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* [PATCH 1/2] taskstats: factor out reply assembling
@ 2006-11-01 18:26 Oleg Nesterov
  2006-11-01 20:31 ` Shailabh Nagar
                   ` (2 more replies)
  0 siblings, 3 replies; 7+ messages in thread
From: Oleg Nesterov @ 2006-11-01 18:26 UTC (permalink / raw)
  To: Andrew Morton
  Cc: Thomas Graf, Shailabh Nagar, Balbir Singh, Jay Lan, linux-kernel

Introduce mk_reply() helper which does all nla_put()s on reply.

Saves 453 bytes and a preparation for the next patch.

Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru>

 taskstats.c |   55 ++++++++++++++++++++++++++++---------------------------
 1 files changed, 28 insertions(+), 27 deletions(-)

--- STATS/kernel/taskstats.c~5_factor	2006-10-31 16:33:56.000000000 +0300
+++ STATS/kernel/taskstats.c	2006-11-01 14:00:03.000000000 +0300
@@ -348,6 +348,25 @@ static int parse(struct nlattr *na, cpum
 	return ret;
 }
 
+static int mk_reply(struct sk_buff *skb, int type, u32 pid, struct taskstats *stats)
+{
+	struct nlattr *na;
+	int aggr;
+
+	aggr = TASKSTATS_TYPE_AGGR_TGID;
+	if (type == TASKSTATS_TYPE_PID)
+		aggr = TASKSTATS_TYPE_AGGR_PID;
+
+	na = nla_nest_start(skb, aggr);
+	NLA_PUT_U32(skb, type, pid);
+	NLA_PUT_TYPE(skb, struct taskstats, TASKSTATS_TYPE_STATS, *stats);
+	nla_nest_end(skb, na);
+
+	return 0;
+nla_put_failure:
+	return -1;
+}
+
 static int taskstats_user_cmd(struct sk_buff *skb, struct genl_info *info)
 {
 	int rc = 0;
@@ -355,7 +374,6 @@ static int taskstats_user_cmd(struct sk_
 	struct taskstats stats;
 	void *reply;
 	size_t size;
-	struct nlattr *na;
 	cpumask_t mask;
 
 	rc = parse(info->attrs[TASKSTATS_CMD_ATTR_REGISTER_CPUMASK], &mask);
@@ -387,27 +405,21 @@ static int taskstats_user_cmd(struct sk_
 		if (rc < 0)
 			goto err;
 
-		na = nla_nest_start(rep_skb, TASKSTATS_TYPE_AGGR_PID);
-		NLA_PUT_U32(rep_skb, TASKSTATS_TYPE_PID, pid);
-		NLA_PUT_TYPE(rep_skb, struct taskstats, TASKSTATS_TYPE_STATS,
-				stats);
+		if (mk_reply(rep_skb, TASKSTATS_TYPE_PID, pid, &stats))
+			goto nla_put_failure;
 	} else if (info->attrs[TASKSTATS_CMD_ATTR_TGID]) {
 		u32 tgid = nla_get_u32(info->attrs[TASKSTATS_CMD_ATTR_TGID]);
 		rc = fill_tgid(tgid, NULL, &stats);
 		if (rc < 0)
 			goto err;
 
-		na = nla_nest_start(rep_skb, TASKSTATS_TYPE_AGGR_TGID);
-		NLA_PUT_U32(rep_skb, TASKSTATS_TYPE_TGID, tgid);
-		NLA_PUT_TYPE(rep_skb, struct taskstats, TASKSTATS_TYPE_STATS,
-				stats);
+		if (mk_reply(rep_skb, TASKSTATS_TYPE_TGID, tgid, &stats))
+			goto nla_put_failure;
 	} else {
 		rc = -EINVAL;
 		goto err;
 	}
 
