[PATCH 1/4] perf report: Update document of --sort option

[PATCH 1/4] perf report: Update document of --sort option

[Namhyung Kim]

Description of the memory sort key (used by --mem-mode) was misplaced.
Move it under the --sort option so that it can be referenced properly.

Signed-off-by: Namhyung Kim <namhyung@kernel.org>
---
 tools/perf/Documentation/perf-report.txt | 32 ++++++++++++++++----------------
 1 file changed, 16 insertions(+), 16 deletions(-)

diff --git a/tools/perf/Documentation/perf-report.txt b/tools/perf/Documentation/perf-report.txt
index 8a301f6afb37..f6faec969e2e 100644
--- a/tools/perf/Documentation/perf-report.txt
+++ b/tools/perf/Documentation/perf-report.txt
@@ -117,6 +117,22 @@ OPTIONS
 	And default sort keys are changed to comm, dso_from, symbol_from, dso_to
 	and symbol_to, see '--branch-stack'.
 
+	If --mem-mode option is used, following sort keys are also available
+	(incompatible with --branch-stack):
+	symbol_daddr, dso_daddr, locked, tlb, mem, snoop, dcacheline.
+
+	- symbol_daddr: name of data symbol being executed on at the time of sample
+	- dso_daddr: name of library or module containing the data being executed
+	on at the time of sample
+	- locked: whether the bus was locked at the time of sample
+	- tlb: type of tlb access for the data at the time of sample
+	- mem: type of memory access for the data at the time of sample
+	- snoop: type of snoop (if any) for the data at the time of sample
+	- dcacheline: the cacheline the data address is on at the time of sample
+
+	And default sort keys are changed to local_weight, mem, sym, dso,
+	symbol_daddr, dso_daddr, snoop, tlb, locked, see '--mem-mode'.
+
 	If the data file has tracepoint event(s), following (dynamic) sort keys
 	are also available:
 	trace, trace_fields, [<event>.]<field>[/raw]
@@ -151,22 +167,6 @@ OPTIONS
 	By default, every sort keys not specified in -F will be appended
 	automatically.
 
-	If --mem-mode option is used, following sort keys are also available
-	(incompatible with --branch-stack):
-	symbol_daddr, dso_daddr, locked, tlb, mem, snoop, dcacheline.
-
-	- symbol_daddr: name of data symbol being executed on at the time of sample
-	- dso_daddr: name of library or module containing the data being executed
-	on at the time of sample
-	- locked: whether the bus was locked at the time of sample
-	- tlb: type of tlb access for the data at the time of sample
-	- mem: type of memory access for the data at the time of sample
-	- snoop: type of snoop (if any) for the data at the time of sample
-	- dcacheline: the cacheline the data address is on at the time of sample
-
-	And default sort keys are changed to local_weight, mem, sym, dso,
-	symbol_daddr, dso_daddr, snoop, tlb, locked, see '--mem-mode'.
-
 -p::
 --parent=<regex>::
         A regex filter to identify parent. The parent is a caller of this
-- 
2.7.0

[PATCH 2/4] perf report: Update document of --percent-limit option

[Namhyung Kim]

The --percent-limit option was changed to be applied to callchains as
well as hist entries recently, but it missed to update the doc.

Reported-by: Arnaldo Carvalho de Melo <acme@kernel.org>
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
---
 tools/perf/Documentation/perf-report.txt | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/tools/perf/Documentation/perf-report.txt b/tools/perf/Documentation/perf-report.txt
index f6faec969e2e..369663b37361 100644
--- a/tools/perf/Documentation/perf-report.txt
+++ b/tools/perf/Documentation/perf-report.txt
@@ -351,7 +351,10 @@ OPTIONS
 
 --percent-limit::
 	Do not show entries which have an overhead under that percent.
-	(Default: 0).
+	(Default: 0).  Note that this option also sets percent limit (threshold)
+	of callchains at once.  However the default value of callchain threshold
+	is different than the default value of hist entries.  Please see
+	--call-graph option for details.
 
