perf/amd/ibs: Account interrupt for discarded samples

[ Upstream commit 01336b5 ]

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: 26db2e0 ("perf/x86/amd/ibs: Work around erratum #1197")
Fixes: d20610c ("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
Signed-off-by: Sasha Levin <sashal@kernel.org>

Author: Ravi Bangoria

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;