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perf/amd/ibs: Account interrupt for discarded samples

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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.

Fixes: 26db2e0c51 ("perf/x86/amd/ibs: Work around erratum #1197")
Fixes: d20610c19b ("perf/amd/ibs: Add support for OP Load Latency Filtering")
Signed-off-by: Ravi Bangoria <ravi.bangoria@amd.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Namhyung Kim <namhyung@kernel.org>
Link: https://patch.msgid.link/20260216042216.1440-2-ravi.bangoria@amd.com
This commit is contained in:
Ravi Bangoria 2026-02-16 04:22:12 +00:00 committed by Peter Zijlstra
parent da45c8d5f0
commit 01336b5559
1 changed files with 6 additions and 2 deletions
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8
arch/x86/events/amd/ibs.c
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@ -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;