mbox series

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

Message ID 20200219021811.20067-1-leo.yan@linaro.org (mailing list archive)
Headers show
Series perf cs-etm: Fix synthesizing instruction samples | expand

Message

Leo Yan Feb. 19, 2020, 2:18 a.m. UTC
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(-)

Comments

Leo Yan March 10, 2020, 5:43 a.m. UTC | #1
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
>
Arnaldo Carvalho de Melo March 10, 2020, 11:45 a.m. UTC | #2
Em Tue, Mar 10, 2020 at 01:43:05PM +0800, Leo Yan escreveu:
> 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!

Thanks, all build tested on x86 and arm64 (with CORESIGHT=1, etc), applied.

- Arnaldo
Leo Yan March 10, 2020, 12:01 p.m. UTC | #3
On Tue, Mar 10, 2020 at 08:45:03AM -0300, Arnaldo Carvalho de Melo wrote:

[...]

> > 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!
> 
> Thanks, all build tested on x86 and arm64 (with CORESIGHT=1, etc), applied.

Thank you, Arnaldo.

Leo