Re: [PATCH RFC V4 4/5] kvm : pv-ticketlocks support for linux guests running on KVM hypervisor
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From: Raghavendra K T <hidden>
Date: 2012-01-16 14:13:54
Also in:
kvm, xen-devel
On 01/16/2012 02:35 PM, Avi Kivity wrote:
On 01/14/2012 08:26 PM, Raghavendra K T wrote:quoted
Extends Linux guest running on KVM hypervisor to support pv-ticketlocks. During smp_boot_cpus paravirtualied KVM guest detects if the hypervisor has required feature (KVM_FEATURE_PVLOCK_KICK) to support pv-ticketlocks. If so, support for pv-ticketlocks is registered via pv_lock_ops. Use KVM_HC_KICK_CPU hypercall to wakeup waiting/halted vcpu. + + debugfs_create_u8("zero_stats", 0644, d_spin_debug,&zero_stats); + + debugfs_create_u32("taken_slow", 0444, d_spin_debug, + &spinlock_stats.contention_stats[TAKEN_SLOW]); + debugfs_create_u32("taken_slow_pickup", 0444, d_spin_debug, + &spinlock_stats.contention_stats[TAKEN_SLOW_PICKUP]); + + debugfs_create_u32("released_slow", 0444, d_spin_debug, + &spinlock_stats.contention_stats[RELEASED_SLOW]); + debugfs_create_u32("released_slow_kicked", 0444, d_spin_debug, + &spinlock_stats.contention_stats[RELEASED_SLOW_KICKED]); + + debugfs_create_u64("time_blocked", 0444, d_spin_debug, + &spinlock_stats.time_blocked); + + debugfs_create_u32_array("histo_blocked", 0444, d_spin_debug, + spinlock_stats.histo_spin_blocked, HISTO_BUCKETS + 1); +Please drop all of these and replace with tracepoints in the appropriate spots. Everything else (including the historgram) can be reconstructed the tracepoints in userspace.
I think Jeremy pointed that tracepoints use spinlocks and hence debugfs is the option.. no ?