Skip to content

Commit

Permalink
io_uring: add netmsg cache
Browse files Browse the repository at this point in the history 
For recvmsg/sendmsg, if they don't complete inline, we currently need
to allocate a struct io_async_msghdr for each request. This is a
somewhat large struct.

Hook up sendmsg/recvmsg to use the io_alloc_cache. This reduces the
alloc + free overhead considerably, yielding 4-5% of extra performance
running netbench.

Signed-off-by: Jens Axboe <axboe@kernel.dk>
  • Loading branch information
Jens Axboe committed Jul 25, 2022
1 parent 9731bc9 commit 43e0bbb
Show file tree
Hide file tree
Showing 4 changed files with 73 additions and 12 deletions.
6 changes: 4 additions & 2 deletions include/linux/io_uring_types.h
View file
Original file line number Diff line number Diff line change
Expand Up @@ -222,8 +222,7 @@ struct io_ring_ctx {
struct io_hash_table cancel_table_locked;
struct list_head cq_overflow_list;
struct io_alloc_cache apoll_cache;
struct xarray personalities;
u32 pers_next;
struct io_alloc_cache netmsg_cache;
} ____cacheline_aligned_in_smp;

/* IRQ completion list, under ->completion_lock */
Expand All @@ -241,6 +240,9 @@ struct io_ring_ctx {
unsigned int file_alloc_start;
unsigned int file_alloc_end;

struct xarray personalities;
u32 pers_next;

struct {
/*
* We cache a range of free CQEs we can use, once exhausted it
Expand Down
3 changes: 3 additions & 0 deletions io_uring/io_uring.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -89,6 +89,7 @@
#include "kbuf.h"
#include "rsrc.h"
#include "cancel.h"
#include "net.h"

#include "timeout.h"
#include "poll.h"
Expand Down Expand Up @@ -297,6 +298,7 @@ static __cold struct io_ring_ctx *io_ring_ctx_alloc(struct io_uring_params *p)
INIT_LIST_HEAD(&ctx->cq_overflow_list);
INIT_LIST_HEAD(&ctx->io_buffers_cache);
io_alloc_cache_init(&ctx->apoll_cache);
io_alloc_cache_init(&ctx->netmsg_cache);
init_completion(&ctx->ref_comp);
xa_init_flags(&ctx->personalities, XA_FLAGS_ALLOC1);
mutex_init(&ctx->uring_lock);
Expand Down Expand Up @@ -2469,6 +2471,7 @@ static __cold void io_ring_ctx_free(struct io_ring_ctx *ctx)
__io_cqring_overflow_flush(ctx, true);
io_eventfd_unregister(ctx);
io_alloc_cache_free(&ctx->apoll_cache, io_apoll_cache_free);
io_alloc_cache_free(&ctx->netmsg_cache, io_netmsg_cache_free);
mutex_unlock(&ctx->uring_lock);
io_destroy_buffers(ctx);
if (ctx->sq_creds)
Expand Down
63 changes: 54 additions & 9 deletions io_uring/net.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -12,6 +12,7 @@

#include "io_uring.h"
#include "kbuf.h"
#include "alloc_cache.h"
#include "net.h"

#if defined(CONFIG_NET)
Expand Down Expand Up @@ -97,18 +98,55 @@ static bool io_net_retry(struct socket *sock, int flags)
return sock->type == SOCK_STREAM || sock->type == SOCK_SEQPACKET;
}

static void io_netmsg_recycle(struct io_kiocb *req, unsigned int issue_flags)
{
struct io_async_msghdr *hdr = req->async_data;

if (!hdr || issue_flags & IO_URING_F_UNLOCKED)
return;

/* Let normal cleanup path reap it if we fail adding to the cache */
if (io_alloc_cache_put(&req->ctx->netmsg_cache, &hdr->cache)) {
req->async_data = NULL;
req->flags &= ~REQ_F_ASYNC_DATA;
}
}

static struct io_async_msghdr *io_recvmsg_alloc_async(struct io_kiocb *req,
unsigned int issue_flags)
{
struct io_ring_ctx *ctx = req->ctx;
struct io_cache_entry *entry;

if (!(issue_flags & IO_URING_F_UNLOCKED) &&
(entry = io_alloc_cache_get(&ctx->netmsg_cache)) != NULL) {
struct io_async_msghdr *hdr;

hdr = container_of(entry, struct io_async_msghdr, cache);
req->flags |= REQ_F_ASYNC_DATA;
req->async_data = hdr;
return hdr;
}

if (!io_alloc_async_data(req))
return req->async_data;

return NULL;
}

static int io_setup_async_msg(struct io_kiocb *req,
struct io_async_msghdr *kmsg)
struct io_async_msghdr *kmsg,
unsigned int issue_flags)
{
struct io_async_msghdr *async_msg = req->async_data;

