Peter Zijlstra <[email protected]> writes: > On Thu, Feb 06, 2014 at 12:50:30PM +0200, Alexander Shishkin wrote: >> Add support for Intel Processor Trace (PT) to kernel's perf/itrace events. >> PT is an extension of Intel Architecture that collects information about >> software execuction such as control flow, execution modes and timings and >> formats it into highly compressed binary packets. Even being compressed, >> these packets are generated at hundreds of megabytes per second per core, >> which makes it impractical to decode them on the fly in the kernel. Thus, >> buffers containing this binary stream are zero-copy mapped to the debug >> tools in userspace for subsequent decoding and analysis. >> >> Signed-off-by: Alexander Shishkin <[email protected]> >> --- >> arch/x86/include/uapi/asm/msr-index.h | 18 + >> arch/x86/kernel/cpu/Makefile | 1 + >> arch/x86/kernel/cpu/intel_pt.h | 127 ++++ >> arch/x86/kernel/cpu/perf_event.c | 4 + >> arch/x86/kernel/cpu/perf_event_intel.c | 10 + >> arch/x86/kernel/cpu/perf_event_intel_pt.c | 991 >> ++++++++++++++++++++++++++++++ >> 6 files changed, 1151 insertions(+) >> create mode 100644 arch/x86/kernel/cpu/intel_pt.h >> create mode 100644 arch/x86/kernel/cpu/perf_event_intel_pt.c > > Andi said that when itrace is enabled the LBR is wrecked; this patch > seems to fail to deal with that.
True, there needs to be a _safe() msr access before any configuration is done, I have a fix for that, but let's first deal with the buffer management. Regards, -- Alex -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