 --percentage::
 	Determine how to display the overhead percentage of filtered entries.
-- 
2.7.0

[RFC/PATCH 3/4] perf tools: Change default calchain percent limit to 0.05%

[Namhyung Kim]

The current default limit of 0.5% is (mostly) for 'fractal' mode which
calculates the percentage relatively.  As we changed the default
callchain mode to 'graph', the existing limit is too high IMHO.
Normally there're many entries under 0.5% overhead, it'd be supprising
that they don't show callchains.

Cc: Andi Kleen <andi@firstfloor.org>
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
---
changed from 0.005 -> 0.05

 tools/perf/Documentation/perf-report.txt | 2 +-
 tools/perf/builtin-report.c              | 2 +-
 tools/perf/builtin-top.c                 | 2 +-
 tools/perf/util/util.c                   | 2 +-
 4 files changed, 4 insertions(+), 4 deletions(-)

diff --git a/tools/perf/Documentation/perf-report.txt b/tools/perf/Documentation/perf-report.txt
index 369663b37361..7c7b6b6129f7 100644
--- a/tools/perf/Documentation/perf-report.txt
+++ b/tools/perf/Documentation/perf-report.txt
@@ -209,7 +209,7 @@ OPTIONS
 	- none: disable call chain display.
 
 	threshold is a percentage value which specifies a minimum percent to be
-	included in the output call graph.  Default is 0.5 (%).
+	included in the output call graph.  Default is 0.05 (%).
 
 	print_limit is only applied when stdio interface is used.  It's to limit
 	number of call graph entries in a single hist entry.  Note that it needs
diff --git a/tools/perf/builtin-report.c b/tools/perf/builtin-report.c
index 72ed0b46d5a1..d7ad5333d50f 100644
--- a/tools/perf/builtin-report.c
+++ b/tools/perf/builtin-report.c
@@ -643,7 +643,7 @@ parse_percent_limit(const struct option *opt, const char *str,
 	return 0;
 }
 
-#define CALLCHAIN_DEFAULT_OPT  "graph,0.5,caller,function,percent"
+#define CALLCHAIN_DEFAULT_OPT  "graph,0.05,caller,function,percent"
 
 const char report_callchain_help[] = "Display call graph (stack chain/backtrace):\n\n"
 				     CALLCHAIN_REPORT_HELP
diff --git a/tools/perf/builtin-top.c b/tools/perf/builtin-top.c
index bf01cbb0ef23..f31cb78c92fb 100644
--- a/tools/perf/builtin-top.c
+++ b/tools/perf/builtin-top.c
@@ -1086,7 +1086,7 @@ parse_percent_limit(const struct option *opt, const char *arg,
 }
 
 const char top_callchain_help[] = CALLCHAIN_RECORD_HELP CALLCHAIN_REPORT_HELP
-	"\n\t\t\t\tDefault: fp,graph,0.5,caller,function";
+	"\n\t\t\t\tDefault: fp,graph,0.05,caller,function";
 
 int cmd_top(int argc, const char **argv, const char *prefix __maybe_unused)
 {
diff --git a/tools/perf/util/util.c b/tools/perf/util/util.c
index b9e2843cfbe7..26b8f6c66d00 100644
--- a/tools/perf/util/util.c
+++ b/tools/perf/util/util.c
@@ -20,7 +20,7 @@
 
 struct callchain_param	callchain_param = {
 	.mode	= CHAIN_GRAPH_ABS,
-	.min_percent = 0.5,
+	.min_percent = 0.05,
 	.order  = ORDER_CALLEE,
 	.key	= CCKEY_FUNCTION,
 	.value	= CCVAL_PERCENT,
-- 
2.7.0

[PATCH 4/4] perf hists browser: Add 'L' key to change percent limit

[Namhyung Kim]

Add 'L' key action to change the percent limit applied to both of hist
entries and callchains.

