Messages in this thread | | | Subject | Re: [PATCH net-next 1/3] perf: generalize perf_callchain | From | Alexei Starovoitov <> | Date | Thu, 25 Feb 2016 08:37:34 -0800 |
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On 2/25/16 6:18 AM, Peter Zijlstra wrote: > On Wed, Feb 17, 2016 at 07:58:57PM -0800, Alexei Starovoitov wrote: >> . avoid walking the stack when there is no room left in the buffer >> . generalize get_perf_callchain() to be called from bpf helper > > If it does two things it should be two patches.
could have been two patches, but it will only add more churn to the same lines. what's the concern?
>> Signed-off-by: Alexei Starovoitov <ast@kernel.org> >> --- >> arch/x86/include/asm/stacktrace.h | 2 +- >> arch/x86/kernel/cpu/perf_event.c | 4 ++-- >> arch/x86/kernel/dumpstack.c | 6 ++++-- >> arch/x86/kernel/stacktrace.c | 18 +++++++++++------- >> arch/x86/oprofile/backtrace.c | 3 ++- >> include/linux/perf_event.h | 13 +++++++++++-- >> kernel/events/callchain.c | 32 ++++++++++++++++++++------------ >> kernel/events/internal.h | 2 -- >> 8 files changed, 51 insertions(+), 29 deletions(-) > > And at the very least this should have had a note that it doesn't break > all the other archs that implement perf-callchain stuff.
the cross-arch interface is two weak functions perf_callchain_kernel() and perf_callchain_user() and back into generic via perf_callchain_store(). Nothing changes there. The code speaks for itself. "non-x86 archs are not broken" would be a silly comment.
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