From 8740767376b32a7772607e1b2b07cde0c24120cc Mon Sep 17 00:00:00 2001 From: Tom Tucker Date: Wed, 30 Apr 2008 20:44:39 -0500 Subject: [PATCH] svcrdma: Use standard Linux lists for context cache Replace the one-off linked list implementation used to implement the context cache with the standard Linux list_head lists. Add a context counter to catch resource leaks. A WARN_ON will be added later to ensure that we've freed all contexts. Signed-off-by: Tom Tucker --- include/linux/sunrpc/svc_rdma.h | 5 ++- net/sunrpc/xprtrdma/svc_rdma_transport.c | 47 +++++++++++++----------- 2 files changed, 29 insertions(+), 23 deletions(-) diff --git a/include/linux/sunrpc/svc_rdma.h b/include/linux/sunrpc/svc_rdma.h index c447c417b3..701439064d 100644 --- a/include/linux/sunrpc/svc_rdma.h +++ b/include/linux/sunrpc/svc_rdma.h @@ -72,7 +72,7 @@ extern atomic_t rdma_stat_sq_prod; */ struct svc_rdma_op_ctxt { struct svc_rdma_op_ctxt *read_hdr; - struct svc_rdma_op_ctxt *next; + struct list_head free_list; struct xdr_buf arg; struct list_head dto_q; enum ib_wr_opcode wr_op; @@ -104,7 +104,8 @@ struct svcxprt_rdma { struct ib_pd *sc_pd; - struct svc_rdma_op_ctxt *sc_ctxt_head; + atomic_t sc_ctxt_used; + struct list_head sc_ctxt_free; int sc_ctxt_cnt; int sc_ctxt_bump; int sc_ctxt_max; diff --git a/net/sunrpc/xprtrdma/svc_rdma_transport.c b/net/sunrpc/xprtrdma/svc_rdma_transport.c index 34141eaf25..817cf4de74 100644 --- a/net/sunrpc/xprtrdma/svc_rdma_transport.c +++ b/net/sunrpc/xprtrdma/svc_rdma_transport.c @@ -103,8 +103,8 @@ static int rdma_bump_context_cache(struct svcxprt_rdma *xprt) spin_lock_bh(&xprt->sc_ctxt_lock); if (ctxt) { at_least_one = 1; - ctxt->next = xprt->sc_ctxt_head; - xprt->sc_ctxt_head = ctxt; + 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--; @@ -123,7 +123,7 @@ struct svc_rdma_op_ctxt *svc_rdma_get_context(struct svcxprt_rdma *xprt) while (1) { spin_lock_bh(&xprt->sc_ctxt_lock); - if (unlikely(xprt->sc_ctxt_head == NULL)) { + if (unlikely(list_empty(&xprt->sc_ctxt_free))) { /* Try to bump my cache. */ spin_unlock_bh(&xprt->sc_ctxt_lock); @@ -136,12 +136,15 @@ struct svc_rdma_op_ctxt *svc_rdma_get_context(struct svcxprt_rdma *xprt) schedule_timeout_uninterruptible(msecs_to_jiffies(500)); continue; } - ctxt = xprt->sc_ctxt_head; - xprt->sc_ctxt_head = ctxt->next; + 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; } return ctxt; @@ -163,10 +166,11 @@ void svc_rdma_put_context(struct svc_rdma_op_ctxt *ctxt, int free_pages) ctxt->sge[i].addr, ctxt->sge[i].length, ctxt->direction); + spin_lock_bh(&xprt->sc_ctxt_lock); - ctxt->next = xprt->sc_ctxt_head; - xprt->sc_ctxt_head = ctxt; + list_add(&ctxt->free_list, &xprt->sc_ctxt_free); spin_unlock_bh(&xprt->sc_ctxt_lock); + atomic_dec(&xprt->sc_ctxt_used); } /* ib_cq event handler */ @@ -412,28 +416,29 @@ static void create_context_cache(struct svcxprt_rdma *xprt, xprt->sc_ctxt_max = ctxt_max; xprt->sc_ctxt_bump = ctxt_bump; xprt->sc_ctxt_cnt = 0; - xprt->sc_ctxt_head = NULL; + 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) { - ctxt->next = xprt->sc_ctxt_head; - xprt->sc_ctxt_head = 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 svc_rdma_op_ctxt *ctxt) +static void destroy_context_cache(struct svcxprt_rdma *xprt) { - struct svc_rdma_op_ctxt *next; - if (!ctxt) - return; - - do { - next = ctxt->next; + 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); - ctxt = next; - } while (next); + } } static struct svcxprt_rdma *rdma_create_xprt(struct svc_serv *serv, @@ -470,7 +475,7 @@ static struct svcxprt_rdma *rdma_create_xprt(struct svc_serv *serv, reqs + cma_xprt->sc_sq_depth + RPCRDMA_MAX_THREADS + 1); /* max */ - if (!cma_xprt->sc_ctxt_head) { + if (list_empty(&cma_xprt->sc_ctxt_free)) { kfree(cma_xprt); return NULL; } @@ -976,7 +981,7 @@ static void svc_rdma_free(struct svc_xprt *xprt) if (rdma->sc_pd && !IS_ERR(rdma->sc_pd)) ib_dealloc_pd(rdma->sc_pd); - destroy_context_cache(rdma->sc_ctxt_head); + destroy_context_cache(rdma); kfree(rdma); } -- 2.39.5