;
>>> @@ -1831,9 +1836,12 @@ static int mptcp_sendmsg(struct sock *sk, struct msghdr *msg, size_t len)
>>> while (msg_data_left(msg)) {
>>> int total_ts, frag_truesize = 0;
>>> struct mptcp_data_frag *dfrag;
>>> - bool dfrag_collapsed;
>>> - size_t psize, offset;
>>> + bool dfrag_collapsed = false;
>>> + unsigned int offset, size;
>>> + struct page *page;
>>> + size_t psize;
>>> u32 copy_limit;
>>> + void *va;
>>>
>>> /* ensure fitting the notsent_lowat() constraint */
>>> copy_limit = mptcp_send_limit(sk);
>>> @@ -1844,21 +1852,31 @@ static int mptcp_sendmsg(struct sock *sk, struct msghdr *msg, size_t len)
>>> * page allocator
>>> */
>>> dfrag = mptcp_pending_tail(sk);
>>> - dfrag_collapsed = mptcp_frag_can_collapse_to(msk, pfrag, dfrag);
>>> + size = 32U;
>>> + page = mptcp_page_frag_alloc_prepare(sk, pfrag, &offset, &size,
>>> + &va);
>>> + if (!page)
>>> + goto wait_for_memory;
>>> +
>>> + dfrag_collapsed = mptcp_frag_can_collapse_to(msk, page, offset,
>>> + dfrag);
>>> if (!dfrag_collapsed) {
>>> - if (!mptcp_page_frag_refill(sk, pfrag))
>>> + size = 32U + sizeof(struct mptcp_data_frag);
>>> + page = mptcp_page_frag_alloc_prepare(sk, pfrag, &offset,
>>> + &size, &va);
>>
>> Since 'size' was updated to contain the maximum available space on the
>> first call to mptcp_page_frag_alloc_prepare(), is it necessary to call
>> it again instead of checking to see if 'size' is large enough for the
>> mptcp_data_frag struct?
>
> As the first call to the mptcp_page_frag_alloc_prepare() with the size
> being 32U, the maximum available space might less than '32U +
> sizeof(struct mptcp_data_frag)', in that case we need to call the
> mptcp_page_frag_alloc_prepare() with the size being '32U +
> sizeof(struct mptcp_data_frag)' anyway, so I am not sure if checking
> the maximum available space on the first call to
> mptcp_page_frag_alloc_prepare() before making the second call will
> make the thing simpler.

Ah, ok. If the larger amount of space is available the underlying call to
page_frag_cache_refill() ends up being very low overhead. So I agree with
you: it's ok to call mptcp_page_alloc_prepare() a second time.

>
>>
>>> + if (!page)
>>> goto wait_for_memory;
>>>
>>> - dfrag = mptcp_carve_data_frag(msk, pfrag, pfrag->offset);
>>> + dfrag = mptcp_carve_data_frag(msk, page, offset);
>>> frag_truesize = dfrag->overhead;
>>> + va += dfrag->overhead;
>>> }
>>>
>>> /* we do not bound vs wspace, to allow a single packet.
>>> * memory accounting will prevent execessive memory usage
>>> * anyway
>>> */
>>> - offset = dfrag->offset + dfrag->data_len;
>>> - psize = pfrag->size - offset;
>>> + psize = size - frag_truesize;
>>> psize = min_t(size_t, psize, msg_data_left(msg));
>>> psize = min_t(size_t, psize, copy_limit);
>>> total_ts = psize + frag_truesize;
>>> @@ -1866,8 +1884,7 @@ static int mptcp_sendmsg(struct sock *sk, struct msghdr *msg, size_t len)
>>> if (!sk_wmem_schedule(sk, total_ts))
>>> goto wait_for_memory;
>>>
>>> - ret = do_copy_data_nocache(sk, psize, &msg->msg_iter,
>>> - page_address(dfrag->page) + offset);
>>> + ret = do_copy_data_nocache(sk, psize, &msg->msg_iter, va);
>>> if (ret)
>>> goto do_error;
>>>
>>> @@ -1876,7 +1893,6 @@ static int mptcp_sendmsg(struct sock *sk, struct msghdr *msg, size_t len)
>>> copied += psize;
>>> dfrag->data_len += psize;
>>> frag_truesize += psize;
>>> - pfrag->offset += frag_truesize;
>>> WRITE_ONCE(msk->write_seq, msk->write_seq + psize);
>>>
>>> /* charge data on mptcp pending queue to the msk socket
>>> @@ -1884,11 +1900,15 @@ static int mptcp_sendmsg(struct sock *sk, struct msghdr *msg, size_t len)
>>> */
>>> sk_wmem_queued_add(sk, frag_truesize);
>>> if (!dfrag_collapsed) {
>>> - get_page(dfrag->page);
>>> + page_frag_alloc_commit(pfrag, offset, frag_truesize);
>>
>> It would be more efficient (but more complicated) to defer the commit
>> until the loop is done or the maximum frag size is reached. This would
>> perform more like the older code, which only had to call refill when
>> mptcp_frag_can_collapse_to() returned false.
>
> page_frag_alloc_commit() is a inlined helper, it does not seems
> to be an issue here as it is updating the reference counting
> and offset as the old code does with less overhead.
>

