[tip: perf/core] perf/amd/ibs: Account interrupt for discarded samples
From: tip-bot2 for Ravi Bangoria
Date: Sat Feb 28 2026 - 05:59:41 EST
The following commit has been merged into the perf/core branch of tip:
Commit-ID: 01336b5559785a136de1cac49705f63a70a755bc
Gitweb: https://git.kernel.org/tip/01336b5559785a136de1cac49705f63a70a755bc
Author: Ravi Bangoria <ravi.bangoria@xxxxxxx>
AuthorDate: Mon, 16 Feb 2026 04:22:12
Committer: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
CommitterDate: Fri, 27 Feb 2026 16:40:22 +01:00
perf/amd/ibs: Account interrupt for discarded samples
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: 26db2e0c51fe83e1dd852c1321407835b481806e ("perf/x86/amd/ibs: Work around erratum #1197")
Fixes: d20610c19b4a22bc69085b7eb7a02741d51de30e ("perf/amd/ibs: Add support for OP Load Latency Filtering")
Signed-off-by: Ravi Bangoria <ravi.bangoria@xxxxxxx>
Signed-off-by: Peter Zijlstra (Intel) <peterz@xxxxxxxxxxxxx>
Acked-by: Namhyung Kim <namhyung@xxxxxxxxxx>
Link: https://patch.msgid.link/20260216042216.1440-2-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 aca89f2..705ef43 100644
--- a/arch/x86/events/amd/ibs.c
+++ b/arch/x86/events/amd/ibs.c
@@ -1293,8 +1293,10 @@ fail:
* 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 @@ fail:
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(®s, ibs_data.regs[1]);
regs.flags |= PERF_EFLAGS_EXACT;