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From: Jens Axboe <axboe@kernel.dk>
To: linux-aio@kvack.org, linux-block@vger.kernel.org,
	linux-api@vger.kernel.org
Cc: hch@lst.de, jmoyer@redhat.com, avi@scylladb.com,
	jannh@google.com, viro@ZenIV.linux.org.uk,
	Jens Axboe <axboe@kernel.dk>
Subject: [PATCH 10/19] io_uring: batch io_kiocb allocation
Date: Sat,  9 Feb 2019 14:13:37 -0700
Message-ID: <20190209211346.26060-11-axboe@kernel.dk> (raw)
In-Reply-To: <20190209211346.26060-1-axboe@kernel.dk>

Similarly to how we use the state->ios_left to know how many references
to get to a file, we can use it to allocate the io_kiocb's we need in
bulk.

Reviewed-by: Hannes Reinecke <hare@suse.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
---
 fs/io_uring.c | 45 ++++++++++++++++++++++++++++++++++++++-------
 1 file changed, 38 insertions(+), 7 deletions(-)

diff --git a/fs/io_uring.c b/fs/io_uring.c
index faf329e81570..d9f7e90766c8 100644
--- a/fs/io_uring.c
+++ b/fs/io_uring.c
@@ -148,6 +148,13 @@ struct io_kiocb {
 struct io_submit_state {
 	struct blk_plug plug;
 
+	/*
+	 * io_kiocb alloc cache
+	 */
+	void *reqs[IO_IOPOLL_BATCH];
+	unsigned int free_reqs;
+	unsigned int cur_req;
+
 	/*
 	 * File reference cache
 	 */
@@ -281,20 +288,40 @@ static void io_ring_drop_ctx_refs(struct io_ring_ctx *ctx, unsigned refs)
 		wake_up(&ctx->wait);
 }
 
-static struct io_kiocb *io_get_req(struct io_ring_ctx *ctx)
+static struct io_kiocb *io_get_req(struct io_ring_ctx *ctx,
+				   struct io_submit_state *state)
 {
 	struct io_kiocb *req;
 
 	if (!percpu_ref_tryget(&ctx->refs))
 		return NULL;
 
-	req = kmem_cache_alloc(req_cachep, __GFP_NOWARN);
-	if (req) {
-		req->ctx = ctx;
-		req->flags = 0;
-		return req;
+	if (!state) {
+		req = kmem_cache_alloc(req_cachep, __GFP_NOWARN);
+		if (unlikely(!req))
+			goto out;
+	} else if (!state->free_reqs) {
+		size_t sz;
+		int ret;
+
+		sz = min_t(size_t, state->ios_left, ARRAY_SIZE(state->reqs));
+		ret = kmem_cache_alloc_bulk(req_cachep, __GFP_NOWARN, sz,
+						state->reqs);
+		if (unlikely(ret <= 0))
+			goto out;
+		state->free_reqs = ret - 1;
+		state->cur_req = 1;
+		req = state->reqs[0];
+	} else {
+		req = state->reqs[state->cur_req];
+		state->free_reqs--;
+		state->cur_req++;
 	}
 
+	req->ctx = ctx;
+	req->flags = 0;
+	return req;
+out:
 	io_ring_drop_ctx_refs(ctx, 1);
 	return NULL;
 }
@@ -980,7 +1007,7 @@ static int io_submit_sqe(struct io_ring_ctx *ctx, const struct sqe_submit *s,
 	if (unlikely(s->sqe->flags))
 		return -EINVAL;
 
-	req = io_get_req(ctx);
+	req = io_get_req(ctx, state);
 	if (unlikely(!req))
 		return -EAGAIN;
 
@@ -1006,6 +1033,9 @@ static void io_submit_state_end(struct io_submit_state *state)
 {
 	blk_finish_plug(&state->plug);
 	io_file_put(state, NULL);
+	if (state->free_reqs)
+		kmem_cache_free_bulk(req_cachep, state->free_reqs,
+					&state->reqs[state->cur_req]);
 }
 