I wasn't concerned as much about the direct cost of the inlined
page_frag_alloc_commit() helper, it was that we could make fewer prepare
calls if the commit was deferred as long as possible. As we discussed
above, I see now that the prepare is not expensive when there is more
space available in the current frag.

> Maybe what we could do is to do the prepare in the inline
> helper instead of a function when cache is enough, so that
> we can avoid a function call as the old code does, as an
> inlined function requires less overhead and is generally
> faster than a function call.
>
> But that requires more refactoring, as this patchset is bigger
> enough now, I guess we try it later if it is possible.

A more generic (possible) optimization would be to inline some of
page_frag_cache_refill(), but I'm not sure the code size tradeoff is
worth it - would have to collect some data to find out for sure!

Thanks,

Mat
Re: [PATCH net-next v2 13/15] net: replace page_frag with page_frag_cache [ In reply to ]
On 2024/4/17 5:40, Mat Martineau wrote:
..

> I wasn't concerned as much about the direct cost of the inlined page_frag_alloc_commit() helper, it was that we could make fewer prepare calls if the commit was deferred as long as possible. As we discussed above, I see now that the prepare is not expensive when there is more space available in the current frag.
>
>> Maybe what we could do is to do the prepare in the inline
>> helper instead of a function when cache is enough, so that
>> we can avoid a function call as the old code does, as an
>> inlined function requires less overhead and is generally
>> faster than a function call.
>>
>> But that requires more refactoring, as this patchset is bigger
>> enough now, I guess we try it later if it is possible.
>
> A more generic (possible) optimization would be to inline some of page_frag_cache_refill(), but I'm not sure the code size tradeoff is worth it - would have to collect some data to find out for sure!

In my arm64 system, It seems inlining some of page_frag_cache_refill() results
in smaller kernel code size as below, has not done the performance test yet, but
the smaller code size seems odd here.

Without this patchset:
linyunsheng@ubuntu:~/ksize$ ./ksize.sh
Linux Kernel total | text data bss
--------------------------------------------------------------------------------
vmlinux 51974159 | 32238573 19087890 647696

With this patchset:
linyunsheng@ubuntu:~/ksize$ ./ksize.sh
Linux Kernel total | text data bss
--------------------------------------------------------------------------------
vmlinux 51970078 | 32234468 19087914 647696


With this patchset and below patch inlining some of page_frag_cache_refill():
linyunsheng@ubuntu:~/ksize$ ./ksize.sh
Linux Kernel total | text data bss
--------------------------------------------------------------------------------
vmlinux 51966078 | 32230468 19087914 647696




diff --git a/include/linux/page_frag_cache.h b/include/linux/page_frag_cache.h
index 529e7c040dad..3e1de20c8146 100644
--- a/include/linux/page_frag_cache.h
+++ b/include/linux/page_frag_cache.h
@@ -60,8 +60,33 @@ static inline bool page_frag_cache_is_pfmemalloc(struct page_frag_cache *nc)

void page_frag_cache_drain(struct page_frag_cache *nc);
void __page_frag_cache_drain(struct page *page, unsigned int count);
-void *page_frag_cache_refill(struct page_frag_cache *nc, unsigned int fragsz,
- gfp_t gfp_mask);
+void *__page_frag_cache_refill(struct page_frag_cache *nc, gfp_t gfp_mask);
+void *page_frag_cache_flush(struct page_frag_cache *nc, gfp_t gfp_mask);
+
+static inline void *page_frag_cache_refill(struct page_frag_cache *nc,
+ unsigned int fragsz, gfp_t gfp_mask)
+{
+ unsigned long size_mask;
+ void *va;
+
+ if (unlikely(!nc->va)) {
+ va = __page_frag_cache_refill(nc, gfp_mask);
+ if (likely(va))
+ return va;
+ }
+
+#if (PAGE_SIZE < PAGE_FRAG_CACHE_MAX_SIZE)
+ /* if size can vary use size else just use PAGE_SIZE */
+ size_mask = nc->size_mask;
+#else
+ size_mask = PAGE_SIZE - 1;
+#endif
+
+ if (unlikely(nc->offset + fragsz > (size_mask + 1)))
+ return page_frag_cache_flush(nc, gfp_mask);
+
+ return (void *)((unsigned long)nc->va & ~size_mask);
+}

