From: David Daney <david.da...@cavium.com>
It is a performance enhancement. When running in a simulator, each
system call to write a character takes a lot of time. Batching them
up decreases the overhead (in the root kernel) of each virtio console
write.
Signed-off-by: David Daney <david.da...@cavium.com>
Signed-off-by: Andreas Herrmann <andreas.herrm...@caviumnetworks.com>
---
tools/kvm/term.c | 7 +++++--
1 file changed, 5 insertions(+), 2 deletions(-)
diff --git a/tools/kvm/term.c b/tools/kvm/term.c
index 3de410b..b153eed 100644
--- a/tools/kvm/term.c
+++ b/tools/kvm/term.c
@@ -52,11 +52,14 @@ int term_getc(struct kvm *kvm, int term)
int term_putc(char *addr, int cnt, int term)
{
int ret;
+ int num_remaining = cnt;
- while (cnt--) {
- ret = write(term_fds[term][TERM_FD_OUT], addr++, 1);
+ while (num_remaining) {
+ ret = write(term_fds[term][TERM_FD_OUT], addr, num_remaining);
if (ret < 0)
return 0;
+ num_remaining -= ret;
+ addr += ret;
}
return cnt;
--
1.7.9.5
--
To unsubscribe from this list: send the line "unsubscribe kvm" in
the body of a message to majord...@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
