[PATCH] perf: excluding "." and ".." directories when calculating tids.

[PATCH] perf: excluding "." and ".." directories when calculating tids.

[Gui Jianfeng]

excluding "." and ".." directories when calculating tids.

Signed-off-by: Gui Jianfeng <guijianfeng@cn.fujitsu.com>
---
 tools/perf/util/thread.c |    2 ++
 1 files changed, 2 insertions(+), 0 deletions(-)

diff --git a/tools/perf/util/thread.c b/tools/perf/util/thread.c
index 1f7ecd4..4f71d1c 100644
--- a/tools/perf/util/thread.c
+++ b/tools/perf/util/thread.c
@@ -17,6 +17,8 @@ int find_all_tid(int pid, pid_t ** all_tid)
 
 	sprintf(name, "/proc/%d/task", pid);
 	items = scandir(name, &namelist, NULL, NULL);
+	/* Excluding "." and ".." directories! */
+	items -= 2;
 	if (items <= 0)
                 return -ENOENT;
 	*all_tid = malloc(sizeof(pid_t) * items);
-- 
1.6.5.2

Re: [PATCH] perf: excluding "." and ".." directories when calculating tids.

[Gui Jianfeng]

Gui Jianfeng wrote:
> excluding "." and ".." directories when calculating tids.

Please ignore this one, will post an updated version.

Thanks,
Gui

> 
> Signed-off-by: Gui Jianfeng <guijianfeng@cn.fujitsu.com>
> ---
>  tools/perf/util/thread.c |    2 ++
>  1 files changed, 2 insertions(+), 0 deletions(-)
> 
> diff --git a/tools/perf/util/thread.c b/tools/perf/util/thread.c
> index 1f7ecd4..4f71d1c 100644
> --- a/tools/perf/util/thread.c
> +++ b/tools/perf/util/thread.c
> @@ -17,6 +17,8 @@ int find_all_tid(int pid, pid_t ** all_tid)
>  
>  	sprintf(name, "/proc/%d/task", pid);
>  	items = scandir(name, &namelist, NULL, NULL);
> +	/* Excluding "." and ".." directories! */
> +	items -= 2;
>  	if (items <= 0)
>                  return -ENOENT;
>  	*all_tid = malloc(sizeof(pid_t) * items);

[PATCH] perf: excluding "." and ".." directories when calculating tids.

[Gui Jianfeng]

Introduce a filter function to skip "." and ".." directories when calculating
tid number.

Signed-off-by: Gui Jianfeng <guijianfeng@cn.fujitsu.com>
---
 tools/perf/util/thread.c |   11 ++++++++++-
 1 files changed, 10 insertions(+), 1 deletions(-)

diff --git a/tools/perf/util/thread.c b/tools/perf/util/thread.c
index 1f7ecd4..9a448b4 100644
--- a/tools/perf/util/thread.c
+++ b/tools/perf/util/thread.c
@@ -7,6 +7,15 @@
 #include "util.h"
 #include "debug.h"
 
+/* Skip "." and ".." directories */
+static int filter(const struct dirent *dir)
+{
+	if (dir->d_name[0] == '.')
+		return 0;
+	else
+		return 1;
+}
+
 int find_all_tid(int pid, pid_t ** all_tid)
 {
 	char name[256];
@@ -16,7 +25,7 @@ int find_all_tid(int pid, pid_t ** all_tid)
 	int i;
 
 	sprintf(name, "/proc/%d/task", pid);
-	items = scandir(name, &namelist, NULL, NULL);
+	items = scandir(name, &namelist, filter, NULL);
 	if (items <= 0)
                 return -ENOENT;
 	*all_tid = malloc(sizeof(pid_t) * items);
-- 
1.6.5.2

Re: [PATCH] perf: excluding "." and ".." directories when calculating tids.

[Adam Schrotenboer]

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On 06/15/2010 10:21 PM, Gui Jianfeng wrote:
> Introduce a filter function to skip "." and ".." directories when calculating
> tid number.
>
> Signed-off-by: Gui Jianfeng <guijianfeng@cn.fujitsu.com>
> ---
>  tools/perf/util/thread.c |   11 ++++++++++-
>  1 files changed, 10 insertions(+), 1 deletions(-)
>
> diff --git a/tools/perf/util/thread.c b/tools/perf/util/thread.c
> index 1f7ecd4..9a448b4 100644
> --- a/tools/perf/util/thread.c
> +++ b/tools/perf/util/thread.c
> @@ -7,6 +7,15 @@
>  #include "util.h"
>  #include "debug.h"
>  
> +/* Skip "." and ".." directories */
> +static int filter(const struct dirent *dir)
> +{
> +	if (dir->d_name[0] == '.')
> +		return 0;
> +	else
> +		return 1;
> +}
> +
>   

Is this safe? Can you _never_ have a d_name with a leading dot, like '
.hidden' ??
Maybe should
if(dir->d_name[0] == '.' && (dir->d_name[1] == '\0' || (dir->d_name[1]
== '.' && dir->d_name[2] == '\0')))

Admittedly I don't think it happens in the current procfs, but I'd want
to be careful regardless.