-	nla_nest_end(rep_skb, na);
-
 	return send_reply(rep_skb, info->snd_pid);
 
 nla_put_failure:
@@ -451,7 +463,6 @@ void taskstats_exit(struct task_struct *
 	void *reply;
 	size_t size;
 	int is_thread_group;
-	struct nlattr *na;
 
 	if (!family_registered)
 		return;
@@ -486,27 +497,17 @@ void taskstats_exit(struct task_struct *
 	if (rc < 0)
 		goto err_skb;
 
-	na = nla_nest_start(rep_skb, TASKSTATS_TYPE_AGGR_PID);
-	NLA_PUT_U32(rep_skb, TASKSTATS_TYPE_PID, (u32)tsk->pid);
-	NLA_PUT_TYPE(rep_skb, struct taskstats, TASKSTATS_TYPE_STATS,
-			*tidstats);
-	nla_nest_end(rep_skb, na);
-
-	if (!is_thread_group)
-		goto send;
+	if (mk_reply(rep_skb, TASKSTATS_TYPE_PID, tsk->pid, tidstats))
+		goto nla_put_failure;
 
 	/*
 	 * Doesn't matter if tsk is the leader or the last group member leaving
 	 */
-	if (!group_dead)
+	if (!is_thread_group || !group_dead)
 		goto send;
 
-	na = nla_nest_start(rep_skb, TASKSTATS_TYPE_AGGR_TGID);
-	NLA_PUT_U32(rep_skb, TASKSTATS_TYPE_TGID, (u32)tsk->tgid);
-	/* No locking needed for tsk->signal->stats since group is dead */
-	NLA_PUT_TYPE(rep_skb, struct taskstats, TASKSTATS_TYPE_STATS,
-			*tsk->signal->stats);
-	nla_nest_end(rep_skb, na);
+	if (mk_reply(rep_skb, TASKSTATS_TYPE_TGID, tsk->tgid, tsk->signal->stats))
+		goto nla_put_failure;
 
 send:
 	send_cpu_listeners(rep_skb, listeners);


^ permalink raw reply	[flat|nested] 7+ messages in thread

* Re: [PATCH 1/2] taskstats: factor out reply assembling
  2006-11-01 18:26 [PATCH 1/2] taskstats: factor out reply assembling Oleg Nesterov
@ 2006-11-01 20:31 ` Shailabh Nagar
  2006-11-02  5:13 ` Balbir Singh
  2006-11-02 10:34 ` Thomas Graf
  2 siblings, 0 replies; 7+ messages in thread
From: Shailabh Nagar @ 2006-11-01 20:31 UTC (permalink / raw)
  To: Oleg Nesterov
  Cc: Andrew Morton, Thomas Graf, Balbir Singh, Jay Lan, linux-kernel

Oleg Nesterov wrote:
> Introduce mk_reply() helper which does all nla_put()s on reply.
> 
> Saves 453 bytes and a preparation for the next patch.
> 
> Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru>

