Re: [GIT PULL v2] hw-breakpoints: Rewrite on top of perf events

Frederic Weisbecker
2009-10-24T14:19:04Z

On Sat, Oct 24, 2009 at 04:16:52PM +0200, Frederic Weisbecker wrote:
> Hi all,
>
> This is the v2 of the hw-breakpoints API rewrite on top of perf events.
> You can find the previous version here:
> http://lwn.net/Articles/351922/
>
> Changes in v2:
>
> - Follow the perf "event " rename
> - The ptrace regression have been fixed (ptrace breakpoint perf events
> weren't released when a task ended)
> - Drop the struct hw_breakpoint and store generic fields in
> perf_event_attr.
> - Separate core and arch specific headers, drop
> asm-generic/hw_breakpoint.h and create linux/hw_breakpoint.h
> - Use new generic len/type for breakpoint
> - Handle off case: when breakpoints api is not supported by an arch
> - Use proper in-kernel perf api provided by Arjan.
>
> There are still a lot of things that need to be cleaned, simplified,
> improved (ptrace side, the bp api, etc....) I guess these things can
> be done incrementally if you agree.
>
> I've also tried to get an arch-independent api. Generic fields for
> breakpoints are stored in perf_event_attr structure (type, len, addr).
> This needs to be discussed and improved before it becomes a perf
> userspace ABI. We need to find a generic enough structure to host
> the breakpoints parameters, something that can better fit to most arch
> (handling breakpoint ranges in powerpc, etc...).
>
> Thanks.
>
> ---
>
> The following patchset are available in the git repository at:
>
> git://git.kernel.org/pub/scm/linux/kernel/git/frederic/random-tracing.git
> perfevents/hw-breakpoint

BTW, this is a branch based on tip:tracing/hw_breakpoint with tip:perf/core
merged inside.