Each worker thread can process 1 command at a time so there's no need to
allocate a upages array per cmd. This patch moves it to per queue. Even a
small device with 128 cmds and 1 queue this brings mem use for the array
from
2 MB = 8 bytes per page pointer * 2048 pointers * 128 cmds
to
16K = 8 bytes per pointer * 2048 * 1 queue
Signed-off-by: Mike Christie <michael.chris...@oracle.com>
---
drivers/vhost/scsi.c | 24 ++++++++++--------------
1 file changed, 10 insertions(+), 14 deletions(-)
diff --git a/drivers/vhost/scsi.c b/drivers/vhost/scsi.c
index 718fa4e0b31e..adb3cd47b4e3 100644
--- a/drivers/vhost/scsi.c
+++ b/drivers/vhost/scsi.c
@@ -83,7 +83,6 @@ struct vhost_scsi_cmd {
/* Pointer to the SGL formatted memory from virtio-scsi */
struct scatterlist *tvc_sgl;
struct scatterlist *tvc_prot_sgl;
- struct page **tvc_upages;
/* Pointer to response header iovec */
struct iovec *tvc_resp_iov;
/* Pointer to vhost_scsi for our device */
@@ -187,6 +186,7 @@ struct vhost_scsi_virtqueue {
struct vhost_scsi_cmd *scsi_cmds;
struct sbitmap scsi_tags;
int max_cmds;
+ struct page **upages;
struct vhost_work completion_work;
struct llist_head completion_list;
@@ -619,7 +619,6 @@ vhost_scsi_get_cmd(struct vhost_virtqueue *vq, struct
vhost_scsi_tpg *tpg,
struct vhost_scsi_nexus *tv_nexus;
struct scatterlist *sg, *prot_sg;
struct iovec *tvc_resp_iov;
- struct page **pages;
int tag;
tv_nexus = tpg->tpg_nexus;
@@ -637,12 +636,10 @@ vhost_scsi_get_cmd(struct vhost_virtqueue *vq, struct
vhost_scsi_tpg *tpg,
cmd = &svq->scsi_cmds[tag];
sg = cmd->tvc_sgl;
prot_sg = cmd->tvc_prot_sgl;
- pages = cmd->tvc_upages;
tvc_resp_iov = cmd->tvc_resp_iov;
memset(cmd, 0, sizeof(*cmd));
cmd->tvc_sgl = sg;
cmd->tvc_prot_sgl = prot_sg;
- cmd->tvc_upages = pages;
cmd->tvc_se_cmd.map_tag = tag;
cmd->tvc_tag = scsi_tag;
cmd->tvc_lun = lun;
@@ -669,7 +666,9 @@ vhost_scsi_map_to_sgl(struct vhost_scsi_cmd *cmd,
struct scatterlist *sgl,
bool is_prot)
{
- struct page **pages = cmd->tvc_upages;
+ struct vhost_scsi_virtqueue *svq = container_of(cmd->tvc_vq,
+ struct vhost_scsi_virtqueue, vq);
+ struct page **pages = svq->upages;
struct scatterlist *sg = sgl;
ssize_t bytes, mapped_bytes;
size_t offset, mapped_offset;
@@ -1598,11 +1597,11 @@ static void vhost_scsi_destroy_vq_cmds(struct
vhost_virtqueue *vq)
kfree(tv_cmd->tvc_sgl);
kfree(tv_cmd->tvc_prot_sgl);
- kfree(tv_cmd->tvc_upages);
kfree(tv_cmd->tvc_resp_iov);
}
sbitmap_free(&svq->scsi_tags);
+ kfree(svq->upages);
kfree(svq->scsi_cmds);
svq->scsi_cmds = NULL;
}
@@ -1628,6 +1627,11 @@ static int vhost_scsi_setup_vq_cmds(struct
vhost_virtqueue *vq, int max_cmds)
return -ENOMEM;
}
+ svq->upages = kcalloc(VHOST_SCSI_PREALLOC_UPAGES, sizeof(struct page *),
+ GFP_KERNEL);
+ if (!svq->upages)
+ goto out;
+
for (i = 0; i < max_cmds; i++) {
tv_cmd = &svq->scsi_cmds[i];
@@ -1639,14 +1643,6 @@ static int vhost_scsi_setup_vq_cmds(struct
vhost_virtqueue *vq, int max_cmds)
goto out;
}
- tv_cmd->tvc_upages = kcalloc(VHOST_SCSI_PREALLOC_UPAGES,
- sizeof(struct page *),
- GFP_KERNEL);
- if (!tv_cmd->tvc_upages) {
- pr_err("Unable to allocate tv_cmd->tvc_upages\n");
- goto out;
- }
-
tv_cmd->tvc_resp_iov = kcalloc(UIO_MAXIOV,
sizeof(struct iovec),
GFP_KERNEL);
--
2.34.1
