On Mon, 2010-10-18 at 09:10 -0400, David Dillow wrote:
> On Mon, 2010-10-18 at 06:11 -0400, Bart Van Assche wrote:
> > As far as I can see the above sync call applies to a buffer in the
> > tx_ring[]. Data in that buffer is only modified by the CPU and never
> > by the HCA. So why is the above sync call present ? Is that call
> > necessary ?
>
> While looking at this, I noticed that we didn't do any syncs in
> srp_send_tsk_mgmt(), so I've pushed this patch for now. We can remove
> the *_sync_for_cpu() calls later if it turns out we really don't need
> them.
If it turns out that we don't need the sync, I'd be receptive to using
something like this to consolidate the handling into __srp_post_send().
If you're feeling adventurous or just want to see if it benchmarks
faster, try it out and let us know how it goes.
diff --git a/drivers/infiniband/ulp/srp/ib_srp.c
b/drivers/infiniband/ulp/srp/ib_srp.c
index cfc1d65..92ced00 100644
--- a/drivers/infiniband/ulp/srp/ib_srp.c
+++ b/drivers/infiniband/ulp/srp/ib_srp.c
@@ -854,10 +854,13 @@ static struct srp_iu *__srp_get_tx_iu(struct
srp_target_port *target,
static int __srp_post_send(struct srp_target_port *target,
struct srp_iu *iu, int len)
{
+ struct ib_device *dev = target->srp_host->srp_dev->dev;
struct ib_sge list;
struct ib_send_wr wr, *bad_wr;
int ret = 0;
+ ib_dma_sync_single_for_device(dev, iu->dma, len, DMA_TO_DEVICE);
+
list.addr = iu->dma;
list.length = len;
list.lkey = target->srp_host->srp_dev->mr->lkey;
@@ -985,9 +988,7 @@ static int srp_response_common(struct srp_target_port
*target, s32 req_delta,
goto out;
}
- ib_dma_sync_single_for_cpu(dev, iu->dma, len, DMA_TO_DEVICE);
memcpy(iu->buf, rsp, len);
- ib_dma_sync_single_for_device(dev, iu->dma, len, DMA_TO_DEVICE);
err = __srp_post_send(target, iu, len);
if (err)
@@ -1130,7 +1131,6 @@ static int srp_queuecommand(struct scsi_cmnd *scmnd,
struct srp_request *req;
struct srp_iu *iu;
struct srp_cmd *cmd;
- struct ib_device *dev;
int len;
if (target->state == SRP_TARGET_CONNECTING)
@@ -1147,10 +1147,6 @@ static int srp_queuecommand(struct scsi_cmnd *scmnd,
if (!iu)
goto err;
- dev = target->srp_host->srp_dev->dev;
- ib_dma_sync_single_for_cpu(dev, iu->dma, srp_max_iu_len,
- DMA_TO_DEVICE);
-
req = list_first_entry(&target->free_reqs, struct srp_request, list);
scmnd->scsi_done = done;
@@ -1177,9 +1173,6 @@ static int srp_queuecommand(struct scsi_cmnd *scmnd,
goto err;
}
- ib_dma_sync_single_for_device(dev, iu->dma, srp_max_iu_len,
- DMA_TO_DEVICE);
-
if (__srp_post_send(target, iu, len)) {
shost_printk(KERN_ERR, target->scsi_host, PFX "Send failed\n");
goto err_unmap;
@@ -1442,7 +1435,6 @@ static int srp_cm_handler(struct ib_cm_id *cm_id, struct
ib_cm_event *event)
static int srp_send_tsk_mgmt(struct srp_target_port *target,
struct srp_request *req, u8 func)
{
- struct ib_device *dev = target->srp_host->srp_dev->dev;
struct srp_iu *iu;
struct srp_tsk_mgmt *tsk_mgmt;
@@ -1460,8 +1452,6 @@ static int srp_send_tsk_mgmt(struct srp_target_port
*target,
if (!iu)
goto out;
- ib_dma_sync_single_for_cpu(dev, iu->dma, sizeof *tsk_mgmt,
- DMA_TO_DEVICE);
tsk_mgmt = iu->buf;
memset(tsk_mgmt, 0, sizeof *tsk_mgmt);
@@ -1471,8 +1461,6 @@ static int srp_send_tsk_mgmt(struct srp_target_port
*target,
tsk_mgmt->tsk_mgmt_func = func;
tsk_mgmt->task_tag = req->index;
- ib_dma_sync_single_for_device(dev, iu->dma, sizeof *tsk_mgmt,
- DMA_TO_DEVICE);
if (__srp_post_send(target, iu, sizeof *tsk_mgmt))
goto out;
--
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