is equivalent to:
perf script -f trace:<fields> -f sw:<fields> -f hw:<fields>
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+
i.e., the specified fields apply to all event types if the type string
is not given.
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The arguments are processed in the order received. A later usage can
reset a prior request. e.g.:
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-f trace: -f comm,tid,time,ip,sym
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+
The first -f suppresses trace events (field list is ""), but then the
second invocation sets the fields to comm,tid,time,ip,sym. In this case a
warning is given to the user:
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"Overriding previous field request for all events."
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Alternatively, consider the order:
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-f comm,tid,time,ip,sym -f trace:
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The first -f sets the fields for all events and the second -f
suppresses trace events. The user is given a warning message about
the override, and the result of the above is that only S/W and H/W
events are displayed with the given fields.
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For the 'wildcard' option if a user selected field is invalid for an
event type, a message is displayed to the user that the option is
ignored for that type. For example:
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$ perf script -f comm,tid,trace
'trace' not valid for hardware events. Ignoring.
'trace' not valid for software events. Ignoring.
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Alternatively, if the type is given an invalid field is specified it
is an error. For example:
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perf script -v -f sw:comm,tid,trace
'trace' not valid for software events.
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At this point usage is displayed, and perf-script exits.
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+
Finally, a user may not set fields to none for all event types.
i.e., -f "" is not allowed.
projects / linux-drm-fsl-dcu.git / blobdiff