Clarify perf man pages

Clarify perf man pages

[Andi Kleen]

This clarifies two common problems in the perf man pages.
No code changes.

[PATCH 1/2] perf, tools, mem: Clarify load-latency in documentation

[Andi Kleen]

From: Andi Kleen <ak@linux.intel.com>

Clarify in the documentation that perf mem report reports
use-latency, not load/store-latency on Intel systems.
This often causes confusion with users.

Cc: eranian@google.com
Signed-off-by: Andi Kleen <ak@linux.intel.com>
---
 tools/perf/Documentation/perf-mem.txt | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/tools/perf/Documentation/perf-mem.txt b/tools/perf/Documentation/perf-mem.txt
index 888d511..1d78a40 100644
--- a/tools/perf/Documentation/perf-mem.txt
+++ b/tools/perf/Documentation/perf-mem.txt
@@ -18,6 +18,10 @@ from it, into perf.data. Perf record options are accepted and are passed through
 "perf mem -t <TYPE> report" displays the result. It invokes perf report with the
 right set of options to display a memory access profile.
 
+Note that on Intel systems the memory latency reported is the use-latency,
+not the pure load (or store latency). Use latency includes any pipeline
+queueing delays in addition to the memory subsystem latency.
+
 OPTIONS
 -------
 <command>...::
-- 
1.8.5.3

[PATCH 2/2] perf, tools, probe: Clarify x86 register naming for perf probe

[Andi Kleen]

From: Andi Kleen <ak@linux.intel.com>

Clarify how to specify x86 registers in perf probe. I recently
ran into this problem and had to figure it out from the source.

Cc: masami.hiramatsu.pt@hitachi.com
Signed-off-by: Andi Kleen <ak@linux.intel.com>
---
 tools/perf/Documentation/perf-probe.txt | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/tools/perf/Documentation/perf-probe.txt b/tools/perf/Documentation/perf-probe.txt
index b715cb7..1513935 100644
--- a/tools/perf/Documentation/perf-probe.txt
+++ b/tools/perf/Documentation/perf-probe.txt
@@ -136,6 +136,8 @@ Each probe argument follows below syntax.
 'NAME' specifies the name of this argument (optional). You can use the name of local variable, local data structure member (e.g. var->field, var.field2), local array with fixed index (e.g. array[1], var->array[0], var->pointer[2]), or kprobe-tracer argument format (e.g. $retval, %ax, etc). Note that the name of this argument will be set as the last member name if you specify a local data structure member (e.g. field2 for 'var->field1.field2'.)
 'TYPE' casts the type of this argument (optional). If omitted, perf probe automatically set the type based on debuginfo. You can specify 'string' type only for the local variable or structure member which is an array of or a pointer to 'char' or 'unsigned char' type.
 
+On x86 systems %REG is always the short form of the register: for example %AX. %RAX or %EAX is not valid.
+
 LINE SYNTAX
 -----------
 Line range is described by following syntax.
-- 
1.8.5.3

Re: [PATCH 2/2] perf, tools, probe: Clarify x86 register naming for perf probe

[Masami Hiramatsu]

(2014/02/28 23:02), Andi Kleen wrote:
> From: Andi Kleen <ak@linux.intel.com>
> 
> Clarify how to specify x86 registers in perf probe. I recently
> ran into this problem and had to figure it out from the source.
> 
> Cc: masami.hiramatsu.pt@hitachi.com
> Signed-off-by: Andi Kleen <ak@linux.intel.com>

Acked-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>

Thanks!

> ---
>  tools/perf/Documentation/perf-probe.txt | 2 ++
>  1 file changed, 2 insertions(+)
> 
> diff --git a/tools/perf/Documentation/perf-probe.txt b/tools/perf/Documentation/perf-probe.txt
> index b715cb7..1513935 100644
> --- a/tools/perf/Documentation/perf-probe.txt
> +++ b/tools/perf/Documentation/perf-probe.txt
> @@ -136,6 +136,8 @@ Each probe argument follows below syntax.
>  'NAME' specifies the name of this argument (optional). You can use the name of local variable, local data structure member (e.g. var->field, var.field2), local array with fixed index (e.g. array[1], var->array[0], var->pointer[2]), or kprobe-tracer argument format (e.g. $retval, %ax, etc). Note that the name of this argument will be set as the last member name if you specify a local data structure member (e.g. field2 for 'var->field1.field2'.)
>  'TYPE' casts the type of this argument (optional). If omitted, perf probe automatically set the type based on debuginfo. You can specify 'string' type only for the local variable or structure member which is an array of or a pointer to 'char' or 'unsigned char' type.
>  
> +On x86 systems %REG is always the short form of the register: for example %AX. %RAX or %EAX is not valid.
> +
>  LINE SYNTAX
>  -----------
>  Line range is described by following syntax.
> 