if (async_msg)
return -EAGAIN;
if (io_alloc_async_data(req)) {
async_msg = io_recvmsg_alloc_async(req, issue_flags);
if (!async_msg) {
kfree(kmsg->free_iov);
return -ENOMEM;
}
async_msg = req->async_data;
req->flags |= REQ_F_NEED_CLEANUP;
memcpy(async_msg, kmsg, sizeof(*kmsg));
async_msg->msg.msg_name = &async_msg->addr;
Expand Down Expand Up @@ -195,7 +233,7 @@ int io_sendmsg(struct io_kiocb *req, unsigned int issue_flags)

if (!(req->flags & REQ_F_POLLED) &&
(sr->flags & IORING_RECVSEND_POLL_FIRST))
return io_setup_async_msg(req, kmsg);
return io_setup_async_msg(req, kmsg, issue_flags);

flags = sr->msg_flags;
if (issue_flags & IO_URING_F_NONBLOCK)
Expand All @@ -207,20 +245,21 @@ int io_sendmsg(struct io_kiocb *req, unsigned int issue_flags)

if (ret < min_ret) {
if (ret == -EAGAIN && (issue_flags & IO_URING_F_NONBLOCK))
return io_setup_async_msg(req, kmsg);
return io_setup_async_msg(req, kmsg, issue_flags);
if (ret == -ERESTARTSYS)
ret = -EINTR;
if (ret > 0 && io_net_retry(sock, flags)) {
sr->done_io += ret;
req->flags |= REQ_F_PARTIAL_IO;
return io_setup_async_msg(req, kmsg);
return io_setup_async_msg(req, kmsg, issue_flags);
}
req_set_fail(req);
}
/* fast path, check for non-NULL to avoid function call */
if (kmsg->free_iov)
kfree(kmsg->free_iov);
req->flags &= ~REQ_F_NEED_CLEANUP;
io_netmsg_recycle(req, issue_flags);
if (ret >= 0)
ret += sr->done_io;
else if (sr->done_io)
Expand Down Expand Up @@ -495,7 +534,7 @@ int io_recvmsg(struct io_kiocb *req, unsigned int issue_flags)

if (!(req->flags & REQ_F_POLLED) &&
(sr->flags & IORING_RECVSEND_POLL_FIRST))
return io_setup_async_msg(req, kmsg);
return io_setup_async_msg(req, kmsg, issue_flags);

if (io_do_buffer_select(req)) {
void __user *buf;
Expand All @@ -519,13 +558,13 @@ int io_recvmsg(struct io_kiocb *req, unsigned int issue_flags)
ret = __sys_recvmsg_sock(sock, &kmsg->msg, sr->umsg, kmsg->uaddr, flags);
if (ret < min_ret) {
if (ret == -EAGAIN && force_nonblock)
return io_setup_async_msg(req, kmsg);
return io_setup_async_msg(req, kmsg, issue_flags);
if (ret == -ERESTARTSYS)
ret = -EINTR;
if (ret > 0 && io_net_retry(sock, flags)) {
sr->done_io += ret;
req->flags |= REQ_F_PARTIAL_IO;
return io_setup_async_msg(req, kmsg);
return io_setup_async_msg(req, kmsg, issue_flags);
}
req_set_fail(req);
} else if ((flags & MSG_WAITALL) && (kmsg->msg.msg_flags & (MSG_TRUNC | MSG_CTRUNC))) {
Expand All @@ -535,6 +574,7 @@ int io_recvmsg(struct io_kiocb *req, unsigned int issue_flags)
/* fast path, check for non-NULL to avoid function call */
if (kmsg->free_iov)
kfree(kmsg->free_iov);
io_netmsg_recycle(req, issue_flags);
req->flags &= ~REQ_F_NEED_CLEANUP;
if (ret > 0)
ret += sr->done_io;
Expand Down Expand Up @@ -848,4 +888,9 @@ int io_connect(struct io_kiocb *req, unsigned int issue_flags)
io_req_set_res(req, ret, 0);
return IOU_OK;
}

void io_netmsg_cache_free(struct io_cache_entry *entry)
{
kfree(container_of(entry, struct io_async_msghdr, cache));
}
#endif
13 changes: 12 additions & 1 deletion io_uring/net.h
View file
Original file line number Diff line number Diff line change
Expand Up @@ -3,9 +3,14 @@
#include <linux/net.h>
#include <linux/uio.h>

#include "alloc_cache.h"

#if defined(CONFIG_NET)
struct io_async_msghdr {
struct iovec fast_iov[UIO_FASTIOV];
union {
struct iovec fast_iov[UIO_FASTIOV];
struct io_cache_entry cache;
};
/* points to an allocated iov, if NULL we use fast_iov instead */
struct iovec *free_iov;
struct sockaddr __user *uaddr;
Expand Down Expand Up @@ -40,4 +45,10 @@ int io_socket(struct io_kiocb *req, unsigned int issue_flags);
int io_connect_prep_async(struct io_kiocb *req);
int io_connect_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe);
int io_connect(struct io_kiocb *req, unsigned int issue_flags);

void io_netmsg_cache_free(struct io_cache_entry *entry);
#else
static inline void io_netmsg_cache_free(struct io_cache_entry *entry)
{
}
#endif

0 comments on commit 43e0bbb

Please sign in to comment.