Re: PREEMPT is messing with everyone
> Yes, Compiler will remove it but this looks ugly and confusing. > > Why dont we use like this :- Even more fugly. > # ifdef CONFIG_PREEMPT > # include > # endif > > #ifdef CONFIG_PREEMPT > preempt_disable(); > #endif > > #ifdef CONFIG_PREEMPT > preempt_enable(); > #endif > -`J' -- - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
Re: PREEMPT is messing with everyone
Jaswinder Singh wrote:
On 12/5/06, Michal Schmidt <[EMAIL PROTECTED]> wrote:
Jaswinder Singh wrote:
> Hi,
>
> preempt stuff SHOULD only stay in #ifdef CONFIG_PREEMP_* , but it is
> messing with everyone even though not defined.
>
> e.g.
>
> 1. linux-2.6.19/kernel/spinlock.c
>
> Line 18: #include
>
> Line 26: preempt_disable();
>
> Line 32: preempt_disable();
>
> and so on .
Don't worry. These compile into "do { } while (0)" (i.e. nothing) when
CONFIG_PREEMPT is not set.
Yes, Compiler will remove it but this looks ugly and confusing.
Why dont we use like this :-
Because it's ugly and confusing.
#ifdef CONFIG_PREEMPT
#include
#endif
#ifdef CONFIG_PREEMPT
preempt_disable();
#endif
#ifdef CONFIG_PREEMPT
preempt_enable();
#endif
--
bill davidsen <[EMAIL PROTECTED]>
CTO TMR Associates, Inc
Doing interesting things with small computers since 1979
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to [EMAIL PROTECTED]
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
Re: PREEMPT is messing with everyone
Jaswinder Singh skrev: Yes, Compiler will remove it but this looks ugly and confusing. Why dont we use like this :- #ifdef CONFIG_PREEMPT #include #endif #ifdef CONFIG_PREEMPT preempt_disable(); #endif #ifdef CONFIG_PREEMPT preempt_enable(); #endif Surely you're joking. It is much more readable and maintainable to hide the #ifdef-hackery in header files than to clutter the *.c files. Michal - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
Re: PREEMPT is messing with everyone
On 12/5/06, Michal Schmidt <[EMAIL PROTECTED]> wrote:
Jaswinder Singh wrote:
> Hi,
>
> preempt stuff SHOULD only stay in #ifdef CONFIG_PREEMP_* , but it is
> messing with everyone even though not defined.
>
> e.g.
>
> 1. linux-2.6.19/kernel/spinlock.c
>
> Line 18: #include
>
> Line 26: preempt_disable();
>
> Line 32: preempt_disable();
>
> and so on .
Don't worry. These compile into "do { } while (0)" (i.e. nothing) when
CONFIG_PREEMPT is not set.
Yes, Compiler will remove it but this looks ugly and confusing.
Why dont we use like this :-
#ifdef CONFIG_PREEMPT
#include
#endif
#ifdef CONFIG_PREEMPT
preempt_disable();
#endif
#ifdef CONFIG_PREEMPT
preempt_enable();
#endif
Regards,
Jaswinder Singh.
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to [EMAIL PROTECTED]
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
Re: PREEMPT is messing with everyone
Jaswinder Singh wrote:
Hi,
preempt stuff SHOULD only stay in #ifdef CONFIG_PREEMP_* , but it is
messing with everyone even though not defined.
e.g.
1. linux-2.6.19/kernel/spinlock.c
Line 18: #include
Line 26: preempt_disable();
Line 32: preempt_disable();
and so on .
Don't worry. These compile into "do { } while (0)" (i.e. nothing) when
CONFIG_PREEMPT is not set.
2. linux-2.6.19/kernel/sched.c
Line 1096: int preempted;
Line 1104: preempted = !task_running(rq, p);
Line 1106: if (preempted)
Line 2059: if (TASK_PREEMPTS_CURR(p, this_rq))
Linux always does preemptive multitasking of user tasks. These have
nothing to do with CONFIG_PREEMPT.
Line 3355:current->comm, preempt_count(), current->pid);
Line 3342: preempt_disable();
Line 3375: if (prev->state && !(preempt_count() & PREEMPT_ACTIVE)) {
preempt_count() is useful in !CONFIG_PREEMPT kernels too. It stores
information about the current context (hardirq, softirq, ...).
[...]
70 to 80 % of this code is removed when compiled.
but 20 to 30 % code left in binary kernel image.
