On Mon, Sep 19, 2022 at 04:46:46PM -0700, Dave Jiang wrote:
> Add common function to iterate through and extract the events in the
> current trace buffer. The function uses tracefs_iterate_raw_events() from
> libtracefs to go through all the events loaded into a tep_handle. A
> callback is provided to the API call in order to parse the event. For cxl
> monitor, an array of interested "systems" is provided in order to filter
> for the interested events.
>
> Signed-off-by: Dave Jiang <[email protected]>
> ---
> cxl/event_trace.c | 33 +++++++++++++++++++++++++++++++++
> cxl/event_trace.h | 7 +++++++
> cxl/meson.build | 1 +
> meson.build | 2 ++
> 4 files changed, 43 insertions(+)
>
> diff --git a/cxl/event_trace.c b/cxl/event_trace.c
> index ffa2a9b9b036..430146ce66f5 100644
> --- a/cxl/event_trace.c
> +++ b/cxl/event_trace.c
> @@ -16,6 +16,7 @@
> #include <libcxl.h>
> #include <uuid/uuid.h>
> #include <traceevent/event-parse.h>
> +#include <tracefs/tracefs.h>
> #include "json.h"
> #include "event_trace.h"
>
> @@ -164,3 +165,35 @@ err_jevent:
> free(jnode);
> return rc;
> }
> +
> +static int cxl_event_parse_cb(struct tep_event *event, struct tep_record
> *record,
> + int cpu, void *ctx)
> +{
> + struct event_ctx *event_ctx = (struct event_ctx *)ctx;
> + int rc;
> +
> + /* Filter out all the events that the caller isn't interested in. */
> + if (strcmp(event->system, event_ctx->system) != 0)
> + return 0;
> +
While integrating w poison events, I find I'd like to filter on
tep_event->name == "cxl_poison" here.
Something like this:
+ if (event_ctx->name) {
+ if (strcmp(event->name, event_ctx->name) != 0)
+ return 0;
+ }
along w this:
struct event_ctx {
const char *system;
+ const char *name;
struct list_head jlist_head;
};
I guess an all|1 option won't suffice for users wanting a subset.
See how that fits it w your needs for monitor command. I can always
filter after the fact if this type of change is not generally useful.
Thanks,
Alison
> + rc = cxl_event_to_json_callback(event, record, &event_ctx->jlist_head);
> + if (rc < 0)
> + return rc;
> +
> + return 0;
> +}
> +
> +int cxl_parse_events(struct tracefs_instance *inst, struct event_ctx *ectx)
> +{
> + struct tep_handle *tep;
> + int rc;
> +
> + tep = tracefs_local_events(NULL);
> + if (!tep)
> + return -ENOMEM;
> +
> + rc = tracefs_iterate_raw_events(tep, inst, NULL, 0,
> + cxl_event_parse_cb, ectx);
> + tep_free(tep);
> + return rc;
> +}
> diff --git a/cxl/event_trace.h b/cxl/event_trace.h
> index 00975a0b5680..2fbefa1586d9 100644
> --- a/cxl/event_trace.h
> +++ b/cxl/event_trace.h
> @@ -11,4 +11,11 @@ struct jlist_node {
> struct list_node list;
> };
>
> +struct event_ctx {
> + const char *system;
> + struct list_head jlist_head;
> +};
> +
> +int cxl_parse_events(struct tracefs_instance *inst, struct event_ctx *ectx);
> +
> #endif
> diff --git a/cxl/meson.build b/cxl/meson.build
> index 8c7733431613..c59876262e76 100644
> --- a/cxl/meson.build
> +++ b/cxl/meson.build
> @@ -21,6 +21,7 @@ cxl_tool = executable('cxl',
> json,
> versiondep,
> traceevent,
> + tracefs,
> ],
> install : true,
> install_dir : rootbindir,
> diff --git a/meson.build b/meson.build
> index f611e0bdd7f3..c204c8ac52de 100644
> --- a/meson.build
> +++ b/meson.build
> @@ -143,6 +143,8 @@ libudev = dependency('libudev')
> uuid = dependency('uuid')
> json = dependency('json-c')
> traceevent = dependency('libtraceevent')
> +tracefs = dependency('libtracefs')
> +
> if get_option('docs').enabled()
> if get_option('asciidoctor').enabled()
> asciidoc = find_program('asciidoctor', required : true)
>
>
