From: Rusty Russell <rusty@rustcorp.com.au>
To: Paolo Bonzini <pbonzini@redhat.com>
Cc: Asias He <asias@redhat.com>,
"Michael S. Tsirkin" <mst@redhat.com>,
linux-kernel@vger.kernel.org,
virtualization@lists.linux-foundation.org,
Rusty Russell <rusty@rustcorp.com.au>
Subject: [PATCH 01/16] scatterlist: introduce sg_unmark_end
Date: Tue, 19 Feb 2013 18:26:19 +1030 [thread overview]
Message-ID: <1361260594-601-2-git-send-email-rusty@rustcorp.com.au> (raw)
In-Reply-To: <1361260594-601-1-git-send-email-rusty@rustcorp.com.au>
From: Paolo Bonzini <pbonzini@redhat.com>
This is useful in places that recycle the same scatterlist multiple
times, and do not want to incur the cost of sg_init_table every
time in hot paths.
Acked-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
---
block/blk-integrity.c | 2 +-
block/blk-merge.c | 2 +-
include/linux/scatterlist.h | 16 ++++++++++++++++
3 files changed, 18 insertions(+), 2 deletions(-)
diff --git a/block/blk-integrity.c b/block/blk-integrity.c
index da2a818..0f5004f 100644
--- a/block/blk-integrity.c
+++ b/block/blk-integrity.c
@@ -110,7 +110,7 @@ new_segment:
if (!sg)
sg = sglist;
else {
- sg->page_link &= ~0x02;
+ sg_unmark_end(sg);
sg = sg_next(sg);
}
diff --git a/block/blk-merge.c b/block/blk-merge.c
index 936a110..5f24482 100644
--- a/block/blk-merge.c
+++ b/block/blk-merge.c
@@ -143,7 +143,7 @@ new_segment:
* termination bit to avoid doing a full
* sg_init_table() in drivers for each command.
*/
- (*sg)->page_link &= ~0x02;
+ sg_unmark_end(*sg);
*sg = sg_next(*sg);
}
diff --git a/include/linux/scatterlist.h b/include/linux/scatterlist.h
index 4bd6c06..9b83784 100644
--- a/include/linux/scatterlist.h
+++ b/include/linux/scatterlist.h
@@ -172,6 +172,22 @@ static inline void sg_mark_end(struct scatterlist *sg)
}
/**
+ * sg_unmark_end - Undo setting the end of the scatterlist
+ * @sg: SG entryScatterlist
+ *
+ * Description:
+ * Removes the termination marker from the given entry of the scatterlist.
+ *
+ **/
+static inline void sg_unmark_end(struct scatterlist *sg)
+{
+#ifdef CONFIG_DEBUG_SG
+ BUG_ON(sg->sg_magic != SG_MAGIC);
+#endif
+ sg->page_link &= ~0x02;
+}
+
+/**
* sg_phys - Return physical address of an sg entry
* @sg: SG entry
*
--
1.7.10.4
next prev parent reply other threads:[~2013-02-19 8:07 UTC|newest]
Thread overview: 60+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-02-19 7:56 [PATCH 00/16] virtio ring rework Rusty Russell
2013-02-19 7:56 ` Rusty Russell [this message]
2013-02-19 7:56 ` [PATCH 02/16] virtio_ring: virtqueue_add_sgs, to add multiple sgs Rusty Russell
2013-02-19 9:15 ` Wanlong Gao
2013-02-20 9:18 ` Asias He
2013-02-24 22:12 ` Michael S. Tsirkin
2013-02-26 5:14 ` Rusty Russell
2013-02-26 9:30 ` Michael S. Tsirkin
2013-02-26 7:02 ` Paolo Bonzini
2013-02-27 7:28 ` Rusty Russell
2013-02-27 7:49 ` Michael S. Tsirkin
2013-02-27 11:21 ` Rusty Russell
2013-02-28 9:24 ` Paolo Bonzini
2013-03-01 1:01 ` Rusty Russell
2013-02-19 7:56 ` [PATCH 03/16] virtio-blk: reorganize virtblk_add_req Rusty Russell
2013-02-19 7:56 ` [PATCH 04/16] virtio-blk: use virtqueue_start_buf on bio path Rusty Russell
2013-02-20 9:19 ` Asias He
2013-02-21 6:23 ` Rusty Russell
2013-02-19 7:56 ` [PATCH 05/16] virtio-blk: use virtqueue_add_sgs on req path Rusty Russell
2013-02-20 9:20 ` Asias He
2013-02-19 7:56 ` [PATCH 06/16] virtio_blk: remove nents member Rusty Russell
2013-02-20 9:20 ` Asias He
2013-02-19 7:56 ` [PATCH 07/16] virtio_ring: don't count elements twice for add_buf path Rusty Russell
2013-02-20 10:09 ` Wanlong Gao
2013-02-19 7:56 ` [PATCH 08/16] virtio_ring: virtqueue_add_outbuf / virtqueue_add_inbuf Rusty Russell
2013-02-20 10:09 ` Wanlong Gao
2013-02-21 17:09 ` Michael S. Tsirkin
2013-02-22 0:02 ` Rusty Russell
2013-02-25 21:35 ` Michael S. Tsirkin
2013-02-28 5:08 ` Rusty Russell
2013-02-28 7:01 ` Michael S. Tsirkin
2013-03-06 6:03 ` Rusty Russell
2013-02-19 7:56 ` [PATCH 09/16] virtio_net: use simplified virtqueue accessors Rusty Russell
2013-02-20 10:09 ` Wanlong Gao
2013-02-19 7:56 ` [PATCH 10/16] virtio_net: use virtqueue_add_sgs[] for command buffers Rusty Russell
2013-02-20 10:11 ` Wanlong Gao
2013-02-21 6:27 ` Rusty Russell
2013-02-21 8:30 ` Wanlong Gao
2013-02-21 9:41 ` Jason Wang
2013-02-21 9:43 ` Wanlong Gao
2013-02-19 7:56 ` [PATCH 11/16] virtio_rng: use simplified virtqueue accessors Rusty Russell
2013-02-20 10:12 ` Wanlong Gao
2013-02-19 7:56 ` [PATCH 12/16] virtio_console: " Rusty Russell
2013-02-20 10:12 ` Wanlong Gao
2013-02-19 7:56 ` [PATCH 13/16] caif_virtio: " Rusty Russell
2013-02-20 10:13 ` Wanlong Gao
2013-02-19 7:56 ` [PATCH 14/16] virtio_rpmsg_bus: " Rusty Russell
2013-02-20 10:14 ` Wanlong Gao
2013-02-19 7:56 ` [PATCH 15/16] virtio_balloon: " Rusty Russell
2013-02-20 10:15 ` Wanlong Gao
2013-02-19 7:56 ` [PATCH 16/16] 9p/trans_virtio.c: use virtio_add_sgs[] Rusty Russell
2013-02-19 9:15 ` [PATCH 00/16] virtio ring rework Paolo Bonzini
2013-02-21 6:30 ` Rusty Russell
2013-02-20 8:37 ` [PATCH 17/16] virtio-scsi: use virtqueue_add_sgs for command buffers Wanlong Gao
2013-02-20 9:38 ` Asias He
2013-02-20 9:41 ` Wanlong Gao
2013-02-20 9:47 ` [PATCH 17/16 V2] " Wanlong Gao
2013-02-20 10:54 ` Paolo Bonzini
2013-02-20 12:17 ` Asias He
2013-02-21 6:34 ` Rusty Russell
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