From ac68154626ab7fe4ce5f424937c34f42a3e20c5b Mon Sep 17 00:00:00 2001 From: Zhengjun Xing Date: Fri, 12 Jul 2019 09:53:08 +0800 Subject: [PATCH] tracing: Add "gfp_t" support in synthetic_events Add "gfp_t" support in synthetic_events, then the "gfp_t" type parameter in some functions can be traced. Prints the gfp flags as hex in addition to the human-readable flag string. Example output: whoopsie-630 [000] ...1 78.969452: testevent: bar=b20 (GFP_ATOMIC|__GFP_ZERO) rcuc/0-11 [000] ...1 81.097555: testevent: bar=a20 (GFP_ATOMIC) rcuc/0-11 [000] ...1 81.583123: testevent: bar=a20 (GFP_ATOMIC) Link: http://lkml.kernel.org/r/20190712015308.9908-1-zhengjun.xing@linux.intel.com Signed-off-by: Zhengjun Xing [ Added printing of flag names ] Signed-off-by: Tom Zanussi Signed-off-by: Steven Rostedt (VMware) --- kernel/trace/trace_events_hist.c | 19 +++++++++++++++++++ 1 file changed, 19 insertions(+) diff --git a/kernel/trace/trace_events_hist.c b/kernel/trace/trace_events_hist.c index 65e7d071ed28..3a6e42aa08e6 100644 --- a/kernel/trace/trace_events_hist.c +++ b/kernel/trace/trace_events_hist.c @@ -13,6 +13,10 @@ #include #include +/* for gfp flag names */ +#include +#include + #include "tracing_map.h" #include "trace.h" #include "trace_dynevent.h" @@ -752,6 +756,8 @@ static int synth_field_size(char *type) size = sizeof(unsigned long); else if (strcmp(type, "pid_t") == 0) size = sizeof(pid_t); + else if (strcmp(type, "gfp_t") == 0) + size = sizeof(gfp_t); else if (synth_field_is_string(type)) size = synth_field_string_size(type); @@ -792,6 +798,8 @@ static const char *synth_field_fmt(char *type) fmt = "%lu"; else if (strcmp(type, "pid_t") == 0) fmt = "%d"; + else if (strcmp(type, "gfp_t") == 0) + fmt = "%x"; else if (synth_field_is_string(type)) fmt = "%s"; @@ -834,9 +842,20 @@ static enum print_line_t print_synth_event(struct trace_iterator *iter, i == se->n_fields - 1 ? "" : " "); n_u64 += STR_VAR_LEN_MAX / sizeof(u64); } else { + struct trace_print_flags __flags[] = { + __def_gfpflag_names, {-1, NULL} }; + trace_seq_printf(s, print_fmt, se->fields[i]->name, entry->fields[n_u64], i == se->n_fields - 1 ? "" : " "); + + if (strcmp(se->fields[i]->type, "gfp_t") == 0) { + trace_seq_puts(s, " ("); + trace_print_flags_seq(s, "|", + entry->fields[n_u64], + __flags); + trace_seq_putc(s, ')'); + } n_u64++; } } -- 2.30.2