2023-01-18 16:03:01

by Andrzej Hajda

Subject: [PATCH v5 5/7] io_uring: use __xchg if possible

Recently introduced helper simplifies the code.

Signed-off-by: Andrzej Hajda <[email protected]>
---
io_uring/io_uring.c | 7 ++-----
io_uring/slist.h | 6 ++----
2 files changed, 4 insertions(+), 9 deletions(-)

diff --git a/io_uring/io_uring.c b/io_uring/io_uring.c
index 2ac1cd8d23ea62..2b46a692d69022 100644
--- a/io_uring/io_uring.c
+++ b/io_uring/io_uring.c
@@ -54,6 +54,7 @@
#include <linux/fdtable.h>
#include <linux/mm.h>
#include <linux/mman.h>
+#include <linux/non-atomic/xchg.h>
#include <linux/percpu.h>
#include <linux/slab.h>
#include <linux/bvec.h>
@@ -1095,8 +1096,6 @@ static void __io_req_find_next_prep(struct io_kiocb *req)

static inline struct io_kiocb *io_req_find_next(struct io_kiocb *req)
{
- struct io_kiocb *nxt;
-
/*
* If LINK is set, we have dependent requests in this chain. If we
* didn't fail this request, queue the first one up, moving any other
@@ -1105,9 +1104,7 @@ static inline struct io_kiocb *io_req_find_next(struct io_kiocb *req)
*/
if (unlikely(req->flags & IO_DISARM_MASK))
__io_req_find_next_prep(req);
- nxt = req->link;
- req->link = NULL;
- return nxt;
+ return __xchg(&req->link, NULL);
}

static void ctx_flush_and_put(struct io_ring_ctx *ctx, bool *locked)
diff --git a/io_uring/slist.h b/io_uring/slist.h
index f27601fa46607b..d3a743a1adc626 100644
--- a/io_uring/slist.h
+++ b/io_uring/slist.h
@@ -2,6 +2,7 @@
#define INTERNAL_IO_SLIST_H

#include <linux/io_uring_types.h>
+#include <linux/non-atomic/xchg.h>

#define wq_list_for_each(pos, prv, head) \
for (pos = (head)->first, prv = NULL; pos; prv = pos, pos = (pos)->next)
@@ -121,10 +122,7 @@ static inline void wq_list_del(struct io_wq_work_list *list,
static inline
struct io_wq_work_node *wq_stack_extract(struct io_wq_work_node *stack)
{
- struct io_wq_work_node *node = stack->next;
-
- stack->next = node->next;
- return node;
+ return __xchg(&stack->next, stack->next->next);
}

static inline struct io_wq_work *wq_next_work(struct io_wq_work *work)
--
2.34.1

2023-02-27 09:59:20

by Andi Shyti

Subject: Re: [Intel-gfx] [PATCH v5 5/7] io_uring: use __xchg if possible

Hi Andrzej,

On Wed, Jan 18, 2023 at 04:44:48PM +0100, Andrzej Hajda wrote:
> Recently introduced helper simplifies the code.
>
> Signed-off-by: Andrzej Hajda <[email protected]>

Reviewed-by: Andi Shyti <[email protected]>

Thanks,
Andi

2023-03-12 14:41:29

by tip-bot2 for Jacob Pan

Subject: [tip: locking/core] io_uring: use __xchg if possible

The following commit has been merged into the locking/core branch of tip:

Commit-ID: bd1e2670ebd10ad727b92ddd424cca270314f5ee
Gitweb: https://git.kernel.org/tip/bd1e2670ebd10ad727b92ddd424cca270314f5ee
Author: Andrzej Hajda <[email protected]>
AuthorDate: Wed, 18 Jan 2023 16:44:48 +01:00
Committer: Peter Zijlstra <[email protected]>
CommitterDate: Sat, 11 Mar 2023 14:03:59 +01:00

io_uring: use __xchg if possible

Recently introduced helper simplifies the code.

Signed-off-by: Andrzej Hajda <[email protected]>
Signed-off-by: Peter Zijlstra (Intel) <[email protected]>
Reviewed-by: Andi Shyti <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
---
io_uring/io_uring.c | 7 ++-----
io_uring/slist.h | 6 ++----
2 files changed, 4 insertions(+), 9 deletions(-)

diff --git a/io_uring/io_uring.c b/io_uring/io_uring.c
index fd1cc35..0cd89a3 100644
--- a/io_uring/io_uring.c
+++ b/io_uring/io_uring.c
@@ -54,6 +54,7 @@
#include <linux/fdtable.h>
#include <linux/mm.h>
#include <linux/mman.h>
+#include <linux/non-atomic/xchg.h>
#include <linux/percpu.h>
#include <linux/slab.h>
#include <linux/bvec.h>
@@ -1131,8 +1132,6 @@ static void __io_req_find_next_prep(struct io_kiocb *req)

static inline struct io_kiocb *io_req_find_next(struct io_kiocb *req)
{
- struct io_kiocb *nxt;
-
/*
* If LINK is set, we have dependent requests in this chain. If we
* didn't fail this request, queue the first one up, moving any other
@@ -1141,9 +1140,7 @@ static inline struct io_kiocb *io_req_find_next(struct io_kiocb *req)
*/
if (unlikely(req->flags & IO_DISARM_MASK))
__io_req_find_next_prep(req);
- nxt = req->link;
- req->link = NULL;
- return nxt;
+ return __xchg(&req->link, NULL);
}

static void ctx_flush_and_put(struct io_ring_ctx *ctx, bool *locked)
diff --git a/io_uring/slist.h b/io_uring/slist.h
index 7c198a4..051e577 100644
--- a/io_uring/slist.h
+++ b/io_uring/slist.h
@@ -2,6 +2,7 @@
#define INTERNAL_IO_SLIST_H

#include <linux/io_uring_types.h>
+#include <linux/non-atomic/xchg.h>

#define wq_list_for_each(pos, prv, head) \
for (pos = (head)->first, prv = NULL; pos; prv = pos, pos = (pos)->next)
@@ -99,10 +100,7 @@ static inline void wq_list_del(struct io_wq_work_list *list,
static inline
struct io_wq_work_node *wq_stack_extract(struct io_wq_work_node *stack)
{
- struct io_wq_work_node *node = stack->next;
-
- stack->next = node->next;
- return node;
+ return __xchg(&stack->next, stack->next->next);
}

static inline struct io_wq_work *wq_next_work(struct io_wq_work *work)