[PATCH 1/2] sched/prio: Add two inline function named nice_to_rlimit() and rlimit_to_nice() in prio.h.

[PATCH 1/2] sched/prio: Add two inline function named nice_to_rlimit() and rlimit_to_nice() in prio.h.

[Dongsheng Yang]

This patch add two inline functions named nice_to_rlimit() and rlimit_to_nice() in prio.h.
They are handle the convertion between nice value [19,-20] and rlimit style value [1,40].

Signed-off-by: Dongsheng Yang <yangds.fnst@cn.fujitsu.com>
---
 include/linux/sched/prio.h | 16 ++++++++++++++++
 1 file changed, 16 insertions(+)

diff --git a/include/linux/sched/prio.h b/include/linux/sched/prio.h
index ac32258..d9cf5a5 100644
--- a/include/linux/sched/prio.h
+++ b/include/linux/sched/prio.h
@@ -41,4 +41,20 @@
 #define TASK_USER_PRIO(p)	USER_PRIO((p)->static_prio)
 #define MAX_USER_PRIO		(USER_PRIO(MAX_PRIO))
 
+/*
+ * Convert nice value [19,-20] to rlimit style value [1,40].
+ */
+static inline long nice_to_rlimit(long nice)
+{
+	return (MAX_NICE - nice + 1);
+}
+
+/*
+ * Convert rlimit style value [1,40] to nice value [-20, 19].
+ */
+static inline long rlimit_to_nice(long prio)
+{
+	return (MAX_NICE - prio + 1);
+}
+
 #endif /* _SCHED_PRIO_H */
-- 
1.8.2.1

[PATCH 2/2] treewide: remove all open implementation of nice_to_rlimit()/rlimit_to_nice().

[Dongsheng Yang]

As there are already two inline functions in prio.h to handle the convertiion
between nice value and rlimit style value of priority, this patch remove all
open implementation of these two functions.

Signed-off-by: Dongsheng Yang <yangds.fnst@cn.fujitsu.com>
---
 drivers/staging/android/binder.c | 2 +-
 kernel/sched/core.c              | 2 +-
 kernel/sys.c                     | 6 +++---
 3 files changed, 5 insertions(+), 5 deletions(-)

diff --git a/drivers/staging/android/binder.c b/drivers/staging/android/binder.c
index 179b21b..9311bb6 100644
--- a/drivers/staging/android/binder.c
+++ b/drivers/staging/android/binder.c
@@ -436,7 +436,7 @@ static void binder_set_nice(long nice)
 		set_user_nice(current, nice);
 		return;
 	}
-	min_nice = 20 - current->signal->rlim[RLIMIT_NICE].rlim_cur;
+	min_nice = rlimit_to_nice(current->signal->rlim[RLIMIT_NICE].rlim_cur);
 	binder_debug(BINDER_DEBUG_PRIORITY_CAP,
 		     "%d: nice value %ld not allowed use %ld instead\n",
 		      current->pid, nice, min_nice);
diff --git a/kernel/sched/core.c b/kernel/sched/core.c
index ea55072..ff871f5 100644
--- a/kernel/sched/core.c
+++ b/kernel/sched/core.c
@@ -3015,7 +3015,7 @@ EXPORT_SYMBOL(set_user_nice);
 int can_nice(const struct task_struct *p, const int nice)
 {
 	/* convert nice value [19,-20] to rlimit style value [1,40] */
-	int nice_rlim = 20 - nice;
+	int nice_rlim = nice_to_rlimit(nice);
 
