@@ -114,8 +114,11 @@ struct kvm_vcpu_stat {
u64 emulated_inst_exits;
u64 dec_exits;
u64 ext_intr_exits;
+ u64 halt_block_time_successful_poll;
+ u64 halt_block_time_waited;
u64 halt_successful_poll;
u64 halt_attempted_poll;
+ u64 halt_successful_wait;
u64 halt_poll_invalid;
u64 halt_wakeup;
u64 dbell_exits;
@@ -52,8 +52,13 @@ struct kvm_stats_debugfs_item debugfs_entries[] = {
{ "dec", VCPU_STAT(dec_exits) },
{ "ext_intr", VCPU_STAT(ext_intr_exits) },
{ "queue_intr", VCPU_STAT(queue_intr) },
+ { "halt_block_time_successful_poll_ns",
+ VCPU_STAT(halt_block_time_successful_poll) },
+ { "halt_block_time_waited_ns",
+ VCPU_STAT(halt_block_time_waited) },
{ "halt_successful_poll", VCPU_STAT(halt_successful_poll), },
{ "halt_attempted_poll", VCPU_STAT(halt_attempted_poll), },
+ { "halt_successful_wait", VCPU_STAT(halt_successful_wait) },
{ "halt_poll_invalid", VCPU_STAT(halt_poll_invalid) },
{ "halt_wakeup", VCPU_STAT(halt_wakeup) },
{ "pf_storage", VCPU_STAT(pf_storage) },
@@ -2679,8 +2679,8 @@ static int kvmppc_vcore_check_block(struct kvmppc_vcore *vc)
*/
static void kvmppc_vcore_blocked(struct kvmppc_vcore *vc)
{
- int do_sleep = 1;
ktime_t cur, start;
+ int do_sleep = 1;
u64 block_ns;
DECLARE_SWAITQUEUE(wait);
@@ -2688,6 +2688,7 @@ static void kvmppc_vcore_blocked(struct kvmppc_vcore *vc)
cur = start = ktime_get();
if (vc->halt_poll_ns) {
ktime_t stop = ktime_add_ns(start, vc->halt_poll_ns);
+ ++vc->runner->stat.halt_attempted_poll;
vc->vcore_state = VCORE_POLLING;
spin_unlock(&vc->lock);
@@ -2703,8 +2704,10 @@ static void kvmppc_vcore_blocked(struct kvmppc_vcore *vc)
spin_lock(&vc->lock);
vc->vcore_state = VCORE_INACTIVE;
- if (!do_sleep)
+ if (!do_sleep) {
+ ++vc->runner->stat.halt_successful_poll;
goto out;
+ }
}
prepare_to_swait(&vc->wq, &wait, TASK_INTERRUPTIBLE);
@@ -2712,6 +2715,9 @@ static void kvmppc_vcore_blocked(struct kvmppc_vcore *vc)
if (kvmppc_vcore_check_block(vc)) {
finish_swait(&vc->wq, &wait);
do_sleep = 0;
+ /* If we polled, count this as a successful poll */
+ if (vc->halt_poll_ns)
+ ++vc->runner->stat.halt_successful_poll;
goto out;
}
@@ -2723,12 +2729,18 @@ static void kvmppc_vcore_blocked(struct kvmppc_vcore *vc)
spin_lock(&vc->lock);
vc->vcore_state = VCORE_INACTIVE;
trace_kvmppc_vcore_blocked(vc, 1);
+ ++vc->runner->stat.halt_successful_wait;
cur = ktime_get();
out:
block_ns = ktime_to_ns(cur) - ktime_to_ns(start);
+ if (do_sleep)
+ vc->runner->stat.halt_block_time_waited += block_ns;
+ else if (vc->halt_poll_ns)
+ vc->runner->stat.halt_block_time_successful_poll += block_ns;
+
if (halt_poll_max_ns) {
if (block_ns <= vc->halt_poll_ns)
;
vcpu stats are used to collect information about a vcpu which can be viewed in the debugfs. For example halt_attempted_poll and halt_successful_poll are used to keep track of the number of times the vcpu attempts to and successfully polls. These stats are currently not used on powerpc. Implement incrementation of the halt_attempted_poll and halt_successful_poll vcpu stats for powerpc. Since these stats are summed over all the vcpus for a running guest it doesn't matter which vcpu they are attributed to, thus we choose the current runner vcpu of the vcore. Also add new vcpu stats: halt_block_time_successful_poll and halt_block_time_waited to be used to accumulate the total time spend blocked when we either successfully polled, or unsuccessfully polled and then waited respectively, and halt_successful_wait to accumulate the number of times the vcpu waited. Given that halt_poll_time and halt_wait_time are expressed in nanoseconds it is necessary to represent these as 64-bit quantities, otherwise they would overflow after only about 4 seconds. Given that the total time spend either successfully polling or unsuccessfully polling and then waiting will be known, and the number of times that each was done, it will be possible to determine the average block time of the vcore when it either successfully polls or unsuccessfully polls and then waits. This will give the ability to tune the kvm module parameters based on the calculated average block time in each scenario. --- Change Log: V1 -> V2: - Nothing V2 -> V3: - Rename vcpu stats to express with greater clarity what they represent: halt_poll_time -> halt_block_time_successful_poll halt_wait_time -> halt_block_time_waited Signed-off-by: Suraj Jitindar Singh <sjitindarsingh@gmail.com> --- arch/powerpc/include/asm/kvm_host.h | 3 +++ arch/powerpc/kvm/book3s.c | 5 +++++ arch/powerpc/kvm/book3s_hv.c | 16 ++++++++++++++-- 3 files changed, 22 insertions(+), 2 deletions(-)