[PATCH v2 14/19] svcrdma: Remove frmr cache

Chuck Lever
2017-06-16T15:22:14Z

Clean up: Now that the svc_rdma_recvfrom path uses the rdma_rw API,
the details of Read sink buffer registration are dealt with by the
kernel's RDMA core. This cache is no longer used, and can be
removed.

Signed-off-by: Chuck Lever <chuck.lever-QHcLZuEGTsvQT0dZR+AlfA@public.gmane.org>
---
include/linux/sunrpc/svc_rdma.h | 18 ------
net/sunrpc/xprtrdma/svc_rdma_transport.c | 86 ------------------------------
2 files changed, 104 deletions(-)

diff --git a/include/linux/sunrpc/svc_rdma.h b/include/linux/sunrpc/svc_rdma.h
index 06d58a3..fd7775f 100644
--- a/include/linux/sunrpc/svc_rdma.h
+++ b/include/linux/sunrpc/svc_rdma.h
@@ -77,7 +77,6 @@ enum {
*/
struct svc_rdma_op_ctxt {
struct list_head list;
- struct svc_rdma_fastreg_mr *frmr;
struct xdr_buf arg;
struct ib_cqe cqe;
u32 byte_len;
@@ -91,17 +90,6 @@ struct svc_rdma_op_ctxt {
struct page *pages[RPCSVC_MAXPAGES];
};

-struct svc_rdma_fastreg_mr {
- struct ib_mr *mr;
- struct scatterlist *sg;
- int sg_nents;
- unsigned long access_flags;
- enum dma_data_direction direction;
- struct list_head frmr_list;
-};
-
-#define RDMACTXT_F_LAST_CTXT 2
-
#define SVCRDMA_DEVCAP_FAST_REG 1 /* fast mr registration */
#define SVCRDMA_DEVCAP_READ_W_INV 2 /* read w/ invalidate */

@@ -136,9 +124,6 @@ struct svcxprt_rdma {
struct ib_cq *sc_rq_cq;
struct ib_cq *sc_sq_cq;
u32 sc_dev_caps; /* distilled device caps */
- unsigned int sc_frmr_pg_list_len;
- struct list_head sc_frmr_q;
- spinlock_t sc_frmr_q_lock;

spinlock_t sc_lock; /* transport lock */

@@ -210,9 +195,6 @@ extern int svc_rdma_post_send_wr(struct svcxprt_rdma *rdma,
extern struct svc_rdma_op_ctxt *svc_rdma_get_context(struct svcxprt_rdma *);
extern void svc_rdma_put_context(struct svc_rdma_op_ctxt *, int);
extern void svc_rdma_unmap_dma(struct svc_rdma_op_ctxt *ctxt);
-extern struct svc_rdma_fastreg_mr *svc_rdma_get_frmr(struct svcxprt_rdma *);
-extern void svc_rdma_put_frmr(struct svcxprt_rdma *,
- struct svc_rdma_fastreg_mr *);
extern void svc_sq_reap(struct svcxprt_rdma *);
extern void svc_rq_reap(struct svcxprt_rdma *);
extern void svc_rdma_prep_reply_hdr(struct svc_rqst *);
diff --git a/net/sunrpc/xprtrdma/svc_rdma_transport.c b/net/sunrpc/xprtrdma/svc_rdma_transport.c
index c915cba..8864105 100644
--- a/net/sunrpc/xprtrdma/svc_rdma_transport.c
+++ b/net/sunrpc/xprtrdma/svc_rdma_transport.c
@@ -202,7 +202,6 @@ struct svc_rdma_op_ctxt *svc_rdma_get_context(struct svcxprt_rdma *xprt)
out:
ctxt->count = 0;
ctxt->mapped_sges = 0;
- ctxt->frmr = NULL;
return ctxt;

out_empty:
@@ -387,14 +386,12 @@ static struct svcxprt_rdma *rdma_create_xprt(struct svc_serv *serv,
INIT_LIST_HEAD(&cma_xprt->sc_accept_q);
INIT_LIST_HEAD(&cma_xprt->sc_rq_dto_q);
INIT_LIST_HEAD(&cma_xprt->sc_read_complete_q);
- INIT_LIST_HEAD(&cma_xprt->sc_frmr_q);
INIT_LIST_HEAD(&cma_xprt->sc_ctxts);
INIT_LIST_HEAD(&cma_xprt->sc_rw_ctxts);
init_waitqueue_head(&cma_xprt->sc_send_wait);

spin_lock_init(&cma_xprt->sc_lock);
spin_lock_init(&cma_xprt->sc_rq_dto_lock);
- spin_lock_init(&cma_xprt->sc_frmr_q_lock);
spin_lock_init(&cma_xprt->sc_ctxt_lock);
spin_lock_init(&cma_xprt->sc_rw_ctxt_lock);

