diff mbox

[v2,08/21] xprtrdma: Back off rkey when FAST_REG_MR fails

Message ID 20140709165739.3496.39485.stgit@manet.1015granger.net (mailing list archive)
State Superseded, archived
Headers show

Commit Message

Chuck Lever July 9, 2014, 4:57 p.m. UTC 
If posting a FAST_REG_MR Work Reqeust fails, revert the rkey update
to avoid subsequent IB_WC_MW_BIND_ERR completions.

Suggested-by: Steve Wise <swise@opengridcomputing.com>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
---
 net/sunrpc/xprtrdma/verbs.c |   27 ++++++++++++++++++++-------
 1 file changed, 20 insertions(+), 7 deletions(-)


--
To unsubscribe from this list: send the line "unsubscribe linux-rdma" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html

Comments

Schumaker, Anna July 9, 2014, 8:07 p.m. UTC | #1 
On 07/09/2014 12:57 PM, Chuck Lever wrote:
> If posting a FAST_REG_MR Work Reqeust fails, revert the rkey update
> to avoid subsequent IB_WC_MW_BIND_ERR completions.
>
> Suggested-by: Steve Wise <swise@opengridcomputing.com>
> Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
> ---
>  net/sunrpc/xprtrdma/verbs.c |   27 ++++++++++++++++++++-------
>  1 file changed, 20 insertions(+), 7 deletions(-)
>
> diff --git a/net/sunrpc/xprtrdma/verbs.c b/net/sunrpc/xprtrdma/verbs.c
> index ce847d2..14d24ec 100644
> --- a/net/sunrpc/xprtrdma/verbs.c
> +++ b/net/sunrpc/xprtrdma/verbs.c
> @@ -1487,6 +1487,24 @@ rpcrdma_unmap_one(struct rpcrdma_ia *ia, struct rpcrdma_mr_seg *seg)
>  				seg->mr_dma, seg->mr_dmalen, seg->mr_dir);
>  }
>  
> +static void
> +rpcrdma_increment_frmr_rkey(struct rpcrdma_mw *mw)
> +{
> +	struct ib_mr *mr = mw->r.frmr.fr_mr;
> +	u8 key = mr->rkey & 0x000000FF;

It's not super obvious to be how this key is being calculated.  Can you change 0x000000FF into a named constant to help?

It might also be useful to have an frmr_get_rkey() function rather than doing this calculation in two different places.

Anna

> +
> +	ib_update_fast_reg_key(mr, ++key);
> +}
> +
> +static void
> +rpcrdma_decrement_frmr_rkey(struct rpcrdma_mw *mw)
> +{
> +	struct ib_mr *mr = mw->r.frmr.fr_mr;
> +	u8 key = mr->rkey & 0x000000FF;
> +
> +	ib_update_fast_reg_key(mr, --key);
> +}
> +
>  static int
>  rpcrdma_register_frmr_external(struct rpcrdma_mr_seg *seg,
>  			int *nsegs, int writing, struct rpcrdma_ia *ia,
> @@ -1496,8 +1514,6 @@ rpcrdma_register_frmr_external(struct rpcrdma_mr_seg *seg,
>  	struct rpcrdma_mw *mw = seg1->mr_chunk.rl_mw;
>  	struct rpcrdma_frmr *frmr = &mw->r.frmr;
>  	struct ib_send_wr invalidate_wr, frmr_wr, *bad_wr, *post_wr;
> -
> -	u8 key;
>  	int len, pageoff;
>  	int i, rc;
>  	int seg_len;
> @@ -1557,14 +1573,10 @@ rpcrdma_register_frmr_external(struct rpcrdma_mr_seg *seg,
>  		rc = -EIO;
>  		goto out_err;
>  	}
> -
> -	/* Bump the key */
> -	key = (u8)(frmr->fr_mr->rkey & 0x000000FF);
> -	ib_update_fast_reg_key(frmr->fr_mr, ++key);
> -
>  	frmr_wr.wr.fast_reg.access_flags = (writing ?
>  				IB_ACCESS_REMOTE_WRITE | IB_ACCESS_LOCAL_WRITE :
>  				IB_ACCESS_REMOTE_READ);
> +	rpcrdma_increment_frmr_rkey(mw);
>  	frmr_wr.wr.fast_reg.rkey = frmr->fr_mr->rkey;
>  	DECR_CQCOUNT(&r_xprt->rx_ep);
>  
> @@ -1573,6 +1585,7 @@ rpcrdma_register_frmr_external(struct rpcrdma_mr_seg *seg,
>  	if (rc) {
>  		dprintk("RPC:       %s: failed ib_post_send for register,"
>  			" status %i\n", __func__, rc);
> +		rpcrdma_decrement_frmr_rkey(seg1->mr_chunk.rl_mw);
>  		goto out_err;
>  	} else {
>  		seg1->mr_rkey = frmr->fr_mr->rkey;
>
> --
> To unsubscribe from this list: send the line "unsubscribe linux-nfs" in
> the body of a message to majordomo@vger.kernel.org
> More majordomo info at  http://vger.kernel.org/majordomo-info.html

