2023-07-06 09:55:50

by Lu Hongfei

Subject: [PATCH] io_uring: A new function has been defined to make get/put exist in pairs

A new function called io_put_task_refs has been defined for pairing
with io_get_task_refs.

In io_submit_sqes(), when req is not fully sent(i.e. left != 0), it is
necessary to call the io_put_task_refs() to recover the current process's
cached_refs and pair it with the io_get_task_refs(), which is easy to
understand and looks more regular.

Signed-off-by: Lu Hongfei <[email protected]>
---
io_uring/io_uring.c | 2 +-
io_uring/io_uring.h | 5 +++++
2 files changed, 6 insertions(+), 1 deletion(-)

diff --git a/io_uring/io_uring.c b/io_uring/io_uring.c
index e8096d502a7c..43844bc2bc62 100644
--- a/io_uring/io_uring.c
+++ b/io_uring/io_uring.c
@@ -2421,7 +2421,7 @@ int io_submit_sqes(struct io_ring_ctx *ctx, unsigned int nr)
/* try again if it submitted nothing and can't allocate a req */
if (!ret && io_req_cache_empty(ctx))
ret = -EAGAIN;
- current->io_uring->cached_refs += left;
+ io_put_task_refs(left);
}

io_submit_state_end(ctx);
diff --git a/io_uring/io_uring.h b/io_uring/io_uring.h
index d3606d30cf6f..bf01c56322c9 100644
--- a/io_uring/io_uring.h
+++ b/io_uring/io_uring.h
@@ -342,6 +342,11 @@ static inline void io_get_task_refs(int nr)
io_task_refs_refill(tctx);
}

+static inline void io_put_task_refs(int nr)
+{
+ current->io_uring->cached_refs += nr;
+}
+
static inline bool io_req_cache_empty(struct io_ring_ctx *ctx)
{
return !ctx->submit_state.free_list.next;
--
2.39.0

2023-07-06 15:03:07

by Jens Axboe

Subject: Re: [PATCH] io_uring: A new function has been defined to make get/put exist in pairs

On 7/6/23 3:32?AM, Lu Hongfei wrote:
> A new function called io_put_task_refs has been defined for pairing
> with io_get_task_refs.
>
> In io_submit_sqes(), when req is not fully sent(i.e. left != 0), it is
> necessary to call the io_put_task_refs() to recover the current process's
> cached_refs and pair it with the io_get_task_refs(), which is easy to
> understand and looks more regular.

No point having a helper for just a single caller.

--
Jens Axboe