Suggested-by: Arnaldo Carvalho de Melo <acme@kernel.org>
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
---
 tools/perf/ui/browsers/hists.c | 55 ++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 55 insertions(+)

diff --git a/tools/perf/ui/browsers/hists.c b/tools/perf/ui/browsers/hists.c
index 61d578bf4ffd..c6ae69716002 100644
--- a/tools/perf/ui/browsers/hists.c
+++ b/tools/perf/ui/browsers/hists.c
@@ -2029,6 +2029,42 @@ static void hist_browser__update_nr_entries(struct hist_browser *hb)
 	hb->nr_non_filtered_entries = nr_entries;
 }
 
+static void hist_browser__update_percent_limit(struct hist_browser *hb,
+					       double percent)
+{
+	struct hist_entry *he;
+	struct rb_node *nd = rb_first(&hb->hists->entries);
+	u64 total = hists__total_period(hb->hists);
+	u64 min_callchain_hits = total * (percent / 100);
+
+	hb->min_pcnt = callchain_param.min_percent = percent;
+
+	if (!symbol_conf.use_callchain)
+		return;
+
+	while ((nd = hists__filter_entries(nd, hb->min_pcnt)) != NULL) {
+		he = rb_entry(nd, struct hist_entry, rb_node);
+
+		if (callchain_param.mode == CHAIN_GRAPH_REL) {
+			total = he->stat.period;
+
+			if (symbol_conf.cumulate_callchain)
+				total = he->stat_acc->period;
+
+			min_callchain_hits = total * (percent / 100);
+		}
+
+		callchain_param.sort(&he->sorted_chain, he->callchain,
+				     min_callchain_hits, &callchain_param);
+
+		/* force to re-evaluate folding state of callchains */
+		he->init_have_children = false;
+		hist_entry__set_folding(he, false);
+
+		nd = rb_next(nd);
+	}
+}
+
 static int perf_evsel__hists_browse(struct perf_evsel *evsel, int nr_events,
 				    const char *helpline,
 				    bool left_exits,
@@ -2064,6 +2100,7 @@ static int perf_evsel__hists_browse(struct perf_evsel *evsel, int nr_events,
 	"E             Expand all callchains\n"				\
 	"F             Toggle percentage of filtered entries\n"		\
 	"H             Display column headers\n"			\
+	"L             Change percent limit\n"				\
 	"m             Display context menu\n"				\
 	"S             Zoom into current Processor Socket\n"		\
 
@@ -2219,6 +2256,24 @@ static int perf_evsel__hists_browse(struct perf_evsel *evsel, int nr_events,
 				top->zero = !top->zero;
 			}
 			continue;
+		case 'L':
+			if (ui_browser__input_window("Percent Limit",
+					"Please enter the value you want to hide entries under that percent.",
+					buf, "ENTER: OK, ESC: Cancel",
+					delay_secs * 2) == K_ENTER) {
+				char *end;
+				double new_percent = strtod(buf, &end);
+
+				if (new_percent < 0 || new_percent > 100) {
+					ui_browser__warning(&browser->b, delay_secs * 2,
+						"Invalid percent: %.2f", new_percent);
+					continue;
+				}
+
+				hist_browser__update_percent_limit(browser, new_percent);
+				hist_browser__reset(browser);
+			}
+			continue;
 		case K_F1:
 		case 'h':
 		case '?':
-- 
2.7.0

Re: [PATCH 4/4] perf hists browser: Add 'L' key to change percent limit

[Arnaldo Carvalho de Melo]

Em Wed, Feb 03, 2016 at 11:11:23PM +0900, Namhyung Kim escreveu:
> Add 'L' key action to change the percent limit applied to both of hist
> entries and callchains.

Thanks a lot, works like a charm!

