Messages in this thread | | | From | Alexander Shishkin <> | Subject | [PATCH v0 0/5] perf: Introduce instruction trace filtering | Date | Fri, 11 Dec 2015 15:36:33 +0200 |
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Hi Peter,
Newer version of Intel PT supports address-based filtering, and this patchset adds support for it to perf core and the PT pmu driver. It works by configuring a number of address ranges in hardware and telling it to use these ranges to filter its traces. Similar feature also exists in ARM Coresight ETM/PTM and it is also taken into account in this patchset.
Firstly, userspace configures filters via an ioctl(), filters are formatted as an ascii string. Filters may refer to addresses in object files for userspace code or kernel addresses. The latter might be extended in the future to support kernel modules.
For userspace filters, we scan the task's vmas to see if any of them match the defined filters (inode+offset) and if they do, calculate memory offsets and program them into hardware. Note that since different tasks will have different mappings for the same object files, supporting cpu-wide events would require special tricks to context-switch filters for userspace code.
Also, we monitor new mmap and exec events to update (or clear) filter configuration.
This is based on my perf_mmap_close() patchset from yesterday [1], which in turn is based on your perf/core queue.
[1] http://marc.info/?l=linux-kernel&m=144976438631073
Alexander Shishkin (5): perf: Move set_filter() from behind EVENT_TRACING perf: Extend perf_event_aux() to optionally iterate through more events perf: Introduce instruction trace filtering perf/x86/intel/pt: IP filtering register/cpuid bits perf/x86/intel/pt: Add support for instruction trace filtering in PT
arch/x86/include/asm/msr-index.h | 18 + arch/x86/kernel/cpu/intel_pt.h | 32 +- arch/x86/kernel/cpu/perf_event_intel_pt.c | 134 +++++- include/linux/perf_event.h | 40 ++ kernel/events/core.c | 655 ++++++++++++++++++++++++++++-- 5 files changed, 835 insertions(+), 44 deletions(-)
-- 2.6.2
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