diff options
| author | Paolo Bonzini <pbonzini@redhat.com> | 2015-12-22 12:03:33 +0100 |
|---|---|---|
| committer | Stefan Hajnoczi <stefanha@redhat.com> | 2016-02-09 13:52:26 +0000 |
| commit | ad523bca56a7202d2498c550a41be5c986c4d33c (patch) | |
| tree | b3b07fcce95eefd07483b22923de1c4ae62b10bb /util/iov.c | |
| parent | ee8e8f92a730afc17ab8be6e86df6b9a23b8ebc6 (diff) | |
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 <pbonzini@redhat.com>
Message-id: 1450782213-14227-1-git-send-email-pbonzini@redhat.com
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Diffstat (limited to 'util/iov.c')
| -rw-r--r-- | util/iov.c | 8 |
1 files changed, 4 insertions, 4 deletions
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; |