Why Linux kernel is wasting its resources which is not defined at all.
I don't think that's the case.
Any solution ?
Thank you,
Best Regards,
Jaswinder Singh.
Michal
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to [EMAIL PROTECTED]
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
PREEMPT is messing with everyone
Hi,
preempt stuff SHOULD only stay in #ifdef CONFIG_PREEMP_* , but it is
messing with everyone even though not defined.
e.g.
1. linux-2.6.19/kernel/spinlock.c
Line 18: #include
Line 26: preempt_disable();
Line 32: preempt_disable();
and so on .
2. linux-2.6.19/kernel/sched.c
Line 1096: int preempted;
Line 1104: preempted = !task_running(rq, p);
Line 1106: if (preempted)
Line 2059: if (TASK_PREEMPTS_CURR(p, this_rq))
Line 3355:current->comm, preempt_count(), current->pid);
Line 3342: preempt_disable();
Line 3375: if (prev->state && !(preempt_count() & PREEMPT_ACTIVE)) {
Line 3471: preempt_enable_no_resched();
3. linux-2.6.19/kernel/timer.c
Line 444: int preempt_count = preempt_count();
Line 447: if (preempt_count != preempt_count()) {
4. linux-2.6.19/arch/i386/kernel/entry.S
Line 240: preempt_stop
5. linux-2.6.19/arch/i386/irq.c
Line 111:irqctx->tinfo.preempt_count =
Line 112:(irqctx->tinfo.preempt_count & ~SOFTIRQ_MASK) |
Line 113:(curctx->tinfo.preempt_count & SOFTIRQ_MASK);
Line 160: irqctx->tinfo.preempt_count = HARDIRQ_OFFSET;
and so on.
Similarly unnecessary preempt code is also written in other important files.
70 to 80 % of this code is removed when compiled.
but 20 to 30 % code left in binary kernel image.
Why Linux kernel is wasting its resources which is not defined at all.
Any solution ?
Thank you,
Best Regards,
Jaswinder Singh.
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to [EMAIL PROTECTED]
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
PREEMPT is messing with everyone
Hi,
preempt stuff SHOULD only stay in #ifdef CONFIG_PREEMP_* , but it is
messing with everyone even though not defined.
e.g.
1. linux-2.6.19/kernel/spinlock.c
Line 18: #include linux/preempt.h
Line 26: preempt_disable();
Line 32: preempt_disable();
and so on .
2. linux-2.6.19/kernel/sched.c
Line 1096: int preempted;
Line 1104: preempted = !task_running(rq, p);
Line 1106: if (preempted)
Line 2059: if (TASK_PREEMPTS_CURR(p, this_rq))
Line 3355:current-comm, preempt_count(), current-pid);
Line 3342: preempt_disable();
Line 3375: if (prev-state !(preempt_count() PREEMPT_ACTIVE)) {
Line 3471: preempt_enable_no_resched();
3. linux-2.6.19/kernel/timer.c
Line 444: int preempt_count = preempt_count();
Line 447: if (preempt_count != preempt_count()) {
4. linux-2.6.19/arch/i386/kernel/entry.S
Line 240: preempt_stop
5. linux-2.6.19/arch/i386/irq.c
Line 111:irqctx-tinfo.preempt_count =
Line 112:(irqctx-tinfo.preempt_count ~SOFTIRQ_MASK) |
Line 113:(curctx-tinfo.preempt_count SOFTIRQ_MASK);
Line 160: irqctx-tinfo.preempt_count = HARDIRQ_OFFSET;
and so on.
Similarly unnecessary preempt code is also written in other important files.
70 to 80 % of this code is removed when compiled.
but 20 to 30 % code left in binary kernel image.
Why Linux kernel is wasting its resources which is not defined at all.
Any solution ?
Thank you,
Best Regards,
Jaswinder Singh.
-
To unsubscribe from this list: send the line unsubscribe linux-kernel in
the body of a message to [EMAIL PROTECTED]
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
Re: PREEMPT is messing with everyone
Jaswinder Singh wrote:
Hi,
preempt stuff SHOULD only stay in #ifdef CONFIG_PREEMP_* , but it is
messing with everyone even though not defined.
e.g.
1. linux-2.6.19/kernel/spinlock.c
Line 18: #include linux/preempt.h
Line 26: preempt_disable();
Line 32: preempt_disable();
and so on .
Don't worry. These compile into do { } while (0) (i.e. nothing) when
CONFIG_PREEMPT is not set.