@@ -705,86 +702,6 @@ static struct svc_xprt *svc_rdma_create(struct svc_serv *serv,
return ERR_PTR(ret);
}

-static struct svc_rdma_fastreg_mr *rdma_alloc_frmr(struct svcxprt_rdma *xprt)
-{
- struct ib_mr *mr;
- struct scatterlist *sg;
- struct svc_rdma_fastreg_mr *frmr;
- u32 num_sg;
-
- frmr = kmalloc(sizeof(*frmr), GFP_KERNEL);
- if (!frmr)
- goto err;
-
- num_sg = min_t(u32, RPCSVC_MAXPAGES, xprt->sc_frmr_pg_list_len);
- mr = ib_alloc_mr(xprt->sc_pd, IB_MR_TYPE_MEM_REG, num_sg);
- if (IS_ERR(mr))
- goto err_free_frmr;
-
- sg = kcalloc(RPCSVC_MAXPAGES, sizeof(*sg), GFP_KERNEL);
- if (!sg)
- goto err_free_mr;
-
- sg_init_table(sg, RPCSVC_MAXPAGES);
-
- frmr->mr = mr;
- frmr->sg = sg;
- INIT_LIST_HEAD(&frmr->frmr_list);
- return frmr;
-
- err_free_mr:
- ib_dereg_mr(mr);
- err_free_frmr:
- kfree(frmr);
- err:
- return ERR_PTR(-ENOMEM);
-}
-
-static void rdma_dealloc_frmr_q(struct svcxprt_rdma *xprt)
-{
- struct svc_rdma_fastreg_mr *frmr;
-
- while (!list_empty(&xprt->sc_frmr_q)) {
- frmr = list_entry(xprt->sc_frmr_q.next,
- struct svc_rdma_fastreg_mr, frmr_list);
- list_del_init(&frmr->frmr_list);
- kfree(frmr->sg);
- ib_dereg_mr(frmr->mr);
- kfree(frmr);
- }
-}
-
-struct svc_rdma_fastreg_mr *svc_rdma_get_frmr(struct svcxprt_rdma *rdma)
-{
- struct svc_rdma_fastreg_mr *frmr = NULL;
-
- spin_lock(&rdma->sc_frmr_q_lock);
- if (!list_empty(&rdma->sc_frmr_q)) {
- frmr = list_entry(rdma->sc_frmr_q.next,
- struct svc_rdma_fastreg_mr, frmr_list);
- list_del_init(&frmr->frmr_list);
- frmr->sg_nents = 0;
- }
- spin_unlock(&rdma->sc_frmr_q_lock);
- if (frmr)
- return frmr;
-
- return rdma_alloc_frmr(rdma);
-}
-
-void svc_rdma_put_frmr(struct svcxprt_rdma *rdma,
- struct svc_rdma_fastreg_mr *frmr)
-{
- if (frmr) {
- ib_dma_unmap_sg(rdma->sc_cm_id->device,
- frmr->sg, frmr->sg_nents, frmr->direction);
- spin_lock(&rdma->sc_frmr_q_lock);
- WARN_ON_ONCE(!list_empty(&frmr->frmr_list));
- list_add(&frmr->frmr_list, &rdma->sc_frmr_q);
- spin_unlock(&rdma->sc_frmr_q_lock);
- }
-}
-
/*
* This is the xpo_recvfrom function for listening endpoints. Its
* purpose is to accept incoming connections. The CMA callback handler
@@ -922,8 +839,6 @@ static struct svc_xprt *svc_rdma_accept(struct svc_xprt *xprt)
* of an RDMA_READ. IB does not.
*/
if (dev->attrs.device_cap_flags & IB_DEVICE_MEM_MGT_EXTENSIONS) {
- newxprt->sc_frmr_pg_list_len =
- dev->attrs.max_fast_reg_page_list_len;
newxprt->sc_dev_caps |= SVCRDMA_DEVCAP_FAST_REG;
} else
newxprt->sc_snd_w_inv = false;
@@ -1063,7 +978,6 @@ static void __svc_rdma_free(struct work_struct *work)
xprt->xpt_bc_xprt = NULL;
}

- rdma_dealloc_frmr_q(rdma);
svc_rdma_destroy_rw_ctxts(rdma);
svc_rdma_destroy_ctxts(rdma);