From: Namhyung Kim [mailto:[email protected]] On Behalf Of Namhyung Kim > >Hi Tom, > >I implemented 'log2' modifier on top of your v11 patchset. Could you >please take a look at this?
Ah, this seems very useful :) Reviewed-by: Masami Hiramatsu <[email protected]> -- Masami > > > >From 5fc74778b9af5e4e121a0563fb8e54e8f495ca29 Mon Sep 17 00:00:00 2001 >From: Namhyung Kim <[email protected]> >Date: Thu, 5 Nov 2015 23:34:05 +0900 >Subject: [PATCH] tracing: Add hist trigger 'log2' modifier > >Allow users to have numeric fields displayed as log2 values in case >value range is very wide by appending '.log2' to field names. > >For example, > > # echo 'hist:key=bytes_req' > kmalloc/trigger > # cat kmalloc/hist > > { bytes_req: 504 } hitcount: 1 > { bytes_req: 11 } hitcount: 1 > { bytes_req: 104 } hitcount: 1 > { bytes_req: 48 } hitcount: 1 > { bytes_req: 2048 } hitcount: 1 > { bytes_req: 4096 } hitcount: 1 > { bytes_req: 240 } hitcount: 1 > { bytes_req: 392 } hitcount: 1 > { bytes_req: 13 } hitcount: 1 > { bytes_req: 28 } hitcount: 1 > { bytes_req: 12 } hitcount: 1 > { bytes_req: 64 } hitcount: 2 > { bytes_req: 128 } hitcount: 2 > { bytes_req: 32 } hitcount: 2 > { bytes_req: 8 } hitcount: 11 > { bytes_req: 10 } hitcount: 13 > { bytes_req: 24 } hitcount: 25 > { bytes_req: 160 } hitcount: 29 > { bytes_req: 16 } hitcount: 33 > { bytes_req: 80 } hitcount: 36 > >When using '.log2' modifier, the output looks like: > > # echo 'hist:key=bytes_req.log2' > kmalloc/trigger > # cat kmalloc/hist > > { bytes_req: ~ 2^12 } hitcount: 1 > { bytes_req: ~ 2^11 } hitcount: 1 > { bytes_req: ~ 2^9 } hitcount: 2 > { bytes_req: ~ 2^6 } hitcount: 3 > { bytes_req: ~ 2^3 } hitcount: 13 > { bytes_req: ~ 2^5 } hitcount: 19 > { bytes_req: ~ 2^8 } hitcount: 49 > { bytes_req: ~ 2^7 } hitcount: 57 > { bytes_req: ~ 2^4 } hitcount: 74 > >Cc: Tom Zanussi <[email protected]> >Cc: Masami Hiramatsu <[email protected]> >Signed-off-by: Namhyung Kim <[email protected]> >--- > kernel/trace/trace.c | 1 + > kernel/trace/trace_events_hist.c | 18 ++++++++++++++++++ > 2 files changed, 19 insertions(+) > >diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c >index 74f95745acbc..542486468707 100644 >--- a/kernel/trace/trace.c >+++ b/kernel/trace/trace.c >@@ -3837,6 +3837,7 @@ static const char readme_msg[] = > "\t .sym-offset display an address as a symbol and offset\n" > "\t .execname display a common_pid as a program name\n" > "\t .syscall display a syscall id as a syscall name\n\n" >+ "\t .log2 display log2 value rather than raw >number\n\n" > "\t The 'pause' parameter can be used to pause an existing hist\n" > "\t trigger or to start a hist trigger but not log any events\n" > "\t until told to do so. 'continue' can be used to start or\n" >diff --git a/kernel/trace/trace_events_hist.c >b/kernel/trace/trace_events_hist.c >index b040ebefcd64..20a17fdb3fe6 100644 >--- a/kernel/trace/trace_events_hist.c >+++ b/kernel/trace/trace_events_hist.c >@@ -68,6 +68,13 @@ static u64 hist_field_pstring(struct hist_field >*hist_field, void *event) > return (u64)(unsigned long)*addr; > } > >+static u64 hist_field_log2(struct hist_field *hist_field, void *event) >+{ >+ u64 val = *(u64 *)(event + hist_field->field->offset); >+ >+ return (u64) ilog2(roundup_pow_of_two(val)); >+} >+ > #define DEFINE_HIST_FIELD_FN(type) \ > static u64 hist_field_##type(struct hist_field *hist_field, void *event)\ > { \ >@@ -103,6 +110,7 @@ enum hist_field_flags { > HIST_FIELD_EXECNAME = 64, > HIST_FIELD_SYSCALL = 128, > HIST_FIELD_STACKTRACE = 256, >+ HIST_FIELD_LOG2 = 512, > }; > > struct hist_trigger_attrs { >@@ -349,6 +357,11 @@ static struct hist_field *create_hist_field(struct >ftrace_event_field *field, > goto out; > } > >+ if (flags & HIST_FIELD_LOG2) { >+ hist_field->fn = hist_field_log2; >+ goto out; >+ } >+ > if (is_string_field(field)) { > flags |= HIST_FIELD_STRING; > >@@ -500,6 +513,8 @@ static int create_key_field(struct hist_trigger_data >*hist_data, > flags |= HIST_FIELD_EXECNAME; > else if (!strcmp(field_str, "syscall")) > flags |= HIST_FIELD_SYSCALL; >+ else if (!strcmp(field_str, "log2")) >+ flags |= HIST_FIELD_LOG2; > else { > ret = -EINVAL; > goto out; >@@ -942,6 +957,9 @@ hist_trigger_entry_print(struct seq_file *m, > key + key_field->offset, > HIST_STACKTRACE_DEPTH); > multiline = true; >+ } else if (key_field->flags & HIST_FIELD_LOG2) { >+ seq_printf(m, "%s: ~ 2^%-2llu", key_field->field->name, >+ *(u64 *)(key + key_field->offset)); > } else if (key_field->flags & HIST_FIELD_STRING) { > seq_printf(m, "%s: %-50s", key_field->field->name, > (char *)(key + key_field->offset)); >-- >2.6.2 N�����r��y����b�X��ǧv�^�){.n�+����{����zX����ܨ}���Ơz�&j:+v�������zZ+��+zf���h���~����i���z� �w���?�����&�)ߢf��^jǫy�m��@A�a��� 0��h���i
