From 61a67f71dd7e437212a2730c4462dff9b3b7b3da Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Llu=C3=ADs=20Vilanova?= Date: Tue, 4 Jul 2017 10:42:32 +0200 Subject: exec: [tcg] Use different TBs according to the vCPU's dynamic tracing state MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Every vCPU now uses a separate set of TBs for each set of dynamic tracing event state values. Each set of TBs can be used by any number of vCPUs to maximize TB reuse when vCPUs have the same tracing state. This feature is later used by tracetool to optimize tracing of guest code events. The maximum number of TB sets is defined as 2^E, where E is the number of events that have the 'vcpu' property (their state is stored in CPUState->trace_dstate). For this to work, a change on the dynamic tracing state of a vCPU will force it to flush its virtual TB cache (which is only indexed by address), and fall back to the physical TB cache (which now contains the vCPU's dynamic tracing state as part of the hashing function). Signed-off-by: Lluís Vilanova Reviewed-by: Richard Henderson Reviewed-by: Emilio G. Cota Signed-off-by: Emilio G. Cota Message-id: 149915775266.6295.10060144081246467690.stgit@frigg.lan Signed-off-by: Stefan Hajnoczi --- trace/control.h | 3 +++ 1 file changed, 3 insertions(+) (limited to 'trace/control.h') diff --git a/trace/control.h b/trace/control.h index 4ea53e2986..b931824d60 100644 --- a/trace/control.h +++ b/trace/control.h @@ -165,6 +165,9 @@ void trace_event_set_state_dynamic(TraceEvent *ev, bool state); * Set the dynamic tracing state of an event for the given vCPU. * * Pre-condition: trace_event_get_vcpu_state_static(ev) == true + * + * Note: Changes for execution-time events with the 'tcg' property will not be + * propagated until the next TB is executed (iff executing in TCG mode). */ void trace_event_set_vcpu_state_dynamic(CPUState *vcpu, TraceEvent *ev, bool state); -- cgit v1.2.1