* [PATCH] io_uring: ensure REQ_F_ISREG is set async offload
@ 2022-07-21 15:11 Jens Axboe
2022-07-21 23:43 ` Yin Fengwei
0 siblings, 1 reply; 3+ messages in thread
From: Jens Axboe @ 2022-07-21 15:11 UTC (permalink / raw)
To: io-uring; +Cc: Yin Fengwei
If we're offloading requests directly to io-wq because IOSQE_ASYNC was
set in the sqe, we can miss hashing writes appropriately because we
haven't set REQ_F_ISREG yet. This can cause a performance regression
with buffered writes, as io-wq then no longer correctly serializes writes
to that file.
Ensure that we set the flags in io_prep_async_work(), which will cause
the io-wq work item to be hashed appropriately.
Fixes: 584b0180f0f4 ("io_uring: move read/write file prep state into actual opcode handler")
Link: https://lore.kernel.org/io-uring/20220608080054.GB22428@xsang-OptiPlex-9020/
Reported-and-tested-by: Yin Fengwei <fengwei.yin@intel.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
---
Yin, this is the 5.20 version. Once this lands upstream, I'll get the
5.19/18 variant sent to stable as well. Thanks!
diff --git a/io_uring/io_uring.c b/io_uring/io_uring.c
index 624535c62565..4b3fd645d023 100644
--- a/io_uring/io_uring.c
+++ b/io_uring/io_uring.c
@@ -406,6 +406,9 @@ static void io_prep_async_work(struct io_kiocb *req)
if (req->flags & REQ_F_FORCE_ASYNC)
req->work.flags |= IO_WQ_WORK_CONCURRENT;
+ if (req->file && !io_req_ffs_set(req))
+ req->flags |= io_file_get_flags(req->file) << REQ_F_SUPPORT_NOWAIT_BIT;
+
if (req->flags & REQ_F_ISREG) {
if (def->hash_reg_file || (ctx->flags & IORING_SETUP_IOPOLL))
io_wq_hash_work(&req->work, file_inode(req->file));
diff --git a/io_uring/io_uring.h b/io_uring/io_uring.h
index 868f45d55543..5db0a60dc04e 100644
--- a/io_uring/io_uring.h
+++ b/io_uring/io_uring.h
@@ -41,6 +41,11 @@ struct file *io_file_get_normal(struct io_kiocb *req, int fd);
struct file *io_file_get_fixed(struct io_kiocb *req, int fd,
unsigned issue_flags);
+static inline bool io_req_ffs_set(struct io_kiocb *req)
+{
+ return req->flags & REQ_F_FIXED_FILE;
+}
+
bool io_is_uring_fops(struct file *file);
bool io_alloc_async_data(struct io_kiocb *req);
void io_req_task_work_add(struct io_kiocb *req);
diff --git a/io_uring/rw.c b/io_uring/rw.c
index ade3e235f277..c50a0d66d67a 100644
--- a/io_uring/rw.c
+++ b/io_uring/rw.c
@@ -647,11 +647,6 @@ static bool need_read_all(struct io_kiocb *req)
S_ISBLK(file_inode(req->file)->i_mode);
}
-static inline bool io_req_ffs_set(struct io_kiocb *req)
-{
- return req->flags & REQ_F_FIXED_FILE;
-}
-
static int io_rw_init_file(struct io_kiocb *req, fmode_t mode)
{
struct io_rw *rw = io_kiocb_to_cmd(req);
--
Jens Axboe
^ permalink raw reply related [flat|nested] 3+ messages in thread* Re: [PATCH] io_uring: ensure REQ_F_ISREG is set async offload
2022-07-21 15:11 [PATCH] io_uring: ensure REQ_F_ISREG is set async offload Jens Axboe
@ 2022-07-21 23:43 ` Yin Fengwei
2022-07-22 1:36 ` Jens Axboe
0 siblings, 1 reply; 3+ messages in thread
From: Yin Fengwei @ 2022-07-21 23:43 UTC (permalink / raw)
To: Jens Axboe, io-uring
On 7/21/2022 11:11 PM, Jens Axboe wrote:
> If we're offloading requests directly to io-wq because IOSQE_ASYNC was
> set in the sqe, we can miss hashing writes appropriately because we
> haven't set REQ_F_ISREG yet. This can cause a performance regression
> with buffered writes, as io-wq then no longer correctly serializes writes
> to that file.
>
> Ensure that we set the flags in io_prep_async_work(), which will cause
> the io-wq work item to be hashed appropriately.