Acked-by: Shailabh Nagar <nagar@watson.ibm.com>

> 
>  taskstats.c |   55 ++++++++++++++++++++++++++++---------------------------
>  1 files changed, 28 insertions(+), 27 deletions(-)
> 
> --- STATS/kernel/taskstats.c~5_factor	2006-10-31 16:33:56.000000000 +0300
> +++ STATS/kernel/taskstats.c	2006-11-01 14:00:03.000000000 +0300
> @@ -348,6 +348,25 @@ static int parse(struct nlattr *na, cpum
>  	return ret;
>  }
>  
> +static int mk_reply(struct sk_buff *skb, int type, u32 pid, struct taskstats *stats)
> +{
> +	struct nlattr *na;
> +	int aggr;
> +
> +	aggr = TASKSTATS_TYPE_AGGR_TGID;
> +	if (type == TASKSTATS_TYPE_PID)
> +		aggr = TASKSTATS_TYPE_AGGR_PID;
> +
> +	na = nla_nest_start(skb, aggr);
> +	NLA_PUT_U32(skb, type, pid);
> +	NLA_PUT_TYPE(skb, struct taskstats, TASKSTATS_TYPE_STATS, *stats);
> +	nla_nest_end(skb, na);
> +
> +	return 0;
> +nla_put_failure:
> +	return -1;
> +}
> +
>  static int taskstats_user_cmd(struct sk_buff *skb, struct genl_info *info)
>  {
>  	int rc = 0;
> @@ -355,7 +374,6 @@ static int taskstats_user_cmd(struct sk_
>  	struct taskstats stats;
>  	void *reply;
>  	size_t size;
> -	struct nlattr *na;
>  	cpumask_t mask;
>  
>  	rc = parse(info->attrs[TASKSTATS_CMD_ATTR_REGISTER_CPUMASK], &mask);
> @@ -387,27 +405,21 @@ static int taskstats_user_cmd(struct sk_
>  		if (rc < 0)
>  			goto err;
>  
> -		na = nla_nest_start(rep_skb, TASKSTATS_TYPE_AGGR_PID);
> -		NLA_PUT_U32(rep_skb, TASKSTATS_TYPE_PID, pid);
> -		NLA_PUT_TYPE(rep_skb, struct taskstats, TASKSTATS_TYPE_STATS,
> -				stats);
> +		if (mk_reply(rep_skb, TASKSTATS_TYPE_PID, pid, &stats))
> +			goto nla_put_failure;
>  	} else if (info->attrs[TASKSTATS_CMD_ATTR_TGID]) {
>  		u32 tgid = nla_get_u32(info->attrs[TASKSTATS_CMD_ATTR_TGID]);
>  		rc = fill_tgid(tgid, NULL, &stats);
>  		if (rc < 0)
>  			goto err;
>  
> -		na = nla_nest_start(rep_skb, TASKSTATS_TYPE_AGGR_TGID);
> -		NLA_PUT_U32(rep_skb, TASKSTATS_TYPE_TGID, tgid);
> -		NLA_PUT_TYPE(rep_skb, struct taskstats, TASKSTATS_TYPE_STATS,
> -				stats);
> +		if (mk_reply(rep_skb, TASKSTATS_TYPE_TGID, tgid, &stats))
> +			goto nla_put_failure;
>  	} else {
>  		rc = -EINVAL;
>  		goto err;
>  	}
>  
> -	nla_nest_end(rep_skb, na);
> -
>  	return send_reply(rep_skb, info->snd_pid);
>  
>  nla_put_failure:
> @@ -451,7 +463,6 @@ void taskstats_exit(struct task_struct *
>  	void *reply;
>  	size_t size;
>  	int is_thread_group;
> -	struct nlattr *na;
>  
>  	if (!family_registered)
>  		return;
> @@ -486,27 +497,17 @@ void taskstats_exit(struct task_struct *
>  	if (rc < 0)
>  		goto err_skb;
>  
> -	na = nla_nest_start(rep_skb, TASKSTATS_TYPE_AGGR_PID);
> -	NLA_PUT_U32(rep_skb, TASKSTATS_TYPE_PID, (u32)tsk->pid);
> -	NLA_PUT_TYPE(rep_skb, struct taskstats, TASKSTATS_TYPE_STATS,
> -			*tidstats);
> -	nla_nest_end(rep_skb, na);
> -
> -	if (!is_thread_group)
> -		goto send;
> +	if (mk_reply(rep_skb, TASKSTATS_TYPE_PID, tsk->pid, tidstats))
> +		goto nla_put_failure;
>  
>  	/*
>  	 * Doesn't matter if tsk is the leader or the last group member leaving
>  	 */
> -	if (!group_dead)
> +	if (!is_thread_group || !group_dead)
>  		goto send;
>  
> -	na = nla_nest_start(rep_skb, TASKSTATS_TYPE_AGGR_TGID);
> -	NLA_PUT_U32(rep_skb, TASKSTATS_TYPE_TGID, (u32)tsk->tgid);
> -	/* No locking needed for tsk->signal->stats since group is dead */
> -	NLA_PUT_TYPE(rep_skb, struct taskstats, TASKSTATS_TYPE_STATS,
> -			*tsk->signal->stats);
> -	nla_nest_end(rep_skb, na);
> +	if (mk_reply(rep_skb, TASKSTATS_TYPE_TGID, tsk->tgid, tsk->signal->stats))
> +		goto nla_put_failure;
>  
>  send:
>  	send_cpu_listeners(rep_skb, listeners);
> 