2. linux-2.6.19/kernel/sched.c
Line 1096: int preempted;
Line 1104: preempted = !task_running(rq, p);
Line 1106: if (preempted)
Line 2059: if (TASK_PREEMPTS_CURR(p, this_rq))
Linux always does preemptive multitasking of user tasks. These have
nothing to do with CONFIG_PREEMPT.
Line 3355:current-comm, preempt_count(), current-pid);
Line 3342: preempt_disable();
Line 3375: if (prev-state !(preempt_count() PREEMPT_ACTIVE)) {
preempt_count() is useful in !CONFIG_PREEMPT kernels too. It stores
information about the current context (hardirq, softirq, ...).
[...]
70 to 80 % of this code is removed when compiled.
but 20 to 30 % code left in binary kernel image.
Why Linux kernel is wasting its resources which is not defined at all.
I don't think that's the case.
Any solution ?
Thank you,
Best Regards,
Jaswinder Singh.
Michal
-
To unsubscribe from this list: send the line unsubscribe linux-kernel in
the body of a message to [EMAIL PROTECTED]
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
Re: PREEMPT is messing with everyone
On 12/5/06, Michal Schmidt [EMAIL PROTECTED] wrote:
Jaswinder Singh wrote:
Hi,
preempt stuff SHOULD only stay in #ifdef CONFIG_PREEMP_* , but it is
messing with everyone even though not defined.
e.g.
1. linux-2.6.19/kernel/spinlock.c
Line 18: #include linux/preempt.h
Line 26: preempt_disable();
Line 32: preempt_disable();
and so on .
Don't worry. These compile into do { } while (0) (i.e. nothing) when
CONFIG_PREEMPT is not set.
Yes, Compiler will remove it but this looks ugly and confusing.
Why dont we use like this :-
#ifdef CONFIG_PREEMPT
#include linux/preempt.h
#endif
#ifdef CONFIG_PREEMPT
preempt_disable();
#endif
#ifdef CONFIG_PREEMPT
preempt_enable();
#endif
Regards,
Jaswinder Singh.
-
To unsubscribe from this list: send the line unsubscribe linux-kernel in
the body of a message to [EMAIL PROTECTED]
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
Re: PREEMPT is messing with everyone
Jaswinder Singh skrev: Yes, Compiler will remove it but this looks ugly and confusing. Why dont we use like this :- #ifdef CONFIG_PREEMPT #include linux/preempt.h #endif #ifdef CONFIG_PREEMPT preempt_disable(); #endif #ifdef CONFIG_PREEMPT preempt_enable(); #endif Surely you're joking. It is much more readable and maintainable to hide the #ifdef-hackery in header files than to clutter the *.c files. Michal - To unsubscribe from this list: send the line unsubscribe linux-kernel in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
Re: PREEMPT is messing with everyone
Jaswinder Singh wrote:
On 12/5/06, Michal Schmidt [EMAIL PROTECTED] wrote:
Jaswinder Singh wrote:
Hi,
preempt stuff SHOULD only stay in #ifdef CONFIG_PREEMP_* , but it is
messing with everyone even though not defined.
e.g.
1. linux-2.6.19/kernel/spinlock.c
Line 18: #include linux/preempt.h
Line 26: preempt_disable();
Line 32: preempt_disable();
and so on .
Don't worry. These compile into do { } while (0) (i.e. nothing) when
CONFIG_PREEMPT is not set.
Yes, Compiler will remove it but this looks ugly and confusing.
Why dont we use like this :-
Because it's ugly and confusing.
#ifdef CONFIG_PREEMPT
#include linux/preempt.h
#endif
#ifdef CONFIG_PREEMPT
preempt_disable();
#endif
#ifdef CONFIG_PREEMPT
preempt_enable();
#endif
--
bill davidsen [EMAIL PROTECTED]
CTO TMR Associates, Inc
Doing interesting things with small computers since 1979
-
To unsubscribe from this list: send the line unsubscribe linux-kernel in
the body of a message to [EMAIL PROTECTED]
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
Re: PREEMPT is messing with everyone
Yes, Compiler will remove it but this looks ugly and confusing. Why dont we use like this :- Even more fugly. # ifdef CONFIG_PREEMPT # include linux/preempt.h # endif #ifdef CONFIG_PREEMPT preempt_disable(); #endif #ifdef CONFIG_PREEMPT preempt_enable(); #endif -`J' -- - To unsubscribe from this list: send the line unsubscribe linux-kernel in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
