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From: Ravi Bangoria <ravi.bangoria@amd.com>
To: Arnaldo Carvalho de Melo <acme@kernel.org>,
	Namhyung Kim <namhyung@kernel.org>,
	Ian Rogers <irogers@google.com>
Cc: Ravi Bangoria <ravi.bangoria@amd.com>,
	Peter Zijlstra <peterz@infradead.org>,
	Ingo Molnar <mingo@redhat.com>,
	Dapeng Mi <dapeng1.mi@linux.intel.com>,
	James Clark <james.clark@linaro.org>, <x86@kernel.org>,
	<linux-perf-users@vger.kernel.org>,
	<linux-kernel@vger.kernel.org>,
	Manali Shukla <manali.shukla@amd.com>,
	Santosh Shukla <santosh.shukla@amd.com>,
	Ananth Narayan <ananth.narayan@amd.com>,
	Sandipan Das <sandipan.das@amd.com>
Subject: [PATCH v2 3/8] perf test ibs: Remove obsolete privilege test
Date: Thu, 30 Apr 2026 06:11:10 +0000	[thread overview]
Message-ID: <20260430061115.10266-4-ravi.bangoria@amd.com> (raw)
In-Reply-To: <20260430061115.10266-1-ravi.bangoria@amd.com>

Older IBS implementations lacked a hardware privilege filter, so the
kernel enabled swfilt=1. Newer AMD CPUs will provide privilege filtering
via the RIP[63] bit, making swfilt redundant. Remove the perf unit test
that assumes IBS has no hardware-assisted privilege filter.

swfilt is ignored by kernel on platforms that support RIP[63] bit filter
i.e. all amd-ibs-swfilt.sh tests will test hardware assisted privilege
filter.

Without the patch:

  # ./perf test -vv 75
  test child forked, pid 26029
  check availability of IBS swfilt
  run perf record with modifier and swfilt
  [FAIL] IBS PMU should not accept exclude_kernel
   75: AMD IBS software filtering                            : FAILED!

With the patch:

  # ./perf test -vv 75
  check availability of IBS swfilt
  run perf record with modifier and swfilt
  [ perf record: Woken up 3 times to write data ]
  [ perf record: Captured and wrote 0.000 MB /dev/null ]
  [ perf record: Woken up 3 times to write data ]
  [ perf record: Captured and wrote 0.000 MB /dev/null ]
  [ perf record: Woken up 3 times to write data ]
  [ perf record: Captured and wrote 0.000 MB /dev/null ]
  [ perf record: Woken up 1 times to write data ]
  [ perf record: Captured and wrote 0.000 MB /dev/null ]
  check number of samples with swfilt
  [ perf record: Woken up 5 times to write data ]
  [ perf record: Captured and wrote 0.040 MB - ]
  [ perf record: Woken up 3 times to write data ]
  [ perf record: Captured and wrote 0.054 MB - ]
   75: AMD IBS software filtering                            : Ok

Signed-off-by: Ravi Bangoria <ravi.bangoria@amd.com>
---
 tools/perf/tests/shell/amd-ibs-swfilt.sh | 7 -------
 1 file changed, 7 deletions(-)

diff --git a/tools/perf/tests/shell/amd-ibs-swfilt.sh b/tools/perf/tests/shell/amd-ibs-swfilt.sh
index e7f66df05c4b..92ef45bf3043 100755
--- a/tools/perf/tests/shell/amd-ibs-swfilt.sh
+++ b/tools/perf/tests/shell/amd-ibs-swfilt.sh
@@ -22,13 +22,6 @@ fi
 echo "run perf record with modifier and swfilt"
 err=0
 
-# setting any modifiers should fail
-perf record -B -e ibs_op//u -o /dev/null true 2> /dev/null
-if [ $? -eq 0 ]; then
-    echo "[FAIL] IBS PMU should not accept exclude_kernel"
-    exit 1
-fi
-
 # setting it with swfilt should be fine
 perf record -B -e ibs_op/swfilt/u -o /dev/null true
 if [ $? -ne 0 ]; then
-- 
2.43.0


  parent reply	other threads:[~2026-04-30  6:11 UTC|newest]

Thread overview: 11+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2026-04-30  6:11 [PATCH v2 0/8] perf tools amd ibs: Fixes + Zen6 enhancements Ravi Bangoria
2026-04-30  6:11 ` [PATCH v2 1/8] perf test amd ibs: Fix incorrect kernel version check Ravi Bangoria
2026-04-30  6:11 ` [PATCH v2 2/8] perf tool ibs: Sync AMD IBS header file Ravi Bangoria
2026-04-30  6:11 ` Ravi Bangoria [this message]
2026-05-08  0:24   ` [PATCH v2 3/8] perf test ibs: Remove obsolete privilege test Namhyung Kim
2026-05-08  6:05     ` Ravi Bangoria
2026-04-30  6:11 ` [PATCH v2 4/8] perf amd ibs: Suppress bogus TlbRefillLat and DCPhysAd on Zen4+ Ravi Bangoria
2026-04-30  6:11 ` [PATCH v2 5/8] perf amd ibs: Make Fetch status bits dependent on PhyAddrValid for newer platforms Ravi Bangoria
2026-04-30  6:11 ` [PATCH v2 6/8] perf amd ibs: Decode Remote-Socket flag in IBS OP raw dump Ravi Bangoria
2026-04-30  6:11 ` [PATCH v2 7/8] perf amd ibs: Decode Streaming-store " Ravi Bangoria
2026-04-30  6:11 ` [PATCH v2 8/8] perf doc: Document new IBS capabilities in man page Ravi Bangoria

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