From: Ravi Bangoria <ravi.bangoria@amd.com>
Date: Mon, 16 Feb 2026 04:22:12 +0000 (+0000)
Subject: perf/amd/ibs: Account interrupt for discarded samples
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=01336b5559785a136de1cac49705f63a70a755bc;p=thirdparty%2Fkernel%2Flinux.git

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@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
---

diff --git a/arch/x86/events/amd/ibs.c b/arch/x86/events/amd/ibs.c
index aca89f23d2e00..705ef43325be3 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(&regs, ibs_data.regs[1]);
 		regs.flags |= PERF_EFLAGS_EXACT;