From dc102a8fae2d0d6bf5223fc549247f2e23959ae6 Mon Sep 17 00:00:00 2001 From: Mathieu Desnoyers Date: Mon, 12 May 2008 21:21:09 +0200 Subject: Markers - remove extra format argument Denys Vlasenko : > Not in this patch, but I noticed: > > #define __trace_mark(name, call_private, format, args...) \ > do { \ > static const char __mstrtab_##name[] \ > __attribute__((section("__markers_strings"))) \ > = #name "\0" format; \ > static struct marker __mark_##name \ > __attribute__((section("__markers"), aligned(8))) = \ > { __mstrtab_##name, &__mstrtab_##name[sizeof(#name)], \ > 0, 0, marker_probe_cb, \ > { __mark_empty_function, NULL}, NULL }; \ > __mark_check_format(format, ## args); \ > if (unlikely(__mark_##name.state)) { \ > (*__mark_##name.call) \ > (&__mark_##name, call_private, \ > format, ## args); \ > } \ > } while (0) > > In this call: > > (*__mark_##name.call) \ > (&__mark_##name, call_private, \ > format, ## args); \ > > you make gcc allocate duplicate format string. You can use > &__mstrtab_##name[sizeof(#name)] instead since it holds the same string, > or drop ", format," above and "const char *fmt" from here: > > void (*call)(const struct marker *mdata, /* Probe wrapper */ > void *call_private, const char *fmt, ...); > > since mdata->format is the same and all callees which need it can take it there. Very good point. I actually thought about dropping it, since it would remove an unnecessary argument from the stack. And actually, since I now have the marker_probe_cb sitting between the marker site and the callbacks, there is no API change required. Thanks :) Mathieu Signed-off-by: Mathieu Desnoyers CC: Denys Vlasenko Signed-off-by: Ingo Molnar Signed-off-by: Thomas Gleixner --- include/linux/marker.h | 11 +++++------ 1 file changed, 5 insertions(+), 6 deletions(-) (limited to 'include/linux/marker.h') diff --git a/include/linux/marker.h b/include/linux/marker.h index 430f6adf9762..338533abb47b 100644 --- a/include/linux/marker.h +++ b/include/linux/marker.h @@ -44,8 +44,8 @@ struct marker { */ char state; /* Marker state. */ char ptype; /* probe type : 0 : single, 1 : multi */ - void (*call)(const struct marker *mdata, /* Probe wrapper */ - void *call_private, const char *fmt, ...); + /* Probe wrapper */ + void (*call)(const struct marker *mdata, void *call_private, ...); struct marker_probe_closure single; struct marker_probe_closure *multi; } __attribute__((aligned(8))); @@ -72,8 +72,7 @@ struct marker { __mark_check_format(format, ## args); \ if (unlikely(__mark_##name.state)) { \ (*__mark_##name.call) \ - (&__mark_##name, call_private, \ - format, ## args); \ + (&__mark_##name, call_private, ## args);\ } \ } while (0) @@ -117,9 +116,9 @@ static inline void __printf(1, 2) ___mark_check_format(const char *fmt, ...) extern marker_probe_func __mark_empty_function; extern void marker_probe_cb(const struct marker *mdata, - void *call_private, const char *fmt, ...); + void *call_private, ...); extern void marker_probe_cb_noarg(const struct marker *mdata, - void *call_private, const char *fmt, ...); + void *call_private, ...); /* * Connect a probe to a marker. -- cgit v1.2.3 From 0aa977f592f17004f9d1d545f2e1bb9ea71896c3 Mon Sep 17 00:00:00 2001 From: Mathieu Desnoyers Date: Mon, 12 May 2008 21:21:10 +0200 Subject: Markers - define non optimized marker To support the forthcoming "immediate values" marker optimization, we must have a way to declare markers in few code paths that does not use instruction modification based enable. This will be the case of printk(), some traps and eventually lockdep instrumentation. Changelog : - Fix reversed boolean logic of "generic". Signed-off-by: Mathieu Desnoyers Signed-off-by: Ingo Molnar Signed-off-by: Thomas Gleixner --- include/linux/marker.h | 29 ++++++++++++++++++++++++----- 1 file changed, 24 insertions(+), 5 deletions(-) (limited to 'include/linux/marker.h') diff --git a/include/linux/marker.h b/include/linux/marker.h index 338533abb47b..1290653f9241 100644 --- a/include/linux/marker.h +++ b/include/linux/marker.h @@ -58,8 +58,12 @@ struct marker { * Make sure the alignment of the structure in the __markers section will * not add unwanted padding between the beginning of the section and the * structure. Force alignment to the same alignment as the section start. + * + * The "generic" argument controls which marker enabling mechanism must be used. + * If generic is true, a variable read is used. + * If generic is false, immediate values are used. */ -#define __trace_mark(name, call_private, format, args...) \ +#define __trace_mark(generic, name, call_private, format, args...) \ do { \ static const char __mstrtab_##name[] \ __attribute__((section("__markers_strings"))) \ @@ -79,7 +83,7 @@ struct marker { extern void marker_update_probe_range(struct marker *begin, struct marker *end); #else /* !CONFIG_MARKERS */ -#define __trace_mark(name, call_private, format, args...) \ +#define __trace_mark(generic, name, call_private, format, args...) \ __mark_check_format(format, ## args) static inline void marker_update_probe_range(struct marker *begin, struct marker *end) @@ -87,15 +91,30 @@ static inline void marker_update_probe_range(struct marker *begin, #endif /* CONFIG_MARKERS */ /** - * trace_mark - Marker + * trace_mark - Marker using code patching * @name: marker name, not quoted. * @format: format string * @args...: variable argument list * - * Places a marker. + * Places a marker using optimized code patching technique (imv_read()) + * to be enabled when immediate values are present. */ #define trace_mark(name, format, args...) \ - __trace_mark(name, NULL, format, ## args) + __trace_mark(0, name, NULL, format, ## args) + +/** + * _trace_mark - Marker using variable read + * @name: marker name, not quoted. + * @format: format string + * @args...: variable argument list + * + * Places a marker using a standard memory read (_imv_read()) to be + * enabled. Should be used for markers in code paths where instruction + * modification based enabling is not welcome. (__init and __exit functions, + * lockdep, some traps, printk). + */ +#define _trace_mark(name, format, args...) \ + __trace_mark(1, name, NULL, format, ## args) /** * MARK_NOARGS - Format string for a marker with no argument. -- cgit v1.2.3