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Re: [PATCH] perf: excluding "." and ".." directories when calculating tids.

[Gui Jianfeng]

Adam Schrotenboer wrote:
> On 06/15/2010 10:21 PM, Gui Jianfeng wrote:
>> Introduce a filter function to skip "." and ".." directories when calculating
>> tid number.
>>
>> Signed-off-by: Gui Jianfeng <guijianfeng@cn.fujitsu.com>
>> ---
>>  tools/perf/util/thread.c |   11 ++++++++++-
>>  1 files changed, 10 insertions(+), 1 deletions(-)
>>
>> diff --git a/tools/perf/util/thread.c b/tools/perf/util/thread.c
>> index 1f7ecd4..9a448b4 100644
>> --- a/tools/perf/util/thread.c
>> +++ b/tools/perf/util/thread.c
>> @@ -7,6 +7,15 @@
>>  #include "util.h"
>>  #include "debug.h"
>>  
>> +/* Skip "." and ".." directories */
>> +static int filter(const struct dirent *dir)
>> +{
>> +	if (dir->d_name[0] == '.')
>> +		return 0;
>> +	else
>> +		return 1;
>> +}
>> +
>>   
> 
> Is this safe? Can you _never_ have a d_name with a leading dot, like '
> .hidden' ??
> Maybe should
> if(dir->d_name[0] == '.' && (dir->d_name[1] == '\0' || (dir->d_name[1]
> == '.' && dir->d_name[2] == '\0')))
> 
> Admittedly I don't think it happens in the current procfs, but I'd want
> to be careful regardless.

Actually, we only care the numeral directories. So, even if there's a ".hidden",
it's fine to filter out this directory. Just keep things simple here.

Thanks,
Gui

> 
> 

Re: [PATCH] perf: excluding "." and ".." directories when calculating tids.

[Arnaldo Carvalho de Melo]

Em Thu, Jun 17, 2010 at 11:11:35AM +0800, Gui Jianfeng escreveu:
> Adam Schrotenboer wrote:
> > On 06/15/2010 10:21 PM, Gui Jianfeng wrote:
> >> Introduce a filter function to skip "." and ".." directories when calculating
> >> tid number.
> >>
> >> +/* Skip "." and ".." directories */
> >> +static int filter(const struct dirent *dir)
> >> +{
> >> +	if (dir->d_name[0] == '.')
> >> +		return 0;
> >> +	else
> >> +		return 1;
> > 
> > Is this safe? Can you _never_ have a d_name with a leading dot, like '
> > .hidden' ??
> > Admittedly I don't think it happens in the current procfs, but I'd want
> > to be careful regardless.
> 
> Actually, we only care the numeral directories. So, even if there's a ".hidden",
> it's fine to filter out this directory. Just keep things simple here.

Agreed, applying to perf/core, thanks,

- Arnaldo

[tip:perf/urgent] perf tools: Fix find tids routine by excluding "." and ".."

[tip-bot for Gui Jianfeng]

Commit-ID:  c214909b36efec632432acdcbfacdd46a6e11370
Gitweb:     http://git.kernel.org/tip/c214909b36efec632432acdcbfacdd46a6e11370
Author:     Gui Jianfeng <guijianfeng@cn.fujitsu.com>
AuthorDate: Wed, 16 Jun 2010 13:21:44 +0800
Committer:  Arnaldo Carvalho de Melo <acme@redhat.com>
CommitDate: Thu, 1 Jul 2010 14:02:38 -0300

perf tools: Fix find tids routine by excluding "." and ".."

Introduce a filter function to skip "." and ".." directories when calculating
tid number, otherwise tid 0 will be included in the all_tid result array.

Cc: Ingo Molnar <mingo@elte.hu>
LKML-Reference: <4C185F68.1020505@cn.fujitsu.com>
Signed-off-by: Gui Jianfeng <guijianfeng@cn.fujitsu.com>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
---
 tools/perf/util/thread.c |   11 ++++++++++-
 1 files changed, 10 insertions(+), 1 deletions(-)

diff --git a/tools/perf/util/thread.c b/tools/perf/util/thread.c
index 1f7ecd4..9a448b4 100644
--- a/tools/perf/util/thread.c
+++ b/tools/perf/util/thread.c
@@ -7,6 +7,15 @@
 #include "util.h"
 #include "debug.h"
 
+/* Skip "." and ".." directories */
+static int filter(const struct dirent *dir)
+{
+	if (dir->d_name[0] == '.')
+		return 0;
+	else
+		return 1;
+}
+
 int find_all_tid(int pid, pid_t ** all_tid)
 {
 	char name[256];
@@ -16,7 +25,7 @@ int find_all_tid(int pid, pid_t ** all_tid)
 	int i;
 
 	sprintf(name, "/proc/%d/task", pid);
-	items = scandir(name, &namelist, NULL, NULL);
+	items = scandir(name, &namelist, filter, NULL);
 	if (items <= 0)
                 return -ENOENT;
 	*all_tid = malloc(sizeof(pid_t) * items);