Re: [for-next][PATCH 08/12] tracing: Add binary & filter for events
From: Steven Rostedt
Date: Thu Jun 20 2013 - 08:14:54 EST
On Thu, 2013-06-20 at 10:09 +0200, Arend van Spriel wrote:
> On 06/20/2013 05:35 AM, Steven Rostedt wrote:
> > By allowing a binary '&' operation, this gives the user the ability to
> > test a bit.
> > Note, a binary '|' is not added, as it doesn't make sense as fields must
> > be compared to constants (for now), and ORing a constant will always return
> > true.
> > Link:http://lkml.kernel.org/r/1371057385.9844.261.camel@xxxxxxxxxxxxxxxxxx
> > Suggested-by: Arend van Spriel<arend@xxxxxxxxxxxx>
> Actually, my attempt was triggered by the trace-cmd manual page:
> "-f filter
> Specify a filter for the previous event. This must come after a -e. This
> will filter what events get recorded based on the content of the event.
> Filtering is passed to the kernel directly so what filtering is allowed
> may depend on what version of the kernel you have. Basically, it will
> let you use C notation to check if an event should be processed or not.
> ==, >=, <=, >, <, &, |, && and ||
> The above are usually safe to use to compare fields."
Ah thanks. That needs to be updated. Not sure why I wrote all of them.
Perhaps because the report side handles them and I just assumed the
kernel did too.
> > Tested-by: Arend van Spriel<arend@xxxxxxxxxxxx>
> > Signed-off-by: Steven Rostedt<rostedt@xxxxxxxxxxx>
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