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docs: perf: Add new description on HiSilicon uncore PMU v2 

Some news functions are added on HiSilicon uncore PMUs. Document them
to provide guidance on how to use them.

Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Will Deacon <will@kernel.org>
Cc: John Garry <john.garry@huawei.com>
Cc: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Reviewed-by: John Garry <john.garry@huawei.com>
Co-developed-by: Qi Liu <liuqi115@huawei.com>
Signed-off-by: Qi Liu <liuqi115@huawei.com>
Signed-off-by: Shaokun Zhang <zhangshaokun@hisilicon.com>
Link: https://lore.kernel.org/r/1615186237-22263-10-git-send-email-zhangshaokun@hisilicon.com
Signed-off-by: Will Deacon <will@kernel.org>
This commit is contained in:
Shaokun Zhang 2021-03-08 14:50:37 +08:00 committed by Will Deacon
parent a0ab25cd82
commit 9b86b1b41e
1 changed files with 49 additions and 0 deletions
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49
Documentation/admin-guide/perf/hisi-pmu.rst
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@ -53,6 +53,55 @@ Example usage of perf::
$# perf stat -a -e hisi_sccl3_l3c0/rd_hit_cpipe/ sleep 5
$# perf stat -a -e hisi_sccl3_l3c0/config=0x02/ sleep 5
For HiSilicon uncore PMU v2 whose identifier is 0x30, the topology is the same
as PMU v1, but some new functions are added to the hardware.
(a) L3C PMU supports filtering by core/thread within the cluster which can be
specified as a bitmap.
$# perf stat -a -e hisi_sccl3_l3c0/config=0x02,tt_core=0x3/ sleep 5
This will only count the operations from core/thread 0 and 1 in this cluster.
(b) Tracetag allow the user to chose to count only read, write or atomic
operations via the tt_req parameeter in perf. The default value counts all
operations. tt_req is 3bits, 3'b100 represents read operations, 3'b101
represents write operations, 3'b110 represents atomic store operations and
3'b111 represents atomic non-store operations, other values are reserved.
$# perf stat -a -e hisi_sccl3_l3c0/config=0x02,tt_req=0x4/ sleep 5
This will only count the read operations in this cluster.
(c) Datasrc allows the user to check where the data comes from. It is 5 bits.
Some important codes are as follows:
5'b00001: comes from L3C in this die;
5'b01000: comes from L3C in the cross-die;
5'b01001: comes from L3C which is in another socket;
5'b01110: comes from the local DDR;
5'b01111: comes from the cross-die DDR;
5'b10000: comes from cross-socket DDR;
etc, it is mainly helpful to find that the data source is nearest from the CPU
cores. If datasrc_cfg is used in the multi-chips, the datasrc_skt shall be
configured in perf command.
$# perf stat -a -e hisi_sccl3_l3c0/config=0xb9,datasrc_cfg=0xE/,
hisi_sccl3_l3c0/config=0xb9,datasrc_cfg=0xF/ sleep 5
(d)Some HiSilicon SoCs encapsulate multiple CPU and IO dies. Each CPU die
contains several Compute Clusters (CCLs). The I/O dies are called Super I/O
clusters (SICL) containing multiple I/O clusters (ICLs). Each CCL/ICL in the
SoC has a unique ID. Each ID is 11bits, include a 6-bit SCCL-ID and 5-bit
CCL/ICL-ID. For I/O die, the ICL-ID is followed by:
5'b00000: I/O_MGMT_ICL;
5'b00001: Network_ICL;
5'b00011: HAC_ICL;
5'b10000: PCIe_ICL;
Users could configure IDs to count data come from specific CCL/ICL, by setting
srcid_cmd & srcid_msk, and data desitined for specific CCL/ICL by setting
tgtid_cmd & tgtid_msk. A set bit in srcid_msk/tgtid_msk means the PMU will not
check the bit when matching against the srcid_cmd/tgtid_cmd.
If all of these options are disabled, it can works by the default value that
doesn't distinguish the filter condition and ID information and will return
the total counter values in the PMU counters.
The current driver does not support sampling. So "perf record" is unsupported.
Also attach to a task is unsupported as the events are all uncore.