--
To unsubscribe from this list: send the line "unsubscribe linux-rdma" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Chuck Lever July 9, 2014, 8:27 p.m. UTC | #2 
On Jul 9, 2014, at 4:07 PM, Anna Schumaker <Anna.Schumaker@netapp.com> wrote:

> On 07/09/2014 12:57 PM, Chuck Lever wrote:
>> If posting a FAST_REG_MR Work Reqeust fails, revert the rkey update
>> to avoid subsequent IB_WC_MW_BIND_ERR completions.
>> 
>> Suggested-by: Steve Wise <swise@opengridcomputing.com>
>> Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
>> ---
>> net/sunrpc/xprtrdma/verbs.c |   27 ++++++++++++++++++++-------
>> 1 file changed, 20 insertions(+), 7 deletions(-)
>> 
>> diff --git a/net/sunrpc/xprtrdma/verbs.c b/net/sunrpc/xprtrdma/verbs.c
>> index ce847d2..14d24ec 100644
>> --- a/net/sunrpc/xprtrdma/verbs.c
>> +++ b/net/sunrpc/xprtrdma/verbs.c
>> @@ -1487,6 +1487,24 @@ rpcrdma_unmap_one(struct rpcrdma_ia *ia, struct rpcrdma_mr_seg *seg)
>> 				seg->mr_dma, seg->mr_dmalen, seg->mr_dir);
>> }
>> 
>> +static void
>> +rpcrdma_increment_frmr_rkey(struct rpcrdma_mw *mw)
>> +{
>> +	struct ib_mr *mr = mw->r.frmr.fr_mr;
>> +	u8 key = mr->rkey & 0x000000FF;
> 
> It's not super obvious to be how this key is being calculated.  Can you change 0x000000FF into a named constant to help?

Bumping the rkey is the same for any RDMA consumer, so it would be
even better to use a common helper.

include/rdma/ib_verbs.h has ib_inc_rkey() . . .

> It might also be useful to have an frmr_get_rkey() function rather than doing this calculation in two different places.

. . . but there isn’t an ib_dec_rkey(). I could add one.

> Anna
> 
>> +
>> +	ib_update_fast_reg_key(mr, ++key);
>> +}
>> +
>> +static void
>> +rpcrdma_decrement_frmr_rkey(struct rpcrdma_mw *mw)
>> +{
>> +	struct ib_mr *mr = mw->r.frmr.fr_mr;
>> +	u8 key = mr->rkey & 0x000000FF;
>> +
>> +	ib_update_fast_reg_key(mr, --key);
>> +}
>> +
>> static int
>> rpcrdma_register_frmr_external(struct rpcrdma_mr_seg *seg,
>> 			int *nsegs, int writing, struct rpcrdma_ia *ia,
>> @@ -1496,8 +1514,6 @@ rpcrdma_register_frmr_external(struct rpcrdma_mr_seg *seg,
>> 	struct rpcrdma_mw *mw = seg1->mr_chunk.rl_mw;
>> 	struct rpcrdma_frmr *frmr = &mw->r.frmr;
>> 	struct ib_send_wr invalidate_wr, frmr_wr, *bad_wr, *post_wr;
>> -
>> -	u8 key;
>> 	int len, pageoff;
>> 	int i, rc;
>> 	int seg_len;
>> @@ -1557,14 +1573,10 @@ rpcrdma_register_frmr_external(struct rpcrdma_mr_seg *seg,
>> 		rc = -EIO;
>> 		goto out_err;
>> 	}
>> -
>> -	/* Bump the key */
>> -	key = (u8)(frmr->fr_mr->rkey & 0x000000FF);
>> -	ib_update_fast_reg_key(frmr->fr_mr, ++key);
>> -
>> 	frmr_wr.wr.fast_reg.access_flags = (writing ?
>> 				IB_ACCESS_REMOTE_WRITE | IB_ACCESS_LOCAL_WRITE :
>> 				IB_ACCESS_REMOTE_READ);
>> +	rpcrdma_increment_frmr_rkey(mw);
>> 	frmr_wr.wr.fast_reg.rkey = frmr->fr_mr->rkey;
>> 	DECR_CQCOUNT(&r_xprt->rx_ep);
>> 
>> @@ -1573,6 +1585,7 @@ rpcrdma_register_frmr_external(struct rpcrdma_mr_seg *seg,
>> 	if (rc) {
>> 		dprintk("RPC:       %s: failed ib_post_send for register,"
>> 			" status %i\n", __func__, rc);
>> +		rpcrdma_decrement_frmr_rkey(seg1->mr_chunk.rl_mw);
>> 		goto out_err;
>> 	} else {
>> 		seg1->mr_rkey = frmr->fr_mr->rkey;
>> 
>> --
>> To unsubscribe from this list: send the line "unsubscribe linux-nfs" in
>> the body of a message to majordomo@vger.kernel.org
>> More majordomo info at  http://vger.kernel.org/majordomo-info.html
> 