 	return (nice_rlim <= task_rlimit(p, RLIMIT_NICE) ||
 		capable(CAP_SYS_NICE));
diff --git a/kernel/sys.c b/kernel/sys.c
index fba0f29..66a751e 100644
--- a/kernel/sys.c
+++ b/kernel/sys.c
@@ -250,7 +250,7 @@ SYSCALL_DEFINE2(getpriority, int, which, int, who)
 			else
 				p = current;
 			if (p) {
-				niceval = 20 - task_nice(p);
+				niceval = nice_to_rlimit(task_nice(p));
 				if (niceval > retval)
 					retval = niceval;
 			}
@@ -261,7 +261,7 @@ SYSCALL_DEFINE2(getpriority, int, which, int, who)
 			else
 				pgrp = task_pgrp(current);
 			do_each_pid_thread(pgrp, PIDTYPE_PGID, p) {
-				niceval = 20 - task_nice(p);
+				niceval = nice_to_rlimit(task_nice(p));
 				if (niceval > retval)
 					retval = niceval;
 			} while_each_pid_thread(pgrp, PIDTYPE_PGID, p);
@@ -277,7 +277,7 @@ SYSCALL_DEFINE2(getpriority, int, which, int, who)
 
 			do_each_thread(g, p) {
 				if (uid_eq(task_uid(p), uid)) {
-					niceval = 20 - task_nice(p);
+					niceval = nice_to_rlimit(task_nice(p));
 					if (niceval > retval)
 						retval = niceval;
 				}
-- 
1.8.2.1

Re: [PATCH 2/2] treewide: remove all open implementation of nice_to_rlimit()/rlimit_to_nice().

[Peter Zijlstra]

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On Thu, May 08, 2014 at 06:33:49PM +0900, Dongsheng Yang wrote:
> As there are already two inline functions in prio.h to handle the convertiion
> between nice value and rlimit style value of priority, this patch remove all
> open implementation of these two functions.
> 
> Signed-off-by: Dongsheng Yang <yangds.fnst@cn.fujitsu.com>
> ---
>  drivers/staging/android/binder.c | 2 +-
>  kernel/sched/core.c              | 2 +-
>  kernel/sys.c                     | 6 +++---
>  3 files changed, 5 insertions(+), 5 deletions(-)
> 
> diff --git a/drivers/staging/android/binder.c b/drivers/staging/android/binder.c
> index 179b21b..9311bb6 100644
> --- a/drivers/staging/android/binder.c
> +++ b/drivers/staging/android/binder.c
> @@ -436,7 +436,7 @@ static void binder_set_nice(long nice)
>  		set_user_nice(current, nice);
>  		return;
>  	}
> -	min_nice = 20 - current->signal->rlim[RLIMIT_NICE].rlim_cur;
> +	min_nice = rlimit_to_nice(current->signal->rlim[RLIMIT_NICE].rlim_cur);
>  	binder_debug(BINDER_DEBUG_PRIORITY_CAP,
>  		     "%d: nice value %ld not allowed use %ld instead\n",
>  		      current->pid, nice, min_nice);

One does wonder WTF binder is smoking.. must be strong stuff. That's
some qualitee crackpot code there.

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Re: [PATCH 2/2] treewide: remove all open implementation of nice_to_rlimit()/rlimit_to_nice().

[Peter Zijlstra]

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On Thu, May 08, 2014 at 10:51:13PM +0800, Dongsheng Yang wrote:
> Just want to avoid using hardcoding of 20. If no, there is no meaning we
> collect
> priority related information into prio.h.  And convertion between nice
> value [-20,19]
> and rlimit style value [0,40] is used by several callers currently.
> 

Yeah, not really a comment on your patch, just a general observation on
the thing you touched :-)

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Re: [PATCH 2/2] treewide: remove all open implementation of nice_to_rlimit()/rlimit_to_nice().

[Dongsheng Yang]

On 05/09/2014 12:26 AM, Peter Zijlstra wrote:
> On Thu, May 08, 2014 at 10:51:13PM +0800, Dongsheng Yang wrote:
>> Just want to avoid using hardcoding of 20. If no, there is no meaning we
>> collect
>> priority related information into prio.h.  And convertion between nice
>> value [-20,19]
>> and rlimit style value [0,40] is used by several callers currently.
>>
> Yeah, not really a comment on your patch, just a general observation on
> the thing you touched :-)

Ha, okey, thanx for your reply. :)

[tip:sched/core] sched/prio: Add two inline function named nice_to_rlimit() and rlimit_to_nice() in prio.h.

