From 5ad628a7617607baac53745f8025638b967470a2 Mon Sep 17 00:00:00 2001 From: James Clark Date: Mon, 22 Jul 2024 11:11:56 +0100 Subject: coresight: Use per-sink trace ID maps for Perf sessions This will allow sessions with more than CORESIGHT_TRACE_IDS_MAX ETMs as long as there are fewer than that many ETMs connected to each sink. Each sink owns its own trace ID map, and any Perf session connecting to that sink will allocate from it, even if the sink is currently in use by other users. This is similar to the existing behavior where the dynamic trace IDs are constant as long as there is any concurrent Perf session active. It's not completely optimal because slightly more IDs will be used than necessary, but the optimal solution involves tracking the PIDs of each session and allocating ID maps based on the session owner. This is difficult to do with the combination of per-thread and per-cpu modes and some scheduling issues. The complexity of this isn't likely to worth it because even with multiple users they'd just see a difference in the ordering of ID allocations rather than hitting any limits (unless the hardware does have too many ETMs connected to one sink). Signed-off-by: James Clark Reviewed-by: Mike Leach Signed-off-by: James Clark Signed-off-by: Suzuki K Poulose Link: https://lore.kernel.org/r/20240722101202.26915-15-james.clark@linaro.org --- include/linux/coresight.h | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) (limited to 'include/linux') diff --git a/include/linux/coresight.h b/include/linux/coresight.h index 7d62b88bfb5c..9c3067e2e38b 100644 --- a/include/linux/coresight.h +++ b/include/linux/coresight.h @@ -290,6 +290,7 @@ struct coresight_device { bool sysfs_sink_activated; struct dev_ext_attribute *ea; struct coresight_device *def_sink; + struct coresight_trace_id_map perf_sink_id_map; /* sysfs links between components */ int nr_links; bool has_conns_grp; @@ -384,7 +385,7 @@ struct coresight_ops_link { struct coresight_ops_source { int (*cpu_id)(struct coresight_device *csdev); int (*enable)(struct coresight_device *csdev, struct perf_event *event, - enum cs_mode mode); + enum cs_mode mode, struct coresight_trace_id_map *id_map); void (*disable)(struct coresight_device *csdev, struct perf_event *event); }; -- cgit v1.2.3