Re: [patch V6 07/11] rseq: Implement time slice extension enforcement timer

[Peter Zijlstra]

On Fri, Jan 23, 2026 at 05:41:16PM +0000, Prakash Sangappa wrote:

> The database setup is on an older environment. The python script provided does not run as is.
> So, modified it to gather the stats by parsing trace-cmd report output.

I 'wrote' it against this thing:

  https://github.com/rostedt/trace-cmd/blob/master/python/tracecmd.py


> ========================================
> RSEQ SLICE HISTOGRAM (us)
> ========================================
> 
> Task: ora_dbwr_lmb-666257    Mean: 1593.058 ns
>   Latency (us)    | Count
>   ------------------------------
>   EXPIRED         | 3
>   0 us            | 8
>   1 us            | 116
>   2 us            | 25
>   3 us            | 2
>   4 us            | 1
>   7 us            | 1
> 
> Task: ora_dbwd_lmb-666196    Mean: 1548.641 ns
>   Latency (us)    | Count
>   ------------------------------
>   EXPIRED         | 6
>   0 us            | 19
>   1 us            | 203
>   2 us            | 33
>   4 us            | 2
>   5 us            | 1
> 
> 
> [..]
> 
> Task: oracle_668951_l-668951    Mean: 1797.796 ns
>   Latency (us)    | Count
>   ------------------------------
>   1 us            | 5
>   2 us            | 1
>   3 us            | 2
> 
> Task: oracle_671571_l-671571    Mean: 3285.425 ns
>   Latency (us)    | Count
>   ------------------------------
>   1 us            | 1
>   3 us            | 1
>   5 us            | 1
>   6 us            | 1
>   10 us           | 1
> 
> Task: oracle_672277_l-672277    Mean: 2361.600 ns
>   Latency (us)    | Count
>   ------------------------------
>   1 us            | 4
>   2 us            | 3
>   5 us            | 1
>   7 us            | 1
>   9 us            | 1
>   11 us           | 1
> 
> Task: ora_dbwb_lmb-666192    Mean: 1548.157 ns
>   Latency (us)    | Count
>   ------------------------------
>   EXPIRED         | 10
>   0 us            | 24
>   1 us            | 182
>   2 us            | 39
>   3 us            | 2
>   4 us            | 4
>   5 us            | 1
>   14 us           | 1

Thanks! that seems to confirm that 5us should be good enough for you
guys too.