From: James Clark <james.clark@arm.com>
To: coresight@lists.linaro.org, suzuki.poulose@arm.com,
gankulkarni@os.amperecomputing.com, mike.leach@linaro.org,
leo.yan@linux.dev, anshuman.khandual@arm.com
Cc: James Clark <james.clark@arm.com>,
Alexander Shishkin <alexander.shishkin@linux.intel.com>,
Maxime Coquelin <mcoquelin.stm32@gmail.com>,
Alexandre Torgue <alexandre.torgue@foss.st.com>,
Peter Zijlstra <peterz@infradead.org>,
Ingo Molnar <mingo@redhat.com>,
Arnaldo Carvalho de Melo <acme@kernel.org>,
Namhyung Kim <namhyung@kernel.org>,
Mark Rutland <mark.rutland@arm.com>, Jiri Olsa <jolsa@kernel.org>,
Ian Rogers <irogers@google.com>,
Adrian Hunter <adrian.hunter@intel.com>,
John Garry <john.g.garry@oracle.com>,
Will Deacon <will@kernel.org>,
linux-arm-kernel@lists.infradead.org,
linux-kernel@vger.kernel.org,
linux-stm32@st-md-mailman.stormreply.com,
linux-perf-users@vger.kernel.org
Subject: [PATCH v2 09/16] coresight: Clarify comments around the PID of the sink owner
Date: Tue, 4 Jun 2024 15:30:18 +0100 [thread overview]
Message-ID: <20240604143030.519906-10-james.clark@arm.com> (raw)
In-Reply-To: <20240604143030.519906-1-james.clark@arm.com>
"Process being monitored" and "pid of the process to monitor" imply that
this would be the same PID if there were two sessions targeting the same
process. But this is actually the PID of the process that did the Perf
event open call, rather than the target of the session. So update the
comments to make this clearer.
Reviewed-by: Anshuman Khandual <anshuman.khandual@arm.com>
Reviewed-by: Mike Leach <mike.leach@linaro.org>
Signed-off-by: James Clark <james.clark@arm.com>
---
drivers/hwtracing/coresight/coresight-tmc-etr.c | 5 +++--
drivers/hwtracing/coresight/coresight-tmc.h | 5 +++--
2 files changed, 6 insertions(+), 4 deletions(-)
diff --git a/drivers/hwtracing/coresight/coresight-tmc-etr.c b/drivers/hwtracing/coresight/coresight-tmc-etr.c
index e75428fa1592..8962fc27d04f 100644
--- a/drivers/hwtracing/coresight/coresight-tmc-etr.c
+++ b/drivers/hwtracing/coresight/coresight-tmc-etr.c
@@ -36,7 +36,8 @@ struct etr_buf_hw {
* etr_perf_buffer - Perf buffer used for ETR
* @drvdata - The ETR drvdaga this buffer has been allocated for.
* @etr_buf - Actual buffer used by the ETR
- * @pid - The PID this etr_perf_buffer belongs to.
+ * @pid - The PID of the session owner that etr_perf_buffer
+ * belongs to.
* @snaphost - Perf session mode
* @nr_pages - Number of pages in the ring buffer.
* @pages - Array of Pages in the ring buffer.
@@ -1662,7 +1663,7 @@ static int tmc_enable_etr_sink_perf(struct coresight_device *csdev, void *data)
goto unlock_out;
}
- /* Get a handle on the pid of the process to monitor */
+ /* Get a handle on the pid of the session owner */
pid = etr_perf->pid;
/* Do not proceed if this device is associated with another session */
diff --git a/drivers/hwtracing/coresight/coresight-tmc.h b/drivers/hwtracing/coresight/coresight-tmc.h
index c77763b49de0..2671926be62a 100644
--- a/drivers/hwtracing/coresight/coresight-tmc.h
+++ b/drivers/hwtracing/coresight/coresight-tmc.h
@@ -171,8 +171,9 @@ struct etr_buf {
* @csdev: component vitals needed by the framework.
* @miscdev: specifics to handle "/dev/xyz.tmc" entry.
* @spinlock: only one at a time pls.
- * @pid: Process ID of the process being monitored by the session
- * that is using this component.
+ * @pid: Process ID of the process that owns the session that is using
+ * this component. For example this would be the pid of the Perf
+ * process.
* @buf: Snapshot of the trace data for ETF/ETB.
* @etr_buf: details of buffer used in TMC-ETR
* @len: size of the available trace for ETF/ETB.
--
2.34.1
next prev parent reply other threads:[~2024-06-04 14:32 UTC|newest]
Thread overview: 28+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-06-04 14:30 [PATCH v2 00/16] coresight: Use per-sink trace ID maps for Perf sessions James Clark
2024-06-04 14:30 ` [PATCH v2 01/16] perf cs-etm: Print error for new PERF_RECORD_AUX_OUTPUT_HW_ID versions James Clark
2024-06-04 14:30 ` [PATCH v2 02/16] perf auxtrace: Allow number of queues to be specified James Clark
2024-06-05 5:26 ` Adrian Hunter
2024-06-05 8:19 ` James Clark
2024-06-04 14:30 ` [PATCH v2 03/16] perf: cs-etm: Create decoders after both AUX and HW_ID search passes James Clark
2024-06-04 14:30 ` [PATCH v2 04/16] perf: cs-etm: Allocate queues for all CPUs James Clark
2024-06-04 14:30 ` [PATCH v2 05/16] perf: cs-etm: Move traceid_list to each queue James Clark
2024-06-04 14:30 ` [PATCH v2 06/16] perf: cs-etm: Create decoders based on the trace ID mappings James Clark
2024-06-04 14:30 ` [PATCH v2 07/16] perf: cs-etm: Support version 0.1 of HW_ID packets James Clark
2024-06-04 14:30 ` [PATCH v2 08/16] coresight: Remove unused ETM Perf stubs James Clark
2024-06-04 14:30 ` James Clark [this message]
2024-06-04 14:30 ` [PATCH v2 10/16] coresight: Move struct coresight_trace_id_map to common header James Clark
2024-06-04 14:30 ` [PATCH v2 11/16] coresight: Expose map arguments in trace ID API James Clark
2024-06-06 13:50 ` Suzuki K Poulose
2024-06-06 14:10 ` James Clark
2024-06-04 14:30 ` [PATCH v2 12/16] coresight: Make CPU id map a property of a trace ID map James Clark
2024-06-04 14:30 ` [PATCH v2 13/16] coresight: Use per-sink trace ID maps for Perf sessions James Clark
2024-06-07 13:18 ` Suzuki K Poulose
2024-06-07 13:40 ` James Clark
2024-06-04 14:30 ` [PATCH v2 14/16] coresight: Remove pending trace ID release mechanism James Clark
2024-06-07 13:43 ` Suzuki K Poulose
2024-06-10 15:27 ` James Clark
2024-06-04 14:30 ` [PATCH v2 15/16] coresight: Re-emit trace IDs when the sink changes in per-thread mode James Clark
2024-06-10 10:29 ` Suzuki K Poulose
2024-06-10 14:05 ` James Clark
2024-06-04 14:30 ` [PATCH v2 16/16] coresight: Emit sink ID in the HW_ID packets James Clark
2024-06-05 20:35 ` [PATCH v2 00/16] coresight: Use per-sink trace ID maps for Perf sessions Leo Yan
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