[tip-bot for Dongsheng Yang]

Commit-ID:  b482e5f5c22ef95ffe7c4d86fc9719455fb24bca
Gitweb:     http://git.kernel.org/tip/b482e5f5c22ef95ffe7c4d86fc9719455fb24bca
Author:     Dongsheng Yang <yangds.fnst@cn.fujitsu.com>
AuthorDate: Thu, 8 May 2014 18:33:48 +0900
Committer:  Thomas Gleixner <tglx@linutronix.de>
CommitDate: Mon, 19 May 2014 22:02:42 +0900

sched/prio: Add two inline function named nice_to_rlimit() and rlimit_to_nice() in prio.h.

This patch add two inline functions named nice_to_rlimit() and
rlimit_to_nice() in prio.h.  They are handle the convertion between
nice value [19,-20] and rlimit style value [1,40].

Cc: mingo@redhat.com
Signed-off-by: Dongsheng Yang <yangds.fnst@cn.fujitsu.com>
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/e1f9c9f2023719e0738e16cd6807c74c68b08fad.1399532322.git.yangds.fnst@cn.fujitsu.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
---
 include/linux/sched/prio.h | 16 ++++++++++++++++
 1 file changed, 16 insertions(+)

diff --git a/include/linux/sched/prio.h b/include/linux/sched/prio.h
index ac32258..d9cf5a5 100644
--- a/include/linux/sched/prio.h
+++ b/include/linux/sched/prio.h
@@ -41,4 +41,20 @@
 #define TASK_USER_PRIO(p)	USER_PRIO((p)->static_prio)
 #define MAX_USER_PRIO		(USER_PRIO(MAX_PRIO))
 
+/*
+ * Convert nice value [19,-20] to rlimit style value [1,40].
+ */
+static inline long nice_to_rlimit(long nice)
+{
+	return (MAX_NICE - nice + 1);
+}
+
+/*
+ * Convert rlimit style value [1,40] to nice value [-20, 19].
+ */
+static inline long rlimit_to_nice(long prio)
+{
+	return (MAX_NICE - prio + 1);
+}
+
 #endif /* _SCHED_PRIO_H */

[tip:sched/core] sched: Remove all open implementation of nice_to_rlimit()/rlimit_to_nice().

[tip-bot for Dongsheng Yang]

Commit-ID:  f6156cfc0d785f8ef195d6c2f538113e041b6d44
Gitweb:     http://git.kernel.org/tip/f6156cfc0d785f8ef195d6c2f538113e041b6d44
Author:     Dongsheng Yang <yangds.fnst@cn.fujitsu.com>
AuthorDate: Thu, 8 May 2014 18:33:49 +0900
Committer:  Thomas Gleixner <tglx@linutronix.de>
CommitDate: Mon, 19 May 2014 22:02:42 +0900

sched: Remove all open implementation of nice_to_rlimit()/rlimit_to_nice().

As there are already two inline functions in prio.h to handle the convertiion
between nice value and rlimit style value of priority, this patch remove all
open implementation of these two functions.

