Commit 42385b02 authored by Pavel Begunkov's avatar Pavel Begunkov Committed by Jens Axboe
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io_uring/net: move mm accounting to a slower path 



We can also move mm accounting to the extended callbacks. It removes a
few cycles from the hot path including skipping one function call and
setting io_req_task_complete as a callback directly. For user backed I/O
it shouldn't make any difference taking into considering atomic mm
accounting and page pinning.

Signed-off-by: default avatarPavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/1062f270273ad11c1b7b45ec59a6a317533d5e64.1667557923.git.asml.silence@gmail.com


Signed-off-by: default avatarJens Axboe <axboe@kernel.dk>
parent 40725d1b

io_uring/net.c

+3 −0
Original line number Diff line number Diff line
@@ -1097,6 +1097,7 @@ int io_send_zc(struct io_kiocb *req, unsigned int issue_flags) 
			return ret;

		msg.sg_from_iter = io_sg_from_iter;

	} else {

		io_notif_set_extended(zc->notif);

		ret = import_single_range(WRITE, zc->buf, zc->len, &iov,

					  &msg.msg_iter);

		if (unlikely(ret))
@@ -1158,6 +1159,8 @@ int io_sendmsg_zc(struct io_kiocb *req, unsigned int issue_flags) 
	unsigned flags;

	int ret, min_ret = 0;



	io_notif_set_extended(sr->notif);



	sock = sock_from_file(req->file);

	if (unlikely(!sock))

		return -ENOTSOCK;

io_uring/notif.c

+13 −18
Original line number Diff line number Diff line
@@ -9,11 +9,14 @@ 
#include "notif.h"

#include "rsrc.h"



static void __io_notif_complete_tw(struct io_kiocb *notif, bool *locked)

static void io_notif_complete_tw_ext(struct io_kiocb *notif, bool *locked)

{

	struct io_notif_data *nd = io_notif_to_data(notif);

	struct io_ring_ctx *ctx = notif->ctx;



	if (nd->zc_report && (nd->zc_copied || !nd->zc_used))

		notif->cqe.res |= IORING_NOTIF_USAGE_ZC_COPIED;



	if (nd->account_pages && ctx->user) {

		__io_unaccount_mem(ctx->user, nd->account_pages);

		nd->account_pages = 0;
@@ -21,16 +24,6 @@ static void __io_notif_complete_tw(struct io_kiocb *notif, bool *locked) 
	io_req_task_complete(notif, locked);

}



static void io_notif_complete_tw_ext(struct io_kiocb *notif, bool *locked)

{

	struct io_notif_data *nd = io_notif_to_data(notif);



	if (nd->zc_report && (nd->zc_copied || !nd->zc_used))

		notif->cqe.res |= IORING_NOTIF_USAGE_ZC_COPIED;



	__io_notif_complete_tw(notif, locked);

}



static void io_tx_ubuf_callback(struct sk_buff *skb, struct ubuf_info *uarg,

				bool success)

{
@@ -59,11 +52,14 @@ void io_notif_set_extended(struct io_kiocb *notif) 
{

	struct io_notif_data *nd = io_notif_to_data(notif);



	if (nd->uarg.callback != io_tx_ubuf_callback_ext) {

		nd->account_pages = 0;

		nd->zc_report = false;

		nd->zc_used = false;

		nd->zc_copied = false;

		nd->uarg.callback = io_tx_ubuf_callback_ext;

		notif->io_task_work.func = io_notif_complete_tw_ext;

	io_notif_to_data(notif)->uarg.callback = io_tx_ubuf_callback_ext;

	}

}



struct io_kiocb *io_alloc_notif(struct io_ring_ctx *ctx)
@@ -81,10 +77,9 @@ struct io_kiocb *io_alloc_notif(struct io_ring_ctx *ctx) 
	notif->task = current;

	io_get_task_refs(1);

	notif->rsrc_node = NULL;

	notif->io_task_work.func = __io_notif_complete_tw;

	notif->io_task_work.func = io_req_task_complete;



	nd = io_notif_to_data(notif);

	nd->account_pages = 0;

	nd->uarg.flags = SKBFL_ZEROCOPY_FRAG | SKBFL_DONT_ORPHAN;

	nd->uarg.callback = io_tx_ubuf_callback;

	refcount_set(&nd->uarg.refcnt, 1);