Re: [PATCH v2 1/5] perf/amd/ibs: Account interrupt for discarded samples

[Michael Petlan]

Hi Ravi,

On Mon, 16 Feb 2026, Ravi Bangoria wrote:
> Add interrupt throttling accounting for below cases:
> 
>   o IBS Op PMU: A software filter (in addition to the hardware filter)
>     drops samples whose load latency is below the user-specified
>     threshold.
> 
>   o IBS Fetch PMU: Samples discarded due to the zero-RIP erratum (#1197).
> 
> Although these samples are discarded, the NMI cost is still incurred, so
> they should be counted for interrupt throttling.
> 

Maybe worth tagging

Fixes: 26db2e0c51fe83e1dd852c1321407835b481806e ("perf/x86/amd/ibs: Work around erratum #1197")
Fixes: d20610c19b4a22bc69085b7eb7a02741d51de30e ("perf/amd/ibs: Add support for OP Load Latency Filtering")

?

Cheers,
Michael

> Signed-off-by: Ravi Bangoria <ravi.bangoria@xxxxxxx>
> ---
>  arch/x86/events/amd/ibs.c | 8 ++++++--
>  1 file changed, 6 insertions(+), 2 deletions(-)
> 
> diff --git a/arch/x86/events/amd/ibs.c b/arch/x86/events/amd/ibs.c
> index aca89f23d2e0..705ef43325be 100644
> --- a/arch/x86/events/amd/ibs.c
> +++ b/arch/x86/events/amd/ibs.c
> @@ -1293,8 +1293,10 @@ static int perf_ibs_handle_irq(struct perf_ibs *perf_ibs, struct pt_regs *iregs)
>  		 * within [128, 2048] range.
>  		 */
>  		if (!op_data3.ld_op || !op_data3.dc_miss ||
> -		    op_data3.dc_miss_lat <= (event->attr.config1 & 0xFFF))
> +		    op_data3.dc_miss_lat <= (event->attr.config1 & 0xFFF)) {
> +			throttle = perf_event_account_interrupt(event);
>  			goto out;
> +		}
>  	}
>  
>  	/*
> @@ -1326,8 +1328,10 @@ static int perf_ibs_handle_irq(struct perf_ibs *perf_ibs, struct pt_regs *iregs)
>  		regs.flags &= ~PERF_EFLAGS_EXACT;
>  	} else {
>  		/* Workaround for erratum #1197 */
> -		if (perf_ibs->fetch_ignore_if_zero_rip && !(ibs_data.regs[1]))
> +		if (perf_ibs->fetch_ignore_if_zero_rip && !(ibs_data.regs[1])) {
> +			throttle = perf_event_account_interrupt(event);
>  			goto out;
> +		}
>  
>  		set_linear_ip(&regs, ibs_data.regs[1]);
>  		regs.flags |= PERF_EFLAGS_EXACT;
> -- 
> 2.43.0
> 
> 
>