Applied,

- Arnaldo
 
> Suggested-by: Arnaldo Carvalho de Melo <acme@kernel.org>
> Signed-off-by: Namhyung Kim <namhyung@kernel.org>
> ---
>  tools/perf/ui/browsers/hists.c | 55 ++++++++++++++++++++++++++++++++++++++++++
>  1 file changed, 55 insertions(+)
> 
> diff --git a/tools/perf/ui/browsers/hists.c b/tools/perf/ui/browsers/hists.c
> index 61d578bf4ffd..c6ae69716002 100644
> --- a/tools/perf/ui/browsers/hists.c
> +++ b/tools/perf/ui/browsers/hists.c
> @@ -2029,6 +2029,42 @@ static void hist_browser__update_nr_entries(struct hist_browser *hb)
>  	hb->nr_non_filtered_entries = nr_entries;
>  }
>  
> +static void hist_browser__update_percent_limit(struct hist_browser *hb,
> +					       double percent)
> +{
> +	struct hist_entry *he;
> +	struct rb_node *nd = rb_first(&hb->hists->entries);
> +	u64 total = hists__total_period(hb->hists);
> +	u64 min_callchain_hits = total * (percent / 100);
> +
> +	hb->min_pcnt = callchain_param.min_percent = percent;
> +
> +	if (!symbol_conf.use_callchain)
> +		return;
> +
> +	while ((nd = hists__filter_entries(nd, hb->min_pcnt)) != NULL) {
> +		he = rb_entry(nd, struct hist_entry, rb_node);
> +
> +		if (callchain_param.mode == CHAIN_GRAPH_REL) {
> +			total = he->stat.period;
> +
> +			if (symbol_conf.cumulate_callchain)
> +				total = he->stat_acc->period;
> +
> +			min_callchain_hits = total * (percent / 100);
> +		}
> +
> +		callchain_param.sort(&he->sorted_chain, he->callchain,
> +				     min_callchain_hits, &callchain_param);
> +
> +		/* force to re-evaluate folding state of callchains */
> +		he->init_have_children = false;
> +		hist_entry__set_folding(he, false);
> +
> +		nd = rb_next(nd);
> +	}
> +}
> +
>  static int perf_evsel__hists_browse(struct perf_evsel *evsel, int nr_events,
>  				    const char *helpline,
>  				    bool left_exits,
> @@ -2064,6 +2100,7 @@ static int perf_evsel__hists_browse(struct perf_evsel *evsel, int nr_events,
>  	"E             Expand all callchains\n"				\
>  	"F             Toggle percentage of filtered entries\n"		\
>  	"H             Display column headers\n"			\
> +	"L             Change percent limit\n"				\
>  	"m             Display context menu\n"				\
>  	"S             Zoom into current Processor Socket\n"		\
>  
> @@ -2219,6 +2256,24 @@ static int perf_evsel__hists_browse(struct perf_evsel *evsel, int nr_events,
>  				top->zero = !top->zero;
>  			}
>  			continue;
> +		case 'L':
> +			if (ui_browser__input_window("Percent Limit",
> +					"Please enter the value you want to hide entries under that percent.",
> +					buf, "ENTER: OK, ESC: Cancel",
> +					delay_secs * 2) == K_ENTER) {
> +				char *end;
> +				double new_percent = strtod(buf, &end);
> +
> +				if (new_percent < 0 || new_percent > 100) {
> +					ui_browser__warning(&browser->b, delay_secs * 2,
> +						"Invalid percent: %.2f", new_percent);
> +					continue;
> +				}
> +
> +				hist_browser__update_percent_limit(browser, new_percent);
> +				hist_browser__reset(browser);
> +			}
> +			continue;
>  		case K_F1:
>  		case 'h':
>  		case '?':
> -- 
> 2.7.0

[tip:perf/core] perf report: Update documentation of --sort option

[tip-bot for Namhyung Kim]

Commit-ID:  c6f5f6b662719ded53700deefec7dbc4227c9778
Gitweb:     http://git.kernel.org/tip/c6f5f6b662719ded53700deefec7dbc4227c9778
Author:     Namhyung Kim <namhyung@kernel.org>
AuthorDate: Wed, 3 Feb 2016 23:11:20 +0900
Committer:  Arnaldo Carvalho de Melo <acme@redhat.com>
CommitDate: Wed, 3 Feb 2016 12:24:21 -0300

perf report: Update documentation of --sort option

The description of the memory sort key (used by --mem-mode) was
misplaced.  Move it under the --sort option so that it can be referenced
properly.

Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Cc: Andi Kleen <andi@firstfloor.org>
Cc: David Ahern <dsahern@gmail.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Wang Nan <wangnan0@huawei.com>
Link: http://lkml.kernel.org/r/1454508683-5735-1-git-send-email-namhyung@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
---
 tools/perf/Documentation/perf-report.txt | 32 ++++++++++++++++----------------
 1 file changed, 16 insertions(+), 16 deletions(-)

diff --git a/tools/perf/Documentation/perf-report.txt b/tools/perf/Documentation/perf-report.txt
index 8a301f6..1cb8fac 100644
--- a/tools/perf/Documentation/perf-report.txt
+++ b/tools/perf/Documentation/perf-report.txt
@@ -117,6 +117,22 @@ OPTIONS
 	And default sort keys are changed to comm, dso_from, symbol_from, dso_to
 	and symbol_to, see '--branch-stack'.
 