^ permalink raw reply	[flat|nested] 7+ messages in thread

* Re: [PATCH 1/2] taskstats: factor out reply assembling
  2006-11-01 18:26 [PATCH 1/2] taskstats: factor out reply assembling Oleg Nesterov
  2006-11-01 20:31 ` Shailabh Nagar
@ 2006-11-02  5:13 ` Balbir Singh
  2006-11-02 13:22   ` Oleg Nesterov
  2006-11-02 10:34 ` Thomas Graf
  2 siblings, 1 reply; 7+ messages in thread
From: Balbir Singh @ 2006-11-02  5:13 UTC (permalink / raw)
  To: Oleg Nesterov
  Cc: Andrew Morton, Thomas Graf, Shailabh Nagar, Jay Lan, linux-kernel

Oleg Nesterov wrote:
> Introduce mk_reply() helper which does all nla_put()s on reply.
> 
> Saves 453 bytes and a preparation for the next patch.
> 
> Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru>
> 
>  taskstats.c |   55 ++++++++++++++++++++++++++++---------------------------
>  1 files changed, 28 insertions(+), 27 deletions(-)
> 
> --- STATS/kernel/taskstats.c~5_factor	2006-10-31 16:33:56.000000000 +0300
> +++ STATS/kernel/taskstats.c	2006-11-01 14:00:03.000000000 +0300
> @@ -348,6 +348,25 @@ static int parse(struct nlattr *na, cpum
>  	return ret;
>  }
>  
> +static int mk_reply(struct sk_buff *skb, int type, u32 pid, struct taskstats *stats)
> +{
> +	struct nlattr *na;
> +	int aggr;
> +
> +	aggr = TASKSTATS_TYPE_AGGR_TGID;
> +	if (type == TASKSTATS_TYPE_PID)
> +		aggr = TASKSTATS_TYPE_AGGR_PID;
> +
> +	na = nla_nest_start(skb, aggr);
> +	NLA_PUT_U32(skb, type, pid);
> +	NLA_PUT_TYPE(skb, struct taskstats, TASKSTATS_TYPE_STATS, *stats);
> +	nla_nest_end(skb, na);
> +
> +	return 0;
> +nla_put_failure:
> +	return -1;
> +}
> +

How about using

aggr = (type == TASKSTATS_TYPE_PID) ? TASKSTATS_TYPE_AGGR_PID  :
				TASKSTATS_TYPE_AGGR_TGID;



