diff mbox series

[10/27] aio: don't zero entire aio_kiocb aio_get_req()

Message ID 20181130165646.27341-11-axboe@kernel.dk (mailing list archive)
State New, archived
Headers show
Series [01/27] aio: fix failure to put the file pointer | expand

Commit Message

Jens Axboe Nov. 30, 2018, 4:56 p.m. UTC 
It's 192 bytes, fairly substantial. Most items don't need to be cleared,
especially not upfront. Clear the ones we do need to clear, and leave
the other ones for setup when the iocb is prepared and submitted.

Signed-off-by: Jens Axboe <axboe@kernel.dk>
---
 fs/aio.c | 19 ++++++++++++-------
 1 file changed, 12 insertions(+), 7 deletions(-)

Comments

Christoph Hellwig Dec. 4, 2018, 2:49 p.m. UTC | #1 
> -	req = kmem_cache_alloc(kiocb_cachep, GFP_KERNEL|__GFP_ZERO);
> -	if (unlikely(!req))
> -		return NULL;
> +	req = kmem_cache_alloc(kiocb_cachep, GFP_KERNEL);
> +	if (req) {
> +		percpu_ref_get(&ctx->reqs);
> +		req->ki_ctx = ctx;
> +		INIT_LIST_HEAD(&req->ki_list);
> +		refcount_set(&req->ki_refcnt, 0);
> +		req->ki_eventfd = NULL;
> +	}
>  
> -	percpu_ref_get(&ctx->reqs);
> -	INIT_LIST_HEAD(&req->ki_list);
> -	refcount_set(&req->ki_refcnt, 0);
> -	req->ki_ctx = ctx;
>  	return req;

Why the reformatting?  Otherwise this looks fine to me:

Reviewed-by: Christoph Hellwig <hch@lst.de>
Jens Axboe Dec. 4, 2018, 3:27 p.m. UTC | #2 
On 12/4/18 7:49 AM, Christoph Hellwig wrote:
>> -	req = kmem_cache_alloc(kiocb_cachep, GFP_KERNEL|__GFP_ZERO);
>> -	if (unlikely(!req))
>> -		return NULL;
>> +	req = kmem_cache_alloc(kiocb_cachep, GFP_KERNEL);
>> +	if (req) {
>> +		percpu_ref_get(&ctx->reqs);
>> +		req->ki_ctx = ctx;
>> +		INIT_LIST_HEAD(&req->ki_list);
>> +		refcount_set(&req->ki_refcnt, 0);
>> +		req->ki_eventfd = NULL;
>> +	}
>>  
>> -	percpu_ref_get(&ctx->reqs);
>> -	INIT_LIST_HEAD(&req->ki_list);
>> -	refcount_set(&req->ki_refcnt, 0);
>> -	req->ki_ctx = ctx;
>>  	return req;
> 
> Why the reformatting?  Otherwise this looks fine to me:
> 
> Reviewed-by: Christoph Hellwig <hch@lst.de>

Probably just the (over) abuse of likely/unlikely in aio.c. I can get
rid of it.
diff mbox series

Patch

diff --git a/fs/aio.c b/fs/aio.c
index eaceb40e6cf5..681f2072f81b 100644
--- a/fs/aio.c
+++ b/fs/aio.c
@@ -1009,14 +1009,15 @@  static inline struct aio_kiocb *aio_get_req(struct kioctx *ctx)
 {
 	struct aio_kiocb *req;
 
-	req = kmem_cache_alloc(kiocb_cachep, GFP_KERNEL|__GFP_ZERO);
-	if (unlikely(!req))
-		return NULL;
+	req = kmem_cache_alloc(kiocb_cachep, GFP_KERNEL);
+	if (req) {
+		percpu_ref_get(&ctx->reqs);
+		req->ki_ctx = ctx;
+		INIT_LIST_HEAD(&req->ki_list);
+		refcount_set(&req->ki_refcnt, 0);
+		req->ki_eventfd = NULL;
+	}
 
-	percpu_ref_get(&ctx->reqs);
-	INIT_LIST_HEAD(&req->ki_list);
-	refcount_set(&req->ki_refcnt, 0);
-	req->ki_ctx = ctx;
 	return req;
 }
 
@@ -1730,6 +1731,10 @@  static ssize_t aio_poll(struct aio_kiocb *aiocb, struct iocb *iocb)
 	if (unlikely(!req->file))
 		return -EBADF;
 
+	req->head = NULL;
+	req->woken = false;
+	req->cancelled = false;
+
 	apt.pt._qproc = aio_poll_queue_proc;
 	apt.pt._key = req->events;
 	apt.iocb = aiocb;