Change the WR context pool to be shared across mount points. This
reduces the RDMA transport memory footprint significantly since
idle mounts don't consume WR context memory.
Signed-off-by: Tom Tucker <tom@xxxxxxxxxxxxxxxxxxxxx>
---
include/linux/sunrpc/svc_rdma.h | 6 --
net/sunrpc/xprtrdma/svc_rdma_transport.c | 121 +++---------------------------
2 files changed, 12 insertions(+), 115 deletions(-)
diff --git a/include/linux/sunrpc/svc_rdma.h b/include/linux/sunrpc/svc_rdma.h
index d8d74c4..ef2e3a2 100644
--- a/include/linux/sunrpc/svc_rdma.h
+++ b/include/linux/sunrpc/svc_rdma.h
@@ -73,7 +73,6 @@ extern atomic_t rdma_stat_sq_prod;
struct svc_rdma_op_ctxt {
struct svc_rdma_op_ctxt *read_hdr;
int hdr_count;
- struct list_head free_list;
struct xdr_buf arg;
struct list_head dto_q;
enum ib_wr_opcode wr_op;
@@ -131,11 +130,6 @@ struct svcxprt_rdma {
atomic_t sc_dma_used;
atomic_t sc_ctxt_used;
- struct list_head sc_ctxt_free;
- int sc_ctxt_cnt;
- int sc_ctxt_bump;
- int sc_ctxt_max;
- spinlock_t sc_ctxt_lock;
struct list_head sc_rq_dto_q;
spinlock_t sc_rq_dto_lock;
struct ib_qp *sc_qp;
diff --git a/net/sunrpc/xprtrdma/svc_rdma_transport.c b/net/sunrpc/xprtrdma/svc_rdma_transport.c
index 80104f4..19ddc38 100644
--- a/net/sunrpc/xprtrdma/svc_rdma_transport.c
+++ b/net/sunrpc/xprtrdma/svc_rdma_transport.c
@@ -84,69 +84,23 @@ struct svc_xprt_class svc_rdma_class = {
.xcl_max_payload = RPCSVC_MAXPAYLOAD_TCP,
};
-static int rdma_bump_context_cache(struct svcxprt_rdma *xprt)
-{
- int target;
- int at_least_one = 0;
- struct svc_rdma_op_ctxt *ctxt;
-
- target = min(xprt->sc_ctxt_cnt + xprt->sc_ctxt_bump,
- xprt->sc_ctxt_max);
-
- spin_lock_bh(&xprt->sc_ctxt_lock);
- while (xprt->sc_ctxt_cnt < target) {
- xprt->sc_ctxt_cnt++;
- spin_unlock_bh(&xprt->sc_ctxt_lock);
-
- ctxt = kmalloc(sizeof(*ctxt), GFP_KERNEL);
-
- spin_lock_bh(&xprt->sc_ctxt_lock);
- if (ctxt) {
- at_least_one = 1;
- INIT_LIST_HEAD(&ctxt->free_list);
- list_add(&ctxt->free_list, &xprt->sc_ctxt_free);
- } else {
- /* kmalloc failed...give up for now */
- xprt->sc_ctxt_cnt--;
- break;
- }
- }
- spin_unlock_bh(&xprt->sc_ctxt_lock);
- dprintk("svcrdma: sc_ctxt_max=%d, sc_ctxt_cnt=%d\n",
- xprt->sc_ctxt_max, xprt->sc_ctxt_cnt);
- return at_least_one;
-}
+/* WR context cache. Created in svc_rdma.c */
+extern struct kmem_cache *svc_rdma_ctxt_cachep;
struct svc_rdma_op_ctxt *svc_rdma_get_context(struct svcxprt_rdma *xprt)
{
struct svc_rdma_op_ctxt *ctxt;
while (1) {
- spin_lock_bh(&xprt->sc_ctxt_lock);
- if (unlikely(list_empty(&xprt->sc_ctxt_free))) {
- /* Try to bump my cache. */
- spin_unlock_bh(&xprt->sc_ctxt_lock);
-
- if (rdma_bump_context_cache(xprt))
- continue;
-
- printk(KERN_INFO "svcrdma: sleeping waiting for "
- "context memory on xprt=%p\n",
- xprt);
- schedule_timeout_uninterruptible(msecs_to_jiffies(500));
- continue;
- }
- ctxt = list_entry(xprt->sc_ctxt_free.next,
- struct svc_rdma_op_ctxt,
- free_list);
- list_del_init(&ctxt->free_list);
- spin_unlock_bh(&xprt->sc_ctxt_lock);