>  static int taskstats_user_cmd(struct sk_buff *skb, struct genl_info *info)
>  {
>  	int rc = 0;
> @@ -355,7 +374,6 @@ static int taskstats_user_cmd(struct sk_
>  	struct taskstats stats;
>  	void *reply;
>  	size_t size;
> -	struct nlattr *na;
>  	cpumask_t mask;
>  
>  	rc = parse(info->attrs[TASKSTATS_CMD_ATTR_REGISTER_CPUMASK], &mask);
> @@ -387,27 +405,21 @@ static int taskstats_user_cmd(struct sk_
>  		if (rc < 0)
>  			goto err;
>  
> -		na = nla_nest_start(rep_skb, TASKSTATS_TYPE_AGGR_PID);
> -		NLA_PUT_U32(rep_skb, TASKSTATS_TYPE_PID, pid);
> -		NLA_PUT_TYPE(rep_skb, struct taskstats, TASKSTATS_TYPE_STATS,
> -				stats);
> +		if (mk_reply(rep_skb, TASKSTATS_TYPE_PID, pid, &stats))
> +			goto nla_put_failure;
>  	} else if (info->attrs[TASKSTATS_CMD_ATTR_TGID]) {
>  		u32 tgid = nla_get_u32(info->attrs[TASKSTATS_CMD_ATTR_TGID]);
>  		rc = fill_tgid(tgid, NULL, &stats);
>  		if (rc < 0)
>  			goto err;
>  
> -		na = nla_nest_start(rep_skb, TASKSTATS_TYPE_AGGR_TGID);
> -		NLA_PUT_U32(rep_skb, TASKSTATS_TYPE_TGID, tgid);
> -		NLA_PUT_TYPE(rep_skb, struct taskstats, TASKSTATS_TYPE_STATS,
> -				stats);
> +		if (mk_reply(rep_skb, TASKSTATS_TYPE_TGID, tgid, &stats))
> +			goto nla_put_failure;
>  	} else {
>  		rc = -EINVAL;
>  		goto err;
>  	}
>  
> -	nla_nest_end(rep_skb, na);
> -
>  	return send_reply(rep_skb, info->snd_pid);
>  
>  nla_put_failure:
> @@ -451,7 +463,6 @@ void taskstats_exit(struct task_struct *
>  	void *reply;
>  	size_t size;
>  	int is_thread_group;
> -	struct nlattr *na;
>  
>  	if (!family_registered)
>  		return;
> @@ -486,27 +497,17 @@ void taskstats_exit(struct task_struct *
>  	if (rc < 0)
>  		goto err_skb;
>  
> -	na = nla_nest_start(rep_skb, TASKSTATS_TYPE_AGGR_PID);
> -	NLA_PUT_U32(rep_skb, TASKSTATS_TYPE_PID, (u32)tsk->pid);
> -	NLA_PUT_TYPE(rep_skb, struct taskstats, TASKSTATS_TYPE_STATS,
> -			*tidstats);
> -	nla_nest_end(rep_skb, na);
> -
> -	if (!is_thread_group)
> -		goto send;
> +	if (mk_reply(rep_skb, TASKSTATS_TYPE_PID, tsk->pid, tidstats))
> +		goto nla_put_failure;
>  
>  	/*
>  	 * Doesn't matter if tsk is the leader or the last group member leaving
>  	 */
> -	if (!group_dead)
> +	if (!is_thread_group || !group_dead)
>  		goto send;
>  
> -	na = nla_nest_start(rep_skb, TASKSTATS_TYPE_AGGR_TGID);
> -	NLA_PUT_U32(rep_skb, TASKSTATS_TYPE_TGID, (u32)tsk->tgid);
> -	/* No locking needed for tsk->signal->stats since group is dead */
> -	NLA_PUT_TYPE(rep_skb, struct taskstats, TASKSTATS_TYPE_STATS,
> -			*tsk->signal->stats);
> -	nla_nest_end(rep_skb, na);
> +	if (mk_reply(rep_skb, TASKSTATS_TYPE_TGID, tsk->tgid, tsk->signal->stats))
> +		goto nla_put_failure;
>  
>  send:
>  	send_cpu_listeners(rep_skb, listeners);
> 

Looks good!

Acked-by: Balbir Singh <balbir@in.ibm.com>

-- 

	Balbir Singh,
	Linux Technology Center,
	IBM Software Labs

^ permalink raw reply	[flat|nested] 7+ messages in thread

* Re: [PATCH 1/2] taskstats: factor out reply assembling
  2006-11-01 18:26 [PATCH 1/2] taskstats: factor out reply assembling Oleg Nesterov
  2006-11-01 20:31 ` Shailabh Nagar
  2006-11-02  5:13 ` Balbir Singh
@ 2006-11-02 10:34 ` Thomas Graf
  2006-11-02 12:37   ` Shailabh Nagar
  2 siblings, 1 reply; 7+ messages in thread
From: Thomas Graf @ 2006-11-02 10:34 UTC (permalink / raw)
  To: Oleg Nesterov
  Cc: Andrew Morton, Shailabh Nagar, Balbir Singh, Jay Lan,
	linux-kernel

