linux-kernel - Re: [PATCH 01/11] perf/amd/ibs: Throttle interrupts with filtered ldlat samples

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Message-ID: <d686a873-6257-4f6b-ba43-22d49ebca1bd@amd.com>
Date: Mon, 19 Jan 2026 18:26:56 +0530
From: Ravi Bangoria <ravi.bangoria@....com>
To: "Mi, Dapeng" <dapeng1.mi@...ux.intel.com>
CC: Peter Zijlstra <peterz@...radead.org>, Ingo Molnar <mingo@...hat.com>,
	Arnaldo Carvalho de Melo <acme@...nel.org>, Namhyung Kim
	<namhyung@...nel.org>, Ian Rogers <irogers@...gle.com>, James Clark
	<james.clark@...aro.org>, <x86@...nel.org>,
	<linux-perf-users@...r.kernel.org>, <linux-kernel@...r.kernel.org>, "Manali
 Shukla" <manali.shukla@....com>, Santosh Shukla <santosh.shukla@....com>,
	Ananth Narayan <ananth.narayan@....com>, Sandipan Das <sandipan.das@....com>
Subject: Re: [PATCH 01/11] perf/amd/ibs: Throttle interrupts with filtered
 ldlat samples

Hi Dapeng,

>> diff --git a/arch/x86/events/amd/ibs.c b/arch/x86/events/amd/ibs.c
>> index aca89f23d2e0..96bb0974057f 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;
>> +		}
>>  	}
> 
> Not quite familiar with IBS code, but should the below code call the
> throttle as well?
> 
>         /* Workaround for erratum #1197 */
>         if (perf_ibs->fetch_ignore_if_zero_rip && !(ibs_data.regs[1]))
>             goto out;
> 

Yes, it should. I'll add a patch in next version.

Thanks,
Ravi