On Fri, 18 Oct 2019 17:02:24 +0300 Georgi Djakov <[email protected]> wrote:
> The tracepoints can help with understanding the system behavior of a > given interconnect path when the consumer drivers change their bandwidth > demands. This might be interesting when we want to monitor the requested > interconnect bandwidth for each client driver. The paths may share the > same nodes and this will help to understand "who and when is requesting > what". All this is useful for subsystem drivers developers and may also > provide hints when optimizing the power and performance profile of the > system. > > Signed-off-by: Georgi Djakov <[email protected]> > --- > MAINTAINERS | 1 + > drivers/interconnect/core.c | 9 +++++ > include/trace/events/interconnect.h | 52 +++++++++++++++++++++++++++++ > 3 files changed, 62 insertions(+) > create mode 100644 include/trace/events/interconnect.h > > diff --git a/MAINTAINERS b/MAINTAINERS > index 55199ef7fa74..c307c4b8f677 100644 > --- a/MAINTAINERS > +++ b/MAINTAINERS > @@ -8526,6 +8526,7 @@ F: drivers/interconnect/ > F: include/dt-bindings/interconnect/ > F: include/linux/interconnect-provider.h > F: include/linux/interconnect.h > +F: include/trace/events/interconnect.h > > INVENSENSE MPU-3050 GYROSCOPE DRIVER > M: Linus Walleij <[email protected]> > diff --git a/drivers/interconnect/core.c b/drivers/interconnect/core.c > index 7b971228df38..e24092558c29 100644 > --- a/drivers/interconnect/core.c > +++ b/drivers/interconnect/core.c > @@ -24,6 +24,9 @@ static LIST_HEAD(icc_providers); > static DEFINE_MUTEX(icc_lock); > static struct dentry *icc_debugfs_dir; > > +#define CREATE_TRACE_POINTS > +#include <trace/events/interconnect.h> > + > /** > * struct icc_req - constraints that are attached to each node > * @req_node: entry in list of requests for the particular @node > @@ -449,6 +452,9 @@ int icc_set_bw(struct icc_path *path, u32 avg_bw, u32 > peak_bw) > > /* aggregate requests for this node */ > aggregate_requests(node); > + > + trace_icc_set_bw(node, dev_name(path->reqs[i].dev), > + avg_bw, peak_bw); BTW, it's best to do the "dev_name()" from the TP_fast_assign() portion. It keeps the work out of the inlined code here. Although it shouldn't be processed within the fast path, it still adds a cache footprint. trace_icc_set_bw(node, path->reqs[i].dev, avg_bw, peak_bw); > } > > ret = apply_constraints(path); > @@ -461,6 +467,9 @@ int icc_set_bw(struct icc_path *path, u32 avg_bw, u32 > peak_bw) > path->reqs[i].avg_bw = old_avg; > path->reqs[i].peak_bw = old_peak; > aggregate_requests(node); > + > + trace_icc_set_bw(node, dev_name(path->reqs[i].dev), > + old_avg, old_peak); > } > apply_constraints(path); > } > diff --git a/include/trace/events/interconnect.h > b/include/trace/events/interconnect.h > new file mode 100644 > index 000000000000..8e001382e9b0 > --- /dev/null > +++ b/include/trace/events/interconnect.h > @@ -0,0 +1,52 @@ > +/* SPDX-License-Identifier: GPL-2.0 */ > +/* > + * Copyright (c) 2019, Linaro Ltd. > + * Author: Georgi Djakov <[email protected]> > + */ > + > +#if !defined(_TRACE_INTERCONNECT_H) || defined(TRACE_HEADER_MULTI_READ) > +#define _TRACE_INTERCONNECT_H > + > +#include <linux/tracepoint.h> > + > +#undef TRACE_SYSTEM > +#define TRACE_SYSTEM interconnect > + > +struct icc_node; > + > +TRACE_EVENT(icc_set_bw, > + > + TP_PROTO(struct icc_node *n, const char *cdev, u32 avg_bw, u32 peak_bw), TP_PROTO(struct icc_node *n, const struct device *cdev, > + > + TP_ARGS(n, cdev, avg_bw, peak_bw), > + > + TP_STRUCT__entry( > + __string(node_name, n->name) > + __field(u32, node_avg_bw) > + __field(u32, node_peak_bw) > + __string(cdev, cdev) __string(cdev, dev_name(cdev)) > + __field(u32, avg_bw) > + __field(u32, peak_bw) > + ), > + > + TP_fast_assign( > + __assign_str(node_name, n->name); > + __entry->node_avg_bw = n->avg_bw; > + __entry->node_peak_bw = n->peak_bw; > + __assign_str(cdev, cdev); __assign_str(cdev, dev_name(cdev)); -- Steve > + __entry->avg_bw = avg_bw; > + __entry->peak_bw = peak_bw; > + ), > + > + TP_printk("%s avg_bw=%u peak_bw=%u cdev=%s avg_bw=%u peak_bw=%u", > + __get_str(node_name), > + __entry->node_avg_bw, > + __entry->node_peak_bw, > + __get_str(cdev), > + __entry->avg_bw, > + __entry->peak_bw) > +); > +#endif /* _TRACE_INTERCONNECT_H */ > + > +/* This part must be outside protection */ > +#include <trace/define_trace.h>