* Oleg Nesterov <oleg@tv-sign.ru> 2006-11-01 21:26
> Introduce mk_reply() helper which does all nla_put()s on reply.
> 
> Saves 453 bytes and a preparation for the next patch.
> 
> Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru>
> 
>  taskstats.c |   55 ++++++++++++++++++++++++++++---------------------------
>  1 files changed, 28 insertions(+), 27 deletions(-)
> 
> --- STATS/kernel/taskstats.c~5_factor	2006-10-31 16:33:56.000000000 +0300
> +++ STATS/kernel/taskstats.c	2006-11-01 14:00:03.000000000 +0300
> @@ -348,6 +348,25 @@ static int parse(struct nlattr *na, cpum
>  	return ret;
>  }
>  
> +static int mk_reply(struct sk_buff *skb, int type, u32 pid, struct taskstats *stats)
> +{
> +	struct nlattr *na;
> +	int aggr;
> +
> +	aggr = TASKSTATS_TYPE_AGGR_TGID;
> +	if (type == TASKSTATS_TYPE_PID)
> +		aggr = TASKSTATS_TYPE_AGGR_PID;
> +
> +	na = nla_nest_start(skb, aggr);
> +	NLA_PUT_U32(skb, type, pid);
> +	NLA_PUT_TYPE(skb, struct taskstats, TASKSTATS_TYPE_STATS, *stats);
> +	nla_nest_end(skb, na);
> +
> +	return 0;
> +nla_put_failure:
> +	return -1;
> +}

nla_nest_start() may return NULL, either rely on prepare_reply() to be
correct and BUG() on failure or do proper error handling for all
functions.


^ permalink raw reply	[flat|nested] 7+ messages in thread

* Re: [PATCH 1/2] taskstats: factor out reply assembling
  2006-11-02 10:34 ` Thomas Graf
@ 2006-11-02 12:37   ` Shailabh Nagar
  0 siblings, 0 replies; 7+ messages in thread
From: Shailabh Nagar @ 2006-11-02 12:37 UTC (permalink / raw)
  To: Thomas Graf
  Cc: Oleg Nesterov, Andrew Morton, Balbir Singh, Jay Lan, linux-kernel

Thomas Graf wrote:
> * Oleg Nesterov <oleg@tv-sign.ru> 2006-11-01 21:26
>> Introduce mk_reply() helper which does all nla_put()s on reply.
>>
>> Saves 453 bytes and a preparation for the next patch.
>>
>> Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru>
>>
>>  taskstats.c |   55 ++++++++++++++++++++++++++++---------------------------
>>  1 files changed, 28 insertions(+), 27 deletions(-)
>>
>> --- STATS/kernel/taskstats.c~5_factor	2006-10-31 16:33:56.000000000 +0300
>> +++ STATS/kernel/taskstats.c	2006-11-01 14:00:03.000000000 +0300
>> @@ -348,6 +348,25 @@ static int parse(struct nlattr *na, cpum
>>  	return ret;
>>  }
>>  
>> +static int mk_reply(struct sk_buff *skb, int type, u32 pid, struct taskstats *stats)
>> +{
>> +	struct nlattr *na;
>> +	int aggr;
>> +
>> +	aggr = TASKSTATS_TYPE_AGGR_TGID;
>> +	if (type == TASKSTATS_TYPE_PID)
>> +		aggr = TASKSTATS_TYPE_AGGR_PID;
>> +
>> +	na = nla_nest_start(skb, aggr);

	if (!na)
		goto nla_put_failure;

>> +	NLA_PUT_U32(skb, type, pid);
>> +	NLA_PUT_TYPE(skb, struct taskstats, TASKSTATS_TYPE_STATS, *stats);
>> +	nla_nest_end(skb, na);
>> +
>> +	return 0;
>> +nla_put_failure:
>> +	return -1;
>> +}
> 
> nla_nest_start() may return NULL, either rely on prepare_reply() to be
> correct and BUG() on failure or do proper error handling for all
> functions.