- ctxt->xprt = xprt;
- INIT_LIST_HEAD(&ctxt->dto_q);
- ctxt->count = 0;
- atomic_inc(&xprt->sc_ctxt_used);
- break;
+ ctxt = kmem_cache_alloc(svc_rdma_ctxt_cachep, GFP_KERNEL);
+ if (ctxt)
+ break;
+ schedule_timeout_uninterruptible(msecs_to_jiffies(500));
}
+ ctxt->xprt = xprt;
+ INIT_LIST_HEAD(&ctxt->dto_q);
+ ctxt->count = 0;
+ atomic_inc(&xprt->sc_ctxt_used);
return ctxt;
}
@@ -174,9 +128,7 @@ void svc_rdma_put_context(struct svc_rdma_op_ctxt *ctxt, int free_pages)
for (i = 0; i < ctxt->count; i++)
put_page(ctxt->pages[i]);
- spin_lock_bh(&xprt->sc_ctxt_lock);
- list_add(&ctxt->free_list, &xprt->sc_ctxt_free);
- spin_unlock_bh(&xprt->sc_ctxt_lock);
+ kmem_cache_free(svc_rdma_ctxt_cachep, ctxt);
atomic_dec(&xprt->sc_ctxt_used);
}
@@ -461,40 +413,6 @@ static void sq_comp_handler(struct ib_cq *cq, void *cq_context)
tasklet_schedule(&dto_tasklet);
}
-static void create_context_cache(struct svcxprt_rdma *xprt,
- int ctxt_count, int ctxt_bump, int ctxt_max)
-{
- struct svc_rdma_op_ctxt *ctxt;
- int i;
-
- xprt->sc_ctxt_max = ctxt_max;
- xprt->sc_ctxt_bump = ctxt_bump;
- xprt->sc_ctxt_cnt = 0;
- atomic_set(&xprt->sc_ctxt_used, 0);
-
- INIT_LIST_HEAD(&xprt->sc_ctxt_free);
- for (i = 0; i < ctxt_count; i++) {
- ctxt = kmalloc(sizeof(*ctxt), GFP_KERNEL);
- if (ctxt) {
- INIT_LIST_HEAD(&ctxt->free_list);
- list_add(&ctxt->free_list, &xprt->sc_ctxt_free);
- xprt->sc_ctxt_cnt++;
- }
- }
-}
-
-static void destroy_context_cache(struct svcxprt_rdma *xprt)
-{
- while (!list_empty(&xprt->sc_ctxt_free)) {
- struct svc_rdma_op_ctxt *ctxt;
- ctxt = list_entry(xprt->sc_ctxt_free.next,
- struct svc_rdma_op_ctxt,
- free_list);
- list_del_init(&ctxt->free_list);
- kfree(ctxt);
- }
-}
-
static struct svcxprt_rdma *rdma_create_xprt(struct svc_serv *serv,
int listener)
{
@@ -511,7 +429,6 @@ static struct svcxprt_rdma *rdma_create_xprt(struct svc_serv *serv,
spin_lock_init(&cma_xprt->sc_lock);
spin_lock_init(&cma_xprt->sc_read_complete_lock);
- spin_lock_init(&cma_xprt->sc_ctxt_lock);
spin_lock_init(&cma_xprt->sc_rq_dto_lock);
cma_xprt->sc_ord = svcrdma_ord;
@@ -522,20 +439,7 @@ static struct svcxprt_rdma *rdma_create_xprt(struct svc_serv *serv,
atomic_set(&cma_xprt->sc_sq_count, 0);
atomic_set(&cma_xprt->sc_ctxt_used, 0);
- if (!listener) {
- int reqs = cma_xprt->sc_max_requests;
- create_context_cache(cma_xprt,
- reqs << 1, /* starting size */
- reqs, /* bump amount */
- reqs +
- cma_xprt->sc_sq_depth +
- RPCRDMA_MAX_THREADS + 1); /* max */
- if (list_empty(&cma_xprt->sc_ctxt_free)) {
- kfree(cma_xprt);
- return NULL;
- }
- clear_bit(XPT_LISTENER, &cma_xprt->sc_xprt.xpt_flags);
- } else
+ if (listener)
set_bit(XPT_LISTENER, &cma_xprt->sc_xprt.xpt_flags);
return cma_xprt;
@@ -1077,7 +981,6 @@ static void __svc_rdma_free(struct work_struct *work)
/* Destroy the CM ID */
rdma_destroy_id(rdma->sc_cm_id);
- destroy_context_cache(rdma);
kfree(rdma);
}
--
To unsubscribe from this list: send the line "unsubscribe linux-nfs" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
