From: Tom Tucker Subject: [PATCH 11/11] svcrdma: Change WR context get/put to use the kmem cache Date: Wed, 2 Jul 2008 21:27:43 -0500 Message-ID: <1215052063-7330-12-git-send-email-tom@opengridcomputing.com> References: <1215052063-7330-1-git-send-email-tom@opengridcomputing.com> <1215052063-7330-2-git-send-email-tom@opengridcomputing.com> <1215052063-7330-3-git-send-email-tom@opengridcomputing.com> <1215052063-7330-4-git-send-email-tom@opengridcomputing.com> <1215052063-7330-5-git-send-email-tom@opengridcomputing.com> <1215052063-7330-6-git-send-email-tom@opengridcomputing.com> <1215052063-7330-7-git-send-email-tom@opengridcomputing.com> <1215052063-7330-8-git-send-email-tom@opengridcomputing.com> <1215052063-7330-9-git-send-email-tom@opengridcomputing.com> <1215052063-7330-10-git-send-email-tom@opengridcomputing.com> <1215052063-7330-11-git-send-email-tom@opengridcomputing.com> Cc: linux-nfs@vger.kernel.org, Tom Tucker To: bfields@fieldses.org Return-path: Received: from smtp.opengridcomputing.com ([209.198.142.2]:48843 "EHLO smtp.opengridcomputing.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753419AbYGCC1p (ORCPT ); Wed, 2 Jul 2008 22:27:45 -0400 In-Reply-To: <1215052063-7330-11-git-send-email-tom@opengridcomputing.com> Sender: linux-nfs-owner@vger.kernel.org List-ID: 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 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); }