--
Chuck Lever
chuck[dot]lever[at]oracle[dot]com



--
To unsubscribe from this list: send the line "unsubscribe linux-rdma" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
diff mbox

Patch

diff --git a/net/sunrpc/xprtrdma/verbs.c b/net/sunrpc/xprtrdma/verbs.c
index ce847d2..14d24ec 100644
--- a/net/sunrpc/xprtrdma/verbs.c
+++ b/net/sunrpc/xprtrdma/verbs.c
@@ -1487,6 +1487,24 @@  rpcrdma_unmap_one(struct rpcrdma_ia *ia, struct rpcrdma_mr_seg *seg)
 				seg->mr_dma, seg->mr_dmalen, seg->mr_dir);
 }
 
+static void
+rpcrdma_increment_frmr_rkey(struct rpcrdma_mw *mw)
+{
+	struct ib_mr *mr = mw->r.frmr.fr_mr;
+	u8 key = mr->rkey & 0x000000FF;
+
+	ib_update_fast_reg_key(mr, ++key);
+}
+
+static void
+rpcrdma_decrement_frmr_rkey(struct rpcrdma_mw *mw)
+{
+	struct ib_mr *mr = mw->r.frmr.fr_mr;
+	u8 key = mr->rkey & 0x000000FF;
+
+	ib_update_fast_reg_key(mr, --key);
+}
+
 static int
 rpcrdma_register_frmr_external(struct rpcrdma_mr_seg *seg,
 			int *nsegs, int writing, struct rpcrdma_ia *ia,
@@ -1496,8 +1514,6 @@  rpcrdma_register_frmr_external(struct rpcrdma_mr_seg *seg,
 	struct rpcrdma_mw *mw = seg1->mr_chunk.rl_mw;
 	struct rpcrdma_frmr *frmr = &mw->r.frmr;
 	struct ib_send_wr invalidate_wr, frmr_wr, *bad_wr, *post_wr;
-
-	u8 key;
 	int len, pageoff;
 	int i, rc;
 	int seg_len;
@@ -1557,14 +1573,10 @@  rpcrdma_register_frmr_external(struct rpcrdma_mr_seg *seg,
 		rc = -EIO;
 		goto out_err;
 	}
-
-	/* Bump the key */
-	key = (u8)(frmr->fr_mr->rkey & 0x000000FF);
-	ib_update_fast_reg_key(frmr->fr_mr, ++key);
-
 	frmr_wr.wr.fast_reg.access_flags = (writing ?
 				IB_ACCESS_REMOTE_WRITE | IB_ACCESS_LOCAL_WRITE :
 				IB_ACCESS_REMOTE_READ);
+	rpcrdma_increment_frmr_rkey(mw);
 	frmr_wr.wr.fast_reg.rkey = frmr->fr_mr->rkey;
 	DECR_CQCOUNT(&r_xprt->rx_ep);
 
@@ -1573,6 +1585,7 @@  rpcrdma_register_frmr_external(struct rpcrdma_mr_seg *seg,
 	if (rc) {
 		dprintk("RPC:       %s: failed ib_post_send for register,"
 			" status %i\n", __func__, rc);
+		rpcrdma_decrement_frmr_rkey(seg1->mr_chunk.rl_mw);
 		goto out_err;
 	} else {
 		seg1->mr_rkey = frmr->fr_mr->rkey;