/**
* page_frag_alloc_va() - Alloc a page fragment.
diff --git a/mm/page_frag_cache.c b/mm/page_frag_cache.c
index 8b1d35aafcc1..74f643d472fb 100644
--- a/mm/page_frag_cache.c
+++ b/mm/page_frag_cache.c
@@ -18,8 +18,7 @@
#include <linux/page_frag_cache.h>
#include "internal.h"

-static bool __page_frag_cache_refill(struct page_frag_cache *nc,
- gfp_t gfp_mask)
+void *__page_frag_cache_refill(struct page_frag_cache *nc, gfp_t gfp_mask)
{
struct page *page = NULL;
gfp_t gfp = gfp_mask;
@@ -40,7 +39,7 @@ static bool __page_frag_cache_refill(struct page_frag_cache *nc,

if (unlikely(!page)) {
nc->va = NULL;
- return false;
+ return NULL;
}

nc->va = page_address(page);
@@ -57,8 +56,9 @@ static bool __page_frag_cache_refill(struct page_frag_cache *nc,

nc->pfmemalloc = page_is_pfmemalloc(page);
nc->offset = 0;
- return true;
+ return nc->va;
}
+EXPORT_SYMBOL(__page_frag_cache_refill);

/**
* page_frag_cache_drain - Drain the current page from page_frag cache.
@@ -83,20 +83,12 @@ void __page_frag_cache_drain(struct page *page, unsigned int count)
}
EXPORT_SYMBOL(__page_frag_cache_drain);

-void *page_frag_cache_refill(struct page_frag_cache *nc, unsigned int fragsz,
- gfp_t gfp_mask)
+void *page_frag_cache_flush(struct page_frag_cache *nc, gfp_t gfp_mask)
{
unsigned long size_mask;
- unsigned int offset;
struct page *page;
void *va;

- if (unlikely(!nc->va)) {
-refill:
- if (!__page_frag_cache_refill(nc, gfp_mask))
- return NULL;
- }
-
#if (PAGE_SIZE < PAGE_FRAG_CACHE_MAX_SIZE)
/* if size can vary use size else just use PAGE_SIZE */
size_mask = nc->size_mask;
@@ -105,41 +97,23 @@ void *page_frag_cache_refill(struct page_frag_cache *nc, unsigned int fragsz,
#endif

va = (void *)((unsigned long)nc->va & ~size_mask);
- offset = nc->offset;
-
- if (unlikely(offset + fragsz > (size_mask + 1))) {
- page = virt_to_page(va);
-
- if (!page_ref_sub_and_test(page, nc->pagecnt_bias & size_mask))
- goto refill;
-
- if (unlikely(nc->pfmemalloc)) {
- free_unref_page(page, compound_order(page));
- goto refill;
- }
-
- /* OK, page count is 0, we can safely set it */
- set_page_count(page, size_mask);
- nc->pagecnt_bias |= size_mask;
-
- nc->offset = 0;
- if (unlikely(fragsz > (size_mask + 1))) {
- /*
- * The caller is trying to allocate a fragment
- * with fragsz > PAGE_SIZE but the cache isn't big
- * enough to satisfy the request, this may
- * happen in low memory conditions.
- * We don't release the cache page because
- * it could make memory pressure worse
- * so we simply return NULL here.
- */
- return NULL;
- }
+ page = virt_to_page(va);
+ if (!page_ref_sub_and_test(page, nc->pagecnt_bias & size_mask))
+ return __page_frag_cache_refill(nc, gfp_mask);
+
+ if (unlikely(nc->pfmemalloc)) {
+ free_unref_page(page, compound_order(page));
+ return __page_frag_cache_refill(nc, gfp_mask);
}

+ /* OK, page count is 0, we can safely set it */
+ set_page_count(page, size_mask);
+ nc->pagecnt_bias |= size_mask;
+ nc->offset = 0;
+
return va;
}
-EXPORT_SYMBOL(page_frag_cache_refill);
+EXPORT_SYMBOL(page_frag_cache_flush);

/*
* Frees a page fragment allocated out of either a compound or order 0 page.


>
> Thanks,
>
> Mat
>
> .
>