+	If the --mem-mode option is used, the following sort keys are also available
+	(incompatible with --branch-stack):
+	symbol_daddr, dso_daddr, locked, tlb, mem, snoop, dcacheline.
+
+	- symbol_daddr: name of data symbol being executed on at the time of sample
+	- dso_daddr: name of library or module containing the data being executed
+	on at the time of the sample
+	- locked: whether the bus was locked at the time of the sample
+	- tlb: type of tlb access for the data at the time of the sample
+	- mem: type of memory access for the data at the time of the sample
+	- snoop: type of snoop (if any) for the data at the time of the sample
+	- dcacheline: the cacheline the data address is on at the time of the sample
+
+	And the default sort keys are changed to local_weight, mem, sym, dso,
+	symbol_daddr, dso_daddr, snoop, tlb, locked, see '--mem-mode'.
+
 	If the data file has tracepoint event(s), following (dynamic) sort keys
 	are also available:
 	trace, trace_fields, [<event>.]<field>[/raw]
@@ -151,22 +167,6 @@ OPTIONS
 	By default, every sort keys not specified in -F will be appended
 	automatically.
 
-	If --mem-mode option is used, following sort keys are also available
-	(incompatible with --branch-stack):
-	symbol_daddr, dso_daddr, locked, tlb, mem, snoop, dcacheline.
-
-	- symbol_daddr: name of data symbol being executed on at the time of sample
-	- dso_daddr: name of library or module containing the data being executed
-	on at the time of sample
-	- locked: whether the bus was locked at the time of sample
-	- tlb: type of tlb access for the data at the time of sample
-	- mem: type of memory access for the data at the time of sample
-	- snoop: type of snoop (if any) for the data at the time of sample
-	- dcacheline: the cacheline the data address is on at the time of sample
-
-	And default sort keys are changed to local_weight, mem, sym, dso,
-	symbol_daddr, dso_daddr, snoop, tlb, locked, see '--mem-mode'.
-
 -p::
 --parent=<regex>::
         A regex filter to identify parent. The parent is a caller of this

[tip:perf/core] perf report: Update documention of --percent-limit option

[tip-bot for Namhyung Kim]

Commit-ID:  1ba2fc6de4ac1a87e3ece65651795760ea5cf658
Gitweb:     http://git.kernel.org/tip/1ba2fc6de4ac1a87e3ece65651795760ea5cf658
Author:     Namhyung Kim <namhyung@kernel.org>
AuthorDate: Wed, 3 Feb 2016 23:11:21 +0900
Committer:  Arnaldo Carvalho de Melo <acme@redhat.com>
CommitDate: Wed, 3 Feb 2016 12:24:21 -0300

perf report: Update documention of --percent-limit option

The --percent-limit option was changed to be applied to callchains as
well as to hist entries recently, but it missed to update the doc.

Reported-by: Arnaldo Carvalho de Melo <acme@kernel.org>
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Cc: Andi Kleen <andi@firstfloor.org>
Cc: David Ahern <dsahern@gmail.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Wang Nan <wangnan0@huawei.com>
Link: http://lkml.kernel.org/r/1454508683-5735-2-git-send-email-namhyung@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
---
 tools/perf/Documentation/perf-report.txt | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/tools/perf/Documentation/perf-report.txt b/tools/perf/Documentation/perf-report.txt
index 1cb8fac..89cab84 100644
--- a/tools/perf/Documentation/perf-report.txt
+++ b/tools/perf/Documentation/perf-report.txt
@@ -351,7 +351,10 @@ OPTIONS
 
 --percent-limit::
 	Do not show entries which have an overhead under that percent.
-	(Default: 0).
+	(Default: 0).  Note that this option also sets the percent limit (threshold)
+	of callchains.  However the default value of callchain threshold is
+	different than the default value of hist entries.  Please see the
+	--call-graph option for details.
 
 --percentage::
 	Determine how to display the overhead percentage of filtered entries.

