mirror of https://gitee.com/openkylin/qemu.git
736ec1677f
The trace-events "disable" keyword turns an event into a nop at compile-time. This is important for high-frequency events that can impact performance. The "disable" keyword is currently broken in the simple trace backend. This patch fixes the problem as follows: Trace events are identified by their TraceEventID number. When events are disabled there are two options for assigning TraceEventID numbers: 1. Skip disabled events and don't assign them a number. 2. Assign numbers for all events regardless of the disabled keyword. The simple trace backend and its binary file format uses approach #1. The tracetool infrastructure has been using approach #2 for a while. The result is that the numbers used in simple trace files do not correspond with TraceEventIDs. In trace/simple.c we assumed that they are identical and therefore emitted bogus numbers. This patch fixes the bug by using TraceEventID for trace_event_id() while sticking to approach #1 for simple trace file numbers. This preserves simple trace file format compatibility. Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com> |
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| __init__.py | ||