From 8948896c9e098c6fd31a6a698a598a7cbd7fa40e Mon Sep 17 00:00:00 2001 From: Tom Tucker Date: Wed, 28 May 2008 15:14:02 -0500 Subject: [PATCH] svcrdma: Change WR context get/put to use the kmem cache 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 --- 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 d8d74c4ab504..ef2e3a20bf3b 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 80104f4999d5..19ddc382b777 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); } -- 2.34.1