 /*
@@ -1015,6 +1045,7 @@ static void io_submit_state_start(struct io_submit_state *state,
 				  struct io_ring_ctx *ctx, unsigned max_ios)
 {
 	blk_start_plug(&state->plug);
+	state->free_reqs = 0;
 	state->file = NULL;
 	state->ios_left = max_ios;
 }
-- 
2.17.1


  parent reply index

Thread overview: 35+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-02-09 21:13 [PATCHSET v14] io_uring IO interface Jens Axboe
2019-02-09 21:13 ` [PATCH 01/19] fs: add an iopoll method to struct file_operations Jens Axboe
2019-02-09 21:13 ` [PATCH 02/19] block: wire up block device iopoll method Jens Axboe
2019-02-09 21:13 ` [PATCH 03/19] block: add bio_set_polled() helper Jens Axboe
2019-02-09 21:13 ` [PATCH 04/19] iomap: wire up the iopoll method Jens Axboe
2019-02-09 21:13 ` [PATCH 05/19] Add io_uring IO interface Jens Axboe
2019-02-10 12:03   ` Thomas Gleixner
2019-02-10 14:19     ` Jens Axboe
2019-02-09 21:13 ` [PATCH 06/19] io_uring: add fsync support Jens Axboe
2019-02-09 21:13 ` [PATCH 07/19] io_uring: support for IO polling Jens Axboe
2019-02-09 21:13 ` [PATCH 08/19] fs: add fget_many() and fput_many() Jens Axboe
2019-02-09 21:13 ` [PATCH 09/19] io_uring: use fget/fput_many() for file references Jens Axboe
2019-02-09 21:13 ` Jens Axboe [this message]
2019-02-09 21:13 ` [PATCH 11/19] block: implement bio helper to add iter bvec pages to bio Jens Axboe
2019-02-09 21:13 ` [PATCH 12/19] io_uring: add support for pre-mapped user IO buffers Jens Axboe
2019-02-09 21:13 ` [PATCH 13/19] net: split out functions related to registering inflight socket files Jens Axboe
2019-02-09 21:13 ` [PATCH 14/19] io_uring: add file set registration Jens Axboe
2019-02-09 23:52   ` Matt Mullins
2019-02-10  0:47     ` Jens Axboe
     [not found]       ` <60e4c6a489549daad1fb2c5e8eee5496c668d79a.camel@fb.com>
2019-02-10  2:34         ` Jens Axboe
2019-02-10  2:57           ` Jens Axboe
2019-02-10 19:55             ` Matt Mullins
2019-02-09 21:13 ` [PATCH 15/19] io_uring: add submission polling Jens Axboe
2019-02-09 21:13 ` [PATCH 16/19] io_uring: add io_kiocb ref count Jens Axboe
2019-02-10  9:19   ` Hannes Reinecke
2019-02-09 21:13 ` [PATCH 17/19] io_uring: add support for IORING_OP_POLL Jens Axboe
2019-02-10  9:28   ` Hannes Reinecke
2019-02-09 21:13 ` [PATCH 18/19] io_uring: allow workqueue item to handle multiple buffered requests Jens Axboe
2019-02-10  9:31   ` Hannes Reinecke
2019-02-09 21:13 ` [PATCH 19/19] io_uring: add io_uring_event cache hit information Jens Axboe
2019-02-10  9:36   ` Hannes Reinecke
2019-02-10 13:39     ` Jens Axboe
  -- strict thread matches above, loose matches on Subject: below --
2019-02-11 19:00 [PATCHSET v15] io_uring IO interface Jens Axboe
2019-02-11 19:00 ` [PATCH 10/19] io_uring: batch io_kiocb allocation Jens Axboe
2019-02-08 17:34 [PATCHSET v13] io_uring IO interface Jens Axboe
2019-02-08 17:34 ` [PATCH 10/19] io_uring: batch io_kiocb allocation Jens Axboe
2019-02-09  9:43   ` Hannes Reinecke

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