Commit-ID: 2055fdaf8703d3101b12e0d9b7cbceaeabe35c17 Gitweb: http://git.kernel.org/tip/2055fdaf8703d3101b12e0d9b7cbceaeabe35c17 Author: Robert Richter <robert.richter@xxxxxxx> AuthorDate: Tue, 7 Aug 2012 19:43:16 +0200 Committer: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx> CommitDate: Wed, 8 Aug 2012 12:42:21 -0300 perf list: Document precise event sampling for AMD IBS Updating man perf-list. Signed-off-by: Robert Richter <robert.richter@xxxxxxx> Cc: Ingo Molnar <mingo@xxxxxxxxxx> Link: http://lkml.kernel.org/r/1344361396-7237-7-git-send-email-robert.richter@xxxxxxx Signed-off-by: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx> --- tools/perf/Documentation/perf-list.txt | 42 ++++++++++++++++++++++--------- 1 files changed, 30 insertions(+), 12 deletions(-) diff --git a/tools/perf/Documentation/perf-list.txt b/tools/perf/Documentation/perf-list.txt index 232be51..d1e39dc 100644 --- a/tools/perf/Documentation/perf-list.txt +++ b/tools/perf/Documentation/perf-list.txt @@ -20,20 +20,38 @@ EVENT MODIFIERS --------------- Events can optionally have a modifer by appending a colon and one or -more modifiers. Modifiers allow the user to restrict when events are -counted with 'u' for user-space, 'k' for kernel, 'h' for hypervisor. -Additional modifiers are 'G' for guest counting (in KVM guests) and 'H' -for host counting (not in KVM guests). +more modifiers. Modifiers allow the user to restrict the events to be +counted. The following modifiers exist: + + u - user-space counting + k - kernel counting + h - hypervisor counting + G - guest counting (in KVM guests) + H - host counting (not in KVM guests) + p - precise level The 'p' modifier can be used for specifying how precise the instruction -address should be. The 'p' modifier is currently only implemented for -Intel PEBS and can be specified multiple times: - 0 - SAMPLE_IP can have arbitrary skid - 1 - SAMPLE_IP must have constant skid - 2 - SAMPLE_IP requested to have 0 skid - 3 - SAMPLE_IP must have 0 skid +address should be. The 'p' modifier can be specified multiple times: + + 0 - SAMPLE_IP can have arbitrary skid + 1 - SAMPLE_IP must have constant skid + 2 - SAMPLE_IP requested to have 0 skid + 3 - SAMPLE_IP must have 0 skid + +For Intel systems precise event sampling is implemented with PEBS +which supports up to precise-level 2. + +On AMD systems it is implemented using IBS (up to precise-level 2). +The precise modifier works with event types 0x76 (cpu-cycles, CPU +clocks not halted) and 0xC1 (micro-ops retired). Both events map to +IBS execution sampling (IBS op) with the IBS Op Counter Control bit +(IbsOpCntCtl) set respectively (see AMD64 Architecture Programmer’s +Manual Volume 2: System Programming, 13.3 Instruction-Based +Sampling). Examples to use IBS: -The PEBS implementation now supports up to 2. + perf record -a -e cpu-cycles:p ... # use ibs op counting cycles + perf record -a -e r076:p ... # same as -e cpu-cycles:p + perf record -a -e r0C1:p ... # use ibs op counting micro-ops RAW HARDWARE EVENT DESCRIPTOR ----------------------------- @@ -97,4 +115,4 @@ SEE ALSO linkperf:perf-stat[1], linkperf:perf-top[1], linkperf:perf-record[1], http://www.intel.com/Assets/PDF/manual/253669.pdf[Intel®; 64 and IA-32 Architectures Software Developer's Manual Volume 3B: System Programming Guide], -http://support.amd.com/us/Processor_TechDocs/24593.pdf[AMD64 Architecture Programmer’s Manual Volume 2: System Programming] +http://support.amd.com/us/Processor_TechDocs/24593_APM_v2.pdf[AMD64 Architecture Programmer’s Manual Volume 2: System Programming] -- To unsubscribe from this list: send the line "unsubscribe linux-tip-commits" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
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