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authorCao jin <caoj.fnst@cn.fujitsu.com>2016-07-29 19:05:38 +0800
committerPaolo Bonzini <pbonzini@redhat.com>2016-09-13 19:08:44 +0200
commitd90f3cca87844ea797a1c96b88758478ac575e1f (patch)
treefe80d6b45bc225aabc1dcbdf7f466df16eb43b97 /cpus.c
parent1d45cea5496fe509f0b66f01b876067e68a5faa0 (diff)
cpus: update comments
The returned value of cpu_get_clock() is plused with the offset, so it is the time elapsed in virtual machine when vm is active. Cc: Paolo Bonzini <pbonzini@redhat.com> Cc Peter Crosthwaite <crosthwaite.peter@gmail.com> Cc: Richard Henderson <rth@twiddle.net> Signed-off-by: Cao jin <caoj.fnst@cn.fujitsu.com> Message-Id: <1469790338-28990-4-git-send-email-caoj.fnst@cn.fujitsu.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Diffstat (limited to 'cpus.c')
-rw-r--r--cpus.c11
1 files changed, 8 insertions, 3 deletions
diff --git a/cpus.c b/cpus.c
index e11caf7ced..030843132f 100644
--- a/cpus.c
+++ b/cpus.c
@@ -191,8 +191,12 @@ int64_t cpu_icount_to_ns(int64_t icount)
return icount << icount_time_shift;
}
-/* return the host CPU cycle counter and handle stop/restart */
-/* Caller must hold the BQL */
+/* return the time elapsed in VM between vm_start and vm_stop. Unless
+ * icount is active, cpu_get_ticks() uses units of the host CPU cycle
+ * counter.
+ *
+ * Caller must hold the BQL
+ */
int64_t cpu_get_ticks(void)
{
int64_t ticks;
@@ -229,7 +233,8 @@ static int64_t cpu_get_clock_locked(void)
return time;
}
-/* return the host CPU monotonic timer and handle stop/restart */
+/* Return the monotonic time elapsed in VM, i.e.,
+ * the time between vm_start and vm_stop */
int64_t cpu_get_clock(void)
{
int64_t ti;