Cc: mingo@redhat.com
Signed-off-by: Dongsheng Yang <yangds.fnst@cn.fujitsu.com>
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/a568a1e3cc8e78648f41b5035fa5e381d36274da.1399532322.git.yangds.fnst@cn.fujitsu.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
---
 drivers/staging/android/binder.c | 2 +-
 kernel/sched/core.c              | 2 +-
 kernel/sys.c                     | 6 +++---
 3 files changed, 5 insertions(+), 5 deletions(-)

diff --git a/drivers/staging/android/binder.c b/drivers/staging/android/binder.c
index 179b21b..9311bb6 100644
--- a/drivers/staging/android/binder.c
+++ b/drivers/staging/android/binder.c
@@ -436,7 +436,7 @@ static void binder_set_nice(long nice)
 		set_user_nice(current, nice);
 		return;
 	}
-	min_nice = 20 - current->signal->rlim[RLIMIT_NICE].rlim_cur;
+	min_nice = rlimit_to_nice(current->signal->rlim[RLIMIT_NICE].rlim_cur);
 	binder_debug(BINDER_DEBUG_PRIORITY_CAP,
 		     "%d: nice value %ld not allowed use %ld instead\n",
 		      current->pid, nice, min_nice);
diff --git a/kernel/sched/core.c b/kernel/sched/core.c
index c134eb0..084832c 100644
--- a/kernel/sched/core.c
+++ b/kernel/sched/core.c
@@ -3033,7 +3033,7 @@ EXPORT_SYMBOL(set_user_nice);
 int can_nice(const struct task_struct *p, const int nice)
 {
 	/* convert nice value [19,-20] to rlimit style value [1,40] */
-	int nice_rlim = 20 - nice;
+	int nice_rlim = nice_to_rlimit(nice);
 
 	return (nice_rlim <= task_rlimit(p, RLIMIT_NICE) ||
 		capable(CAP_SYS_NICE));
diff --git a/kernel/sys.c b/kernel/sys.c
index fba0f29..66a751e 100644
--- a/kernel/sys.c
+++ b/kernel/sys.c
@@ -250,7 +250,7 @@ SYSCALL_DEFINE2(getpriority, int, which, int, who)
 			else
 				p = current;
 			if (p) {
-				niceval = 20 - task_nice(p);
+				niceval = nice_to_rlimit(task_nice(p));
 				if (niceval > retval)
 					retval = niceval;
 			}
@@ -261,7 +261,7 @@ SYSCALL_DEFINE2(getpriority, int, which, int, who)
 			else
 				pgrp = task_pgrp(current);
 			do_each_pid_thread(pgrp, PIDTYPE_PGID, p) {
-				niceval = 20 - task_nice(p);
+				niceval = nice_to_rlimit(task_nice(p));
 				if (niceval > retval)
 					retval = niceval;
 			} while_each_pid_thread(pgrp, PIDTYPE_PGID, p);
@@ -277,7 +277,7 @@ SYSCALL_DEFINE2(getpriority, int, which, int, who)
 
 			do_each_thread(g, p) {
 				if (uid_eq(task_uid(p), uid)) {
-					niceval = 20 - task_nice(p);
+					niceval = nice_to_rlimit(task_nice(p));
 					if (niceval > retval)
 						retval = niceval;
 				}

[tip:sched/core] sched: Consolidate open coded implementations of nice level frobbing into nice_to_rlimit () and rlimit_to_nice()

[tip-bot for Dongsheng Yang]

Commit-ID:  7aa2c016db2162defff77f6f5731bff3f25e5175
Gitweb:     http://git.kernel.org/tip/7aa2c016db2162defff77f6f5731bff3f25e5175
Author:     Dongsheng Yang <yangds.fnst@cn.fujitsu.com>
AuthorDate: Thu, 8 May 2014 18:33:49 +0900
Committer:  Ingo Molnar <mingo@kernel.org>
CommitDate: Thu, 22 May 2014 11:16:36 +0200

sched: Consolidate open coded implementations of nice level frobbing into nice_to_rlimit() and rlimit_to_nice()