-- 
Masami HIRAMATSU
IT Management Research Dept. Linux Technology Center
Hitachi, Ltd., Yokohama Research Laboratory
E-mail: masami.hiramatsu.pt@hitachi.com

[tip:perf/core] perf mem: Clarify load-latency in documentation

[tip-bot for Andi Kleen]

Commit-ID:  b63940970492f5f187d546e191bc2c6831491fe3
Gitweb:     http://git.kernel.org/tip/b63940970492f5f187d546e191bc2c6831491fe3
Author:     Andi Kleen <ak@linux.intel.com>
AuthorDate: Fri, 28 Feb 2014 06:02:14 -0800
Committer:  Arnaldo Carvalho de Melo <acme@redhat.com>
CommitDate: Fri, 14 Mar 2014 11:20:44 -0300

perf mem: Clarify load-latency in documentation

Clarify in the documentation that 'perf mem report' reports use-latency,
not load/store-latency on Intel systems.

This often causes confusion with users.

Signed-off-by: Andi Kleen <ak@linux.intel.com>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lkml.kernel.org/r/1393596135-4227-2-git-send-email-andi@firstfloor.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
---
 tools/perf/Documentation/perf-mem.txt | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/tools/perf/Documentation/perf-mem.txt b/tools/perf/Documentation/perf-mem.txt
index 888d511..1d78a40 100644
--- a/tools/perf/Documentation/perf-mem.txt
+++ b/tools/perf/Documentation/perf-mem.txt
@@ -18,6 +18,10 @@ from it, into perf.data. Perf record options are accepted and are passed through
 "perf mem -t <TYPE> report" displays the result. It invokes perf report with the
 right set of options to display a memory access profile.
 
+Note that on Intel systems the memory latency reported is the use-latency,
+not the pure load (or store latency). Use latency includes any pipeline
+queueing delays in addition to the memory subsystem latency.
+
 OPTIONS
 -------
 <command>...::

[tip:perf/core] perf probe: Clarify x86 register naming for perf probe

[tip-bot for Andi Kleen]

Commit-ID:  5b4398209d646635a4d84c46a5c7193fbce1a07c
Gitweb:     http://git.kernel.org/tip/5b4398209d646635a4d84c46a5c7193fbce1a07c
Author:     Andi Kleen <ak@linux.intel.com>
AuthorDate: Fri, 28 Feb 2014 06:02:15 -0800
Committer:  Arnaldo Carvalho de Melo <acme@redhat.com>
CommitDate: Fri, 14 Mar 2014 11:20:44 -0300

perf probe: Clarify x86 register naming for perf probe

Clarify how to specify x86 registers in perf probe. I recently ran into
this problem and had to figure it out from the source.

Signed-off-by: Andi Kleen <ak@linux.intel.com>
Acked-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Cc: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Link: http://lkml.kernel.org/r/1393596135-4227-3-git-send-email-andi@firstfloor.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
---
 tools/perf/Documentation/perf-probe.txt | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/tools/perf/Documentation/perf-probe.txt b/tools/perf/Documentation/perf-probe.txt
index b715cb7..1513935 100644
--- a/tools/perf/Documentation/perf-probe.txt
+++ b/tools/perf/Documentation/perf-probe.txt
@@ -136,6 +136,8 @@ Each probe argument follows below syntax.
 'NAME' specifies the name of this argument (optional). You can use the name of local variable, local data structure member (e.g. var->field, var.field2), local array with fixed index (e.g. array[1], var->array[0], var->pointer[2]), or kprobe-tracer argument format (e.g. $retval, %ax, etc). Note that the name of this argument will be set as the last member name if you specify a local data structure member (e.g. field2 for 'var->field1.field2'.)
 'TYPE' casts the type of this argument (optional). If omitted, perf probe automatically set the type based on debuginfo. You can specify 'string' type only for the local variable or structure member which is an array of or a pointer to 'char' or 'unsigned char' type.
 
+On x86 systems %REG is always the short form of the register: for example %AX. %RAX or %EAX is not valid.
+
 LINE SYNTAX
 -----------
 Line range is described by following syntax.