Messages in this thread | | | Date | Thu, 19 Nov 2009 04:20:24 +0100 | From | Ingo Molnar <> | Subject | Re: [PATCH] cleanup sched_yield (sys)call nesting. |
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* Sven-Thorsten Dietrich <sven@thebigcorporation.com> wrote:
> Subject: clean up chaining in sched_yield() > From: Sven-Thorsten Dietrich <sdietrich@suse.de> > > The call to sys_sched_yield for in-Kernel is messy. > and the return code from sys_sched_yield is ignored when called from > in-kernel. > > Signed-off-by: Sven-Thorsten Dietrich <sdietrich@suse.de> > > diff --git a/kernel/sched.c b/kernel/sched.c > index 3c11ae0..db2c0f9 100644 > --- a/kernel/sched.c > +++ b/kernel/sched.c > @@ -6647,12 +6647,12 @@ SYSCALL_DEFINE3(sched_getaffinity, pid_t, pid, unsigned int, len, > } > > /** > - * sys_sched_yield - yield the current processor to other threads. > + * do_sched_yield - yield the current processor to other threads. > * > * This function yields the current CPU to other tasks. If there are no > * other threads running on this CPU then this function will return. > */ > -SYSCALL_DEFINE0(sched_yield) > +static inline void do_sched_yield(void) > { > struct rq *rq = this_rq_lock(); > > @@ -6669,6 +6669,11 @@ SYSCALL_DEFINE0(sched_yield) > preempt_enable_no_resched(); > > schedule(); > +} > + > +SYSCALL_DEFINE0(sched_yield) > +{ > + do_sched_yield(); > > return 0; > } > @@ -6746,7 +6751,7 @@ EXPORT_SYMBOL(__cond_resched_softirq); > void __sched yield(void) > { > set_current_state(TASK_RUNNING); > - sys_sched_yield(); > + do_sched_yield(); > } > EXPORT_SYMBOL(yield);
Why do you consider an in-kernel call to sys_*() 'messy'? It is not - and we rely on being able to do it with various syscalls.
Also, your patch bloats the scheduler a bit, for no good reason.
Thanks,
Ingo
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