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boundary="===============1799756741175575242==" Errors-To: lttng-dev-bounces@lists.lttng.org Sender: "lttng-dev" --===============1799756741175575242== Content-Language: en-CA Content-Type: multipart/alternative; boundary="_000_CO1PR03MB59371096D2E4AB93558EA072E5239CO1PR03MB5937namp_" --_000_CO1PR03MB59371096D2E4AB93558EA072E5239CO1PR03MB5937namp_ Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Hello! I've run into an issue with getcpu not having a vsdo implementation and tak= ing anywhere from 600ns to 80us (avg 1 us) when using lttng-ust tracepoints= . I am on lttng v2.13 and kernel version 4.9.253-l4t, running on a jetson (ar= m64). I was digging around and found that rseq might be the recommended nex= t step I am wondering: 1. Are there examples of using rseq system call to replace getcpu 2. Are there any existing patches that I can apply to get better getcpu = performance Thanks in advance, Akhil --_000_CO1PR03MB59371096D2E4AB93558EA072E5239CO1PR03MB5937namp_ Content-Type: text/html; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable
Hello!

I've run into an issue with getcpu not having a vsdo implementation and tak= ing anywhere from 600ns to 80us (avg 1 us) when using lttng-ust tracepoints= . 
I am on lttng v2.13 and kernel version 4.9.253-l4t, running on a jetso= n (arm64). I was digging around and found that rseq might be the recommende= d next step

I am wondering:
  1. Are there examples of using rseq system call to= replace getcpu
  2. Are there any existing patches that I can apply to get better getc= pu performance
Thanks in advance,
Akhil
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