Re: [PATCH v1 4/5] perf: Introduce address range filtering

From: Peter Zijlstra
Date: Mon Apr 25 2016 - 10:25:15 EST


On Fri, Apr 22, 2016 at 07:19:11PM +0300, Alexander Shishkin wrote:
> +/*
> + * Address range filtering: limiting the data to certain
> + * instruction address ranges. Filters are ioctl()ed to us from
> + * userspace as ascii strings.
> + *
> + * Filter string format:
> + *
> + * ACTION SOURCE:RANGE_SPEC
> + * where ACTION is one of the
> + * * "filter": limit the trace to this region
> + * * "start": start tracing from this address
> + * * "stop": stop tracing at this address/region;
> + * SOURCE is either "file" or "kernel"
> + * RANGE_SPEC is
> + * * for "kernel": <start address>[/<size>]
> + * * for "file": <start address>[/<size>]@</path/to/object/file>

SOURCE seems entirely redundant

> + *
> + * if <size> is not specified, the range is treated as a single address.

single instruction, right?