From: Jens Axboe <axboe@kernel.dk>
Date: Tue, 4 Dec 2018 16:44:49 +0000 (-0700)
Subject: aio: don't zero entire aio_kiocb aio_get_req()
X-Git-Tag: v5.0-rc1~115^2~4
X-Git-Url: http://git.osdn.net/view?a=commitdiff_plain;h=2bc4ca9bb600cbe36941da2b2a67189fc4302a04;p=uclinux-h8%2Flinux.git

aio: don't zero entire aio_kiocb aio_get_req()

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.

Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
---

diff --git a/fs/aio.c b/fs/aio.c
index 7556709b9b8d..b167a8dc3a81 100644
--- a/fs/aio.c
+++ b/fs/aio.c
@@ -1010,14 +1010,15 @@ 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);
+	req = kmem_cache_alloc(kiocb_cachep, GFP_KERNEL);
 	if (unlikely(!req))
 		return NULL;
 
 	percpu_ref_get(&ctx->reqs);
+	req->ki_ctx = ctx;
 	INIT_LIST_HEAD(&req->ki_list);
 	refcount_set(&req->ki_refcnt, 0);
-	req->ki_ctx = ctx;
+	req->ki_eventfd = NULL;
 	return req;
 }
 
@@ -1732,6 +1733,10 @@ 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;