>
> Fixes: 584b0180f0f4 ("io_uring: move read/write file prep state into actual opcode handler")
> Link: https://lore.kernel.org/io-uring/20220608080054.GB22428@xsang-OptiPlex-9020/
> Reported-and-tested-by: Yin Fengwei <fengwei.yin@intel.com>
This issue is reported by (from the original report):
If you fix the issue, kindly add following tag
Reported-by: kernel test robot <oliver.sang@intel.com>
Regards
Yin, Fengwei
> Signed-off-by: Jens Axboe <axboe@kernel.dk>
>
> ---
>
> Yin, this is the 5.20 version. Once this lands upstream, I'll get the
> 5.19/18 variant sent to stable as well. Thanks!
>
> diff --git a/io_uring/io_uring.c b/io_uring/io_uring.c
> index 624535c62565..4b3fd645d023 100644
> --- a/io_uring/io_uring.c
> +++ b/io_uring/io_uring.c
> @@ -406,6 +406,9 @@ static void io_prep_async_work(struct io_kiocb *req)
> if (req->flags & REQ_F_FORCE_ASYNC)
> req->work.flags |= IO_WQ_WORK_CONCURRENT;
>
> + if (req->file && !io_req_ffs_set(req))
> + req->flags |= io_file_get_flags(req->file) << REQ_F_SUPPORT_NOWAIT_BIT;
> +
> if (req->flags & REQ_F_ISREG) {
> if (def->hash_reg_file || (ctx->flags & IORING_SETUP_IOPOLL))
> io_wq_hash_work(&req->work, file_inode(req->file));
> diff --git a/io_uring/io_uring.h b/io_uring/io_uring.h
> index 868f45d55543..5db0a60dc04e 100644
> --- a/io_uring/io_uring.h
> +++ b/io_uring/io_uring.h
> @@ -41,6 +41,11 @@ struct file *io_file_get_normal(struct io_kiocb *req, int fd);
> struct file *io_file_get_fixed(struct io_kiocb *req, int fd,
> unsigned issue_flags);
>
> +static inline bool io_req_ffs_set(struct io_kiocb *req)
> +{
> + return req->flags & REQ_F_FIXED_FILE;
> +}
> +
> bool io_is_uring_fops(struct file *file);
> bool io_alloc_async_data(struct io_kiocb *req);
> void io_req_task_work_add(struct io_kiocb *req);
> diff --git a/io_uring/rw.c b/io_uring/rw.c
> index ade3e235f277..c50a0d66d67a 100644
> --- a/io_uring/rw.c
> +++ b/io_uring/rw.c
> @@ -647,11 +647,6 @@ static bool need_read_all(struct io_kiocb *req)
> S_ISBLK(file_inode(req->file)->i_mode);
> }
>
> -static inline bool io_req_ffs_set(struct io_kiocb *req)
> -{
> - return req->flags & REQ_F_FIXED_FILE;
> -}
> -
> static int io_rw_init_file(struct io_kiocb *req, fmode_t mode)
> {
> struct io_rw *rw = io_kiocb_to_cmd(req);
>
^ permalink raw reply [flat|nested] 3+ messages in thread* Re: [PATCH] io_uring: ensure REQ_F_ISREG is set async offload
2022-07-21 23:43 ` Yin Fengwei
@ 2022-07-22 1:36 ` Jens Axboe
0 siblings, 0 replies; 3+ messages in thread
From: Jens Axboe @ 2022-07-22 1:36 UTC (permalink / raw)
To: Yin Fengwei, io-uring
On 7/21/22 5:43 PM, Yin Fengwei wrote:
>
> On 7/21/2022 11:11 PM, Jens Axboe wrote:
>> If we're offloading requests directly to io-wq because IOSQE_ASYNC was
>> set in the sqe, we can miss hashing writes appropriately because we
>> haven't set REQ_F_ISREG yet. This can cause a performance regression
>> with buffered writes, as io-wq then no longer correctly serializes writes
>> to that file.
>>
>> Ensure that we set the flags in io_prep_async_work(), which will cause
>> the io-wq work item to be hashed appropriately.
>>
>> Fixes: 584b0180f0f4 ("io_uring: move read/write file prep state into actual opcode handler")
>> Link: https://lore.kernel.org/io-uring/20220608080054.GB22428@xsang-OptiPlex-9020/
>> Reported-and-tested-by: Yin Fengwei <fengwei.yin@intel.com>
> This issue is reported by (from the original report):
>
> If you fix the issue, kindly add following tag
> Reported-by: kernel test robot <oliver.sang@intel.com>
Sorry, I missed that in the original. I'll be rebasing this branch this
weekend anyway, I'll try and remember to make the edit.
--
Jens Axboe
^ permalink raw reply [flat|nested] 3+ messages in thread
end of thread, other threads:[~2022-07-22 1:36 UTC | newest]
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2022-07-21 15:11 [PATCH] io_uring: ensure REQ_F_ISREG is set async offload Jens Axboe
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2022-07-22 1:36 ` Jens Axboe
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