Messages in this thread | | | Date | Thu, 25 Apr 2013 01:08:51 +0200 | Subject | Re: [PATCH V2 1/4] perf: Add hardware breakpoint address mask | From | Frederic Weisbecker <> |
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2013/4/23 Jacob Shin <jacob.shin@amd.com>: > From: Jacob Shin <jacob.shin@amd.com> > Date: Mon, 22 Apr 2013 17:02:37 -0500 > Subject: [PATCH 1/4] perf: Add hardware breakpoint address mask > > Some architectures (for us, AMD Family 16h) allow for "don't care" bit > mask to further qualify a hardware breakpoint address, in order to > trap on range of addresses. Update perf uapi to add bp_addr_mask field.
It would be nice to describe a bit what this "don't care" bit mask is about. Is it a range of address/bitmask to ignore in the middle of the range we want to breakpoint in? I mean, that's confusing.
> > Signed-off-by: Jacob Shin <jacob.shin@amd.com> > --- > include/uapi/linux/perf_event.h | 5 ++++- > kernel/events/hw_breakpoint.c | 9 +++++++++ > 2 files changed, 13 insertions(+), 1 deletion(-) > > diff --git a/include/uapi/linux/perf_event.h b/include/uapi/linux/perf_event.h > index fb104e5..e22e1d1 100644 > --- a/include/uapi/linux/perf_event.h > +++ b/include/uapi/linux/perf_event.h > @@ -286,7 +286,10 @@ struct perf_event_attr { > __u64 config1; /* extension of config */ > }; > union { > - __u64 bp_len; > + struct { > + __u32 bp_len; > + __u32 bp_addr_mask; > + };
Do we need len and mask to work at the same time? I can't think of a situation when len and mask mix up together in a useful way to define a range.
Thanks.
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