[PATCH 23/32] powerpc: copy_thread(): rename 'arg' argument to 'kthread_arg'

[PATCH 23/32] powerpc: copy_thread(): rename 'arg' argument to 'kthread_arg'

[Alex Dowad]

The 'arg' argument to copy_thread() is only ever used when forking a new
kernel thread. Hence, rename it to 'kthread_arg' for clarity (and consistency
with do_fork() and other arch-specific implementations of copy_thread()).

Signed-off-by: Alex Dowad <alexinbeijing@gmail.com>
---
 arch/powerpc/kernel/process.c | 9 +++++++--
 1 file changed, 7 insertions(+), 2 deletions(-)

diff --git a/arch/powerpc/kernel/process.c b/arch/powerpc/kernel/process.c
index b4cc7be..febb50d 100644
--- a/arch/powerpc/kernel/process.c
+++ b/arch/powerpc/kernel/process.c
@@ -1114,8 +1114,11 @@ static void setup_ksp_vsid(struct task_struct *p, unsigned long sp)
  */
 extern unsigned long dscr_default; /* defined in arch/powerpc/kernel/sysfs.c */
 
+/*
+ * Copy architecture-specific thread state
+ */
 int copy_thread(unsigned long clone_flags, unsigned long usp,
-		unsigned long arg, struct task_struct *p)
+		unsigned long kthread_arg, struct task_struct *p)
 {
 	struct pt_regs *childregs, *kregs;
 	extern void ret_from_fork(void);
@@ -1127,6 +1130,7 @@ int copy_thread(unsigned long clone_flags, unsigned long usp,
 	sp -= sizeof(struct pt_regs);
 	childregs = (struct pt_regs *) sp;
 	if (unlikely(p->flags & PF_KTHREAD)) {
+		/* kernel thread */
 		struct thread_info *ti = (void *)task_stack_page(p);
 		memset(childregs, 0, sizeof(struct pt_regs));
 		childregs->gpr[1] = sp + sizeof(struct pt_regs);
@@ -1137,11 +1141,12 @@ int copy_thread(unsigned long clone_flags, unsigned long usp,
 		clear_tsk_thread_flag(p, TIF_32BIT);
 		childregs->softe = 1;
 #endif
-		childregs->gpr[15] = arg;
+		childregs->gpr[15] = kthread_arg;
 		p->thread.regs = NULL;	/* no user register state */
 		ti->flags |= _TIF_RESTOREALL;
 		f = ret_from_kernel_thread;
 	} else {
+		/* user thread */
 		struct pt_regs *regs = current_pt_regs();
 		CHECK_FULL_REGS(regs);
 		*childregs = *regs;
-- 
2.0.0.GIT

Re: [23/32] powerpc: copy_thread(): rename 'arg' argument to 'kthread_arg'

[Michael Ellerman]

On Fri, 2015-13-03 at 18:14:46 UTC, Alex Dowad wrote:
> The 'arg' argument to copy_thread() is only ever used when forking a new
> kernel thread. Hence, rename it to 'kthread_arg' for clarity (and consistency
> with do_fork() and other arch-specific implementations of copy_thread()).
 
I don't understand the bit about consistency with do_fork() ?

Otherwise it looks fine.

cheers

Re: [23/32] powerpc: copy_thread(): rename 'arg' argument to 'kthread_arg'

[Alex Dowad]

On 19/03/15 08:45, Michael Ellerman wrote:
> On Fri, 2015-13-03 at 18:14:46 UTC, Alex Dowad wrote:
>> The 'arg' argument to copy_thread() is only ever used when forking a new
>> kernel thread. Hence, rename it to 'kthread_arg' for clarity (and consistency
>> with do_fork() and other arch-specific implementations of copy_thread()).
>   
> I don't understand the bit about consistency with do_fork() ?
This series of patches includes one patch which renames the arg for 
do_fork(), and others which rename the same arg for each arch-specific 
implementation of copy_thread(). So if all of them are accepted and 
merged, then all will be consistent. If only some of the patches are 
accepted, I will rewrite the commit message so it doesn't mention 
"consistency".

