From ad523bca56a7202d2498c550a41be5c986c4d33c Mon Sep 17 00:00:00 2001 From: Paolo Bonzini Date: Tue, 22 Dec 2015 12:03:33 +0100 Subject: iov: avoid memcpy for "simple" iov_from_buf/iov_to_buf memcpy can take a large amount of time for small reads and writes. For virtio it is a common case that the first iovec can satisfy the whole read or write. In that case, and if bytes is a constant to avoid excessive growth of code, inline the first iteration into the caller. Signed-off-by: Paolo Bonzini Message-id: 1450782213-14227-1-git-send-email-pbonzini@redhat.com Signed-off-by: Stefan Hajnoczi --- util/iov.c | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-) (limited to 'util/iov.c') diff --git a/util/iov.c b/util/iov.c index e802ee15bc..062f4e50c3 100644 --- a/util/iov.c +++ b/util/iov.c @@ -20,8 +20,8 @@ #include "qemu/iov.h" #include "qemu/sockets.h" -size_t iov_from_buf(const struct iovec *iov, unsigned int iov_cnt, - size_t offset, const void *buf, size_t bytes) +size_t iov_from_buf_full(const struct iovec *iov, unsigned int iov_cnt, + size_t offset, const void *buf, size_t bytes) { size_t done; unsigned int i; @@ -39,8 +39,8 @@ size_t iov_from_buf(const struct iovec *iov, unsigned int iov_cnt, return done; } -size_t iov_to_buf(const struct iovec *iov, const unsigned int iov_cnt, - size_t offset, void *buf, size_t bytes) +size_t iov_to_buf_full(const struct iovec *iov, const unsigned int iov_cnt, + size_t offset, void *buf, size_t bytes) { size_t done; unsigned int i; -- cgit v1.2.1