From: Chuck Lever <chuck.lever@oracle.com>
To: linux-rdma@vger.kernel.org, linux-nfs@vger.kernel.org
Subject: [PATCH v4 08/30] xprtrdma: Reduce max_frwr_depth
Date: Mon, 17 Dec 2018 11:40:04 -0500 [thread overview]
Message-ID: <20181217164003.24133.23440.stgit@manet.1015granger.net> (raw)
In-Reply-To: <20181217162406.24133.27356.stgit@manet.1015granger.net>
Some devices advertise a large max_fast_reg_page_list_len
capability, but perform optimally when MRs are significantly smaller
than that depth -- probably when the MR itself is no larger than a
page.
By default, the RDMA R/W core API uses max_sge_rd as the maximum
page depth for MRs. For some devices, the value of max_sge_rd is
1, which is also not optimal. Thus, when max_sge_rd is larger than
1, use that value. Otherwise use the value of the
max_fast_reg_page_list_len attribute.
I've tested this with CX-3 Pro, FastLinq, and CX-5 devices. It
reproducibly improves the throughput of large I/Os by several
percent.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
---
net/sunrpc/xprtrdma/frwr_ops.c | 15 +++++++++++----
1 file changed, 11 insertions(+), 4 deletions(-)
diff --git a/net/sunrpc/xprtrdma/frwr_ops.c b/net/sunrpc/xprtrdma/frwr_ops.c
index f587e44..16976b0 100644
--- a/net/sunrpc/xprtrdma/frwr_ops.c
+++ b/net/sunrpc/xprtrdma/frwr_ops.c
@@ -193,10 +193,17 @@
if (attrs->device_cap_flags & IB_DEVICE_SG_GAPS_REG)
ia->ri_mrtype = IB_MR_TYPE_SG_GAPS;
- ia->ri_max_frwr_depth =
- min_t(unsigned int, RPCRDMA_MAX_DATA_SEGS,
- attrs->max_fast_reg_page_list_len);
- dprintk("RPC: %s: device's max FR page list len = %u\n",
+ /* Quirk: Some devices advertise a large max_fast_reg_page_list_len
+ * capability, but perform optimally when the MRs are not larger
+ * than a page.
+ */
+ if (attrs->max_sge_rd > 1)
+ ia->ri_max_frwr_depth = attrs->max_sge_rd;
+ else
+ ia->ri_max_frwr_depth = attrs->max_fast_reg_page_list_len;
+ if (ia->ri_max_frwr_depth > RPCRDMA_MAX_DATA_SEGS)
+ ia->ri_max_frwr_depth = RPCRDMA_MAX_DATA_SEGS;
+ dprintk("RPC: %s: max FR page list depth = %u\n",
__func__, ia->ri_max_frwr_depth);
/* Add room for frwr register and invalidate WRs.
next prev parent reply other threads:[~2018-12-17 16:40 UTC|newest]
Thread overview: 40+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-12-17 16:39 [PATCH v4 00/30] NFS/RDMA client for next Chuck Lever
2018-12-17 16:39 ` [PATCH v4 01/30] xprtrdma: Yet another double DMA-unmap Chuck Lever
2018-12-17 16:39 ` [PATCH v4 02/30] xprtrdma: Ensure MRs are DMA-unmapped when posting LOCAL_INV fails Chuck Lever
2018-12-17 16:39 ` [PATCH v4 03/30] xprtrdma: Refactor Receive accounting Chuck Lever
2018-12-17 16:39 ` [PATCH v4 04/30] xprtrdma: Replace rpcrdma_receive_wq with a per-xprt workqueue Chuck Lever
2018-12-17 16:39 ` [PATCH v4 05/30] xprtrdma: No qp_event disconnect Chuck Lever
2018-12-17 16:39 ` [PATCH v4 06/30] xprtrdma: Don't wake pending tasks until disconnect is done Chuck Lever
2018-12-17 17:28 ` Trond Myklebust
2018-12-17 18:37 ` Chuck Lever
2018-12-17 18:55 ` Trond Myklebust
2018-12-17 19:00 ` Chuck Lever
2018-12-17 19:09 ` Trond Myklebust
2018-12-17 19:19 ` Chuck Lever
2018-12-17 19:26 ` Trond Myklebust
2018-12-17 16:39 ` [PATCH v4 07/30] xprtrdma: Fix ri_max_segs and the result of ro_maxpages Chuck Lever
2018-12-18 19:35 ` Anna Schumaker
2018-12-18 19:39 ` Chuck Lever
2018-12-17 16:40 ` Chuck Lever [this message]
2018-12-17 16:40 ` [PATCH v4 09/30] xprtrdma: Remove support for FMR memory registration Chuck Lever
2018-12-17 16:40 ` [PATCH v4 10/30] xprtrdma: Remove rpcrdma_memreg_ops Chuck Lever
2018-12-17 16:40 ` [PATCH v4 11/30] xprtrdma: Plant XID in on-the-wire RDMA offset (FRWR) Chuck Lever
2018-12-17 16:40 ` [PATCH v4 12/30] NFS: Make "port=" mount option optional for RDMA mounts Chuck Lever
2018-12-17 16:40 ` [PATCH v4 13/30] xprtrdma: Recognize XDRBUF_SPARSE_PAGES Chuck Lever
2018-12-17 16:40 ` [PATCH v4 14/30] xprtrdma: Remove request_module from backchannel Chuck Lever
2018-12-17 16:40 ` [PATCH v4 15/30] xprtrdma: Expose transport header errors Chuck Lever
2018-12-17 16:40 ` [PATCH v4 16/30] xprtrdma: Simplify locking that protects the rl_allreqs list Chuck Lever
2018-12-17 16:40 ` [PATCH v4 17/30] xprtrdma: Cull dprintk() call sites Chuck Lever
2018-12-17 16:40 ` [PATCH v4 18/30] xprtrdma: Remove unused fields from rpcrdma_ia Chuck Lever
2018-12-17 16:41 ` [PATCH v4 19/30] xprtrdma: Clean up of xprtrdma chunk trace points Chuck Lever
2018-12-17 16:41 ` [PATCH v4 20/30] xprtrdma: Relocate the xprtrdma_mr_map " Chuck Lever
2018-12-17 16:41 ` [PATCH v4 21/30] xprtrdma: Add trace points for calls to transport switch methods Chuck Lever
2018-12-17 16:41 ` [PATCH v4 22/30] xprtrdma: Trace mapping, alloc, and dereg failures Chuck Lever
2018-12-17 16:41 ` [PATCH v4 23/30] NFS: Fix NFSv4 symbolic trace point output Chuck Lever
2018-12-17 16:41 ` [PATCH v4 24/30] SUNRPC: Simplify defining common RPC trace events Chuck Lever
2018-12-17 16:41 ` [PATCH v4 25/30] SUNRPC: Fix some kernel doc complaints Chuck Lever
2018-12-17 16:41 ` [PATCH v4 26/30] xprtrdma: Update comments in frwr_op_send Chuck Lever
2018-12-17 16:41 ` [PATCH v4 27/30] xprtrdma: Replace outdated comment for rpcrdma_ep_post Chuck Lever
2018-12-17 16:41 ` [PATCH v4 28/30] xprtrdma: Add documenting comment for rpcrdma_buffer_destroy Chuck Lever
2018-12-17 16:41 ` [PATCH v4 29/30] xprtrdma: Clarify comments in rpcrdma_ia_remove Chuck Lever
2018-12-17 16:42 ` [PATCH v4 30/30] xprtrdma: Don't leak freed MRs Chuck Lever
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