Signed-off-by: Dongsheng Yang <yangds.fnst@cn.fujitsu.com>
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/a568a1e3cc8e78648f41b5035fa5e381d36274da.1399532322.git.yangds.fnst@cn.fujitsu.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
---
 drivers/staging/android/binder.c |  2 +-
 include/linux/sched/prio.h       | 16 ++++++++++++++++
 kernel/sched/core.c              |  2 +-
 kernel/sys.c                     |  6 +++---
 4 files changed, 21 insertions(+), 5 deletions(-)

diff --git a/drivers/staging/android/binder.c b/drivers/staging/android/binder.c
index 179b21b..9311bb6 100644
--- a/drivers/staging/android/binder.c
+++ b/drivers/staging/android/binder.c
@@ -436,7 +436,7 @@ static void binder_set_nice(long nice)
 		set_user_nice(current, nice);
 		return;
 	}
-	min_nice = 20 - current->signal->rlim[RLIMIT_NICE].rlim_cur;
+	min_nice = rlimit_to_nice(current->signal->rlim[RLIMIT_NICE].rlim_cur);
 	binder_debug(BINDER_DEBUG_PRIORITY_CAP,
 		     "%d: nice value %ld not allowed use %ld instead\n",
 		      current->pid, nice, min_nice);
diff --git a/include/linux/sched/prio.h b/include/linux/sched/prio.h
index ac32258..d9cf5a5 100644
--- a/include/linux/sched/prio.h
+++ b/include/linux/sched/prio.h
@@ -41,4 +41,20 @@
 #define TASK_USER_PRIO(p)	USER_PRIO((p)->static_prio)
 #define MAX_USER_PRIO		(USER_PRIO(MAX_PRIO))
 
+/*
+ * Convert nice value [19,-20] to rlimit style value [1,40].
+ */
+static inline long nice_to_rlimit(long nice)
+{
+	return (MAX_NICE - nice + 1);
+}
+
+/*
+ * Convert rlimit style value [1,40] to nice value [-20, 19].
+ */
+static inline long rlimit_to_nice(long prio)
+{
+	return (MAX_NICE - prio + 1);
+}
+
 #endif /* _SCHED_PRIO_H */
diff --git a/kernel/sched/core.c b/kernel/sched/core.c
index da302ca..321d800 100644
--- a/kernel/sched/core.c
+++ b/kernel/sched/core.c
@@ -3033,7 +3033,7 @@ EXPORT_SYMBOL(set_user_nice);
 int can_nice(const struct task_struct *p, const int nice)
 {
 	/* convert nice value [19,-20] to rlimit style value [1,40] */
-	int nice_rlim = 20 - nice;
+	int nice_rlim = nice_to_rlimit(nice);
 
 	return (nice_rlim <= task_rlimit(p, RLIMIT_NICE) ||
 		capable(CAP_SYS_NICE));
diff --git a/kernel/sys.c b/kernel/sys.c
index fba0f29..66a751e 100644
--- a/kernel/sys.c
+++ b/kernel/sys.c
@@ -250,7 +250,7 @@ SYSCALL_DEFINE2(getpriority, int, which, int, who)
 			else
 				p = current;
 			if (p) {
-				niceval = 20 - task_nice(p);
+				niceval = nice_to_rlimit(task_nice(p));
 				if (niceval > retval)
 					retval = niceval;
 			}
@@ -261,7 +261,7 @@ SYSCALL_DEFINE2(getpriority, int, which, int, who)
 			else
 				pgrp = task_pgrp(current);
 			do_each_pid_thread(pgrp, PIDTYPE_PGID, p) {
-				niceval = 20 - task_nice(p);
+				niceval = nice_to_rlimit(task_nice(p));
 				if (niceval > retval)
 					retval = niceval;
 			} while_each_pid_thread(pgrp, PIDTYPE_PGID, p);
@@ -277,7 +277,7 @@ SYSCALL_DEFINE2(getpriority, int, which, int, who)
 
 			do_each_thread(g, p) {
 				if (uid_eq(task_uid(p), uid)) {
-					niceval = 20 - task_nice(p);
+					niceval = nice_to_rlimit(task_nice(p));
 					if (niceval > retval)
 						retval = niceval;
 				}