diff options
| author | Shanker Donthineni <sdonthineni@nvidia.com> | 2026-07-31 18:52:43 +0100 |
|---|---|---|
| committer | Will Deacon <will@kernel.org> | 2026-08-02 09:33:43 +0000 |
| commit | 2c43aced9be353f8428678a75495ca9d631dc927 (patch) | |
| tree | 92b3abd04ec1bc699a0ca0b6e64ec4477de605af /tools/perf/scripts/python | |
| parent | 6b4ee75215c9dbcf6a0fd8cf7af2449906e2932c (diff) | |
arm_mpam: Apply T241-MPAM-6 to 63-bit counters
T241-MPAM-6 causes all MBWU counter formats to count 64-byte
requests instead of bytes. Commit dc48eb1ff27c excluded the 63-bit
MSMON_MBWU_LWD format while scaling the shorter counters. Systems
selecting the preferred 63-bit counter consequently report bandwidth
values that are 64 times too small.
Apply the scale to both the sampled value and overflow correction for
the 63-bit format. Unsigned arithmetic retains modulo-u64 behavior
when the scaled counter range exceeds u64.
Fixes: dc48eb1ff27c ("arm_mpam: Add workaround for T241-MPAM-6")
Link: https://lore.kernel.org/lkml/20240816131432.993859-1-sdonthineni@nvidia.com/
Signed-off-by: Shanker Donthineni <sdonthineni@nvidia.com>
Reviewed-by: Fenghua Yu <fenghuay@nvidia.com>
Tested-by: Fenghua Yu <fenghuay@nvidia.com>
Reviewed-by: Ben Horgan <ben.horgan@arm.com>
Signed-off-by: Ben Horgan <ben.horgan@arm.com>
Signed-off-by: Will Deacon <will@kernel.org>
Diffstat (limited to 'tools/perf/scripts/python')
0 files changed, 0 insertions, 0 deletions
