Re: [PATCH v5 0/5] perf cs-etm: Fix synthesizing instruction samples

[Leo Yan]

Hi Arnaldo,

On Wed, Feb 19, 2020 at 10:18:06AM +0800, Leo Yan wrote:
> 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

Could you pick up this patch set?  I confirmed this patch set can
cleanly apply on top of the latest mainline kernel (5.6-rc5).

Or if you want me to resend this patch set, please feel free let me
know.  Thanks!

Leo

> 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(-)
> 
> -- 
> 2.17.1
>