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author | Masami Hiramatsu <mhiramat@kernel.org> | 2021-08-10 11:07:29 +0900 |
---|---|---|
committer | Steven Rostedt (VMware) <rostedt@goodmis.org> | 2021-08-16 11:37:21 -0400 |
commit | 8993665abcce793f00815b3504a486dce70cc2b9 (patch) | |
tree | 9fc1b771c5768a19db19806f0606f6677cefa462 /kernel/trace | |
parent | e66ed86ca6c52488249e95f7b3a6a3d7d6ab5e1e (diff) | |
download | linux-8993665abcce793f00815b3504a486dce70cc2b9.tar.bz2 |
tracing/boot: Support multiple handlers for per-event histogram
Support multiple handlers for per-event histogram in boot-time tracing.
Since the histogram can register multiple same handler-actions with
different parameters, this expands the syntax to support such cases.
With this update, the 'onmax', 'onchange' and 'onmatch' handler subkeys
under per-event histogram option will take a number subkeys optionally
as below. (see [.N])
ftrace.[instance.INSTANCE.]event.GROUP.EVENT.hist {
onmax|onchange[.N] { var = <VAR>; <ACTION> [= <PARAM>] }
onmatch[.N] { event = <EVENT>; <ACTION> [= <PARAM>] }
}
The 'N' must be a digit (or digit started word).
Thus user can add several handler-actions to the histogram,
for example,
ftrace.event.SOMEGROUP.SOMEEVENT.hist {
keys = SOME_ID; lat = common_timestamp.usecs-$ts0
onmatch.1 {
event = GROUP1.STARTEVENT1
trace = latency_event, SOME_ID, $lat
}
onmatch.2 {
event = GROUP2.STARTEVENT2
trace = latency_event, SOME_ID, $lat
}
}
Then, it can trace the elapsed time from GROUP1.STARTEVENT1 to
SOMEGROUP.SOMEEVENT, and from GROUP2.STARTEVENT2 to
SOMEGROUP.SOMEEVENT with SOME_ID key.
Link: https://lkml.kernel.org/r/162856124905.203126.14913731908137885922.stgit@devnote2
Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Diffstat (limited to 'kernel/trace')
-rw-r--r-- | kernel/trace/trace_boot.c | 43 |
1 files changed, 35 insertions, 8 deletions
diff --git a/kernel/trace/trace_boot.c b/kernel/trace/trace_boot.c index 3d0e51368f51..f024f27b3602 100644 --- a/kernel/trace/trace_boot.c +++ b/kernel/trace/trace_boot.c @@ -245,8 +245,9 @@ trace_boot_hist_add_array(struct xbc_node *hnode, char **bufp, } static int __init -trace_boot_hist_add_handler(struct xbc_node *hnode, char **bufp, - char *end, const char *param) +trace_boot_hist_add_one_handler(struct xbc_node *hnode, char **bufp, + char *end, const char *handler, + const char *param) { struct xbc_node *knode, *anode; const char *p; @@ -259,7 +260,7 @@ trace_boot_hist_add_handler(struct xbc_node *hnode, char **bufp, xbc_node_get_data(hnode), param); return -EINVAL; } - append_printf(bufp, end, ":%s(%s)", xbc_node_get_data(hnode), p); + append_printf(bufp, end, ":%s(%s)", handler, p); /* Compose 'action' parameter */ knode = xbc_node_find_child(hnode, "trace"); @@ -294,6 +295,32 @@ trace_boot_hist_add_handler(struct xbc_node *hnode, char **bufp, return 0; } +static int __init +trace_boot_hist_add_handlers(struct xbc_node *hnode, char **bufp, + char *end, const char *param) +{ + struct xbc_node *node; + const char *p, *handler; + int ret; + + handler = xbc_node_get_data(hnode); + + xbc_node_for_each_subkey(hnode, node) { + p = xbc_node_get_data(node); + if (!isdigit(p[0])) + continue; + /* All digit started node should be instances. */ + ret = trace_boot_hist_add_one_handler(node, bufp, end, handler, param); + if (ret < 0) + break; + } + + if (xbc_node_find_child(hnode, param)) + ret = trace_boot_hist_add_one_handler(hnode, bufp, end, handler, param); + + return ret; +} + /* * Histogram boottime tracing syntax. * @@ -305,8 +332,8 @@ trace_boot_hist_add_handler(struct xbc_node *hnode, char **bufp, * name = <HISTNAME> * var { <VAR> = <EXPR> ... } * pause|continue|clear - * onmax|onchange { var = <VAR>; <ACTION> [= <PARAM>] } - * onmatch { event = <EVENT>; <ACTION> [= <PARAM>] } + * onmax|onchange[.N] { var = <VAR>; <ACTION> [= <PARAM>] } + * onmatch[.N] { event = <EVENT>; <ACTION> [= <PARAM>] } * filter = <FILTER> * } * @@ -368,13 +395,13 @@ trace_boot_compose_hist_cmd(struct xbc_node *hnode, char *buf, size_t size) /* Histogram handler and actions */ node = xbc_node_find_child(hnode, "onmax"); - if (node && trace_boot_hist_add_handler(node, &buf, end, "var") < 0) + if (node && trace_boot_hist_add_handlers(node, &buf, end, "var") < 0) return -EINVAL; node = xbc_node_find_child(hnode, "onchange"); - if (node && trace_boot_hist_add_handler(node, &buf, end, "var") < 0) + if (node && trace_boot_hist_add_handlers(node, &buf, end, "var") < 0) return -EINVAL; node = xbc_node_find_child(hnode, "onmatch"); - if (node && trace_boot_hist_add_handler(node, &buf, end, "event") < 0) + if (node && trace_boot_hist_add_handlers(node, &buf, end, "event") < 0) return -EINVAL; p = xbc_node_find_value(hnode, "filter", NULL); |