This patch series is to address issues for synthesizing instruction samples, especially when the instruction sample period is small enough, the current logic cannot synthesize multiple instruction samples within one instruction range packet.
Patch 0001 is to swap packets for instruction samples, so this allow option '--itrace=iNNN' can work well.
Patch 0002 avoids to reset the last branches for every instruction sample; if reset the last branches for every time generating sample, the later samples in the same range packet cannot use the last branches anymore.
Patch 0003 is the fixing for handling different instruction periods, especially for small sample period.
Patch 0004 is an optimization for copying last branches; it only copies last branches once if the instruction samples share the same last branches.
Patch 0005 is a minor fix for unsigned variable comparison to zero.
This patch set has been rebased on the latest perf/core branch; and verified on Juno board with below commands:
# perf script --itrace=i2 # perf script --itrace=i2il16 # perf inject --itrace=i2il16 -i perf.data -o perf.data.new # perf inject --itrace=i100il16 -i perf.data -o perf.data.new
Changes from v4: * Added Mike's review tag for patch 03; * Added Mathieu's review tags for all patches.
Changes from v3: * Refactored patch 0001 with new function cs_etm__packet_swap() (Mike); * Refined instruction sample generation flow with single while loop, which completely uses Mike's suggestions (Mike); * Added Mike's review tags for patch 01/02/04/05.
Changes from v2: * Added patch 0001 which is to fix swapping packets for instruction samples; * Refined minor commit logs and comments; * Rebased on the latest perf/core branch.
Changes from v1: * Rebased patch set on perf/core branch with latest commit 9fec3cd5fa4a ("perf map: Check if the map still has some refcounts on exit").
Leo Yan (5): perf cs-etm: Swap packets for instruction samples perf cs-etm: Continuously record last branch perf cs-etm: Correct synthesizing instruction samples perf cs-etm: Optimize copying last branches perf cs-etm: Fix unsigned variable comparison to zero
tools/perf/util/cs-etm.c | 157 +++++++++++++++++++++++++++------------ 1 file changed, 111 insertions(+), 46 deletions(-)