Thanks! AD
>
> Otherwise it looks fine.
>
> cheers

Re: [23/32] powerpc: copy_thread(): rename 'arg' argument to 'kthread_arg'

[Michael Ellerman]

On Thu, 2015-03-19 at 09:22 +0200, Alex Dowad wrote:
> On 19/03/15 08:45, Michael Ellerman wrote:
> > On Fri, 2015-13-03 at 18:14:46 UTC, Alex Dowad wrote:
> >> The 'arg' argument to copy_thread() is only ever used when forking a new
> >> kernel thread. Hence, rename it to 'kthread_arg' for clarity (and consistency
> >> with do_fork() and other arch-specific implementations of copy_thread()).
> >   
> > I don't understand the bit about consistency with do_fork() ?

> This series of patches includes one patch which renames the arg for 
> do_fork(), and others which rename the same arg for each arch-specific 
> implementation of copy_thread(). So if all of them are accepted and 
> merged, then all will be consistent. If only some of the patches are 
> accepted, I will rewrite the commit message so it doesn't mention 
> "consistency".

Ah OK, I only got patch 23, so I missed the context of the whole series.

I'll apply this one to the powerpc tree.

cheers

Re: [23/32] powerpc: copy_thread(): rename 'arg' argument to 'kthread_arg'

[Alex Dowad]

On 20/03/15 01:54, Michael Ellerman wrote:
> On Thu, 2015-03-19 at 09:22 +0200, Alex Dowad wrote:
>> On 19/03/15 08:45, Michael Ellerman wrote:
>>> On Fri, 2015-13-03 at 18:14:46 UTC, Alex Dowad wrote:
>>>> The 'arg' argument to copy_thread() is only ever used when forking a new
>>>> kernel thread. Hence, rename it to 'kthread_arg' for clarity (and consistency
>>>> with do_fork() and other arch-specific implementations of copy_thread()).
>>>    
>>> I don't understand the bit about consistency with do_fork() ?
>>>
>> This series of patches includes one patch which renames the arg for
>> do_fork(), and others which rename the same arg for each arch-specific
>> implementation of copy_thread(). So if all of them are accepted and
>> merged, then all will be consistent. If only some of the patches are
>> accepted, I will rewrite the commit message so it doesn't mention
>> "consistency".
> Ah OK, I only got patch 23, so I missed the context of the whole series.
>
> I'll apply this one to the powerpc tree.
>
Dear M. Ellerman, sorry for not replying promptly. If you would like to 
apply this directly to the powerpc tree, that is fine, but can I edit 
the commit message to remove the mention of 'consistency'? I doubt that 
all 30+ archs will ever merge this change. Thanks, Alex

Re: [23/32] powerpc: copy_thread(): rename 'arg' argument to 'kthread_arg'

[Michael Ellerman]

On Tue, 2015-03-24 at 21:49 +0200, Alex Dowad wrote:
> On 20/03/15 01:54, Michael Ellerman wrote:
> > On Thu, 2015-03-19 at 09:22 +0200, Alex Dowad wrote:
> >> On 19/03/15 08:45, Michael Ellerman wrote:
> >>> On Fri, 2015-13-03 at 18:14:46 UTC, Alex Dowad wrote:
> >>>> The 'arg' argument to copy_thread() is only ever used when forking a new
> >>>> kernel thread. Hence, rename it to 'kthread_arg' for clarity (and consistency
> >>>> with do_fork() and other arch-specific implementations of copy_thread()).
> >>>    
> >>> I don't understand the bit about consistency with do_fork() ?
> >>>
> >> This series of patches includes one patch which renames the arg for
> >> do_fork(), and others which rename the same arg for each arch-specific
> >> implementation of copy_thread(). So if all of them are accepted and
> >> merged, then all will be consistent. If only some of the patches are
> >> accepted, I will rewrite the commit message so it doesn't mention
> >> "consistency".
> > Ah OK, I only got patch 23, so I missed the context of the whole series.
> >
> > I'll apply this one to the powerpc tree.
>
> Dear M. Ellerman, sorry for not replying promptly. If you would like to 
> apply this directly to the powerpc tree, that is fine, but can I edit 
> the commit message to remove the mention of 'consistency'? I doubt that 
> all 30+ archs will ever merge this change. Thanks, Alex
 
I merged it last week:

  https://git.kernel.org/cgit/linux/kernel/git/mpe/linux.git/commit/?h=next&id=6eca8933d3ff17bff39d5f10a2a22366d8622fa6

And I edited the commit message more or less as you describe.

And feel free to call me Michael or mpe :)

cheers