From: Trond Myklebust <trondmy@gmail.com>
To: linux-nfs@vger.kernel.org
Subject: [PATCH 1/3] SUNRPC: Replace division by multiplication in calculation of queue length
Date: Tue, 16 Jul 2019 16:04:31 -0400 [thread overview]
Message-ID: <20190716200433.38758-1-trond.myklebust@hammerspace.com> (raw)
When checking whether or not a particular xprt queue length is shorter
than the average queue length for all xprts, prefer to use multiplication
rather than division for performance reasons.
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
---
net/sunrpc/xprtmultipath.c | 5 ++---
1 file changed, 2 insertions(+), 3 deletions(-)
diff --git a/net/sunrpc/xprtmultipath.c b/net/sunrpc/xprtmultipath.c
index 9d66ce53355d..5df4e7adedf0 100644
--- a/net/sunrpc/xprtmultipath.c
+++ b/net/sunrpc/xprtmultipath.c
@@ -322,7 +322,6 @@ struct rpc_xprt *xprt_iter_next_entry_roundrobin(struct rpc_xprt_iter *xpi)
struct rpc_xprt *xprt;
unsigned long xprt_queuelen;
unsigned long xps_queuelen;
- unsigned long xps_avglen;
do {
xprt = xprt_iter_next_entry_multiple(xpi,
@@ -333,8 +332,8 @@ struct rpc_xprt *xprt_iter_next_entry_roundrobin(struct rpc_xprt_iter *xpi)
if (xprt_queuelen <= 2)
break;
xps_queuelen = atomic_long_read(&xps->xps_queuelen);
- xps_avglen = DIV_ROUND_UP(xps_queuelen, xps->xps_nactive);
- } while (xprt_queuelen > xps_avglen);
+ /* Exit loop if xprt_queuelen <= average queue length */
+ } while (xprt_queuelen * READ_ONCE(xps->xps_nactive) > xps_queuelen);
return xprt;
}
--
2.21.0
next reply other threads:[~2019-07-16 20:06 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-07-16 20:04 Trond Myklebust [this message]
2019-07-16 20:04 ` [PATCH 2/3] SUNRPC: Skip zero-refcount transports Trond Myklebust
2019-07-16 20:04 ` [PATCH 3/3] SUNRPC: Fix a hang in xprt_switch_set_next_cursor() Trond Myklebust
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