Thanks for catching that bug which was present in the unrefactored code.
The error path from prepare_reply() which generates the skb is being
handled already.

But as you point out, nla_nest_start failure, unlike those of the NLA_PUT_*
macros, isn't handled by having a nla_put_failure label alone. So we'll
need to add something like the above since we certainly don't want a BUG()
on failure !

Thanks,
Shailabh



^ permalink raw reply	[flat|nested] 7+ messages in thread

* Re: [PATCH 1/2] taskstats: factor out reply assembling
  2006-11-02  5:13 ` Balbir Singh
@ 2006-11-02 13:22   ` Oleg Nesterov
  2006-11-02 13:44     ` Balbir Singh
  0 siblings, 1 reply; 7+ messages in thread
From: Oleg Nesterov @ 2006-11-02 13:22 UTC (permalink / raw)
  To: Balbir Singh
  Cc: Andrew Morton, Thomas Graf, Shailabh Nagar, Jay Lan, linux-kernel

On 11/02, Balbir Singh wrote:
>
> Oleg Nesterov wrote:
> > +
> > +	aggr = TASKSTATS_TYPE_AGGR_TGID;
> > +	if (type == TASKSTATS_TYPE_PID)
> > +		aggr = TASKSTATS_TYPE_AGGR_PID;
> 
> How about using
> 
> aggr = (type == TASKSTATS_TYPE_PID) ? TASKSTATS_TYPE_AGGR_PID  :
> 				TASKSTATS_TYPE_AGGR_TGID;

I personally think this is much better. In fact, i did exactly same, but
then changed it because (I think) CodingStyle police doesn't like '?:'.

Or it does?

Oleg.


^ permalink raw reply	[flat|nested] 7+ messages in thread

* Re: [PATCH 1/2] taskstats: factor out reply assembling
  2006-11-02 13:22   ` Oleg Nesterov
@ 2006-11-02 13:44     ` Balbir Singh
  0 siblings, 0 replies; 7+ messages in thread
From: Balbir Singh @ 2006-11-02 13:44 UTC (permalink / raw)
  To: Oleg Nesterov
  Cc: Andrew Morton, Thomas Graf, Shailabh Nagar, Jay Lan, linux-kernel

Oleg Nesterov wrote:
> On 11/02, Balbir Singh wrote:
>> Oleg Nesterov wrote:
>>> +
>>> +	aggr = TASKSTATS_TYPE_AGGR_TGID;
>>> +	if (type == TASKSTATS_TYPE_PID)
>>> +		aggr = TASKSTATS_TYPE_AGGR_PID;
>> How about using
>>
>> aggr = (type == TASKSTATS_TYPE_PID) ? TASKSTATS_TYPE_AGGR_PID  :
>> 				TASKSTATS_TYPE_AGGR_TGID;
> 
> I personally think this is much better. In fact, i did exactly same, but
> then changed it because (I think) CodingStyle police doesn't like '?:'.
> 
> Or it does?
> 
> Oleg.
> 

There is an issue with double assignment if the type is TASKSTATS_TYPE_PID most
of the time. I see the '?' operator in several places in the code.

-- 

	Balbir Singh,
	Linux Technology Center,
	IBM Software Labs

^ permalink raw reply	[flat|nested] 7+ messages in thread

end of thread, other threads:[~2006-11-02 13:45 UTC | newest]

Thread overview: 7+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
2006-11-01 18:26 [PATCH 1/2] taskstats: factor out reply assembling Oleg Nesterov
2006-11-01 20:31 ` Shailabh Nagar
2006-11-02  5:13 ` Balbir Singh
2006-11-02 13:22   ` Oleg Nesterov
2006-11-02 13:44     ` Balbir Singh
2006-11-02 10:34 ` Thomas Graf
2006-11-02 12:37   ` Shailabh Nagar

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