From 62ed448cc53b654036f7d7f3c99f299d79ad14c3 Mon Sep 17 00:00:00 2001 From: Chuck Lever Date: Tue, 7 Jun 2022 16:47:58 -0400 Subject: SUNRPC: Optimize xdr_reserve_space() Transitioning between encode buffers is quite infrequent. It happens about 1 time in 400 calls to xdr_reserve_space(), measured on NFSD with a typical build/test workload. Force the compiler to remove that code from xdr_reserve_space(), which is a hot path on both the server and the client. This change reduces the size of xdr_reserve_space() from 10 cache lines to 2 when compiled with -Os. Signed-off-by: Chuck Lever Reviewed-by: J. Bruce Fields --- net/sunrpc/xdr.c | 17 ++++++++++------- 1 file changed, 10 insertions(+), 7 deletions(-) (limited to 'net') diff --git a/net/sunrpc/xdr.c b/net/sunrpc/xdr.c index b57cf9df4de8..1ad8b4ef14de 100644 --- a/net/sunrpc/xdr.c +++ b/net/sunrpc/xdr.c @@ -919,7 +919,7 @@ void xdr_init_encode(struct xdr_stream *xdr, struct xdr_buf *buf, __be32 *p, EXPORT_SYMBOL_GPL(xdr_init_encode); /** - * xdr_commit_encode - Ensure all data is written to buffer + * __xdr_commit_encode - Ensure all data is written to buffer * @xdr: pointer to xdr_stream * * We handle encoding across page boundaries by giving the caller a @@ -931,22 +931,25 @@ EXPORT_SYMBOL_GPL(xdr_init_encode); * required at the end of encoding, or any other time when the xdr_buf * data might be read. */ -inline void xdr_commit_encode(struct xdr_stream *xdr) +void __xdr_commit_encode(struct xdr_stream *xdr) { int shift = xdr->scratch.iov_len; void *page; - if (shift == 0) - return; page = page_address(*xdr->page_ptr); memcpy(xdr->scratch.iov_base, page, shift); memmove(page, page + shift, (void *)xdr->p - page); xdr_reset_scratch_buffer(xdr); } -EXPORT_SYMBOL_GPL(xdr_commit_encode); +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; -- cgit v1.2.3