Re: [PATCH 3/3] KVM: perf: kvm events analysis tool

From: David Ahern
Date: Mon Feb 20 2012 - 23:58:33 EST


On 2/20/12 8:52 PM, Xiao Guangrong wrote:
+ /* Both begin and end events did not get the key. */
+ if (!event&& key->key == INVALID_KEY)
+ return;
+
Should not be able to get here with event unset, so the next 2 lines should not be needed. ie., you only want to process events where the begin event was seen in which case event is defined.


In some case, the 'begin event' just records the start timestamp, the actually event
is recognised in the 'end event'.

Take mmio-read for example, in the old kernel, we use kvm-exit as the 'begin event'
and kvm_mmio(KVM_TRACE_MMIO_READ...) is the 'end event'.

ah, ok. Please add a comment about this path.

David

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