[tip:perf/core] perf hists browser: Add 'L' hotkey to change percent limit

[tip-bot for Namhyung Kim]

Commit-ID:  b62e8dfcda8cb133c062c0e1207afea2476eb7fd
Gitweb:     http://git.kernel.org/tip/b62e8dfcda8cb133c062c0e1207afea2476eb7fd
Author:     Namhyung Kim <namhyung@kernel.org>
AuthorDate: Wed, 3 Feb 2016 23:11:23 +0900
Committer:  Arnaldo Carvalho de Melo <acme@redhat.com>
CommitDate: Wed, 3 Feb 2016 12:24:22 -0300

perf hists browser: Add 'L' hotkey to change percent limit

Add 'L' key action to change the percent limit applied to both of hist
entries and callchains.

Suggested-by: Arnaldo Carvalho de Melo <acme@kernel.org>
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Cc: Andi Kleen <andi@firstfloor.org>
Cc: David Ahern <dsahern@gmail.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Wang Nan <wangnan0@huawei.com>
Link: http://lkml.kernel.org/r/1454508683-5735-4-git-send-email-namhyung@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
---
 tools/perf/ui/browsers/hists.c | 55 ++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 55 insertions(+)

diff --git a/tools/perf/ui/browsers/hists.c b/tools/perf/ui/browsers/hists.c
index 3a1e096..a5a5390 100644
--- a/tools/perf/ui/browsers/hists.c
+++ b/tools/perf/ui/browsers/hists.c
@@ -2029,6 +2029,42 @@ static void hist_browser__update_nr_entries(struct hist_browser *hb)
 	hb->nr_non_filtered_entries = nr_entries;
 }
 
+static void hist_browser__update_percent_limit(struct hist_browser *hb,
+					       double percent)
+{
+	struct hist_entry *he;
+	struct rb_node *nd = rb_first(&hb->hists->entries);
+	u64 total = hists__total_period(hb->hists);
+	u64 min_callchain_hits = total * (percent / 100);
+
+	hb->min_pcnt = callchain_param.min_percent = percent;
+
+	if (!symbol_conf.use_callchain)
+		return;
+
+	while ((nd = hists__filter_entries(nd, hb->min_pcnt)) != NULL) {
+		he = rb_entry(nd, struct hist_entry, rb_node);
+
+		if (callchain_param.mode == CHAIN_GRAPH_REL) {
+			total = he->stat.period;
+
+			if (symbol_conf.cumulate_callchain)
+				total = he->stat_acc->period;
+
+			min_callchain_hits = total * (percent / 100);
+		}
+
+		callchain_param.sort(&he->sorted_chain, he->callchain,
+				     min_callchain_hits, &callchain_param);
+
+		/* force to re-evaluate folding state of callchains */
+		he->init_have_children = false;
+		hist_entry__set_folding(he, false);
+
+		nd = rb_next(nd);
+	}
+}
+
 static int perf_evsel__hists_browse(struct perf_evsel *evsel, int nr_events,
 				    const char *helpline,
 				    bool left_exits,
@@ -2064,6 +2100,7 @@ static int perf_evsel__hists_browse(struct perf_evsel *evsel, int nr_events,
 	"E             Expand all callchains\n"				\
 	"F             Toggle percentage of filtered entries\n"		\
 	"H             Display column headers\n"			\
+	"L             Change percent limit\n"				\
 	"m             Display context menu\n"				\
 	"S             Zoom into current Processor Socket\n"		\
 
@@ -2219,6 +2256,24 @@ static int perf_evsel__hists_browse(struct perf_evsel *evsel, int nr_events,
 				top->zero = !top->zero;
 			}
 			continue;
+		case 'L':
+			if (ui_browser__input_window("Percent Limit",
+					"Please enter the value you want to hide entries under that percent.",
+					buf, "ENTER: OK, ESC: Cancel",
+					delay_secs * 2) == K_ENTER) {
+				char *end;
+				double new_percent = strtod(buf, &end);
+
+				if (new_percent < 0 || new_percent > 100) {
+					ui_browser__warning(&browser->b, delay_secs * 2,
+						"Invalid percent: %.2f", new_percent);
+					continue;
+				}
+
+				hist_browser__update_percent_limit(browser, new_percent);
+				hist_browser__reset(browser);
+			}
+			continue;
 		case K_F1:
 		case 'h':
 		case '?':