Re: [PATCH v2] tracing: Add NOT to filtering logic
From: Alexei Starovoitov
Date: Tue Dec 02 2014 - 15:45:04 EST
On Tue, Dec 2, 2014 at 12:35 PM, Steven Rostedt <rostedt@xxxxxxxxxxx> wrote:
> Ted noticed that he could not filter on an event for a bit being cleared.
> That's because the filtering logic only tests event fields with a limited
> number of comparisons which, for bit logic, only include "&", which can
> test if a bit is set, but there's no good way to see if a bit is clear.
> This adds a way to do: !(field & 2048)
> Which returns true if the bit is not set, and false otherwise.
> Note, currently !(field1 == 10 && field2 == 15) is not supported.
> That is, the 'not' only works for direct comparisons, not for the
> AND and OR logic.
> Link: http://lkml.kernel.org/r/20141202021912.GA29096@xxxxxxxxx
> Link: http://lkml.kernel.org/r/20141202120430.71979060@xxxxxxxxxxxxxxxxxx
> Suggested-by: "Theodore Ts'o" <tytso@xxxxxxx>
> Signed-off-by: Steven Rostedt <rostedt@xxxxxxxxxxx>
looks good to me.
Acked-by: Alexei Starovoitov <ast@xxxxxxxxxxxx>
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