From 2a27f514a47d39c50aaa5c07831ab35178955d47 Mon Sep 17 00:00:00 2001 From: Suraj Jitindar Singh Date: Tue, 2 Aug 2016 14:03:23 +1000 Subject: KVM: PPC: Implement existing and add new halt polling vcpu stats 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 all running guests 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_poll_success_ns, halt_poll_fail_ns and halt_wait_ns to be used to accumulate the total time spend polling successfully, polling unsuccessfully and waiting respectively, and halt_successful_wait to accumulate the number of times the vcpu waits. Given that halt_poll_success_ns, halt_poll_fail_ns and halt_wait_ns 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 polling or waiting will be known and the number of times that each was done, it will be possible to determine the average poll and wait times. This will give the ability to tune the kvm module parameters based on the calculated average wait and poll times. Signed-off-by: Suraj Jitindar Singh Reviewed-by: David Matlack Signed-off-by: Paul Mackerras --- arch/powerpc/kvm/book3s.c | 4 ++++ 1 file changed, 4 insertions(+) (limited to 'arch/powerpc/kvm/book3s.c') diff --git a/arch/powerpc/kvm/book3s.c b/arch/powerpc/kvm/book3s.c index 47018fcbf7d6..71eb8f3d3b54 100644 --- a/arch/powerpc/kvm/book3s.c +++ b/arch/powerpc/kvm/book3s.c @@ -52,8 +52,12 @@ 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_poll_success_ns", VCPU_STAT(halt_poll_success_ns) }, + { "halt_poll_fail_ns", VCPU_STAT(halt_poll_fail_ns) }, + { "halt_wait_ns", VCPU_STAT(halt_wait_ns) }, { "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) }, -- cgit v1.2.3