The xdr_get_next_encode_buffer() function is called infrequently.
On a typical build/test workload, it's called about 1 time in 400
calls to xdr_reserve_space() (measured on NFSD).
Force the compiler to remove it from xdr_reserve_space(), which is
a hot path. This change reduces the size of xdr_reserve_space() from
10 cache lines to 4 on my test system.
Signed-off-by: Chuck Lever <chuck.lever@xxxxxxxxxx>
---
net/sunrpc/xdr.c | 9 +++++++--
1 file changed, 7 insertions(+), 2 deletions(-)
diff --git a/net/sunrpc/xdr.c b/net/sunrpc/xdr.c
index b57cf9df4de8..08a85375b311 100644
--- a/net/sunrpc/xdr.c
+++ b/net/sunrpc/xdr.c
@@ -945,8 +945,13 @@ inline void xdr_commit_encode(struct xdr_stream *xdr)
}
EXPORT_SYMBOL_GPL(xdr_commit_encode);
-static __be32 *xdr_get_next_encode_buffer(struct xdr_stream *xdr,
- size_t nbytes)
+/*
+ * The buffer space to be reserved crosses the boundary between
+ * xdr->buf->head and xdr->buf->pages, or between two pages
+ * in xdr->buf->pages.
+ */
+static noinline __be32 *xdr_get_next_encode_buffer(struct xdr_stream *xdr,
+ size_t nbytes)
{
__be32 *p;
int space_left;
